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CRS-8 Dragon Hosted Webcast

SpaceX · Youtube · 850 HN points · 8 HN comments
HN Theater has aggregated all Hacker News stories and comments that mention SpaceX's video "CRS-8 Dragon Hosted Webcast".
Youtube Summary
SpaceX’s Falcon 9 rocket will launch the Dragon spacecraft to low Earth orbit to deliver critical cargo to the International Space Station (ISS) for NASA. SpaceX is targeting an afternoon launch of its eighth Commercial Resupply Services mission (CRS-8) from Space Launch Complex 40 at Cape Canaveral Air Force Station, Fla. The instantaneous launch window opens on April 8th at 8:43pm UTC, and a backup launch window opens at 8:20pm UTC on April 9th. Dragon will be deployed about 10 minutes after liftoff and attach to the ISS about two days after launch. Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship in the Atlantic Ocean.
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Apr 08, 2016 · 5 points, 0 comments · submitted by vanwilder77
Apr 08, 2016 · 845 points, 354 comments · submitted by cryptoz
Reminds me of one of the most inspirational interviews by him after three failed Falcon 1 launches:

> Musk: Optimism, pessimism, fuck that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work.

Which is something which differentiates Elon from a lot of people, the ability to execute (and by that I mean get the job done), while under insane amounts of stress, that is a very rare quality.
Oh my god that wired reporter was just raking him over the coals there.
Wasn't that at a point where Tesla was under a huge capital crunch as well? Can't imagine what pressure he was under.
Yes, I think 2008 was a very hard year for Elon. The issue with Tesla was that something like 200 Roadsters were manufactured incorrectly and all had to be fixed at immense cost and time delay. He was also going through a divorce at the time. And all SpaceX launches had exploded off the Pacific island that they were forced to use since their competitors successfully lobbied for it to be illegal for SpaceX to launch from the USA. Rough year.
> their competitors successfully lobbied for it to be illegal for SpaceX to launch from the USA

Do you remember how the managed to do that?

ULA lobbied to ban them from a launch site (at Vandenberg) that was nearby their own, which had a very expensive rocket and very, very expensive payload on it, claiming that a SpaceX rocket launch would be too dangerous. Forced them to launch from Kwajalein Atoll, which made things much harder. Probably contributed to at least one failure, thanks to the corrosive, salty atmosphere.

Edit: Not unfair to assume that it was motivated by anti-competitive interests before any real concern about possible effects on their pad.

What was the payload that was so expensive?
A large NRO spy sat of some sort.
His wife also decided it was a convenient time to divorce him in 2008.

His current wife also recently decided to announce a divorce. At least he is on a big winning streak with his businesses this time.

Where did you see Talulah announce the divorce? All I've seen was comments from Elon that they split amicably.
Oh goodness. Last I saw they were back together after being divorced. What a bumpy road.
Maybe they'll make it the third time he marries the same woman. He obviously is hellbent on making it work.
The SpaceX subreddit has an excellent megathread with lots of information about this launch.

Here is a link to the technical webcast:

This is SpaceX's first ISS cargo mission since their last attempt last summer, which ended in an explosion and loss of all cargo. They will also be attempting a barge landing of the first stage, which they have not yet successfully completed. They will likely stream the landing attempt, but live video is no guarantee as there is usually too much interference.

Count degrees of freedom that have to be zeroed out in that landing: three coordinates of position, three coordinates of motion, two axes of tilt, rates of yaw, pitch, and roll.

That adds to 11 dimensions of control. And their flight computer nailed it, without even zeroing one at a time! Only roll rate around the axis of the rocket was zeroed well before touchdown. Impressive!

If you're zeroing in the position, you don't have to worry about the motion.

The number of degrees you have to take car of is 6: X, Y, Z, yaw, pitch, and roll.

> If you're zeroing in the position, you don't have to worry about the motion.

Sure you do. Landing too fast in any of the three directions won't do.

Heck, I'll just be pedantic and say you have 7 DOF since you really should use a quaternion to avoid the gimbal-lock singularity when using Euler angles :P
Using quaternion does not add any DOF.
You're right, assuming your quaternions are coded correctly...
To a layman the two are nearly identical, however the Von Hiesen is an older model of Neutrino Compressors and thus shares many aesthetic components as the contemporary hypercarbolators (I tend to use the American spelling for that word) due to the placement of the backfeed tube.
gimbal and quaternions are two different ways of describing an object's rotation in 3d.

gimbal is very intuitive, you just write down three angles: pitch, roll, and yaw. to imagine the objects rotation when I give you the three angles, you just apply them one after the other.

however, there is an issue. When the object's rotation is large enough that say, roll becomes 90, suddenly pitch and yaw correspond to the same 'thing '. which means one axis of rotation can no longer be realized.

in practice this can be seen with physical gimbals (three concentric rings, one per axis) or in numerical gimbal representation, where values might end up being unworkable.

quaternions eliminate this problem by using four values instead of three (quater, quattro, quad bike - the prefix stands for 4) 3 values are the components of a 3d vector, and the 4th is how much rotation to apply around it.

The above post argue that this 4th value seems like an extra degree of freedom, it isnt. it simply is a matter of representation if coded correctly.

Yes, 6 positions, but you also have to take of their first derivative (velocity) which makes it 12.
Yes, but the only means you have of controlling those also impacts the motion.
Yes. Welcome to underactuated control, where you have more output goals than control parameters. That's why this is rocket science.

Here's a way to start thinking about this. Consider the 1D case, stopping a car with the goal of being at zero speed at a specified point. 2 goals, one controlled input. This is an under actuated problem. Setting a constant deceleration is not enough to do this. However, if you have a deceleration start time and a deceleration value after that point, you now have two variables, and can solve for zero speed at the desired point. This is essentially what Space-X is doing in the vertical direction.

They have limited ability to throttle the main engines (off, or 70% to 100%), and I suspect that in the final landing phase, they use that range to keep the vertical component constant while doing any horizontal positioning. The main engines gimbal; they don't have to change attitude for minor horizontal adjustments. So the simple approach is to get the attitude stabilized on approach, and the landing vertical. Their successful landings look like that. Their unsuccessful ones show non-vertical attitudes as the control system tries to make big horizontal adjustments.

This is also why New Shepard (with a minimum TWR < 1) has a much easier problem to solve (on the scale of 'solving problems related to rockets).
If you don't take care of the motion, the next thing you do immediately after landing on the barge is slide off the barge!
Or make a big hole in it, as happened last time.
congratulations to them again, but sure there has to be some land mass somewhere they can use. Or are they just predicting a day they don't want to be bound to any nation?
The first stage of rockets launched from the US end up over the Atlantic. Unless you want to launch many percentage points more of fuel to propel it farther than it would otherwise go, you're going to have to catch it in the ocean.

The ocean landing is much more technically difficult, but it gives them the ability to use those extra percentage points of fuel on payload.

It's just practicality. Surely they could lease an island or two, they've done it in the past but the barge landing gives opens up much more possibilities.
Elon Musk has tweeted before that many launches will have spent so much fuel that it would be impossible to return to land--necessitating a sea landing for consistency.
That estimate is incomplete. The drone ship has its own pitch and yaw thanks to the motion of the ocean and is moving on two axes to intercept, plus vertical displacement thanks to the swell. Incredible.
First successful landing on the drone ship

Also, primary Dragon deployment appears successful as well.

Footage of the landing starts at 35:47, taken from nearby flying drone.

Absolutely surreal footage, a 25 storey rocket just drifts into shot at a crazy angle and plants itself.

Very impressive with the ocean swells tossing the drone ship around as well.

Also, I liked the running commentary between the various reporters. It almost felt like a sporting event.

I think those are SpaceX PR people rather than reporters. The sports-event feel is clearly a consciously-constructed show.
The SpaceX people in the broadcast are mostly engineers and occasionally product managers. Listen to them introduce themselves.
Does anyone know if they analyze the wave patterns on the droneship and send that data to the rocket so it can tilt or time its landing to match? Or is it just the current tilt and position that's taken into account? Or is barge tilt even considered?
I read somewhere that the droneship and rocket don't communicate at all.

They both have their "plans" on what to do, and the rocket basically is doing everything from what it can "see". There is no back-and-forth communication happening at all.

I never understood all the fuss about the the movement of the barge until I saw this landing. Even after it landed I was nervous it would tip over given the apparent motion of the barge!
It looks really dramatic, but it might not be close to tipping, really.

I'd guess the fuel is very nearly depleted at landing. This would put the center of mass somewhere fairly low on the stage, close to the engines which are dense, heavy things.

This means that the landed stage isn't as susceptible to toppling as it looks. At minimum, it would have to tilt so far that the CoM went beyond the line connecting the ends of two adjacent landing legs and tilt along a radius that crossed the midpoint of that line. Other tilt vectors would require more tilt to overturn the stage, based on CoM & landing leg geometry.

Wind loads could assist a tipover. The stage is ~12 feet diameter, it's really tall, it presents lots of sail area and it's pretty light at landing. Wind force would be a fun estimation to do.

They planned on welding down the legs once they landed and safed the rocket.
After landing, around 36m56s, the cold gas thrusters fired at the top, and I think it's to keep the rocket steady.

We added that timestamp to the URL above. Thanks!
I think the video has been replaced with a shorter one, since the timestamp of the landing is now closer to 27:15.
Ok, we'll update the URL to that. Thanks.
Not sure if this changed, but at 35m 47s they just show a static shot of the rocket on the drone ship. The 'live' footage of the landing was earlier in the video (27m 20s).

Awesome to watch.

This link was working for me before but not know maybe they shrunk the video. This does work
Thanks for posting that. Amazing!
Not sure what to make of the chanting of 'U-S-A U-S-A' after that. That sound just reminds me of a Trump rally these days.

But otherwise: that was really fantastic.


It's actually quite a sweet display of patriotism. I sound more negative than I mean to be. Perhaps it was just funny to realize that the context I'm most familiar with the sound of that chant is from reporting on the current campaign.

Since when did being patriotic become offensive behavior? I for one am proud of the accomplishment and realize that it took many people from lots of different countries, but the reality is SpaceX, Tesla, Google, Microsoft, Facebook, Twitter the list goes on are all American companies. American and proud.
> it took many people from lots of different countries

In a indirect way it did, (standing on the shoulders of giants, heritage of the people working there, etc,) however, unlike the other companies you mentioned, SpaceX only hires American citizens (because of government contracts and ITAR.) So it's basically an all-American effort.

Yeah, I love Elon's American accent.
I'm pretty sure Elon considers himself thoroughly American at this point.

There are quite a few foreign born American citizens working at SpaceX, myself included. You may find this shocking, but seeing as English wasn't our first language, some of us even have foreign accents.

I don't consider them, or myself, any less American.

You jest, but being an immigrant is a very American thing. Visit it sometime if you had not, it's quite a different place from what many people imagine from media dramatizations.
His maternal grandfather is American and he took the citizenship oath in 2002 -- Which is why America is pretty cool, many millions of Americans have foreign accents!
ITAR allows greencard holders, so not everyone's an American citizen.
Not only greencard holders but ITAR even has exemptions for non-US persons, that is those who aren't US citizens or Permanent Residents.

I don't work directly with anyone like this but I know SpaceX has a few, not sure of the exact number, employees who are neither citizens nor permanent residents.

From what I've heard the process of getting a non-US person ITAR cleared is extremely costly, both in time and money and is thus used very sparingly.

Since people realized that the difference between patriotism and xenophobia is very small? John Lennon: "Imagine there's no countries.."
> Since when did being patriotic become offensive behavior?

Patriotism can have a hugely different emotional response depending on where you live. It can connote “home!” or “remember, we have weaponized drones hovering above your head”.

Imagine this video feed was from Iran, and ended in a patriotic arabic chant. Would you think, “it is good to see that they are Iranian and proud”?

It is not about being offended. It is about political undertone and tacit military implications.

(That said, I am proud, as a fellow human, of what was accomplished. Also, I live in a country pretty solidly allied with the US.)

Iranians are not arabic in general.
Persian, not Arabic.
Now this is just my opinion, but I wouldn't see any of that if any country was chanting their name for an accomplishment like this.

This is almost a universally good thing, and having pride that your country was able to do it isn't a bad thing to me! I would fully expect another nations company to be chanting their nation's name, and I would probably join along with them if I were there!

It's a celebration, not a contest.

(side note, I was born and raised in the US, so my view might be tainted by that)

I second this. Even if Iran, N Korea, China e.t.c were doing this I'd be very happy for them. Space missiles and nuclear missiles have things common to them, but if the only intention of the folks working on it was to make space exploration cheaper, I'd cheer for them.

What space X did landing in the middle of the ocean on a tiny little platform, was nothing short of genius.

I understand both sides. I expected a SpaceX chant more than a USA one. And yes nowadays patriotism is devalued it seems.
Its great if you're an American. If you're not, it just sounds like passive-aggressive bloviation.
>Since when did being patriotic become offensive?

Since the SJWs and identity politics erased all common sense.

Chanting USA demeans and marginalizes other countries. Its quite offensive to people to support one country over another.


So do you think we should boycott the Olympics? Should I give the North Korean regime same level of "support" as South Korean regime?
I think you missed the sarcasm indicator (/s).

(That doesn't mean it was particularly funny, though)

It's not that offensive, but it did have a bit of a jarring effect. I was all happy with the success and saw it as a human achievement. [1] The cheering was wonderful. But then the USA chants made me feel left out, because I'm not a US citizen. I guess I just wished these people would share my view of it being a human achievement and not limited to USA with its 4% of humans. It's likely plenty of them do think that, but the USA chanting sure sends a different emotional signal and diminishes the moment a bit.


[1] I probably wouldn't think much of a USA chant during a Facebook or Google product launch. While these companies do plenty of wonderful things, I view space travel as several tiers of importance higher.

It's a US achievement and it's an achievement that will benefit all of humanity. There's no contradiction between those two things.

America gets bashed non-stop about pretty much everything, no matter what choices it makes or what direction it goes. The criticism is overwhelming sometimes, I get sick of browsing many sites like Reddit for example because of the extremely common US bashing. Quite frankly, I'll take the cheers and USA chants on this one.

A human achievement. Competition among teams is good though, team USA is ahead. Hopefully team <your country> can push themselves to move forward.
That's kind of funny that you would find a USA chant at a Google product launch less "jarring".

In this context it didn't phase me at all (I am a US citizen though...), but at a Google press event, it would be really unsettling.

It's probably a cultural thing. From my vantage point outside of America, chanting support for your country like a sports team feels awkward and myopic. It's not something most other civilised countries do — I associate it more readily with failed/fascist/dictatorial regimes.
If you're interested in reading/thinking more about tribalism and people reacting to displays like this, I found this essay really interesting:
I think it is a cultural thing, but thinking about it now it would sound really similar to how you describe if they were chanting "America" instead of "USA".

I don't know, but the point is that I can see where you are coming from. I think that the "USA" thing has become "normalized" to me because of other things in the media (sports, wartime, etc...) that it doesn't phase me, but changing the wording makes it pretty clear.

I'm not American and I think it's great. Anytime I read stories of American engineering (like about the SR-71, or the Manhattan Project[1]) I feel a kind of pride for them. Strange feeling. But they accomplish some amazing stuff and there's no reason they shouldn't express joy for their own country.

1: Granted, that had some key foreign influence.

I'm Australian but FWIW some friends and I were talking about this over breakfast. I personally think that while it's a bit jarring from the outside, Americans celebrating the rebuilding of American spaceflight capabilities makes a lot of sense.

Also, it would probably be worse to have official communication policy restricting what people could chant on livestreams.

I think this is a large part of it. The Apollo program, and to a lesser extent the Space Shuttles, are not just historical events, but events that had a major cultural impact on the country. You cannot divorce the nationalistic response of people involved in this endeavor from the connection America's space program has to historical achievements we celebrate throughout our history classes in school. The successes of the spaceflight industry were always, from the beginning, tied to a sense of nationalism given the context in which it arose and delivered success. It's a unique industry in American culture, and I'm not surprised it's hard for individuals from other countries to immediately understand.
A similar thing happened at every Space Shuttle launch I was lucky enough to go to. I wouldn't read too much into it. A few people get really excited and proud to be American when they see a display of some impressive literally-earth-shaking technology (the noise from a shuttle launch was amazing!). They start chanting it and the rest of the crowd joins in. It's a nice moment of unity even if it is within the confines of national identity.
That was also a bit irritating for me. I am from Germany and celebrating Germany became a bit frowned upon for obvious reasons. Besides during the World Cup, of course. Nonetheless it seems a bit strange to me, the country has really not too much to do with this success notwithstanding that, to some extend, it provided the environment that enabled this success. Shouting »SpaceX!« would seem more appropriate to me but probably still feel a bit strange. And last but not least the first thing that I associated with this were the celebrations after the death of Osama bin Laden which I think were pretty inappropriate.
I can understand the distaste for nationalistic displays in Germany and I think it says a lot for the German people that this is considered distasteful.

This is a peacetime effort that is likely to improve all of mankind. If you want to criticize the celebratory reaction to killing someone then I will probably agree with you. This is something else. Pride in one's nation and it's achievements is not inherently shameful.

Do you believe that nationalistic displays are never appropriate? Why is it ok to celebrate your nation during World Cup but not after a significant technological achievement in peacetime?

I am not going to tell you what to do and what not do, I meant what I wrote quite literally, I felt irritated by those chants because that would never happen here and probably be considered inappropriate. I really can't think of many things that could, would or should cause a similar reaction over here. If half of Germany would work together to single-handedly stop the climate change or something like that, then I would say it is time to pad our shoulders, but besides that I can't think of much. And even if we shout »Germany!« when we win a soccer match, we - or at least that is the case for me - mean the team, not the country as a whole.
I just realized this as well. We really do chant for the team, not the country.
It's not just Germany by the way. I think this applies in most of Europe where patriotism is closely linked with nationalism because of our history. For example, in the UK showing an English flag is immediately associated with the BNP. In Holland displaying the flag outside of national holidays is associated with far-right wing parties as well. Of course none of this applies when it comes to international football matches.

At the same time I think most Europeans realize this doesn't apply in the US, yet many people's initial reaction would be one of (mild) discomfort. As a European living in the US (and loving the country and the people) I'm still often equal parts amazed and amused by the flag waving and USA chanting.

That's one of the saddest things I've read, that displaying your own flag is looked down upon. I cannot imagine any long-term good coming from that kind of attitude.
Avoiding the pitfalls of blind nationalism. again.
As the hencq said, most if not all European nations had their share of bad times due to nationalism and in consequence the idea of nations got deemphasized. That is the origin of the European Union, together instead of against each other. This admittedly works much better in good times and a we against the rest mentality quickly springs back when the outlook worsens.

For many Europeans the American attitude towards the country and the flag looks a bit like a fetish. It's a piece of the Earth within a man-made line on a map, a piece of fabric designed by some guys. The important things are of course what this symbols stand for, freedom, the American dream, going to the Moon, helping to end World War II. But then again this is also only half of the truth or do you also think of slavery, racism or the millions of victims in US (supported) wars when you look at an US flag?

Similarly the obsession with the constitution looks a bit strange from here. »I can have guns, it's good to have guns, it's in the constitution!« It is just a piece of paper, a set of laws. Some guys thought that those would make good rules to run a society and so they wrote them down. But maybe they were wrong in some regards, a constitution is no eternal God-given truth.

It really makes a difference where you grow up and to what ideas you are exposed. For the better or the worse.

So then make Europe the country and Germany the state. That works. Wave the European flag and chant: Europe! Europe! Europe!

Here in the USA we seldom wave state flags or chant the names of states. Maybe in Texas I could see that happening. I do recommend being the Texas of Europe.

>So then make Europe the country and Germany the state. That works. Wave the European flag and chant: Europe! Europe! Europe!

That tends to be the opposite goal of those nationalistic flag-wavers.

I don't understand this German mentality (my heritage is German). It is like German's are ashamed to be German. WWII was a long time ago, it is ok to be patriotic and proud of your collective country.
Patriotic displays were one of the major tools that enabled WW2. Maybe not as a cause, but certainly as an absolutely required component.

We frown upon these things not because of what happened, we frown upon them because of what we don't want to happen again. The past might be long gone, but the future is always right around the corner.

I came across the slogan »Proud not to be proud.« recently and really like it. I really like Germany and am glad that I can live here. But for me being proud has a lot to do with personally having done something for the thing to be proud of. I have zero stakes in the beautiful landscape, my influence on the society, economy and whatnot is negligible. Why would I be proud of the country? I also think that nation states are probably not the best way forward but that will take us to far now.
Some Americans agree with you:
Pride in personal achievements has a catch: it's only available to those who actually did achieve something. Those who did not still have a desire for pride and "group pride" (be it national, ethnic, religious, supportership of some sports team or even just membership in some specific profession) fills that gap.

As much as i despise patriotic displays, i still think they can offer great value as a lesser evil when even more dangerous group pride identities (e.g. religious or ethnic radicalization) are just waiting to fill the gap for those in need. Not only the american, but also the french or british group identities are much more accessible than for example german (much of national identity defined by difficult relationship with history, newcomers don't share that heritage) or belgian (much of national identity defined by being of either flemish or wallonian ethnicity, newcomers are neither).

The US doesn't have the tense history with Nationalism that Germany does. Chanting USA is rather common at national sporting events, in times of triumph and often whenever someone starts the chant.
> The US doesn't have the tense history with Nationalism that Germany does.

Not yet anyway.

Be different.

Fly a German flag from a pole in your front yard. Really! People here in the USA do it sometimes. (or go European, or both if you want to treat Germany like Americans treat states)

Find something good in the news and celebrate it. I checked the news today. OK, maybe today isn't a great day for Germany, because the best I found was this: Uh, well, it's something. Celebrate it. Germany! Germany! Germany!

Be sure to also check the French and Russian news in case a bit of Schadenfreude is called for. When you find something suitable, wave your flag and say: Germany! Germany! Germany!

>the celebrations after the death of Osama bin Laden which I think were pretty inappropriate.

Osama Bin Laden doesn't deserve any civil person's remorse. He helped orchestrate the murder of 3000 civilians. Give no pause to people who have absolutely no respect for the civilized world and cannot be reasoned with. The world will not have peace as long as religious extremists exist. Osama Bin Laden's existence would have only brought more senseless violence.

That was also a bit irritating for me. I am from Germany and celebrating Germany became a bit frowned upon for obvious reasons. Besides during the World Cup, of course.

My first thought is, then what if people around the world started to care about spaceflight to the same degree they pay attention to the World Cup? But considering the broad geopolitical implications tied up in spaceflight and ballistic missile technology, this does become weird and problematic in just a few steps, doesn't it? Hopefully, from here on out, all of the jingoism will just be noise, and all of the major wars will be, at worst, cold.

What would a German crowd have chanted or sang to celebrate something like this?
Yeeeaaaahhhhh! Woooooo! Exactly the same minus the USA bit.
> the country has really not too much to do with this success

Yes, it does. The country has a lot to do with it. Particularly our values, culture, etc. that enabled this to be possible here and nowhere else.

You do realize that other countries have space programs too?
And I expect them to cheer there efforts as well, and as they do I'll be cheering for them.
Except this effort was for all intents and purposes entirely financed by the American Government through contracts with SpaceX.
That comment was quite surly aimed at »[…] here and nowhere else«.
Yes, but what other country has a private company like SpaceX?

- Arianespace

- Mitsubishi Heavy Industries

- Antrix Corporation

- COSMOS international

- Eurockot Launch Services

- International Launch Services

- ISC Kosmotras

- Sea Launch

- Starsem

> Really?

Yeah, really. Has a single one of them launched a rocket and then successfully landed it? No. That's why you're here, talking about Space X and AMERICA.

That's the entire point of this part of the discussion, there are people that think it is awesome that the people at SpaceX managed to achieve this but they really don't care that it is an American company. I wouldn't be any prouder or whatnot if it were a German company.
So I guess that's a no?
It's an extremely fair point.

So is this: now make a list of all the other meaningful space programs and their budgets, it's a really short list. ESA is soon going to have a mere 1/4 the budget of NASA. The rest of the world outside of Russia and China should really be stepping up their space game.

It's patriotism, we should be proud our country has a company that is doing this. Donald Trump has nothing to do with it.
Patriotism is offensive iff it becomes jingoistic or if it comes at the expense of a global humanistic perspective.

The chanting seems a bit over the top, especially for a private company mission to serve the International Space Station.

Patriotism is also offensive if, when politely questioned, it leads to knee-jerk reactions. It has the potential to become just another source of unnecessary emotional conflict and short-circuited thinking.
My interpretation of the "USA-USA" chanting was is relation to the decreasing funding for NASA[1] and the fact that many recent missions to the ISS have been launched from Baikonur in Russia[2]. I hear the "USA-USA" chanting as in we're back in the game (and we can reuse our stage 1s!).



Elon Musk always states the mission of SpaceX is to "make human a multiplanet species".

This makes me always see the advancement of SpaceX advancement of humanity, not just a single country.

But judging from the U-S-A chanting, not everyone at SpaceX thinks this way.

I would be hesitant to make assumptions on how SpaceX employees feel about this accomplishment as it relates to human advancement based on a simple three letter chant that is quite common in the US.

I can certainly understand how those from other countries, particularly Europe, might view the USA chants as over the top nationalism, but I think it's a stretch to assume that those taking part in it somehow view today’s accomplishments as solely the purview of Americans.

I was born in Eastern Europe and while I immigrated to the US at an early age, I have at times felt uncomfortable by the more visible aspects of American patriotism. Since it was brought up in a post above, I found the widespread celebrations of UBL’s death to be distasteful and jingoistic, and this is coming from someone who has deployed to Afghanistan and Iraq multiple times. I too feel that it can, in certain contexts, come off as overly nationalistic. Context is, as usual, important though, and in this context I view the SpaceX USA chants as pretty harmless.

I also find the insinuation that the employees taking part in these chants are guilty of nationalistic fervor to be insulting. There are many employees here, myself included, who didn’t have the good grace to be born in the US but have nonetheless adopted America as our homes and are now allowed to work on some of the coolest space launch vehicles in existence. The fact that some might express themselves in this manner doesn’t bother me, even if it isn’t something I would do myself. I for one don’t partake in the USA chants, although this arguably has as much to do with my relatively low key personality as it does with a conscious choice to refrain from outward shows of patriotism. I’m the kind of person that would politely clap at a touchdown or slam dunk rather than yell and cheer. One of my supervisors however, a Canadian citizen and US permanent resident, has a much more boisterous personality than I do and always joins in these chants. I know one or two Brits here who do as well.

It’s also important to understand the atmosphere during these launches. SpaceX isn’t exactly the easiest place to work, I just finished a 58 hour work week ending in a 12 hour shift before launch, I was not alone in this regard. People are tired, stressed, and somewhat on edge. While the live feed featuring the employees may look staged or choreographed, I can assure you that their reactions aren’t. The moments after a successful launch are an incredible relief and you can feel the energy in the building. The excitement is infectious and if that boils over into chants of U-S-A then so be it.

I’m also not sure what could be done to prevent this from happening. Again, those from other countries might view these chants as strange, but they really are very innocuous here in the US. I don’t see it as overly nationalistic, but again, context is key. Even as someone who doesn’t actively take part in them, if we got word from above that these chants were no longer allowed or discouraged, I would be extraordinarily pissed. Employees are already sacrificing a lot for this mission, they don’t need their spontaneous celebrations micromanaged.

SpaceX is an American company, located within the borders of the US, staffed largely by US citizens or permanent residents, funded largely(exclusively?) by US taxpayers, investors and companies, relying primarily on a US educated workforce, and 60 years of American led R&D in space technology. If all of that culminates in a successful launch and first stage recovery on a freakin’ ship in the middle of the ocean, I for one, can certainly excuse the USA chants.

I hope that my post doesn't come across as overly defensive or sensitive, it has been a long week and I certainly may be guilty of being overly emotional, but it’s always somewhat disheartening to see a thread relating to a successful SpaceX mission turn into an admonishment of perceived American nationalism.

Or maybe they just don't see patriotism as incompatible with that view.

I'm pretty unpatriotic, but I still recognize that people can be patriotic and aim for the advancement of all humanity.

Americans have no other chant to use. It's U-S-A or nothing.

Maybe we should get one, but for now, that's it.

America FUCK yeh!?
Nothing wrong with being proud of your country when an American company does something worth being proud of.
I would imagine many of the employees come from the aerospace industry, meaning defense contractors. South of LA down to Orange County is a bit of a red patch in a blue state. Just an observation.
It was a surprising thing to do. Unexpected and kind of funny. Reminded me of Taiwan #1 chant. However, it's not out of place. Considering modern history, if anything, this is where chant like that should happen. Something people of US of A should be proud of. (they made it, they're paying for it!)
After a decade and a half of wars and general malaise at home, this kind of thing reminds me that we're still moving forward as a country and a society and that we still have the capacity do really hard things. I'm so proud of the SpaceX team for representing America like that.

Way to go, anyone at SpaceX who's reading this.

That was pretty impressive, and while I love that New Shepard has flown three times, putting something into orbit and having the booster land on a drone ship is pretty freakin' awesome.

For me, the really amazing thing is that if SpaceX has been pricing their launches to cover their costs (and I realize that is a big if), they have been developing the re-usable tech on the back of those flights. And now they have 5 (or 6) test flights where two were successful that is moving that tech forward. Developing it on top of an already profitable space flight business, that is pretty amazing.

Really impressed.

Mr. Musk wins the first quarter of 2016, no doubt
We're in the second quarter now :)
I'm pretty sure the launches are actually profitable, so more than cover their costs.
Various SpaceX execs have said they need to launch somewhere around 12 rockets/yr to be profitable in the long term (they likely have plenty of cash on hand right now, as most of their contracts pay quite a bit up front, and they have gotten a lot of funding from a couple NASA sponsored development programs).

So yes, the launches themselves are profitable.

I've watched several times now and seeing things like this make me optimistic about the future of humanity. The commercial space industry is literally being born before our eyes (not the utility space industry of lift/transport, but the one where private companies begin to capitalize on the resources of space).

My only problem with this whole thing: Weyland-Yutani Corporation sounds so much cooler than SpaceX.

A rocket lands like it's done it 1000 times from space, and my company can't even code a simple microservice or use containers.
Lol. I catch myself chastising myself often around SpaceX launches. They are launching rockets faster than I can get my SaaS launched out of Beta!?!
I get why companies with huge infrastructure use containers, the efficient spread of resources. I absolutely do not get why an average web app running on a few servers would use them.
Edit: my reasons look so small compared to that rocket landing. Makes me feel like whatever I'm working on is just _not_ BIG enough.

Rolling upgrades, artifact transport, and cleaner host machine alone can give you extra donut and YouTube time. Also doing forensics can be easier knowing the a specific container is at fault.

About the clean base host, One doesnt have to install anything really. No worries about runtimes, supporting libs, etc. This allows new machines to start even faster from zero.

More donut and YouTube time.

All of that can be done with simple shell scripts and chroot jails on bare metal.

Also I don't see how it eliminates runtimes and libraries.

Doesn't eliminate them, but as a sysadmin doesn't have to worry about what version of it or even if runtimes such as ruby/Java/Python exist, any devel libs, exist in the machine.

That same container can move from my desktop to any environment.

To be fair, I doubt the rocket is running microservices either :)
Embedded systems like this is normally coded (on top of an RTOS) as individual services each running on one thread exchanging messages with other services. Pretty much like microservices (just not over http)

(Take a look at e.g. which is NASAs approach to reusing the typical architecture for flight software)

So like a small version of erlang? Once you've started programming in erlang you start to look at concurrency and reliability in a certain way. Especially after you've done some server which took too many hours to stop hanging and crashing on interthread issues.
To put this in perspective, they just landed a supersonic toothpick upright on a turbulent matchbox.

When I launched the replay of the live stream at whatever point it was, when I heard the wild cheering I knew they had finally landed a first-stage at sea before I even saw the footage of that supersonic toothpick landing.

Like throwing a pencil over the Empire State Building and landing it perfectly.
Except your example would be much harder =P
Well, equip that pencil with computers and propulsion and steering systems, and it might be possible ;)
Paper fins on the eraser end and waiting for a snowy day would be easier.
It was a unnervingly close to the edge of said matchbox. Can't they build a bigger drone ship? Seems a lot cheaper than losing one over the side.
I would think better than bigger is more stable; instead of a conventional barge, they could use a semi-submersible or some other optimized hull form to ensure a more favorable motion response in a given sea area. I think I remember reading that they use a run-of-the-mill cargo barge, which is probably ideal for logistics compared to a highly specialized vessel.

I'd love to hear from naval archs or hydrodynamicists who are working on this (surely there are some).

If the circumstances would cause them to lose one over the side, it's probably already lost.
Couldn't they make the landing pad a bit more forgiving? Like have two big ring-halves pop-up around it when it lands and "catch" it if it tips. I know they'd want to eventually master landing without it, but not having the whole thing explode seems like a good way to quickly run new flights.
You realize the rocket is 15 stories tall and made of aluminum foil under high pressure, right? Any means of "catching" it is indistinguishable from a collision. That's besides the absurd scale and cost of building such a thing.
It's far too fragile for that sort of thing. The moment you tried to catch it, you'd break it. The only solution is to keep it upright to begin with.
No point in spending big on small optimizations like that while they are still working on the part of the process that contains 99% of the difficulty. So far the recovered rocket parts probably have little more value to SpaceX than a very interesting log file. Even if they already send this one up again, it will be more to show off (which is perfectly fine) than for direct monetary reasons.

Once they have an economically meaningful recovery rate, advanced landing pad features might still become a tool to get some margin of error or to reduce the rocket mass overhead necessary for landing. But right now, just tipping over instead of dropping like a meteor (or stopping in mid-air like a cartoon animal, then dropping) is still the goal, not the most pressing danger.

I did a bit of research on that after a comment by Josh here on HN, basically when the first stage isn't pressurized by all of the propellant it is more like an empty beer can. (ok a really really tall beer can :-). Once it is on the barge it has the gas thrusters on top (you can see them in the video) which are well positioned to provide maximum torque to the rest of the structure, but they have limited amounts of reaction mass.

The next step would be some way to secure the booster, post landing, in a structurally supportive way, on the barge. I can't wait to see how they pull that off.

They have clamps that they were planning on welding to the deck to keep the rocket attached.
That would be interesting. I was thinking perhaps a set of explosive bolts on the landing legs which punched into the deck once it was stable.

I was also quite pleased that they had solid video of it coming into land with a drone that was hovering off barge. That was a brilliant move on SpaceX's part.

That was actually NASA's plane that was doing the filming!
In the new field of vtoL rocketry, you want to have as much of the landing gear as possible on the pad and as little as possible on the rocket. An expensive array of mass produced "autograpples" embedded in the platform would be preferable over any solution that adds mass to the rocket.
So far they haven't lost any of them because of the size of the ship. People keep saying they should build a bigger or more stable ship, but every loss so far has been because of things like failed landing legs, sticky valves, or insufficient hydraulic fluid.
Successful landing on the autonomous drone ship. Awesome to be witnessing the amazing progress.
Yeah, it's absolutely an amazing thing to watch.
Totally agree! Big congrats to the SpaceX team on this historical accomplishment.
Holy cow, congratulations to everyone involved. This almost made me cry.
Watched this in public with my coworkers, so I controlled myself. Had I been alone I would have wept with joy. This is so incredible.
I wept like a little baby in front of all my coworkers when the first iPhone came out. Such a beautiful accomplishment.
I thought the ipod was far more impressive, and that sticking an antenna and microphone on it was not only obvious, but expected. Unless you're talking about software or cameras or something...
Bbeing emotional is key to being human
History in the making. Successful landing on 'Of Course I Still Love You'.

Very, very inspirational.

I'm hoping that the drone ship name is an Iain Banks tribute - if so, it's hard to think of anything more fitting
They are indeed.
It is, Elon Musk has mentioned the Culture novels in a bunch of interviews, he was a massive sci-fi fan growing up.

I'm very conflicted about SpaceX.

On one hand, I can appreciate the technical performance like everyone, and I do believe this may have a great impact for sending things to space, including humans.

On the other hand, SpaceX's main goal of having men living on mars to me sounds completely insane. No matter how cheap is the trip to mars, I would not live there as I could not afford to, and I doubt anyone on Earth currently can. Maybe a scientific base with public funding would make some sense but it would still be so insanely expensive that it'd be tough to sell to the tax payer. And it's clearly not what SpaceX has in mind, anyway. Also I don't share the fear of an upcoming cataclysm that would make Earth worse a place where to live than mars. I just don't get it.

For reference:

What SpaceX is doing is raising the bar. Not to where it needs to be, but at least a little bit out of the deep hole it is currently buried in.

As a child I was fascinated by technology and sci-fi, because of the unlimited potential held by it. It seemed to me like people could go anywhere, achieve anything, if only they set their minds to it. Growing up involved being told over and over again about all the things that aren't possible, all the ways in which that is naive thinking. The bar of what could be achieved was constantly lowered.

All that lowering of the bar? It is BS. Things are only impossible because they're believed to be impossible. We don't need more technology, we don't need more resources, we just need to believe we can do better. SpaceX is demonstrating that with every launch. Any spacefaring company could have done what they did, but they simply lacked the ambition and the belief. When (not if) they put people on mars and turn a profit doing so, it is a challenge to the rest of us to raise the bar in our own line of work.

I agree with you on being skeptical about the Mars plan. I won't say it will be affordable in the future, but I also don't believe when you say it definitely never will be, without any reasoning behind it.

The "How (and Why) SpaceX Will Colonize Mars"[1] acknowledges the part on how it would be made affordable. It is similar, but not the same, as Tesla's plan to make EVs affordable.

The question then remains, will it happen, rather than how it would be possible. As I said, I am skeptical about the Mars plan too, despite the plan.


True. Saving earth would be much easier in almost every way imaginable (economic, logistic, structure) than trying to establish a new earth in space. Not saying we should not explore possibilities, but human sense and desire for exploration was always driven by the search for places that are good for humans to live in or provide value to our direct needs, while space is so hostile to our race that the efforts would be enormous and the benefits little. We have been to the moon, but found nothing too valuable and efforts have largely scaled down since then. We humans are bound to earth by our very own evolution, finely tuned for this environment. We are children of the earth and children we will remain.
To those that aren't aware, Elon is part of this weird futurist SV clique along with Pete Theil, Ray Kurzweil, Eliezer Yudkowsky etc. They're trying to create a utopian libertarian society and aren't too concerned about the details. It's pretty cool and definitely pretty crazy/idealistic

I can already see the future - being a remote web dev on Mars! If you don't work hard enough they might cut off your oxygen. What a motivator! Ayn Rand would be proud

Or maybe they'll be all applying for research grants (wouldn't THAT be ironic)

I don't think the current tax system can allow anyone to become rich enough to afford living on mars, and I doubt settling on mars can exempt from taxation.
The sun will not explode tomorrow, but it will eventually. You gotta start to move sometime if you don't want humanity die out.
Earth will remain inhabitable for about 500 million years. Making any kind of a plan for such a time frame is just dumb.
The thing being defended against isn't the sun blowing up. It's a species-ending impact or some other localized global catastrophe that would cause the loss of 100,000 years of culture, art, and history.

Everything we've worked for during the entire history of the human existence can be erased in an instant. All other benefits of being interplanetary aside, redundancy is important.

> The thing being defended against isn't the sun blowing up.

It was in the post I was replying to.

> It's a species-ending impact or some other localized global catastrophe that would cause the loss of 100,000 years of culture, art, and history.

Do you plan on building museums on mars or something? Whatever you plan on doing on mars in order to preserve "culture, art and history", you can do it for much, much less money on Earth.

> Everything we've worked for during the entire history of the human existence can be erased in an instant.

That's a gross exaggeration.

me too, there is so much uninhabited space on earth that Musk can improve upon...
As Dr. Zubrin once said "I think societies are like individuals, we grow when we challenge ourselves, we stagnate when we do not." -

I truly believe the whole point of going to Mars is to challenge ourselves. New skills will be required; new passions will be planted in future generations. The benefits will dwarf the cost of the program.

But above everything, humans are wired to explore. Obviously we're exploring things in many other fields, but "exploring other planets" is a different kind of exploration.

> The benefits will dwarf the cost of the program.

There will be no benefit if nobody can pay the costs.

> I truly believe the whole point of going to Mars is to challenge ourselves.

SpaceX does not just want to go to mars, they want to have people permanently live there.

> But above everything, humans are wired to explore.

The point of exploration is to discover new places and what they look like. We know what mars is and what it looks like. We're currently exploring it. Sure, bringing humans there will make us know a bit more about it, and in that sense that's still exploration, but that's very marginal an improvement over what's currently done.

Also, exploration is a scientific endeavor, and as I said SpaceX's goals are clearly not just scientific. It's that non-scientific part I find insane.

I agree with this, but I don't understand people who look at Earth and see no interesting challenges of this class.

Climate change? Widespread torture of thousands and thousands of marginalized classes of humans all over the world? Healthcare? Those are vastly more challenging than Mars.

I think the appeal of Mars is that it's somewhat challenging, but it's not messy at all. It appeals to people who can't stomach chaotic systems. They need a clear goal and they need "dumb" opponents, i.e. the laws of physics, materials science, etc. In the face of an intelligent opponent, the challenge becomes too high and they lose interest.

The idea of putting together a solution to a problem with known constraints, and then finding out those constraints changed, or worse yet there was active interference from another human is soul crushing to these people, so they retreat to difficult engineering problems where they will be challenged but not surprised.

I'm embarrassed to say I was screaming and cheering like a little school girl upon landing.
Nothing to be embarrassed by. I was too, and I was high-fiving my wife, who I made watch it. :)
my wife is like "meh" about it. Same thing with virtual reality, I've got an Oculus DK2 that she's not even interested in trying out.
Wifey not into space tech, but when I explained what this meant, she was like "Wow! I didn't think that it would be even possible to have a stick rocket go up, turn around and land on a little pad in the ocean". That's crazy.
Not wanting to be overly dramatic, but as someone who wasn't around in the sixties this feels like our moon landing!
Not even close. Impressive nonetheless.
It's going to lead to a manned Mars landing. The time will come.
In a way it's even more important. Apollo was an amazing achievement, but it wasn't set up to be sustainable. Spending billions just to beat the Russians doesn't last.

If you want to see more interesting space activity than a bunch of comsats, some probes, and the ISS, you need to make space a lot cheaper. That's been stagnant for a very long time, and what we saw today is the second step towards something that promises to cut the cost of space by an order or magnitude or more. We're finally seeing something that might make space something more like aviation, not just a bunch of national prestige projects with a handful of commercial uses.

If people are living on Mars in 50 years (which looks more and more likely now) then it'll be because of this, far more so than the legacy of Apollo.

Ok, I'll bite. What was the first?
Landing first stage on land.
Yes, that's what I meant. The first landing was a huge step, proving the whole crazy concept can work. This was another huge step, proving that the whole crazy concept can work out at sea, where it needs to happen most of the time.
Not quite the moon landing... but I haven't felt this way since I watched the Apollo rockets lift off.
Here's a video of the landing:
Seems like something has changed. Landing is at about 27:15
That really felt like watching history being made. And damn, that ship is getting some waves.
Gorgeous success! Fascinating to hear chants of USA USA USA in the background.
Gifv of landing:

Fascinating how it seems to bounce or slide at the end. Also: WOW!

Quite unreal.
Watching the webcast feels like being at some blockbuster movie premiere. There's a largish crowd following the launch and applauding on every launch stage completion. Not that it's a bad thing per se, it's rather the opposite, it however, feels quite weird and staged as opposed to launches done by ESA, Roscosmos or even NASA.
There is the technical webcast in complete silence
The NASA people seemed pretty happy when Curiosity landed on Mars:
I cried like a baby that night. I wish my son had been a bit older to be able to stay up and have watched it with me.
That was a memorable night. I remember feeling like I was going to pay for it in the morning, but it was worth every bit.
I'm curious why it feels "staged" to you? Are you that uncomfortable with expressions of genuine enthusiasm?
They might not show it but surely the people working at ESA, Roscomos and NASA are excited and celebrating successful launches as well.
Of course they do, why wouldn't they? The way they're doing it, seems more spontaneous.
ESA and Roscosmos launches are fairly sedate (almost fell asleep watching an Ariane 5 launch), but since the beginning launches managed by NASA have been pretty heavy with theatrics. Someone else mentioned JPL/Curiosity, which is one good example. Let's also not forget the massive cheering crowds at every Shuttle launch:

The SpaceX hype is just a logical continuation of that, IMO.

It's probably propaganda, but I might be okay with progress propaganda.
Pretty sure the large crowd are the people who built the rocket, which somehow makes it okay in my book.
Honestly that's the most amazing thing, besides watching my daughter be born, that I've ever witnessed.
My three year old daughter watching the launch, in the hospital room where we await the birth of our twins:

We had twins when our first was three.

Best of luck to you, my friend. The first year or two will be unlike anything you've endured in your life, but you will make it through.

Maybe this is a stupid question but why do they land that thing on floating vessel vs. fixed target on land? Seems like it will be more difficult to manage this in the ocean given that the vessel itself is moving around with the ebbs and flows of the waves..
The ocean landing is more difficult. But you have to realize getting to orbit is not about height, it's about speed. By the time the first stage is separated the rocket is going 3000 m/sec away from the launch pad. It takes a lot of fuel to arrest that motion and go back the other way, whereas the barge will be right where you want to land given the situation at separation.
It's harder to land on water but it requires less fuel overall, and is safer. Check out the launch/recovery diagram on this article and it will become more obvious why it would require more fuel to return the booster to land:

Most of the earth is water. The launch vehicle travels a significant lateral distance and the can burn less fuel getting to a nearby boat vs far away land.
Probably because that's the direction the rocket is going: out over the Atlantic.
I don't think this is a stupid question, and the Verge came up with a very similar response to what I would think. Having a barge that can be compensating for current wind conditions could enable SpaceX to launch at more times than previous - expanding their launch windows AND launch points. Let's see what the Verge says:

The main part that they point out that I wasn't thinking of is fuel. They're saving on putting fuel into the rocket because they are now putting that fuel in the place that weight doesn't matter - in the sea. Literally. Weight doesn't matter there - they can create a larger platform (preferable) to put even more fuel into! ..pretty brilliant if you ask me.


Hello, Of Course I Still Love You, nice to land on you.

[I love that SpaceX has the Falcon and the Dragon, and that the autonomous landing drones are named for starships in Ian M. Banks' Culture series. Cool technology _should_ get cool names.]

That's so freakin' cool!

Does anyone know how the rocket meets the drone surface at landing so precisely especially when the drone is pitching and rolling? Is it processing on the rocket or some other mechanism?

F9 is not believed to have any information from ground sources during descent, based on FCC filings. The altitude of the barge only changes by a meter or so in decent seas, and the legs can withstand a drop of several meters, so probably they target sea level +N, where N is the maximum expected height of the deck.
Wait, really? They just punch in the coordinates and that's it? Cameras or radar or anything?
Pretty much. GPS is really good these days. It does have a radar altimeter, but that's only for height.

F9 has demonstrated landing in fog and at night, so visual cues are clearly unnecessary.

The ship can hold position to within less than a meter. It's easier to just plan the position beforehand than try to have the rocket receive the ship's position in realtime somehow.

It's interesting to consider how much more difficult this stuff would be without the GPS satellites already in space.

You'd think they'd want some redundancy though. Do they really do it only based on GPS, or do they have other optical/radar/radio systems?

Also does the US government give SpaceX access to the military GPS signals?

I don't know if they care too much about redundancy. The landing is still very much optional, after all. They have no redundancy in case of engine failure for this phase, which is probably much more likely. GPS is kind of inherently redundant anyway, as long as you have multiple receivers. You need four satellites for positioning, but way more than that are visible at any given time.
It has very good inertial guidance as well. The GPS is probably the best available; considering they launch GPS satellites, I'd expect they aren't restricted. However, civilian GPS use isn't really much different anymore; intentional degradation was turned off in 2000, though certain dynamic limits still apply on the receiver side.
Amazing, well done Space X. Watching the live feed gave me goosebumps and was more exciting than the any blockbuster I have ever watched.
Does anyone know how do they "secure" it to the drone?
I don't think there is any clamping mechanism if that's what you're talking about. Apparently they rely on the sea being calm enough not to make the rocket tilt over. Also remember that the tanks are mostly empty so the center of gravity is fairly low.
They have jacks that attach to the hold-down points; those jacks will probably be welded to the deck. Elon also mentioned the metal shoes over the legs some time ago, and they may also have those, but there's less evidence of those. (You can see the jacks on the deck of the barge in various photos and videos.)
They weld "shoes" onto the deck that hold the tips of the legs.
Thanks. I was trying to picture a fixing mechanism that could work over the entire surface, but hey, all the metal is meltable!
Is it an instantaneous weld that happens on landing?
Engineers are waiting on a vessel a safe distance away in case the landing doesn't go well. Then they go in and weld the feet once the rocket has vented the leftover LOX (Liquid Oxygen). I think they are also attaching guide wires to the top, but i can't confirm that.
No, they probably fly several people out on a helicopter.
There is a support ship nearby. The Go Quest.
And land it where? It's easier to just use a boat.
No. They really don't need anything that instantaneous. The center of gravity of the rocket is _very_ low. The rocket is basically a bunch of really heavy engines and a couple thin walled propellant tanks. Those tanks are very close to empty at this point (the heavier propellant, kerosene, is in the lower tank).

It's quite stable. The welded shoes are just a 'belt and suspenders' approach.

It's crazy how they can do this in real life and I still can't land this in the game[1].

[1] -

Sensors, control systems, software, hardware and of course the weather. So many things can wrong despite your best efforts. Just think about it, the entire rocket goes through multiple cycles of extreme temperature/pressure variations in a very short span, the different materials used in the vehicle expand and contract at different magnitudes. You have got to get your calculations absolutely right. It is mind boggling to even think about it. Kudos to all the Engineers, Scientists and the support staff for pulling off such a feat. I feel lucky to be able to witness history in the making.
Like launching a pencil over the Empire State Building only to have it land upright inside a shoebox during a windstorm, or some such analogy. ;-)
Onboarding view of the landing:
Live Press Conference:
That landing was amazing to see. The landing they did on land was more spectacular, but having seen their failed landings on the barge earlier it feels so good they succeed at last. Godspeed SpaceX!
After main engine cut-off(MECO-1), 1st stage turns around and fire it's engine to zero out all it's lateral velocity.

Wish there was a video of that!

Here's ground video from last year with the boostback burn.

Did the 1st stage fire in the video? I don't see any visible re-ignition.
This is my kind of Super Bowl. A win for humanity.
The SpaceX Reusable Rocket Story and other attempts
Self driving electric cars, virtual reality, now this. I think 2016 is the future you guys.
Tuned in just in time to see stage 1 sitting happily on the drone ship. Not as much data about what can go wrong, but hey, they got an intact stage 1 back and going over that is going to provide them with mountains of data. Looking forward to more.
I literally tuned in 5 seconds before it touched down. So glad I caught that - feels like it's bit of a step forward for mankind actually. Huge congrats to the SpaceX team. We're all very proud of the awesome work you're doing!!!
> I literally tuned in 5 seconds before it touched down.

No, you probably didn't. The link in this post is to a youtube recording bookmarked to the point a few seconds before touchdown.

Amazing stuff! BTW, can we buy those "Occupy Mars" T-shirts somewhere? :-)
Elon is having a very good week!
Here is footage of the Falcon 9 stage 1 landing and the celebration that ensued... (if you missed it)

So annoyed my alarm didn't wake me this morning to watch this live, glad it didn't explode this time and made an awesome landing. Huge congratulations to SpaceX!
Musk is having the week of his life.
It came down at quite the angle.
Looked intentionally parabolic to me.
This is intentional. I think the plans are that SpaceX would be directing the first stage to de-orbit and enter the atmosphere with an "incorrect" trajectory, so that if the landing burn fails the rocket will be safely sent out to sea. Part of the landing burn is a redirect maneuver, so that the rocket will always have a crazy angle when it comes in, but will also keep land/people safe.
There's no land or people around in this case, but they don't want to punch a hole in their fancy ship if the engine fails to relight.
I don't think that's the correct explanation.
Perhaps that's not what happened here - it sounds like Elon later explained that there were high winds at the landing site that might have caused the heavy lean. However, what I said about the last minute divert maneuver is possible/probable for future landings. Here is a recent discussion about it:
Here's the NASA press conference where he says it:
In the press conference, Elon credited 50mph winds for the tilt.
Wow!! Wow!!! Wowww!!!! That is SOOO COOL!!! >.<
Missed it by five minutes :) Is there a replay?
You should be able to rewind the YouTube stream.
The landing takes place at approximately 36 minutes into the video.
Shows my age - I'm so used to live streams being non-rewindable that this didn't even occur to me.
Just seeing the first stage come in for a landing was amazing. Being able to stream that video was a wonderful surprise.
Can somebody please remind me again why we have to land this thing on a barge on water instead of land?
It's because there's not enough fuel to make it back to a landing pad.
And they actually explained that in the video:
Thanks guys.
According to this one did have enough fuel, but the next couple won't, so they wanted the practice.
serious answer: play kerbal space program for a few hours. it gives you lots of intuition for such questions.
It's cheaper that going back to the pad.
The part that's landing is the stage 1 rocket, which pushes the payload through max atmospheric pressure and near the edge of the atmosphere. By the time it's done doing its thing, it's going really fast away from its launch position. To land back where it started, it needs to reverse its (horizontal) velocity, which takes fuel. Some launch profiles leave it enough fuel to fly all the way back home, but some don't. I believe it's expected that the heavy launcher (basically three stage1's side-by-side) will always have to land the central stage at sea, because the center stage will keep pushing after the side stages are done, and it will be going way too fast to come back again.

Not an expert, but that's my understanding of things.

Somebody tweeted last week that Elon Musk is the new Steve Jobs.

I think he's the new Tony Stark.

You may have that backwards.

Can't wait to see this first stage land again! (and again and again...)
Is there anyone here who doesn't drink the SpaceX Kool-Aid?
Why don't you? Serious question.
It's not a worthy character trait. Jesus.
Very nice, congrats SpaceX!
Wow simply amazing.
255 babies are born every minute. This is something else.
Technically speaking, reproduction of the human is a much more complicated process - we still can't do it artificially.
Agreed. But one of these things took millions of years. There's no natural equivalent of launching a rocket.
You're completely ignoring the fact that one of these processes is built precisely on top of the other! Our ability to do this was afforded to us by nature and evolution. I think the crowd should have been chanting "Evolution! Evolution!"
We detached this subthread from and marked it off-topic.
Max-Q, looking good!
Yesss! They landed it!
Wowwww, amazing. Congrats!
They did it! On the ground!
Wow! Mind blowing stuff today
Woohooo. It landed back safely.
That was so cool. If you feel like launching one yourself, they have a user's guide:

And pricing information:

(edit: added pricing info which might be helpful)

It gets really interesting when you can put 5 people in orbit for under $80M (that is $16M apiece), Add a Bigelow module that they can spend a week in, and land back on land? I'm not sure where things are going, but it is the first time that I felt I could "see" non-NASA people going into space on a regular basis as an actual possibility. If you're re-using the boosters it could be cheaper still.

Now we need to figure out when an Amazon rocket with a BE-4 will launch (it needs a couple of BE-4s to get enough delta V to insert stuff into low earth orbit)

Perhaps space is the "next big thing" that everyone was wondering about?

The Falcon Heavy specs & pricing is fascinating. 12-13 tons to Mars for $85M? I wonder if we could see a human team on Mars within the decade.
If you expand your time horizon enough, then yes, space is the next big thing.
> Perhaps space is the "next big thing" that everyone was wondering about?

When we will be able to generate value by being in space. Asteroid mining, for example, would make space travel expand a lot.

They lost a golden opportunity to start this with "Congratulations on your purchase of a Space X Falcon 9..."
Once they start reusing them, it's really just a rental.
Or FedEx, even - SpaceX is doing the driving.
I'd rather rent the electric car!
It doesn't have to be either/or.

I'm expecting to see Teslas on Mars before I die.

Where's my rocket Tesla?
And given the Martian atmosphere, if you want to drive a car on Mars it has to be electric. It's all starting to make sense...
Actually, you could manufacture ethane out of the martian atmosphere, and it could be burned in an internal combustion engine using the CO2 atmosphere as oxidizer.
Interesting to see the margins of error on 3.6 - 10-15km in a 200x360km orbit. A lot less accurate than I would have expected, and makes standard mission designs (with separately-propelled payloads) make a lot more sense.
My KSP launches are similarly inaccurate
And it's the period that matter most of the time, not the actual ap/pe, I'd like to see the error on that.
Launch vehicles can't be controlled during atmospheric flight. All the control is in the first seconds with the roll and pitchover maneuvers and the rest of the way is maintaining a zero angle of attack during the gravity turn.

This causes errors to accumulate and they must be corrected with rocket burns with the payload satellite or space craft.

15 km may seem like quite far off, but it doesn't take a big rocket burn to correct.

This is absolutely not the case, angle of attack is not zero, but moreover most of the orbital insertion is exo-atmospheric and you can burn in whatever attitude you want. The factor determining the accuracy of the apogee of your orbit is how accurately you can shut the engine off at the right moment and control your velocity.
I like the bus for scale on pg 10.
Where's the Buy Now button??
My American Express card doesn't have a set spending limit... :)
...and PayPal integration.
I'll pay with Ethereum!
Let's hear it for the Bitcoin address. :)
Soon we will have "model rockets" which will do the same thing without reaching space....
Sounds like something SpaceX should sell. Maybe there's some value for them in miniaturizing the technology, and the small profit from the model rockets could offset the cost a bit? Or maybe just look at it as PR?
Edit: I was very much under the impression that there were concrete regulations against private individuals using active guidance on model rockets, but after searching around, I can't find any such thing. Goes to show, trust but verify, including your own memories.
They're tons of fun but yeah, there's a reason they are done way out in the middle of nowhere.

My favorite was when you'd get a false start, enough to get you off the launch rod and flop onto the ground right as the main motor took off. We called those land sharks.

You know, memories are the only thing have to think back on...
While I totally get why actively guided rockets are prohibited, what I want to know is by what law are they able to enact this prohibition.
I'm glad they're not prohibited. Would think guided is a helluva lot safer than point-shoot-and-hope ;)
Active guidance on anything rocket-propelled is strictly prohibited/regulated by federal law.

This is widely believed, but not true. Here's a nice example of a small model rocket with active guidance.[1] It's launched at a 45 degree angle and then corrects to vertical. After beginning descent, it pops a parachute and lands safely. Built by a 13 year old girl.

For rockets above a certain size, you have to start talking to FAA air traffic control, and they're going to insist that you operate in some unpopulated area. But that's not about whether it has guidance technology.


The problem is getting a compact throttlable rocket engine. While you can throttle solid rocket motors[0], the solid rocket motors you can buy at your local hobby shop would not be very good for this, as they don't burn for very long. Hybrid rocket engines might be the thing to use for this and amateurs have built such things[1].

[0] [1]

Where's the call to action? Who designed the page?

> SpaceX offers open and fixed pricing for its Falcon 9 and Falcon Heavy launch services. Modest discounts are available, for contractually committed, multi-launch purchases. SpaceX can also offer crew transportation services to commercial customers seeking to transport astronauts to alternate LEO destinations.

With such big ticket items, I wouldn't have imagined there is a price list available. I would think these things are negotiated over expensive dinners. You almost expect to see a "Buy Now" button on the page.

> Where's the call to action? Who designed the page?

Assuming that that wasn't tongue in cheek...

Their target audience is "people who want to launch something into orbit". They don't need a call to action, they already have a rather well-defined need.

> I would think these things are negotiated over expensive dinners.

That sort of shit is exactly what Musk has been complaining about every time he talks about how fucked-up the existing space delivery industry is.

Think of it this way: You don't negotiate the price of delivery for something you're gonna ship via FedEx over a dinner.

One of the goals of SpaceX is to make the space delivery industry as much like every other delivery industry as is humanly possible.

Was most definitely tongue in cheek
It was tongue in cheek.

And I am completely on board with the open pricing model. It's incredible and probably makes their competitors very nervous.

That's the point. Space-X's pricing has terrified the industry. Now the question is whether you get a discount on used boosters.

What Space-X doesn't give you is a firm launch date. Spaceflight Now listed today's launch as "Delayed from Aug. 13, Sept. 2, Jan. 3, Feb. 7, March 20 and March 29. [March 16]" This is Space-X's biggest problem. They're about a year behind on their launch manifest. They don't even put dates on future launches any more. Customers don't like this; some have switched to Arianespace or ULA or Russia for their satellite launches.

Space-X is trying to catch up. Next launch date is April 28th, and there are two launches a month scheduled for the next few months. First Falcon Heavy launch is scheduled for November, but that may slip.

"We are backed up in how much stuff we have to deliver to space" certainly seems like one of the better problems have.
Sounds similar to Tesla's Model 3 "problem" (>375K preorders).
This feels like one of those cases where the ticket is so big and so many are lined up to pay (because it is so much cheaper), that they just slap the price on it.
Clearly they need to be doing A/B testing to determine their optimum pricing.
That's why websites that don't give a price quote for their products without contacting a sales rep now get frequently mocked with the words: "If SpaceX can do it, you can do it.".
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