SpaceX just landed a rocket on a drone ship for the first time
techcrunch.com
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I've become so used to writing (and working with) less than perfect (sloppy) software, I'm ashamed to be called an engineer (not that anyone calls me that). I wouldn't be able to write software that lands a rocket anywhere without first crashing ~100 prototypes.
edit, one example of the kind of problems they deal with: initial rocket testing was done on an island near Hawaii, so the engineers had to build their own living space and stay there full time rolling out this big heavy rocket onto an open field for testing and then rolling it back into it's hangar every day in grueling heat. they'd work 15 hr days which was pretty much expected and thankless. when there was component failure Elon would use his Jet to get parts at radio shack in a different state and fly it over to CA for testing, and then straight to the island speed up the work. Something that would take NASA months would take SpaceX days or weeks since they didn't need "space grade" components but instead used common parts. They'd just ensure that those parts passed enough tests that they could be confident of the quality.
Amazon link for anyone interested: http://www.amazon.com/Elon-Musk-SpaceX-Fantastic-Future/dp/0...
They seem to use Grafana at least :) http://grafana.org/blog/2016/01/19/Grafana-Its-Rocket-Scienc...
Also, after the landing they vent the remaining oxygen, and afterwards people come aboard to weld the rocket legs to the surface so it wouldn't slide off.
Maybe very strong winds would be an issue, or very rough seas immediately after landing but they wouldn't launch in rough weather anyway.
There are two main tanks in the stage, the top ~half is liquid oxygen, and the bottom ~half is kerosene. The liquid oxygen is lighter, and boils off pretty quickly once they open up the vents. So what little fuel is left (the kerosene in the bottom tank) also settles to the bottom, which helps push the CoM even lower.
For the vertical landing, this would seem to work against them, but I guess the mostly empty tanks don't dominate the considerations. Falcon has oxidizer on top in the conventional manner, as far as I know (they mention LOX feed lines going through the fuel tank).
[1] The N1 rocket had oxidizer below the fuel in every stage, apparently because they wished to use spherical tanks, and this allowed packing them in a conical shape - the oxidizer tanks are much larger.
It is however true that they can vent it pretty quickly though, leaving the only remaining propellant in the bottom tank.
Actually, an inverted pendulum -- where most of the weight is on the top -- is easiest to balance on top of the rocket thrust. Coming down at high speed, this would be aerodynamically unstable, but this is why they have the grid fins, to move the center of aerodynamic pressure behind the center of gravity.
After watching the video I don't know what Musk is talking about. Maybe he's talking about a maximum double amplitude.
https://www.nasaspaceflight.com/2015/06/spacex-augments-upgr...
Some pictures of Marmac 303 : http://www.worldmarine.com/projects/barges
The cost of cleaning, refitting, and fixing issues from a splash landing is more expensive than doing it this way. At least that's what SpaceX's whole model is pretty much based on.
PS: Being literal rocket scientists I a going to assume landing is a much more workable design.
And who plugs them, and where. In space, before landing?
I think that one of the great things that comes out of this is that we start using our imaginations and trying to understand the whys and hows of space travel. It's really exciting to see.
Also, I assume it's a lot easier to be sure that the rocket's in good shape if you don't have to check the interior for leaks, and whatever chemicals seeped in with the water?
Seems like every thing else in history has really been a missile. This thing can land, so seems like it's literally the first rocket. Do we have a definition of missile vs rocket?
A rocket is just something with a rocket engine. Note that missiles do not need to use rocket engines and rockets don't need to carry warheads.
Maybe it helps to think by analogy. Which is harder, putting a car on a ferry to carry it across a river, or just driving it into the river and fishing it out the other end? Sure, you'll have to replace the engine and the electronics and lots of other stuff (i.e. all the most expensive parts of a car), but if you're only doing it once, it's cheaper to ford that river Oregon-Trail-style than to get yourself a ferry. But if you're doing it many times ...
The point is, there's lots of extremely high precision, expensive stuff on a rocket, that don't appreciate being dunked in water in exactly the same way that, say, your computer or car wouldn't. Those engines are incredibly complicated, high performance, and expensive, and they don't have the benefits of economies of scale like other consumer goods that are manufactured in the amounts of millions or billions per year. Each rocket has nine Merlin engines on it; that's an awful lot to essentially have to replace with every launch. The barge is cheaper.
Falling into the ocean would cause it to break up. Even the one they 'soft landed' (a practice run before landing on the barge) broke up.
https://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Boo...
Also, an SRB is relatively simple compared to a liquid-fuel rocket.
See the SRB from Space Shuttle launches. NASA thought the ocean splash and recovery would keep the costs down. It didn't. Ended up the cost to refurb and launch is almost equal to building a new one.
Elon wants to avoid this hence these barge or land returns.
Still, it says something that no actor has ever even bothered attempting to reuse a liquid fueled rocket that is landed in water. The only successful track record of reuse of liquid fuel rockets is the space shuttle, and those landed on a runway. And that isn't preserving the fuel tanks for reuse, mind you, just the engines.
Hell, when they fell into the water, the impact bent the sections into ovals. They actually had a giant vise that they used to bend those things back into round. (Feynmann noted this in one of his autobiographical books.)
Dunk the whole thing in seawater and suddenly you have corrosion everywhere.
In short, big stuff is fragile. You can't tip over something the size of a large office building an expect it to survive.
They are figuring out vertical landings so that when they go to other planets they can land, possibly refuel, and take back off without having to get the rocket back upright.
There also aren't seas on Mars to gently splash the rocket down on. :)
It would also have to slow to a near-stop by itself to not be destroyed by the force of hitting the water. Considering that you can do all that with the stuff already on the rocket, seems easier to add some legs and land it than to figure out a way to make it float, survive the seas for a day or 2, and get a ship with a crane tall enough to pick it up and load it.
Happy to see that he enjoys those books aswell as I do.
https://en.wikipedia.org/wiki/List_of_spacecraft_in_the_Cult...
That was a perfect landing.
As far as not aiming for the center. Of course it is aiming for the center. That's where you have the greatest margins. Yet, this is nothing like what Blue Origin has been doing. The comparison is simply not warranted.
Rather than go into a long explanation I'll just give you this data point:
Blue Origin is FALLING down from zero velocity. It reaches a terminal velocity of around 300 to 400 miles per hour. It uses fins to navigate down to a spot that, for all intents and purposes, is almost straight down.
Falcon 9 is FLYING down from somewhere around 17,000 miles per hour. During that time it has to flip around and use three of it's engines to slow down enough not to burn-up on re-entry. The grid fins also need to fly the rocket to a ship, in the middle of the ocean, about 600 miles from the coast...and then use a precisely timed single engine burn to land it.
Here are a couple of pictures to further illustrate the point:
Like I said. Perfect landing.
In this particular case, they were dealing with winds of something like 25MPH. Dealing with that in a vehicle this clumsy to control has to be tough.
SpaceX also aims next to the ship first, then corrects at the last moment to land on the ship. This is so they don't make a big hole in the ship if the engine fails to restart. I believe BO does this too, but BO's rocket can hover and take its time with this maneuver. The Falcon 9 first stage has too much thrust to hover, even with only one engine running at minimum throttle, so it has to do everything at once.
A perfect landing is one where you get to recover and reuse the rocket. It was perfect.
Much less than that. Closer to 4,000mph (from memory). You're thinking about 2nd stage.
However, I would disagree that Mars is just more of the same as was the Moon landing. It would be not unlike saying that because Columbus went to America, later discoveries weren't so impressive.
You're right, this landing is a much bigger deal long-term. The Apollo program proved that one of the world superpowers, with a decades-long presidential mandate and a giant, massive bucket of funding, could do incredible things.[1] It was awesome, and it's clearly one of the defining moments in human history. However, the pace of space travel actually decreased after the Apollo program.[2] This probably had something to do with the fact that nobody wanted to spend untold billions of dollars to keep doing this stuff. The Moon landing was a big deal, but it was a one-off big deal. It didn't have world-changing impacts on the future, only on the moment.
The whole Mars objective of SpaceX probably isn't going to be their lasting contribution to humanity. All their technological achievements so far pale in comparison to how hard it will be to live on Mars. They may well fail. However, the reusability improvements they are making have significant potential to increase the rate of space flight for the rest of our existence. That's a gift-that-keeps-on-giving big deal, and enables all sorts of options that were prohibitively expensive before. We're all really hoping the graph in [2] starts spiking up soon.
[1] https://en.wikipedia.org/wiki/Budget_of_NASA#Cost_of_Apollo_... [2] https://en.wikipedia.org/wiki/Timeline_of_spaceflight#Orbita...
I very much agree with this sentiment and your other points. I think the comment you are replying to is thinking about this achievement in a 20th century frame-of-reference[1], and not considering the tremendous amount of potential cheaper space travel has.
[1] By this I mean that he is thinking of space exploration nothing more than an inspirational endeavour.
A small note to put things into perspective: moon landing happened only 12 (!) years after Sputnik. It happened only 8 (!) years after Kennedy's speech and Gagarin's first space walk. The first launch of actual Apollo equipment was 3.5 years before the manned landing.
In other words: humans went from launching the first satellite to putting people on the Moon in 12 years. In 8 years from first person in space to first person on the Moon.
That's the speed of focused progress. Something we very much lack these days.
I think the "space race" was born with the seeds of its own doom. Wanting to beat the Russians to the moon provided the political and economic will to put a huge effort into the Apollo program - but after that was achieved the interest evaporated.
If you are more interested in the pissing contest than the science and exploration, it isn't surprising that the latter gets short shrift in the long run.
Actually, Robert Zubrin advocated such an approach for years. Mars One shows that there are plenty who would volunteer for such a thing. Hell, Mars One crew are essentially volunteering for semi-solitary exile unto death. I wonder if the Chinese or Russians are going to go the, "So it's risky? Screw It!" route?
Thank God. We were very close to midnight, during the 1960s and 70s.
http://thebulletin.org/timeline
(Jess, correct me if I'm mistaken.)
Unfortunately, the clock hands are currently set at 3 minutes to midnight, the closest we've been since 1953. The hands were much farther from midnight in the '60s and '70s.
What we saw here is part of a shift that could make a future Moon mission cost $10 million instead of $1 billion, which will help put an end to the sad title of "last person on the Moon."
The Space Shuttle was reusable too.
With the Space Shuttle, we returned the primary motors to the ocean, but it was incredibly expensive to refurbish them (they were essentially scrapped and used as parts), and of course the shuttle itself was completely reused.
What SpaceX achieved here is a potentially better margin of costs for reuse, but even that hasn't been proven until we actually start reusing the rockets, seeing how their reliability trails off after each use, etc.
As great as I think this achievement is, it's not orders of magnitude better than the Space Shuttle. And it remains to be seen whether space travel will become truly accessible and cheap because of it.
I think it might be. The Space Shuttle cost an estimated $1B / launch. So while it was technically reusable, it wasn't practically reusable in the same way that Musk is aiming for (launch, land, refuel, refly).
I strongly disagree. Landing on the moon provides evidence that humanity is technologically capable of space travel. More or less a proof of concept. But markedly reducing the cost of going into outer space means that humanity now has access to space tourism and whatever future benefits space brings.
No one knows about the first digital computers in the 1940s. The general public sees the computer revolution as happening in the 80s and 90s, because that is when computers were made available to consumers.
Fifty years since we stepped on the moon, and we're just now re-using rockets? It's a great accomplishment, no doubt. Many congratulations to all involved.
But this should have been done in the 1970s. The same economic drivers that lead us to do it today were still there back in the day. What happened is that we lost sight of the economics of space travel -- if we ever had our eye on them in the first place. We chased a rabbit down the wrong hole. Political systems exist and thrive for political reasons. NASA was always going to be about bringing home the bacon to defense contractors and looking good for the current administration. Elon is stuck with an economics/efficiency goal: make it both safe and cheap.
Just to be clear, my comment has nothing to do with the great folks at Space-X. I'm a huge fan. My point is that they're just continuing the natural evolution of spaceflight. But in the big picture, it's an incremental achievement (and yep, I know how difficult it was. All of this stuff is difficult.)
The next big goal is probably regularly-scheduled private manned spaceflights. And no, I don't mean sub-orbital fun rides. More like week-long tourist trips to the space station or a moon base. This would indicate that 1) access to space is truly becoming relatively cheap and reliable, and 2) there's actually somewhere to go.
Historic things are things we do for the first time, sure. Re-landing a rocket qualifies, but it is much in the category of orbital-docking: necessary but a footnote. Anybody remember the first manned space mission that did docking? How about that remembering the first one to leave Earth orbit? Space fans like me would know. But not in the history books for the general public.
Note that the question was about how historically important this is. Not how critical it is to spaceflight, or any other qualifier. It can be stupendously important in terms of the technical details, yet have very little value historically.
speaking of duration, that's a big deal in both fuel and effect on human passengers.
but lets get to the important stuff, mars is actually a planet, with an atmosphere. saying the two are equivalent is more or less saying kicking a field goal outside on a windy day is the same as kicking one in a dome. except when you miss everyone dies.
you also need 5x escape velocity from mars (we want them to come back too), which means more fuel and landing with lots of fuel. or at the very least sending fuel prior and hope nothing happens to it.
Also terraforming mars will probably involve dumping methane into the atmosphere.
It was just 66 years after the Wright brothers!
ps - I think the landing yesterday was a pretty sizable achievement.
But perhaps more relevant to point, the shuttle itself was "reusable". It remains to be seen if SpaceX can reuse rockets in a more cost effective way than the shuttle.
Given that the launch cost of a Falcon is already way less than the reused launch cost of a Shuttle I think if they can get 3-4 launches per rocket they'll massively reduce the cost to put stuff up.
They already have done that anyway, they undercut pretty much everyone who is currently launching, sometimes hilariously.
Musk said in one of his speeches to congress (iirc) (paraphrasing) "Our launch costs are so low that the cost of launch plus the satellite is less than ULA's launch cost alone, so you buy a launch and get a satellite for free".
They've designed this for that purpose but he mentioned in the post launch talk that they will do 10 test firings on this one before they re-launch it.
I think they'll pull it off but they might have a few undergo rapidly unplanned disassembly along the way.
Falcon 9 has about half the payload capability of the shuttle, but Falcon Heavy has more than twice the capacity, so you can make meaningful comparisons. Falcon Heavy's cost is $1,890,000 per metric ton to LEO [1], and Falcon 9's is around $5,856,000.
The shuttle payload cost to LEO was initially estimated at $260/kg(!!) [2], but turned out to be $60,000/kg [3], or $60,000,000 per metric ton.
Which makes Falcon 9 around 10 times more cost-effective than the shuttle, and Falcon Heavy around 31 times.
The spaceshuttle had a maximum payload of 25,060 kg (24,310 kg to LEO) [4]. Falcon 9 has capacity for only 10,450 kg to LEO [5], but Falcon Heavy allows 53,000 kg [6].
[1] http://www.nss.org/articles/falconheavy.html
[2] https://en.wikipedia.org/wiki/Space_Shuttle_program
[3] https://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle...
[4] http://www.esa.int/Our_Activities/Human_Spaceflight/Space_Sh...
They've also extensively studied the stage they recovered in December, and while they're pretty quiet about what they've found, what we've heard so far is quite promising. One of the engines apparently ate some debris and acted a little weird when fired, but everything else looked good. It sounds like it's not going to be too far from Elon's "wash it off and relaunch" goal.
There was a self published Sci-fi book from a few years back, where some dot-com billionaires funded a "big and dumb" design philosophy reusable two stage to orbit rocket. It also used aluminum computer aided machining and friction stir welding to increase seam strength and lower structural weight.
http://www.amazon.com/The-Rocket-Company-Library-Flight/dp/1...
Very few people are aware of who SpaceX are, let alone the specifics of their launches.
I think they've done a great deal just as SpaceX has I don't understand the dismissal of what they do why can't people be excited for both?
Reaching 100 km straight up is not that hard. You can do half that just with a balloon, and you can easily exceed it with a simple sounding rocket. The point is that the vast majority of the energy required to actually get into orbit comes from horizontal velocity. Going straight up is way, way easier going fast enough sideways so that you never hit the Earth on the way back "down".
So ...
> I think they've done a great deal just as SpaceX
Simply isn't true. Blue Origin is doing cool stuff, I won't begrudge them that, but it's not within an order of magnitude of the same kind of accomplishment. The take-off mass of New Origin is 75 Mg. The take-off mass of a Falcon 9 is 541 Mg, and keep in mind it is designed to be capable of using the Falcon Heavy configuration, which is almost triple that in total take-off mass. The SpaceX rockets, owing to their much larger size, are capable of things that the Blue Origin rockets simply are not.
Just going to space isn't very useful nor very hard. BO's main market for this appears to be tourism. There might be a bit of a market for very short term microgravity experiments, but that's about it. And getting stuff to space is something hobbyists have done for fun, it's not a huge challenge anymore.
Going to orbit, on the other hand, is both vastly more difficult and vastly more useful. Lots of companies will pay tens or hundreds of millions of dollars to put their stuff into orbit.
All you have to do to understand the difference in excitement is to look at the implications. SpaceX's landing is likely to lead to a near-term reduction in the cost of launches by 50-75%, and a long-term reduction by a couple of orders of magnitude. That's huge. That's the difference between a one-off Apollo-style Mars mission that only a government can afford, and privately-funded colonization. BO's landing means that you'll soon be able to pay a few hundred thousand dollars for five minutes in space. That's cool, but it's basically a better amusement park ride.
I suspect BO is working bottom-up for where SpaceX is right now. But they are going to start with reusability from the get-go.
Sure, BO has a long way to go, but it's not that they're only doing the tourist rocket.
Hey, I like SpaceX a lot, but that doesn't mean I'm going to judge BO only by what they have flying today.
I'm not judging BO, I'm sure they know what they're doing and their future plans look pretty good from what I know. But given the large difference in current achievements, I'd hope it wouldn't be too big of a surprise why someone would get excited about what SpaceX is doing but not BO.
I'm all for you being excited about whatever excites you, but when I read HN, that's not really what I'm hoping to read about.
As for not wanting to read about what excites me, the comment up there explicitly asked why people aren't excited for both companies, and I answered the question. If that's not what you want to read about, I think you took a wrong turn.
What SpaceX has done is cool and a big step in commoditization of space but essentially they had the balls to finally do something that could probably have been done 20 years ago.