SpaceX reveals fully reusable, vertically landing rocket design [video] | Hacker News Reader

SpaceX reveals fully reusable, vertically landing rocket design [video]

spacex.com

152 pointsequark86 comments

The "Uprising" lyrics are an inspired poke at the traditional space industry: "endless red tape to keep the truth confined... it's time the fat cats had a heart attack, you know that their time's coming to an end..."

This also happens to be a much cooler music video than the original.

How is carrying all that fuel used in landing up to space more efficient than, say, a parachute?

I'm assuming someone at Space X did at least some back of the napkin math, but color me skeptical.

They want their craft to be able to land on any surface. Two of their chief product values are modularity and versatility.

I toured SpaceX HQ just yesterday and saw this video (or some of it). The employee presenting said that landing on Mars w/ a parachute is not a good option. Powered landing makes their craft able to land on any surface.

This is a paraphrase; and I am not a rocket scientist, so don't quote me on this.

This is certainly part of it. The powered landing will give them precision control to touch down right on the launchpad instead of having to pick up the assets at sea, saving lots of time and money. But it also allows for a module to land on the Moon or Mars. Mars has an atmosphere, but only with about 1% the density of Earth's, so for vessels with this scale of mass, parachutes aren't much use, besides the issue once again of being able to position your landing spot precisely. Supposedly at every design step where it's applicable Elon has opted to make everything as ready for Mars as possible.

Supposedly at every design step where it's applicable Elon has opted to make everything as ready for Mars as possible.

Absolutely correct. I got that vibe from all employees I listened to yesterday. The underlying motivation of the company is: to go to and colonize Mars. Everything they do before then is to gain credibility, survive, and fund R&D toward reaching their ultimate goal.

I saw Elon give a talk about colonizing Mars at a Mars Society conference at Stanford 10 years ago, before he founded SpaceX. He's thinking long-term.

There's something more than slightly Heinlein about that company. I love it.

Elon wants to be the Man who sold the Moon. Or Mars, as the case may be. Don't blame him. I want to be that man too.

I was thinking Long Range Foundation, but that works too.

I work at NASA (though not on rockets), and that's a fair assessment; I think you correctly articulated what the SpaceX employee was telling you.

Aerobraking and parachutes alone aren't enough on Mars, even for small payloads (less than people-sized). Just look at the MER and MSL entry, descent, & landing systems. The reason being that mass scales with the volume while aerobraking and parachutes obviously rely on cross-sectional area. Even MSL, which is an order of magnitude lighter than a Dragon capsule, requires a sophisticated hybrid EDL system.

Also, although it may be Musk's goal to go to Mars, there is good profit to be made in Near Earth Objects and the Moon, none of which have much of an atmosphere to speak of.

For me the more pressing question is would I want to be in the capsule that uses parachutes for landing or rocket engines. My unscientific guess that using parachutes for landing humans is safer - one engine failure of eight (?) engines and capsule is off-course and crew is gone.

I suspect it would be designed so that the lose of one engine wouldn't cause it to crash, just like the lose of one parachute cord shouldn't cause other vehicles to crash.

I'd also be surprised if they did anything to foreclose the use of a parachute. If NASA or somebody else wants to eat the weight of a parachute as a backup, I doubt SpaceX will say no.

For you amateur rocketeers, I recommend trying Kerbal Space Program, a nice little rocket assembly and flying game:

http://kerbalspaceprogram.com/

an example: http://www.youtube.com/watch?v=9RvVjysJKB4

My kids are going to eat this up. Thank you.

I also recommend Orbiter 2010, but it is a simulator and is not easy.

http://orbit.medphys.ucl.ac.uk/

Update: TO date, one of my kids loves this. The others are kind of 'meh'.

I love it though.

I saw an interview where Musk said the rocket cost $50M to build but the fuel was about $100-200K so a few kg less to orbit would be ok if they could relaunch quickly.

but i did lol a little when i saw the legs push out from the rocket, when i think reusable i think drop it in the sea and have a boat go pick it up not land on the pad you just fired it from.

if this works out United Launch Alliance with Boing and the rest can just quit the rocket business, its like the intro to Patton "You know i actually pity those poor bastards we're going up against. By God, I do. We're not just going to shoot the bastards. . ."

I thought the whole reason NASA's shuttles jettisoned their rockets and large fuel tank was because getting that added weight in to space was prohibitive. How is it that they propose to get not only the entire rocket in to space but also enough fuel to provide a soft landing on re-entry of all 3 pieces? I realize rocket tech has come a long way since the Shuttle's design, but is it really that much further along?

I really do hope they can pull it off though!

Not an expert on this subject, but the landing phase requires much less fuel than take-off. You only need to slow the craft and during the final approach use fine grain thrusters to maintain control.

I do hope this is feasible.

It requires less fuel because air friction works with you during deceleration, not against you, and because, by the time you do the landing, the craft weighs a lot less, not because you only need to slow down.

I think the video left out a lot of the dull part of aero breaking, making it look as if all breaking was done on rocket power.

I do not see how this would be cheaper and safer than just using a disposable run-of-the-mill steel pipe as main engine (yes, that is exaggerating), but they must have done the math.

It also would take a lot more monopropellant to maneuver the entire assembly for docking with the ISS.

In a recent interview, Elon Musk was saying how we wouldn't have airplane travel the way we have today if the airplanes wouldn't be reusable.

He was saying that to point out that this is how reusable rockets should revolutionize space travel, in a way just as big.

Hmm, well, but it's interesting that the US went down that road and built an unreliable "reusable" spacecraft that had a high failure rate and had be largely reconditioned at high expense after every flight. Meanwhile, the Russians are using an incrementally improved capsule design from the '60s that's simpler, cheaper, and safer.

I'm not saying that a true reusable speacecraft wouldn't be revolutionary. And maybe it's possible with '10s tech in a way that it wasn't in the '70s. But picking "reusable" as a goal in and of itself, rather than using metrics like reliability or cost per pound to orbit, seems like a dodgy business.

jfruh, I disagree with you there. By setting the goal of reusable and reliable he could change the cost structure in a way that would make a fundamental improvement in financing of space missions.

The rest of the video make no sense with rockets helping for reentry. Why not just use pilot guided shoots?

By setting the goal of reusable and reliable he could change the cost structure

But there's the assumption, isn't it? Actually two: that reusable will be cheaper, and that reusable and reliable can go together.

I'm certainly not saying they can't -- I am, quite literally, not a rocket scientist -- but the Space Shuttle program was the triumph of the idea that "Of course it'll be cheaper if we can re-use the vehicle." Which didn't work out in practice for the reasons outlined upthread. My point is that a space program should pick the goals of "This should get people up and back safely and cost $X a launch" because those are measurable. Maybe the best way to do that is with a reusable vehicle! But to make reusability a goal in and of itself, due to a sentimental attachment to the kind of vehicles we used to travel by sea, seems silly.

When it comes to spacecraft Fuel is cheap manpower is expensive.

The Americans built the first ever reusable spacecraft but they never really stuck with one design. Just about every shuttle was slightly different which resulted in slightly improved performance, reduced safety, and dramatically increased costs. They then kept using them well past the designed lifetime which once again radically increased the costs. All while flying them a minimum number of times each year.

How cheap is the fuel? Say, a space shuttle? I've heard a launch costs $450 million, but it doesn't say if it was fuel alone.

While the shuttle was technically 'reusable', it required a lot more retooling between flights than simply putting more fuel in the tank. It was a _very_ complicated machine, and invariably needed to have various components and consumables replaced after every flight.

The marginal cost on a Space Shuttle launch is actually rather low--a few tens of millions if we kept up with the original launch rates (less than the cost of a Falcon 9h!).

Also, no work was ever done to bring down operational costs. In fact, such costs ballooned as the program dragged on, despite numerous design studies showing ways to reduce them.

It's supposed to be on the order of one to two percent of the program cost, depending on exactly what fuel you use and how often you fly.

In U.S. dollars in the year 2000, it came to about $16 of fuel per pound of payload launched. We had a homework assignment to figure out that number in our propulsion class at the University of Washington.

Shocking. The rest of that $10k per pound is amortized launcher costs and operations. (If you include the initial R&D, it goes up to something like $50k per pound.)

The shuttle was a truly immoral launch vehicle.

That's incredible. You should do a blog post about that. It's really fascinating and I don't think is been published anywhere.

The shuttle had wings, Falcon 9 / Dragon does not. That's also why it had expensive/brittle tiles rather than ablative shielding, was strapped on sideways, had solid rocket boosters to handle the added weight, and didn't have an eject capability. Also all of its stuff splashed at parachute speed into the sea. The shuttle wasn't so much reusable as rebuild-able. By contrast this SpaceX concept looks like it could pretty much be stacked back up, fuelled and re-launched.

The Shuttle had to have a lot of design compromises to get the political support needed for funding the program. NASA didn't have any need to haul satellites into polar orbit, but the Air Force thought that it might be useful so the Shuttle ended up having far more payload space and delta-V than it needed for the missions NASA ran. Of course, most of those excess capabilities ended up not ever being used except for the repair of the Hubble, but they made the Shuttle far more expensive and less reliable.

The video gives the idea, but full details here:

http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2011/09/29/...

I love this quote "Now we need to make sure that those simulations and reality agree, because generally when they don't reality wins."

Reminds me of one of my favorite Feynman quotes:

"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." — Richard P. Feynman, minority report on the Space Shuttle Challenger Accident ( http://quotes.cat-v.org/science )

How did they manage to flip the second craft from it's reentry position (nosecone down) back around for landing?

Wouldn't carrying the extra fuel to slow the craft on reentry make this cost prohibitive, thus why most craft use parachutes or similar passive slowing devices?

physics.

Haha... the point I was trying to make is that flipping a spacecraft in a vacuum is easy as there are very few external forces involved.

Flipping a craft while hurtling toward the earth at some large velocity through an atmosphere which generates friction with very few control surfaces is not.

Nowhere in the video do they show any drogue or drag chutes but I would assume they enter into the picture as well, and would be involved in the mid-altitude slowing and flip of the second stage.

You can definitely do a deorbit burn and then flip around using thrusters before aerodynamics kick in. The Space Shuttle did it all the time.

The extra reaction mass is just a balance between the various costs. Building a new rocket per launch vs some constant factor off the top of your payload capacity.

  > How did they manage to flip the second craft from it's reentry position [...]?

Apologies, I think I don't understand...

The video is a concept video, not a real-life recording.. it's CG. But you're asking about real-world physics. And everyone else is talking about it too, as if the video actually happened, even though it's just a CG animation.

I'm just really confused; sorry. Heh. I know I'm missing something obvious here -- figured I'd ask what it was, even though I look silly. :)

The video wouldn't have much point unless it was showing the design of how the rockets will actually work. Sure, the actual design and details of the rocket may be different in real life, but the basic idea of having the components soft-land back at HQ would be real.

I think it's possible to flip by shifting the center of mass, which can be done by moving some mass (for example, fuel) inside.

I believe the video showed the final stage vehicle flipping using thrusters in orbit, then re-entering engine facing Earth.

No, it flipped, decelerated, flipped back (off screen), re-entered brown bit first - that is the ablative shielding, then it must have flipped (off screen) while falling through atmosphere after re-entry because it came in to the landing pad feet first.

Yeah, I saw this too. You'd better make sure you're going slow enough before you turn that thing sideways or you'll do a Challenger...

It should slow right down though, it's an empty tank.

That's the problem, it will slow down so fast it might not stay in one piece (this is what happened to Challenger, hence my comment.) A pipe like that going sideways has a tremendous aerodynamic resistance.

No, I mean, it will slow quickly while doing the nose-first heat shielded re-entry, all the way down to terminal velocity, and then be safe to do its flip to feet-first.

Wow, this seems almost as important to space travel practicality as the assembly line was for cars. To think where we (as people) were 100 years ago and to contemplate where we might be in the next 100 years... exciting times we live in.

Youtube link...

http://www.youtube.com/watch?v=p176UpWQOs4

Very awesome. Quite an amazing feat if they can vertically land a rocket on such a small target like that. Dig the Muse soundtrack too.

To quote Steve Ballmer: "I've got four words for you: I LOVE THIS COMPANY!"

Unfortunate music choices aside, the video was well done and clearly demonstrated the concept without narration or text.

I'm hoping that the materials are finally here to usher in the next generation of space vehicles, because this idea wasn't nearly as plausible back in the 60's.

From SpaceX page:

"SpaceX CEO & CTO Elon Musk will discuss the future of human spaceflight in advance of his company’s planned flight later this year to the International Space Station, the first private mission to ISS for NASA, at a National Press Club luncheon today at 1pm EST."

I thought it was impossible (or highly impractical, mass-wise) to build a single-stage orbital rocket. Are there additional boosters this rocket is using?

It's not single stage. It's 2 stage and a capsule, just like regular Falcon 9.

Both the Falcon 1, and the Falcon 9 have multiple stages (and both have already made orbit).

I suspect this announcement has a lot to do with positioning SpaceX to compete with Bezos' Blue Origin on upcoming contracts. Blue Origin has been working in stealth mode exclusively on a reusable design, while SpaceX has focused on a conventional launch vehicle that they can market right now. Musk & Co. have had admirable success, but reusable systems are a whole different ballgame, and very little of their current hardware is likely to be applicable in that context.

How would we react if one of the commercial missions goes wrong?

There must be a certain difference of standards, when a public organization kills people for science, and when a private company kills people for profit.

They've had failed launches. They seem to keep on going full steam ahead.

Actually, private companies were killing people for profits since always. The whole concept of corporations was iirc created because private people didn't want to be accountable for ships that sank and killed the sailors.

Even now, private companies killing people is nothing unusual. Think oil rigs, or airplanes. Sure - a spaceship exploding and killing the crew is quite spectacular, but when you build a company like SpaceX, you build it with the knowledge that something like this will happen.

With every manned flight, you have the procedures in place for the catastrophic failure, and when it happens, you execute "Plan Red". Nobody is running around screaming. At least I'd like to think so :)

There are lots of dangerous jobs out there that people pursue for profit, from deep sea fishing to building skyscrapers. People who work in dangerous jobs are usually just paid high wages, and people go on with their lives.

Are they going to land on a single torch? How?

What did I just watch?

A reusable rocket concept with some magically fuel supply that seems to defy physics ;)

There's nothing magical about the fuel supply. In the past, people didn't try to bring rockets back down and land them on their tails because of the technical challenges, not because of fuel concerns.

It takes a lot less fuel to land than to take off for two reasons: wind resistance helps instead of hinders and so much fuel has already been burnt that there is a lot less weight to slow down than there was to accelerate on the way up.

Coming down, the empty fuel tank is basically an aluminium balloon.

Where are they hiding all the fuel?

Also, this isn't a design. It's a video. I have some video about a UN mission to colonize Alpha Centauri that went slightly awry (the mission that is, not the video).

Can you put that on youtube or something? Sounds interesting.

I'm pretty sure he's referring to Sid Meier's Alpha Centauri, a classic awesome 90's video game http://en.wikipedia.org/wiki/Sid_Meier%27s_Alpha_Centauri

I'm not sure I follow how this is supposed to be progress. This looks like NASA did before the had real shuttles, and (though I'm not an aeronautical engineer) it seems really strange to me that they think launching and bringing down, not one, but 3 different parts of a space vehicle safely and exactly where they want it... Sounds far fetched to me.

Virgin Galactic seems to have a much better design and plan - plus, they actually have a working spacecraft, spaceport, and they're selling tickets for the first flights in 2013 right now. SpaceX is a CG animation of a rehashed 30-year old design. Wanna know who my money's on?

You know SpaceX has successfully launched and recovered space vehicles right? In fact they were the first private firm to launch and recover an orbital spacecraft.

I'm a big fan of Virgin Galatic, but their design so far is for suborbital tourist visits.

SpaceX is a lot more than CG animation. They have done some pretty amazing things in just a few years, and successfully privatized space exploration.

Their first ISS mission is a month from now, and their past and future manifest is impressive http://www.spacex.com/launch_manifest.php

No disrespect to anything Virgin Galactic is doing (I hope to buy a ticket one day!, and am also a big fan of Rutan's work), but SpaceX is doing a lot more impressive things than suborbital passenger flight.

I'll bite.

VG is putting tourists into sub-LEO. SpaceX is building rockets that can reach any orbit, carry many tons of payload and even send manned missions to the Moon or Mars.

When Musk started SpaceX he decided to use tried and true designs and instead focus on refining those designs for performance, safety and cost. He did so by moving the entire manufacturing chain in-house. Many would argue that he has achieved his goal.

Rockets (which usually have to be multi-stage) are more cost effective and more capable than the Shuttles. The Shuttles are too fuel hungry and too inflexible (in the configuration they settled on) to fly to the Moon or Mars (or even move beyond LEO). They are not "space planes", capable of zooming around space at will, they are Earth gliders with rockets attached.

I haven't read his rationale for the self-landing rocket stages, but I would guess it's about recovery costs. It's not cheap to track down and fish rockets stages out of the ocean. They also have to be completely rebuilt after their plunge into salt water. Heat damage is likely an issue as well. If keeping that amount of reserve fuel would not limit the rocket's main mission, it would undoubtedly save a lot of money in recovery and restoration costs.

It's progress because the Shuttle missions were a step in the wrong direction if the ultimate goal is to make space accessible. Well designed rockets can be more capable, just as safe (if not more so) and can operate at a fraction of the Shuttle program's cost.

"I haven't read his rationale for the self-landing rocket stages, but I would guess it's about recovery costs."

At the press club he mentioned that a $50m rocket might have 200k of fuel costs in it, so if you can reuse most of it, you are way ahead on cost.

Virgin Galactic only does LEO hops that last for ~10 minutes. SpaceX has actually sent a rocket in orbit around the earth and are on track to send successive launches to the ISS in 2012 and 2013. Just 'cause it looks like an Apollo design; there's a reason why they were chosen in the first place. It's cause they're simple and pretty reliable.

Also, I wouldn't bet against Elon Musk.

>I'm not sure I follow how this is supposed to be progress. This looks like NASA did before the had real shuttles...

That's not exactly an engineering critique. Yes, it's progress - sometimes you have to go back to where you took a wrong turn.

>>Yes, it's progress - sometimes you have to go back to where you took a wrong turn.

Great way to describe it!

Well, the space shuttle's booster rockets were similarly reusable, don't see why this couldn't work in theory, except for the no parachutes trick. It's probably to make the video more dramatic.

I wonder what kind of maintenance cost those boosters had. They didn't have the same needs as the shuttle, it wasn't catastrophic if they broke on re-entry, but one did blow up during launch. It's probably important that the crew re-entry vehicle is small and so is easier to maintain than the shuttle was.

It's no parachute so that it can land on the moon or mars where there is no atmosphere, or very little atmosphere compared to earth.

I'm sure that the first few tries will use parachutes too because I'm not sure rocket science is far enough along at this point to do it without.

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