SpaceX says 'reusable rocket' could help colonize Mars

That might be just crazy enough to work.. If anyone can pull this off, its SpaceX!

Correct link to the video:
http://www.youtub...bJE&

Can they at least test unmanned reusable rocket to proof that it works before worrying about escape pod? This would be huge if this works!

Sounds like their ship will need quite a lot of fuel, especially to slow after initial decent through the upper atmosphere and hover down to execute a precisely controlled landing. It sounds pretty cool though. :)

SpaceX's stages are monocoque, made up from prefab rings friction stir welded together & bulkheads to divide them into tankage - no separate tanks, so increasing fuel/oxidizer capacity is more a matter of stretching the stage(s) by adding rings and moving the bulkheads.

This is all very cute of them, and reusable rockets are great, but let's not pretend they're going to Mars with it. That's a feat beyond the capabilities of chemically based propulsion systems.

On the other hand, if they can produce a sufficiently powerful ion drive or similar, then we might be talking about something more interesting.

That might be just crazy enough to work.. If anyone can pull this off, its SpaceX!

Correct link to the video:
http://www.youtub...bJE&

Thanks for the link!

This is all very cute of them, and reusable rockets are great, but let's not pretend they're going to Mars with it. That's a feat beyond the capabilities of chemically based propulsion systems.

On the other hand, if they can produce a sufficiently powerful ion drive or similar, then we might be talking about something more interesting.

You miss the point - Elon Musk's approach is to lower the cost of launching the components of Mars vehicles. Launch cost is a big part of the equation.

Interesting, and sound in theory.

However, anyone ever notice how often the Shuttle Program's launches (and landings) were delayed due to weather?

How about delayed LANDINGS of these re-usable components?

One puff of bad wind and you drop a partially fueld bomb in someone's back yard...

Nanobanano -- yeah, the animation shows it descending over a populated area, and that just isn't realistic unless they can get some serious flight heritage built up. It will have to land somewhere remote the first hundred or so times at least.

axemaster -- it takes LESS Delta-V to get to Mars then it does to get to the moon. Well at least the way apollo got to the moon - earth orbit with apogee at moon. We obviously did that with chemical rockets. To get to mars you orbit the sun, and that trajectory is actually easier to achieve. We send probes to mars all the time. They are lighter of course, but use much smaller rockets also.

of course all of that stuff for stage recovery adds weight and will cost them payload mass to orbit - especially the second stage recovery. Every added pound to the second stage is a pound you cant put in orbit, which isn't quite true of the first stage. Many people have tried stage recovery, and all of them failed because the recovery components ate up all of the payload mass. If SpaceX succeeds they will achieve something that many people have tried at and failed.

Interesting, and sound in theory.

However, anyone ever notice how often the Shuttle Program's launches (and landings) were delayed due to weather?

How about delayed LANDINGS of these re-usable components?

One puff of bad wind and you drop a partially fueld bomb in someone's back yard...

I would like to point out that when the shuttle's booster rockets land in the water, they do not explode. The amount of fuel needed to land an expended stage is negligible compared to the amount of fuel it has initially.

This is only ever so slightly more dangerous than the shuttle's system, and will likely be a lot less expensive.

If spaceX can pull it off, then Elon will officially be the most awesome guy this century.

Nothing new here , boring !

If youre saving 60 million dollars a launch, that's a lot more extra trips. Doesn't that override payload loss?

"We are going to try to do it. We have a design that on paper, doing the calculations, doing the simulations, it does work."

At SpaceX everything works great on paper:):)

Are they burning the thruster the whole way down? That seems inefficient. Seems like you just fire it in orbit to slow your tangential velocity so you don't burn up on reentry. Then let the rocket hit terminal velocity or use thrusters to orient the rocket in the least aerodynamic position to make terminal velocity as small as possible and then just fire the thrusters prior to landing. Please correct me if I'm wrong.

Elon Musk > Richard Branson

Oh, if anyone can do it Elon can...

http://www.notabl...lon.html

I don't understand why you should use rocket thrusters to land when air resistance via parachutes or a steerable parawing would do the job at no fuel cost and small weight penalty compared with fuel burned. Doesn't look so elegant as on the very pretty animation by SpaceX I expect.

The space programs as they currently are are nonsensical. When the ISS goes out of commission the buggers will scatter it, instead of leaving it where it is and recycling/re-manufacturing it where it is. So wasteful!

All power to them. However, I was wondering exactly how reusable these modules would really be?

There's a lot of stress, both mechanical and thermal involved in the launch and re-entry process. The returned modules would still need to be inspected with a fine-tooth comb and likely refurbished to some extent. That takes time and therefore money. How many times can a module be refurbished? These factors may make the reusability equation less favorable, but perhaps still good enough...

I presume the rocket will achieve escape velocity (to put the capsule into orbit) then on the way down it will experience the same heat load as the Shuttle's ET or the Shuttle coming down from orbit. The ET was designed to disintegrate from the heat, and the Shuttle have to have insulating tiles to survive, so heat shielding on the rocket is a must. Does anybody have any info on the latest tech on heat shielding, especially metallic ones that was investigated years ago but never came into use? With metallic shield, i guess maintenance issues would not be such a ball breaker as in the case of the Shuttle's, provided weight issues are overcome.

Braindead: Chutes would work for most of the descent, but a braking rocket would be needed for the last few feet. A parachute landing isn't easy to control, for accuracy or impact speed. But you're right that rockets wouldn't be practical all the way down.

The first stage will going well less than orbital velocity and will be nearly empty. Rocket equation-wise, landing it will be "easy" and will not require heat shielding. The second stage will need to kill orbital velocity and also be empty but will need heat shielding, presumably the advanced PICA ablative stuff used on Dragon.

Parawings are not going to be able to do this job, the X-38 program found the upper limit of mass there. The orientation will likely be controlled at all times, the difference in terminal velocity is not enough to let it tumble.

In both cases, the most fuel-efficient (avoiding gravity losses) method is to fire the engine as late as possible. For reliability, the actual profile will be less aggressive.

The statement about the impossibility of chemical propulsion not being capable of getting Man on Mars is wrong and sounds more like a statement of dogma and faith than one of fact. In particular, orbital refueling will allow tremendous capability beyond LEO.

Skepticus:

I presume the rocket will achieve escape velocity (to put the capsule into orbit)

Fortunately, the effort required is not that great. The usual orbital speed is about 8 km/s, which involves only 1/2 the energy needed for escape speed (11 km/s).

Trekgeek1- it will not fire all the way down, but it is still going to be coming in very fast. Not having it break apart is more difficult than keeping it from burning up - at least on the first stage.

The first stage separates at Mach 11, the second stage stops at about double that. Which is why the second stage has a thin heat shield and the first stage doesn't.

I presume the rocket will achieve escape velocity (to put the capsule into orbit) then on the way down it will experience the same heat load as the Shuttle's ET or the Shuttle coming down from orbit. Does anybody have any info on the latest tech on heat shielding, especially metallic ones that was investigated years ago but never came into use?

Orbital velocity, not escape velocity. I believe second stage will use PICA-X heat shield, as used on the Dragon:

http://en.wikiped...try#PICA

Empty rocket stage is big and light, an ideal combination for aerobraking.

This is huge. If fuel costs are only $200,000 out of $60,000,000 then, even assuming it costs $1,000,000 per launch, this means we can make 60 launches for the current price of one. Assuming that the rocket might require more fuel, and let's say it reduces the Falcon 9 payload capacity from 10 tons to something like 7, that still means they've found a way to launch 42 tons into orbit for the current price of 10.

The ISS weighs at ~420 tons. This rocket could launch all the components of the ISS for the current cost of 10 launches... That's not to mention that the current cost of a Falcon 9 launch is drastically cheaper than the shuttle at $60 million vs $450 million.. What this means is that this reusable rocket could launch all the ISS components and it would cost less than 1.5 Shuttle launches.. This IS huge.

plasticpower:
Yeah, and imagine if those were 420 tons of Bigelow modules instead of ISS tin cans. That means we could launch LEO station with almost 10 times the pressurised volume of ISS for a price of less than 1.5 shuttle launches!

All power to them. However, I was wondering exactly how reusable these modules would really be?

There's a lot of stress, both mechanical and thermal involved in the launch and re-entry process. The returned modules would still need to be inspected with a fine-tooth comb and likely refurbished to some extent. That takes time and therefore money. How many times can a module be refurbished? These factors may make the reusability equation less favorable, but perhaps still good enough...

That is what is missing in my estimation. There is no word about the re-design of the rockets or modules to handle the increased stresses of re-entry. Let us not forget that the designs as they currently stand were made for single launch with NO re-entry.

Let us not forget that the designs as they currently stand were made for single launch with NO re-entry.

False. First stage recovery has been part of the plan all along and all of the structure was (IIRC) designed to a 1.4 safety factor instead of the more typical 1.2 - no redesign required. Of course, adding the legs and managing the re-entry requires additional design effort.

I expect the first stage recovery to be relatively easy to implement, and with 9 engines at stake, along with the rest of the stage, the economic advantage is obvious.

It's the second stage recovery that will be a major challenge IMO.

It's quite amusing to see casual observers postulate that SpaceX hasn't thought of the most basic things.

@nkalanaga,

A parachute landing isn't easy to control, for accuracy or impact speed.

Parachute perhaps, but parafoils are very controllable and precise. NASA actually got pretty far with its computer-controlled parafoil landings on the X-38 project, before the project was cancelled:

http://en.wikiped...ASA_X-38

Obviously, a parafoil recovery landing would be subject to favorable weather conditions, but then so is the launch itself in the first place.

Seems to me parafoils would be a much cheaper and safer (not to mention, more light-weight) way to go, than relying on continuously-firing and precisely-controlled multiple engines in tight cooperation, fighting aerodynamic instabilities all the way down to the ground and not suffering a single failure in the process, particularly after having survived a few launches and been "re-used" for landings a few times.

Well, if they can pull it off as-proposed, more power to them. It just seems like a rather risky proposal...

Maybe aerobraking and powered braking is simply enough to land it safely, and parachutes are not needed. Dont forget that the engines and residual fuel is already there, because it is a rocket. Makes sense to use them first.

Skepticus:

I presume the rocket will achieve escape velocity (to put the capsule into orbit)

Fortunately, the effort required is not that great. The usual orbital speed is about 8 km/s, which involves only 1/2 the energy needed for escape speed (11 km/s).

Sorry about the mix up of orbital and escape velocities. You are right of course, but when the time comes to realize their vision of going to Mars, unless they power on from orbit, the reusable rocket will be subjected to escape velocity and changes in heat shielding is again the problem.

I'm sure that most of you have seen this, but for those who haven't here are links to video of experimental tail first Earth landing rocket systems - SpaceX are just coming in from higher and faster:
Armadillo: http://www.youtub...AEBRR0dI
Blue Origin: http://www.blueor...tter.htm
The idea of landing is sound - the question is, are the rather extreme engineering stresses on a rocket too much to allow for reliable reusability?

Funny thing, they never talk about landing. Its impossible to land, the atmosphere is to thin to slow a ship down for a safe landing.
Solution: Build Space Elevators, save fuel by moving ships into space and launching at GEO Orbital space. Then using rockets to accelerate, without using all the fuel. Then use the remaining fuel to slow yourself down. But you still run into the problem when the planet of Mars pushes you down into the atmosphere. You'll need enough fuel to safely land.

We may need to figure out a way to get a space elevator on mars.

@Derrick: Yeah, thanks for that. Instead, why haven't they thought to build transporters like I saw on Star Trek? That would save the immense cost of designing and building a space elevator.

Sorry if that sounded a bit snarky, but the discussion is how to manage current technology, and not hope for the tech we might have a century from now.

That is what is missing in my estimation. There is no word about the re-design of the rockets or modules to handle the increased stresses of re-entry. Let us not forget that the designs as they currently stand were made for single launch with NO re-entry.

Not entirely true - SpaceX planned to recover the first stage, although parachutes were envisaged, not a powered landing.

Funny thing, they never talk about landing. Its impossible to land, the atmosphere is to thin to slow a ship down for a safe landing.

Actually, parachutes and aerobraking have been a big part of unmanned Mars exploration since the Viking landers. I am a big fan of Space Elevators, but we'll have walked on Mars long before we're able to build a space elevator there. There's the problem of what to do with Phobos and Deimos slicing your cable, for starters...!

Instead, why haven't they thought to build transporters like I saw on Star Trek? That would save the immense cost of designing and building a space elevator.

The transporters were a plot device designed to cut down on the special effects budget that would have otherwise have had to show the Enterprise landing everytime they went to a planet's surface.I think I am safe in saying a matter transporter is and will likely remain impossible to achieve,considering that the billions of molecules in a living organism would have to be copied and reproduced in the correct location at the destination.Anything less than a perfect copy,and you are dead.

I wonder, would a catapault or rail gun rocket launcher contribute to a more practical reusable system?

NASA is experimenting with a horizontal launch system:

http://www.nasa.g...nch.html

http://www.networ...de/66243

But I wonder, why can't such a system be used to give vertical lift vehicles a "free" elevation and velocity advantage? It should significantly cut onboard fuel (and supporting) mass requirements.

It doesn't even have to be all that huge. Just situating it high in the mountains and delivering a boost of a few hundred kph would provide a significant launch mass advantage.

Watching Musk is like watching a skate board maker claiming that his next step will be to build an advanced skate board that will roll to the moon.

Watching the fanbouys ooh and ahhh at his comments allows me to nicely separate the fools from the realists.

I wonder, would a catapault or rail gun rocket launcher contribute to a more practical reusable system?

That would work for launching supplies to orbit,but the extreme acceleration would kill humans.

This is all very cute of them, and reusable rockets are great, but let's not pretend they're going to Mars with it. That's a feat beyond the capabilities of chemically based propulsion systems.

On the other hand, if they can produce a sufficiently powerful ion drive or similar, then we might be talking about something more interesting.

You're missing the point, as people often do with this subject.

The rocket is the launch vehicle. The spacecraft it lobs into orbit might very well be powered by an electric drive, but to get off the ground you will still need a rocket. Ion drive won't be getting anything into orbit in the first place.

I can't believe all this---.

I can't believe all this---.

What do you mean??

That would work for launching supplies to orbit,but the extreme acceleration would kill humans.

That's not true. We use catapults to launch manned aircraft, every day. Even the Wright brothers used a primitive catapult launch system.

http://en.wikiped...catapult

And rail guns are easily controlled. Essentially, all they are is an electric motor laid out flat. You can control the thrust as easily as you might control the acceleration of an electric car.

"Peddle to the metal, commander!"
-Galaxy Quest (the movie)

ubavontuba:
There is a slight difference between accelerating to 250km/h and to reach escape velocity.

I think the rail gun needed to comfortably launch someone into space (read: not in a liquified state) would probably be rather long and inefficient. Unless someone makes some sort of inertial negation/dampening system, that is.

Perhaps by submerging the "lucky" test subjects in some capsules filled with jelly, and popping them into space one by one? If it doesn't work, one could simply smear them on bits of toast at the nearest space station.

I wonder, would a catapault or rail gun rocket launcher contribute to a more practical reusable system?

That would work for launching supplies to orbit,but the extreme acceleration would kill humans.

I believe ubavontuba suggested

and delivering a boost of a few hundred kph

Not orbital or even escape velocities. I happen to think a boost assist is good idea. Rockets consume an incredible amount of energy (and potential cargo capacity) just lifting off.

It is technically feasible, but is it economical? I think it may be cheaper to just make the tank a bit bigger than to bother with catapult or rail gun launch assist system.

Economical in the short term - no. In the longer term quite possibly. Fuel won't get any cheaper. The idea is to be capable of launching a lot of cargo into orbit at a potential frequency that NASA has never been capable of.

The price of fuel can make or break a company when there is competition. If fuel usage can be reduced and cargo capacity increased with the same stroke the large capital expenditure may make longer-term financial sense.

However, I seriously doubt Mr. Musk would commit to such an investment until he saw the long-term demand, and even then it would likely take compeitition from another vendor before looking at long-term cost reduction projects. Presently I don't see any real competition, at least until the Chinese mature their space program.

@Quasi_Intellectual

There is a slight difference between accelerating to 250km/h and to reach escape velocity.

I never suggested otherwise.

I think the rail gun needed to comfortably launch someone into space (read: not in a liquified state) would probably be rather long and inefficient. Unless someone makes some sort of inertial negation/dampening system, that is.

What makes you think it must be all, or nothing? I never suggested this. Go back and read my first post again.

It is technically feasible, but is it economical? I think it may be cheaper to just make the tank a bit bigger than to bother with catapult or rail gun launch assist system.

That kind of thinking would have forced aircraft carriers to be prohibitively long.

The launch assist mechanism is built one time, and used repeatedly. And (a side benefit), it would cut lower atmosphere rocket emissions.

The best reusable concept that I have seen that is backed up by both theory and some experimentation is air launch single stage to orbit (search on tLad for experimental work). An early paper that discusses this concept is AIAA 2001-4619. The paper goes into detail about the necessary trade-offs for various reusable schemes. The physics of rocketry is not forgiving with respect to fuel use. Recovery with parachutes is lighter easier and much, much less expensive.

The best reusable concept that I have seen that is backed up by both theory and some experimentation is air launch single stage to orbit (search on tLad for experimental work). An early paper that discusses this concept is AIAA 2001-4619. The paper goes into detail about the necessary trade-offs for various reusable schemes. The physics of rocketry is not forgiving with respect to fuel use. Recovery with parachutes is lighter easier and much, much less expensive.

I was thinking along those lines.A tri-engined aircraft could take off from a runway using conventional jet engines,and at a certain altitude,ramjets could take over,accelerating the ship to high mach speeds,and finally,a rocket would ignite to achieve orbital insertion.Using a ramjet would save weight,as an oxidant wouldn't have to be carried.

If you haven't already, take a look at what Virgin Galactic is doing (with Burt Rutan's original design, from Scaled Composites.)

http://www.virgingalactic.com/

Yes, it's a suborbital fun-ride scheme. However, I see no reason why it couldn't be engineered and scaled up to support heavier rocket ships with more utilitarian applications.

If you haven't already, take a look at what Virgin Galactic is doing (with Burt Rutan's original design, from Scaled Composites.)

http://www.virgingalactic.com/

Yes, it's a suborbital fun-ride scheme. However, I see no reason why it couldn't be engineered and scaled up to support heavier rocket ships with more utilitarian applications.

Sorry,it wouldn't work,not even close.Read: http://www.daught...ss1.html

Sorry,it wouldn't work,not even close.Read: http://www.daught...ss1.html

Of course it'll work. Same concept, except instead of a passenger-carrying winged/tailed reusable suborbital vehicle, you can loft up there a two-stage rocket. Basically, you get rid of the first stage and replace it with the carrier aircraft.

Similar concept has already been used by NASA, successfully, with the Pegasus launcher:

http://www.orbita...Pegasus/

Difference is, Rutan's carrier aircraft is purpose-built and weight-optimized, and as a result can carry 35,000 pounds to 50,000 feet. And that's just for the commercial Virgin venture, where cost and design scale are subject to tight constraints, not to mention the redundant fuselages.

For low-orbit launches, the carrier aircraft itself can be scaled up, and an extra couple of engines added (and larger engines used) to increase the weight of the rocket vehicle to something more like 100,000 pounds. Shouldn't be that hard.

Sorry,it wouldn't work,not even close.
Read: http://www.daught...ss1.html

Well said. It's a great high-altitude research aircraft,
but it's not even close to being a spaceship.

The Falcon/Dragon vehicle, on the other hand, is a true spaceship.
Comparing the two is like comparing a life preserver to a yacht.

The Falcon/Dragon vehicle, on the other hand, is a true spaceship.

Yes, but with all the attendant risks, costs, and complexity. Sure, it may be slightly cheaper and slightly more reliable than existing rockets, but it's no technological leap.

And, unlike high-altitude air-launches, it's subject to fixed launchpad locations and fair-weather constraints just like all the other rockets of its type. And it offers no real safe-abort options along most of its launch trajectory.

I'm convinced air-launching is the future of spaceflight, for all but the heaviest-lift tasks (and even then, might be more economical to loft several small payloads and assemble them in-orbit...)

Of course it'll work. Same concept, except instead of a passenger-carrying winged/tailed reusable suborbital vehicle, you can loft up there a two-stage rocket. Basically, you get rid of the first stage and replace it with the carrier aircraft.

Did you go to the link I posted? You would have seen how Rutan knows plenty about aircraft,but nothing about space travel,which is a whole different ballgame.By the time Spaceshipone was redesigned for space,and capable of attaining orbit,it would be far too heavy to lift on the current mother-ship,for one thing.I like the Pegasus idea.If they mated a ramjet to it,it might launch satellites even more economically.

Theres a large fixed cost when it comes to launching payloads into space, and the market is chronically launch-starved. The best thing to lower the costs per payload (apart from reusability) is simply to increase the number of launches.

By the time Spaceshipone was redesigned for space

Firstly, they've long since moved on past SpaceShipOne. They are close to completing SpaceShipTwo. Did you go to the link *I* posted?

it would be far too heavy to lift on the current mother-ship

Did you read the *post* I posted? Firstly, they're on mother-ship 2.0 which is larger and lifts a larger mass. It's almost large enough to lift the Pegasus to 50,000 ft; probably already large enough to lift one to 40,000 ft. Secondly, did you read the part where I suggested replacing SpaceShipWhatever with an actual two-stage rocket? No, I guess not. Do you ever read past the first paragraph?

Did you read the *post* I posted? Firstly, they're on mother-ship 2.0 which is larger and lifts a larger mass. It's almost large enough to lift the Pegasus to 50,000 ft; probably already large enough to lift one to 40,000 ft. Secondly, did you read the part where I suggested replacing SpaceShipWhatever with an actual two-stage rocket? No, I guess not. Do you ever read past the first paragraph?

Yes,I read all your posts,and went to your links(some of which I have seen on other websites). SS2 is still a suborbital ship,just much bigger than SS1. Did you know that Rutan scaled back his goals for a proposed SpaceShipThree from an orbital craft to a point-to-point suborbital machine in 2008? That strongly suggests to me that Rutan,who is somewhat more astute in these things than either of us,realizes that there is much more involved in building an orbiter than simply strapping on more rockets.

SS2 is still a suborbital ship,just much bigger than SS1

Yes indeed, much bigger and heavier, and the _aircraft_carrying_it_ to 50,000 feet (White Knight 2) is also much bigger and more capable. My focus was on the White Knight side of the equation, and my point is that the Space Ship part may be substituted by an actual orbital stage: and perhaps one not designed for re-entry or reuse or for carrying passengers, which were among the requirements imposed by Virgin Galactic. The concept of high-altitude carrier-aircraft air-launch itself is very promising, quite sound and proven, and IMO quite scalable.

there is much more involved in building an orbiter than simply strapping on more rockets

Rutan had to build a reusable craft with a large cabin and wide field of view from plentiful windows. That doesn't bode well for re-entry from orbital speeds. He was limited by the requirements of the spacecraft much more than he was by the requirements of the launch platform jet.

My focus was on the White Knight side of the equation, and my point is that the Space Ship part may be substituted by an actual orbital stage: and perhaps one not designed for re-entry or reuse or for carrying passengers, which were among the requirements imposed by Virgin Galactic. The concept of high-altitude carrier-aircraft air-launch itself is very promising, quite sound and proven, and IMO quite scalable.

Okay,we can agree on that point-it could be a very useful platform from which to launch supplies for the ISS,for example,and saving a bucket of money in the process.