Inflatable Spaceship Ready for Test

colonist writes "Nature reports that an inflatable re-entry vehicle could one day carry astronauts or robots to the surface of Earth or Mars. The heat shield (that can withstand 900 C) and the parachute are inflatable. The advantage of inflatable structures is weight: a 130 kg vehicle can carry about 200 kg of cargo back from the space station. The vehicle is made by Return and Rescue Space Systems."

Comments

Parallel

[StevenHenderson]

Nature reports that an inflatable re-entry vehicle could one day carry astronauts or robots to the surface of Earth or Mars

Well, hey if they can do this, I'm gonna go ahead and use my water wings to go down Niagra Falls!

What happens if...

[CypherXero]

It deflates in space?

Re:What happens if...

[TykeClone]

The same thing that happens in cartoons - it will make a farting noise and zip back and forth until it stops, at which point it will realize that it is not obeying the law of gravity, say "Yipes" and fall.

Re:What happens if...

[cs02rm0]

I guess you'd want a system of valves and pockets so that you could blow it up easily but if one bit got punctured it wouldn't all deflate. I'm no rocket scientist though (IANA.. blah blah) and maybe the weight of a bunch of valves would defeat the object of using it.

Re:What happens if...

[Mark_in_Brazil]

it will make a farting noise and zip back and forth until it stops

You've forgotten something important. Borrowing from the advertising campaign for Alien... "in space, nobody can hear you fart..."

--Mark

Re:What happens if...

[TykeClone]

I'd like to cite Bugs Bunny as a counterexample and would say that yes, they can :)

Re:What happens if...

[WindBourne]

Nothing. It is only a concern when in the atmosphere :)

Paging Dr. Schlock...

[Robotech_Master]

...I'm sure that eminent mad scientist from Sluggy Freelance can attest to the efficiency of inflatable technology...

Re:Paging Dr. Schlock...

[PatrickThomson]

Dr. Schlock? close. you're thinking of sargeant schlock, from another long-running daily comic strip, Schlock Mercenary. It is by far the best and most realistic scifi cartoon out there, I recommend it to everyone.

Re:Paging Dr. Schlock...

[WhiteDragon]

schlockmercenary is a great comic, but Dr. Schlock is still a very froody character from sluggy :-)

Re:Paging Dr. Schlock...

[NeoSkandranon]

+1 Sluggite

=)

Re:Paging Dr. Schlock...

[abb3w]

No, he's definitely referring to Dr. Schlock from Sluggy Freelance, the time travelling expert in inflatable technology.

Re:Paging Dr. Schlock...

[Anonymous Coward]

OT, but footfall is an awesome book.

Inflatable?

[keiferb]

I hear "inflatable", and instantly think of the three pool floats we had to replace each year because one sprung a leak. Our first AeroBed also springs to mind almost as quickly as it sprung its first, second, and third leaks.

I'm no astrophysicist, but isn't something like this going to be fairly prone to puncture by even the tiniest of debris?

Re:Inflatable?

[erick99]

This is the only part of the article that even hints at the durability of the "craft":

The surface is made from a tough, flexible polymer coated with a paint that can withstand temperatures of around 900 C. The exact composition of the paint is a closely guarded secret, says Joachim Thäter, an engineer at RRSS.

I was more amazed that it can withstand the heat of re-entry when you consider that the ceramic tiles on the shuttle glow red from the friction of the atmosphere.

Probably there is far more detail that clears these things up but I doubt the average non slashdot reader is all that picky about the details.

Cheers,

Erick

Re:Inflatable?

[Slashbot Hive-Mind]

Believe it or not, but the scientists and engineers working on this are not complete morons. Unlike you (and I don't mean this as an insult), they have experience and a budget they can put towards researching this. If its used, you can be sure that much thought has gone into it. No-one wants a repeat of the last shuttle disaster.

Re:Inflatable?

[JacquesItch]

I was more amazed that it can withstand the heat of re-entry when you consider that the ceramic tiles on the shuttle glow red from the friction of the atmosphere.

Mars' atmosphere is much thinner than Earth's so it wouldn't generate nearly as much heat.

JacquesItch

Re:Inflatable?

[Down_in_the_Park]

If you compare the form of the Space shuttle, which has to fly and land later on, and the re-entry vehicle, you probably notice that it is a kind of inverse parachute and thus by design slower. Afer all it doesn't have to land on wheels.

Re:Inflatable?

[WhiplashII]

The space shuttle goes up to about 1500 C as I recall. Designs like this rely on rapid decelleration at high altitude, so they do not get as hot. It basically depends on your exposed surface area to mass ratio. An inflatable object gets a very large surface with very low mass, so it works well.

As an extreme example of this, back in the Apollo days there was a design for an inflatible parachute to allow one person to return to earth wearing nothing more than a Mercury-class space suit!

Re:Inflatable?

[Smidge204]

They also plan to use the design as a re-entry-to-earth vehicle for astronauts.

=Smidge=

Re:Inflatable?

[Anonymous Coward]

However, on the bright side, the inflatable spaceship will breath new life into the tired old term "They can put a man on the moon but ... "

Re:Inflatable?

[RealUlli]

I was more amazed that it can withstand the heat of re-entry when you consider that the ceramic tiles on the shuttle glow red from the friction of the atmosphere.

I think that's because the tiles on the shuttle get pushed through the air much harder. The trick in this technique is the comparativly low density of the reentry vehicle. If you have the surface of a football field to slow down a rather smallish mass, you get much better deceleration and are able to dissipate the energy much better to the surrounding air. (The Space Shuttle gets so hot because it can't dissipate the energy quickly enough - so, if you touch more air, that air can take the heat away...)

Just my 2 cents...

Ulli

Re:Inflatable?

[WindBourne]

I would be willing to bet that it is compartmented. In addition, the outer shield is not inflated. Finally, anything that would puncture the outshield probably would have done so to the shuttle or other structures.

Re:Inflatable?

[AmericanInKiev]

Here's an argument for sucess.

In order to areo-brake - you must generate energy roughly equivelent to the energy of a launch (adjusted for the new mass, less fuel and ejected stages)

You do this by rubbing yourself against the atmosphere.

Because the density ratio of atmosphere/orbitor is so low, most of the rubbing is done at a low altitude when the air is harder.

If, on the otherhand, you can improve the density ratio at a higher point, then you can take a nice gentle rub starting at the tip of the atmosphere, sliding and slowing as you come down to earth.

This in essence allows you to spread the heat across a much wider area, reduce the max heat at any one point and in general avoiding the columbia problem which is a single point of failure caused by astronomical heat of high density confrontation.

AIK

Re:Inflatable?

[Rei]

Yes, however, there are two factors that make this a far easier technical challenge:

A) An inflatable structure like this has a *much* larger surface area. The goal here is not to "soak up" the heat, but to radiate it away. This is largely surface area limited. This allows it to keep the temperature down.

B) The very large cross-sectional area of an inflatable reentry system allows the craft to begin to slow down from air resistance at higher altitudes. Not only does this mean that the craft doesn't need as much fuel for reentry, but it allows for a steadier velocity reduction profile.

C) Lower temperatures of reentry make *huge* differences. Look at the tensile strength of aluminum alloys at different temperatures, for example, here's some data on Aluminum AA 1100 O (a cheap aluminum):

Temperature (K) Tensile Strength (MPa)
53, 172
183, 103
242, 96
328, 90
386, 69
441, 55
503, 41
566, 28
628, 20
691, 14

Here's data from a good aluminum alloy - AA 7178 T76 T7651:
53, 730
183, 634
242, 606
328, 572
386, 475
441, 214
503, 103
566, 76
628, 58
691, 45

Now, we're not dealing with an aluminum parachute or anything here - aluminum is just something that I happened to have data for offhand. However, you often see tensile strength fall off like this with most materials. Temperature is a *very* important factor.

Re:Inflatable?

[Anonymous Coward]

Surely even the largest chunks of foam insulation will just bounce off!

(With apoligies.)

Re:Inflatable?

[Rei]

Yes, it's not like we have any gigantic inflatable structures that last for very long periods of time out there.

Oh, wait, we do: They're called "Blimps".

The bigger you make it, the *safer* it is against puncture resistance. Blimps require tears a number of inches long to pose a threat. Micrometeorites aren't exactly going to be a big problem here.

I'm glad to see this finally implemented; it is the next logical reentry step. Huge surface area and huge cross-sectional area. It'd be wonderful - it would even reduce the amount of fuel you need for reentry.

Re:Inflatable?

[cpt_rhetoric]

No worries, comes with a patch kit. Why do you think in the "Right Stuff" they practice keeping that ball floating by blowing.

Re:Inflatable?

[SmittyTheBold]

back in the Apollo days there was a design for an inflatible parachute to allow one person to return to earth wearing nothing more than a Mercury-class space suit!

I can't be the only one excited by that idea - once the whole "space tourism" thing gets more economically feasible, you'll have all the rich playboy thrill-seekers paying to go up and "space dive." Maybe in my lifetime it'll become cheap enough for regular guys like me to do it.

Re:Inflatable?

[Anonymous Coward]

Not what's being talked about, but another inflatable space thingy: http://www.thespacereview.com/article/187/1

I saw one of those "This is educational... really!" shows about these moduals a month or two ago, specifically, they were showing the impact testing using a "meteorite gun" as well as test inflating one in NASA's huge assed vacuum chamber. Basically, these things have better impact resistance and repairability then the thin sheets of metal that we're currently using. I presume the technology can be ported between projects..

Re:Inflatable?

[Zaak]

...the ceramic tiles on the shuttle glow red from the friction of the atmosphere.

Just a small pedanticism: The shuttle tiles are heated by air compression, not friction.

TTFN

Re:Inflatable?

[cfuse]

As an extreme example of this, back in the Apollo days there was a design for an inflatible parachute to allow one person to return to earth wearing nothing more than a Mercury-class space suit!

Does this qualify as base jumping or baseo (building, aerial, span, earth, orbit)?

Re:Inflatable?

[Hugonz]

Everything will glow red, it's a function of the temperature, so it does not make a difference if the material can withstand it or not... actually its glowing is a good symptom that it has not been destroyed ;)

I've seen this movie before...

[dlleigh]

Except it was Jupiter that time.

http://www.imdb.com/title/tt0086837/

Human factor

[Himring]

Such inventions are what's needed if those who promote the "human factor" of space exploration are to prevail. Killing a shuttle full of astronauts for purposes of some objective experimentation in space isn't worth it. Providing best-possible-safety and life preservation is what's needed at this point. However, it does sound like this device being used as a "life boat" is serendipitous. Actual efforts along these lines should be more pursued on a project level. If we want to put people in space then we need to assure their safe return....

Re:Human factor

[Paulrothrock]

The shuttle, while a marvel of engineering, is a very inefficient way to get to and from space. It's not modular, so you're always launching the entire craft every time, complete with bricks, wings, control surfaces and landing gear which are of no use in space except to provide a bigger target for orbital debris. This means that a simple crew transfer that would be possible for $100 million costs $1 billion.

NASA should focus on a decentralized program of craft development. Have a group that makes crew capsules, the best damn capsule they can. Another group works on propulsion systems, which would also be modular, and still another works on cargo systems. Rockets could be built using only the components that are needed.

A major factor in improving costs is to make the engines and pumps retrievable. That way, all we're throwing away would be pressure tanks, which can be manufactured cheaply.

Re:Human factor

[Anonymous Coward]

Exploration is dangerous. If there is any value at all in exploring space then we must be willing to accept the risks.

If we're not killing a dozen people in space every year then we're not serious about exploring it.

Re:Human factor

[AndroidCat]

Which groups are using Metric and which are using Imperial units? You'd want a group that does nothing but test compatability.

It's a shame that the tanks are splashed. Most of the energy to get them to orbit has been invested by the time they're released. As well as all the hardware and mass, there's a lot of volatiles left. If we had an orbital tug system, it would be nice to snag them and park them somewhere for later use. If.

Re:Human factor

[bziman]

Killing a shuttle full of astronauts for purposes of some objective experimentation in space isn't worth it. Providing best-possible-safety and life preservation is what's needed at this point.

I'd just like to point out that the two major catastrophes that have happened in the Shuttle program didm't give any time for a "life boat" to do any good. We didn't really think there was anything wrong until it was too late.

As far the "worth it" factor, I wanted to be an astronaut when I grew up. And now that I've grown up, and I understand danger and death, I would still like to be an astronaut, danger be damned, because objective experimentation in space is everything. And the people involved in the space program believe in what they do too, or they wouldn't take the risk. They're not going to put themselves wrecklessly in harms way, but they know that sometimes things go wrong.

So, I think it's a bit silly for you to tell them it isn't worth it. Also, as nearly as I can recall, we've never lost a crew in space, including prior to the shuttle program. All of the accidents have happened inside the atmosphere, at which point you're taking chances even in a regular airplane.

Re:Human factor

[Idarubicin]

A major factor in improving costs is to make the engines and pumps retrievable. That way, all we're throwing away would be pressure tanks, which can be manufactured cheaply.

Not necessarily.

The cost of retrieving the engines and pumps might be non-trivial. The cost of testing each engine and pump after retrieval will certainly be non-trivial. Also, each individual engine and pump in a reusable system would have to be significantly more expensive to design and manufacture. You'd be looking at a service life measured in hours, rather than minutes; they would have to survive being dropped into the ocean multiple times--heck, you'd have to make the damn things float; you have to be able to cut them out of the old craft and install them in the new; you have to be able to open them up to repair or replace parts...

Throwing them away might well end up being cheaper.

Re:Human factor

[Cyno]

If we want to put people in space then we need to assure their safe return....

I agree. Money should be no object if we want manned space exploration. Or we can safely explore space unmanned with robots and save a bundle. What's the difference in cost between sending a human and a rover to Mars?

As long as we want to complain about the budget we shouldn't be allowed to risk the lives of our astronauts, IMO.

Re:Human factor

[Anonymous Coward]

Consider the economic loss and additional expense of a space program designed to be perfectly safe for humans (perhaps abandoning human exploration altogether). Divide that value by the number of humans that would have been required for a traditional human-based approach. This represents the amount of money per "risked" human life you're spending to eliminate that risk.

Now, do the same thing for things like cancer, AIDS, lack of safe drinking water, and car accidents. Which gives you a better bang for your buck?

It's unreasonable, impractical and uneconomical to push for solutions that allow absolute safety in a high risk endeavor. This approach stifles exploration, research and innovation. When people gladly volunteer to take these risks, we should be accepting that as a blessing. These are not stupid people here. To suggest that you are smarter than they are by making your own uneducated risk v. cost assessment and demanding that society comply with your results is a bit arrogant.

We should be adopting a "reasonable risk" approach to high-risk activities, not an "absolute safety" approach. Consider how much it would cost to make driving across town an absolute-safe activity. No one would be able to afford to drive.

Re:Human factor

[Anonymous Coward]

NASA should focus on a decentralized program of craft development. Have a group that makes crew capsules, the best damn capsule they can. Another group works on propulsion systems, which would also be modular, and still another works on cargo systems. Rockets could be built using only the components that are needed.

I might add that decentralized development of space vehicles helped compound the troubles of the Apollo XIII crew. The air scrubbers in the Command module used different cartridges than the LM (one set was square, one was round). When the crew had the stay in the Lunar Module to save power, they slowly ran out of oxygen (because the scrubber cartridges were one-use), and couldn't use the cartridges from the Command module. Mission control had to jerry-rig a cartridge (using a sock) to keep the astronauts from asphyxiating.

No aerospace corporation in their right mind decentralizes the development of a vehicle, unless they have a penchant for large explosions. They make design each part to work with each other part.

Instead, what is required is standardized development: every airlock on every vehicle works with every other airlock. Every computer can talk to every other computer.

Modular is one thing, and is very good. Decentralized is quite another thing, and not so good.

Parachute?

[GoMMiX]

I didn't think a parachute could work for a mars landing because the atmosphere was so thin...

Re:Parachute?

[MikeMacK]

I believe they used parachutes to help land the rovers, so they do work. I think the atmosphere is thin, but with a big enough chute it will help to slow it down.

Re:Parachute?

[TykeClone]

Wouldn't this be more like the "bouncy landing" that the first mars rover did?

Re:Parachute?

[Anonymous Coward]

The rovers did use parachutes to slow them down some prior to deploying their airbag system. I do believe that the unsuccessful "beagle" rover used just a parachute system. Is it possible that it didn't work? I guess we'll have to wait for a landing party or another rover to find this out.

Hey, if they can make inflatable furniture

[Jakhel]

and inflatable women, why not make inflatable space ships? Now all we need are inflatable monkeys to put on the ship and we'll be set to go

Re:Hey, if they can make inflatable furniture

[griblik]

Cool.

Let's go :)

Re:Hey, if they can make inflatable furniture

[AndroidCat]

How about inflatable women spaceships? Shades of John-Boy Walton in space!

Re:Hey, if they can make inflatable furniture

[uradu]

> Now all we need are inflatable monkeys to put on the ship and we'll be set to go

Actually, that's what the Michelin man was designed for--way ahead of his time.

Re:Hey, if they can make inflatable furniture

[Anonymous Coward]

Inflatable space ships that doubles as an inflatable women certain solve the bordom problem with space flight...

Re:Hey, if they can make inflatable furniture

[Anonymous Coward]

Actually, they did design inflatable spaceships. First there was the crew quarters for the space station, then for Mars. Just Google "TransHab" if you don't already remember it.

Dream come true

[bman08]

It's my dream to one day, science and god willing, successfully land on the surface of the earth.

Re:Dream come true

[jepaton]

Science has known how to do this for a long time, they call it "jumping".

For more information:

Jump Training Techniques

Re:Dream come true

[tunabomber]

In that case, here's my inflatable space re-entry vehicle prototype!

Only 330 quid. Not bad.

MOD PARENT DOWN

[brainstyle]

You really don't want to follow those links.

Re:MOD PARENT DOWN

[ImaLamer]

You really don't want to follow those links.

Why? WHY! You make me click them with warnings like that...

I just can't help it.

Re:MOD PARENT DOWN

[Anonymous Coward]

extremely disgusting pr0n and moderately annoying browser jacking FYI

Gundam?

[p2sam]

Hey, that's the way they implement heat shields for the Gundam mecha's as well. kewl!! I never thought someone would take it seriously.

"I don't know, Scotty."

[Gulik]

"Maybe it's just the idea of an inflatable rubber starship that bothers me."

Anyone else getting How Much For Just The Planet? flashbacks?

Re:"I don't know, Scotty."

[Anonymous Coward]

wow, Im not the only one who thought of that.

Re:"I don't know, Scotty."

[OpenGLFan]

Sorry, too early. I haven't had my blue orange juice yet.

Re:"I don't know, Scotty."

[red floyd]

I need a pink mint milkshake!

Re:"I don't know, Scotty."

[iamcf13]

...And straberry jam on toast!

I think I still have that book somewhere....

and what about...

[Docrates]

where's the "journal" in journalism?

This article should have also talked about:

- micormeteorites hitting the capsule
- thrust capabilities, if any
- why it is incompatible with the shuttle
- some background on the company (beyond the press release)

Just like the blurbs the other day: We found aliens, they're gray and tall, three eyes and the males have breasts. SETI says so. Then a day later.... JK!, JK! there're are no aliens hidden behind the moon impersonating basketball players... we swear!

Re:and what about...

[Anonymous Coward]

you get thrust capacity from being hit by micrometeorites.

RTFA

[kmmatthews]

It's for re-entry, not for general flight in space.

It's the heat shields that are inflatable, and they are armored - e.g. not the same material as your pool floats...

Re:RTFA

[WormholeFiend]

"It's the heat shields that are inflatable, and they are armored - e.g. not the same material as your pool floats..."

It's only a matter of time before ThinkGeek starts selling pool floats made from orbital re-entry material.

Re:RTFA

[JaredOfEuropa]

It's only a matter of time before ThinkGeek starts selling pool floats made from orbital re-entry material.

Used orbital re-entry material, I should hope. That will earn you some extra bragging rights... "Yup, yup, that thing you're floating around on has actually been in outer space!".

Re:RTFA

[pete-classic]

Uh, that think your mind is floating around in has been in outer space.

We're all made of star poo.

-Peter

Re:RTFA

[Lars T.]

"Can also be used as cover in flamewars."

How do we get back???

[bcarl314]

I know I've posted this before, but the major problem in going to Mars, and to me one which is the most significant problem which we did not have with moon missions, is that Mars, unlike our only natural satellite, has a gravity about 75% that of earth. Meaning that the escape velocity is significantly higher on Mars than on the moon and that some tiny fire-cracker punch won't get you into orbit. So, getting to Mars may not be a problem, but getting off, with enough feul to make it back will be. In fact, I would guess that you'd need to construct a fairly significant lauch vehicle on Mars just to get off the planet.

Re:How do we get back???

[Tyler Eaves]

Well, yes, and no. The reduced surface gravity helps more than you might think. Also, Mars has no atomosphere to speak of. Taking off from Earth, drag is signifigant up to, say, 75,000ft or so.

Re:How do we get back???

[jpnews]

Leave the return vehicle in orbit, same as the Apollo missions. Yes, overall a manned Mars mission is a larger affair, but it's the same principles at work.

Re:How do we get back???

[charliekowalchuk]

Look, unless you happen to be a rocket scientist, perhaps you should leave the heavy thinking to the NASA engineers. (I happen to be one, but think of me as a wanna-be myself, as I am transferring over to the Electric space propulsion division soon)

Anyway, I would agree to your comment, that yes, due to Mars gravity, it would be hard(er), well harder 40 YEARS AGO. Technology and efficiency have taken great strides these past 40 years, and we feel confident in our ability to make a rocket that does what its supposed to do.

I can tell you, that Mars manned missions have been fully detailed with many many different mission paths that could be taken. For instance, using Ion propulsion and launching from the International space station or the moon are one of the many possibilities that have already been detailed by many scientists and engineers.

Give NASA a little faith; you don't need to back seat drive them like some little ol' lady.

Re:How do we get back???

[glpierce]

Just bring a really big rubber band and throw it over a pair of mountains. Sheesh.

Re:How do we get back???

[Paulrothrock]

Maybe, just maybe, they've already thought of this.

Leave a return craft in orbit to achieve escape velocity, or make the return craft on the planet large enough to get off by itself. And nobody ever said we had to bring the propellants with us.

Re:How do we get back???

[bcarl314]

I'm not trying to tell NASA what to do, I'm simply stating a fact that we aren't in Kansas anymore. This is not some little rock with 10 % of the earth's gravity, and unless I missed some major advancements in the past 40 years, the basic physics behind gravity still applies here.

I need to emphasize that I don't think GETTING to Mars is going to be a problem, I think getting OFF Mars will be a problem. Regardless of whether we have some low-orbit module that will break our orbit from Mars and get us back home, we still need to shoot that lander from the surface into a low-Martian orbit. This is where I think the real problem lies.

Look at the size of the rockets we need, and the supporting infrastructure to build, and launch even a 1 ton payload. Granted they won't need to be that large to get them off the surface of Mars, but they will need to be significantly larger and more effecient that what was used on the Mooon.

I do give NASA alot of faith, but it seems that either through budget cuts, poor administration, or confusing the Metric System with the English system, they have raised some doubts in my mind.

Re:How do we get back???

[p3d0]

Escape velocity on Mars is only a little more than double that of the moon, and less than half that of the Earth. Mars also has a fraction of the atmosphere of the Earth. So yes, it takes more than a firecracker, but a hell of a lot less than a Saturn V.

I think the problems relating to a prolonged human journey in space far overshadow the Mars liftoff problem.

Re:How do we get back???

[p3d0]

Incidentally, here's an interesting fact... After Jupiter, the only other planet with higher surface gravity than Earth is Neptune, and even there, gravity is only 12% stronger than on Earth.

Of course, this depends on what you call the "surface" of a gas giant...

Also, surface gravity is not the best measure of how hard it is to lift off a planet. All the gas giants have higher escape velocities and denser atmospheres.

Re:How do we get back???

[DarkMantle]

I remember reading that they may send a "feul capsule" ahead into orbit around Mars. When they get there fuel up, go to the surface, do whatever, and have lots of fuel for leaving. This isn't a huge issue. Hell, they could have enough in the tank to fill up on the way home too.

Re:How do we get back???

[ninjagin]

I read Bob Zubrin's book about the case for mars, and I've seen him on SciAmFrontiers with a machine that can make propellant (and water, I guess, too) just sitting around in the martian atmosphere.

I thought it was a neat idea at the time, but I probably need to pick the book back up again.

I've had the impression that Bob's considered kind of "far out", but I do like all these neat ideas. Myself, rather than drive from the back seat, I enjoy just watching.

Re:How do we get back???

[charliekowalchuk]

Let me start off on an apology if I sounded rude. What I wanted to point out is that your concern about the increased gravity is a serious issue, but it isn't black and white.

Reading your comment, you sound like you are stating that the increased Mars gravity will basically cause a return trip back to earth to be extremely complicated in the sense that it could either not be done, or almost a shot in the dark.

What I was saying is that NASA has already figured all this out. How do I know? Well, I assume they have because I already did these calculations in one of my orbital mechanics classes back at OSU. The science behind this is actually very clean cut. Its rather rigorous math (involving Laplace transforms, 2nd order PDE's, and variable coordinate transfers) but it is all calculable. Of course real world is different, but just over engineer, that's what we've all been doing all along.

All you need to know is, in order to perform mission A with cargo and weight B, we will need to have an ISP (specific impulse) of C. Then the question is...Can I make an engine with an ISP of C with out the extra weight D approaching B? Well 40 years ago, perhaps not, but with advancements, the answer is yes. And the trust can come from many different Engine designs, not just traditional combustion rockets (thus saving fuel and weight).

I guess what your concern is, using something like a Saturn V, can we make it back from Mars? I would venture to guess no. I would like to point out that the Saturn V was made with only going to the moon, not mars.

What I'm trying to say is, if there were no feasible solution to a return trip to mars, do you think that NASA would be hiding it from us, too scared to tell us the truth?

Re:How do we get back???

[uberdave]

You're missing the point. You need a launch vehicle to get you from the Martian surface back into orbit. You cannot leave that vehicle in orbit. It has to be brought to the surface. On the Apollo missions, this was built into the lunar module. Due to the much higher gravitational pull of Mars, the return to orbit vehicle has to be larger, a lot larger.

Re:How do we get back???

[uberdave]

I think what he's trying to get at is that in order to get off of the surface of Mars, you'll need a large rocket, perhaps the size of a Mercury Redstone, or Atlas rocket. It is unlikely that one of these can be delivered to the surface safely in one piece, so there will be a need for some sort of vehicle assembly crane. Fuelling equipment will also be necessary, unless some sort of solid fuel is used. In short, a significant portion, if not the majority, of the mission equipment will be dedicated to getting the crew off of the surface of Mars.

Re:How do we get back???

[charliekowalchuk]

Okay, you guys didn't belive me... so you made me actually prove it so here...

http://nssdc.gsfc.nasa.gov/planetary/mars/mars_c re w.html

and down there you'll see a link giving details how we could go about getting back,

or go here
http://nssdc.gsfc.nasa.gov/planetary/mars/ma rsretu .html

And no, you don't need some Atlas rocket, or something additional, that would be ludicrous because that would just be adding more and more additional weight for the shell, rockets, and equipment, all you need is addtional fuel. Why would you guys think outside of the box, and realize that we build NEW equipment to do this, not try to RE-USE our old equipment, We're NASA for crying out loud, thats what we do (well, the shuttle, that must of been a fluke idea, but we still need new main fuel tanks ^_^)

FINALLY!

[p51d007]

The "heat shield" is back! For 20 years, every American launch used an ablative heat shield for reentry. At least someone is starting to use it again, than trying to "fly" back from space using something so fragile that it could be damaged by a piece of foam insulation going several hundred miles per hour. Ditch the shuttle and bring back ELVs

Re:FINALLY!

[Nerull]

'starting to use it again'

You mean like the Russians have been using for years now?

Those guys who go up in Soyuz do come back, ya know.

Re:FINALLY!

[Idarubicin]

At least someone is starting to use it again, than trying to "fly" back from space using something so fragile that it could be damaged by a piece of foam insulation going several hundred miles per hour.

Dude...it's not the foam insulation at several hundred miles per hour that's the problem. It's the pound-and-a-half of foam plus ice that's the trouble.

The kinetic energy of 750 g of foam at 240 meters per second is about 22 kJ. That's about the energy delivered in ten high-powered rifle shots , or in the neighbourhood of a hundred rounds from a moderately-sized handgun. The leading edge of the Shuttle wing that took the collision is already one of the most heavily reinforced parts of the Shuttle, and it's made with a carbon-fibre composite material--not the brittle tiles. Even so, the foam was a lot more abuse than we could expect it to stand.

When the oxygen tank blew in the Apollo 13 service module, there was a great deal of concern at NASA about it because they were afraid that it might have damaged their heat shield. In that case, they tried the reentry anyway, because (as with Columbia) there wouldn't be any good way to effect rapairs or launch a rescue. It turned out all right, but there were a lot of nervous engineers. I expect that faced with a couple pounds of material at five hundred miles per hour, the Apollo heat shield wouldn't have made it either.

Finally,....

[ImaLamer]

......now my inflatable girlfriend and I can ride in style.

Re:Finally,....

[goranb]

Take my payload!!! :D

Re:Finally,....

[Anonymous Coward]

But make sure it's a woman, though, because one time I... heh.

Re:Finally,....

[Anonymous Coward]

How come your login is not Bud or bundy?

Re:This is all just hot air...

[Anonymous Coward]

Should be able to power the entire space programme off the US presidential elections though.

Re:Chances of Life

[gears5665]

Many of us don't want to come back once we leave. I for one would love to claim 1/6th of the real estate on Mars for my family and my children.

Oh dear

[stormhair]

They'll have to blow it up before it'll work

Re:Oh dear

[rjjm]

Quite. Correct me if I'm wrong, but isn't air at a premium in space?

Re:Oh dear

[Anonymous Coward]

Not really, liquid oxygen expanding to gas has a pretty high expansion, I actually wonder if they fully inflate it with just air, or if they use like suggested in earlier inflatable reentry ideas a foam producing material that dries into a closed cell (heat insulating) foam

Re:Oh dear

[Carnildo]

Breathable air is, but an inflatable heat shield doesn't need breathable air. The prototypes are inflated by canned nitrogen, and future models will be inflated using the exhaust fumes from decomposition of a nitrogen-based powder.

i can't wait

[DeusExMalex]

i can't wait 'till re-entry, when the superheating of the inflatable spaceship will cause it to pop like a balloon in an industrial oven.

But....

[Anonymous Coward]

Any word on how the 200kg of stuff is supposed to get into space in the first place?

Re:But....

[WormholeFiend]

200kg is 444lbs.

about the weight of two naked astronaughts

Re:But....

[Anonymous Coward]

I think they're calleds "rockets"...

Re:But....

[Anonymous Coward]

someone did some extra credit when they did their homework.

Re:But....

[LousyPhreak]

come on who wants 2 naked astronauts?

200kg is also the weight of me with 2 hot chicks (naked of course), which i'd prefer over any 100kg (probably male) ones :)

Re:But....

[Anonymous Coward]

mmmm rent the Uranus experiment and see :D

Re:But....

[David Horn]

I dunno about you, but since when has the average weight of an astronaut been 100kg (15 stones)? I weigh 10.5 stones (I'm 5'11') and don't look thin.

Re:But....

[machine of god]

about the weight of two naked astronaughts

Is that like astronauts at absolute zero?

Re:But....

[WormholeFiend]

at equal volume, muscle tissue weighs twice as much as fat.

Funny Typo.

[g0bshiTe]

"Nature reports that an inflatable re-entry vehicle could one day carry astronauts or robots to the surface of Earth or Mars."

I will be able to tell my children of the day man set foot on Earth.

Re:Chances of Life

[Paulrothrock]

I for one would love to claim 1/6th of the real estate on Mars for my family and my children.

Same here.

In space...

[Anonymous Coward]

...no one can hear you take a bath with the ship.

U.S.S. Rubber Ducky has disappeared from radar. Possible conversion error suspected in its disappearance.

Inflatable Re-entry Vehicle

[Anonymous Coward]

I've got one of those...

Gets incredibly hot on re-entry...

... reducing speed to 35 KPH before it hits the

[Progman3K]

ground...

Astronaut surprise, anyone?

Eeuwww... Gooey

That's Nothing!

[TheSync]

An inflatable re-entry craft is nothing compared to Airship-to-Orbit.

Mission to Earth

[tedhiltonhead]

carry astronauts or robots to the surface of Earth or Mars

Maybe one day we'll even send people to Earth!

This requires a new kind of astronauts

[tratten]

The right stuff?

awesome!

[positroniumman]

just think how much less time it will take NASA to get back to business whenever they lose a spacecraft!

"in other news, NASA commented that the likely cause of crash was that they dropped a weighted baloon from space..."

finally...

[Anonymous Coward]

the goodyear blimp will have a date to the superbowl party that actually puts out!

Doh!

[bruce227]

Oh great, I can see the headlines in the Martian Daily Planet "Earthings arrive in (snigger) "inflatable" (sneer) spaceship (lololol!)"

Re:Doh!

[AndroidCat]

Too long and not misleading enough for headlines. "Earthship Blows Up!"

Re:Assumption is the mother of all ....

[Anonymous Coward]

No typo.

You're just assuming that the only reason for re-entry is for exploring other planets. Not true, otherwise all astronauts are going on a one way trip.

This vehicle could very well one day (it's in testing, so obviously it can't do it yet) carry astronauts or robots (or cargo) to the surface of Earth (ISS/shuttle lifeboat, lunar/asteriod mining) or Mars (exploration).

The next Darwin Awards winner?

[bray]

This almost sounds like the begining of one of those "Darwin Awards" stories.

These were proposed in the 1960s

[Baldrson]

One of the emergency rescue techniques investigated during he early space program was inflatable structures that could bring down lone astronauts.

Re:These were proposed in the 1960s

[Bazzargh]

Mod parent up, he's right. Here's the link

"In the early 1960's Aerojet studied project FIRST (Fabrication of Inflatable Re-entry Structures for Test) in order to evaluate the use of inflatable Rogallo wings for emergency return from orbit. ... The resulting trajectory was found to be practical under automatic or manual control. G loads during re-entry would not exceed 2.0 G."

The can fill it with hot air. And...

[CFD339]

There's a huge oversupply of hot air right now which should keep prices low.

In fact, I think there is a huge storage facility currently for excess hot air in New York at Madison Square Gardin.

-- ;-) --

Hope they think it through...

[payndz]

"Great. We forgot the damn foot pump. Okay, Bob, start blowing..."

Re:Hope they think it through...

[bwy]

In Soviet Russia, the space ship blows up YOU!

Re:Hope they think it through...

[Anonymous Coward]

Or just blows you.

Spaceship gives head!

Ok, I will discuss this option with Egon and D

[Purifier]

...for their next Mars trip! ;) http://www.pouet.net/prod.php?which=10755

bouncy

[Anonymous Coward]

The inflatable castles at the local fair will soon be out of this world!

A man's house is his castle!

Inflatable Parachute

[celerityfm]

WTF? Did I read that right? an inflatable parachute? How does that differ from normal parachutes that fill with air in order to be used? :P

Re:Inflatable Parachute

[eutychus_awakes]

Normal parachutes need a good amount of airflow to properly inflate. In the highest reaches of the atmosphere, there isn't enough air density to cause a parachute to open - it will just flail behind the craft, gaining velocity until it burns up. An inflatable parachute uses internal gas pressure to keep its shape - initially deflecting the hypersonic airflow around and away from the craft, eventually producing the drag necessary to slow the craft down for safe recovery.

Re:Inflatable Parachute

[Raptor CK]

I think it has to do with lower atmospheric pressure, and low speeds due to gravity.

Opening a parachute from too high up will result in it failing to open properly, as I recall, since there's no air to "fill" it. However, add an inflatable framework, and the parachute will properly open, even in a vacuum.

I'd imagine it's less like a parachute, and more like a giant umbrella, so that you come down Mary Poppins-style.

Re:Inflatable Parachute

[celerityfm]

Excellent replies! Thank you, I hand't thought of that angle.

And btw, props to the guy who modded my post as off-topic. I think people shouldn't be allowed to spend their mod points unless they actually RTFA.

am i rite? :P

Sounds good and I hope

[rokkyu]

this won't be another let down.

Re:Sounds good and I hope

[uberdave]

Actually it is supposed to be a let down. :-)

The Jetsons

[Halcyon-X]

I guess the Jetsons were really ahead of their time in figuring that their vehicles could fold up into a suitcase?

Next on the todo list...

[Anonymous Coward]

reduce impact velocity of craft to 60mph

I can just see it now ...

[WCityMike]

Ignition in T minus five ...

four ...

three ...

two ...

one ...

Ignition!

*POP!*

Houston, we have a problem.

Re:I can just see it now ...

[LaCosaNostradamus]

If you think a nail clipper is a problem onboard an aircraft now, just wait until that era, when pins and pens will have to be confiscated in case they are used as a puncturing weapon.

Finally!

[eBayDoug]

We have a use for the gov't surplus of Jenna Jameson Dolls.

Bob's Big Boy meets...

[davidsyes]

Real Doll in orbit...

for some Zero-G fun... For increased frictive pleasure, there'll be no ablative armor.

Contoured surfaces are flexible and conformal for maximum fit and gain.

For command and control, "the eyese have it".

Super Soaker

[MoronBob]

One of my kids just got a super soaker inflateable rocket for his birthday and it works great. It stands about 6 feet tall and reaches just over 100 feet in the air using water and compressed air.

Re:Super Soaker

[Anonymous Coward]

One of my kids just got a super soaker inflateable rocket for his birthday and it works great. It stands about 6 feet tall and reaches just over 100 feet in the air using water and compressed air.

That's nice, but we are talking re-entry, not propulsion.:p

There's NO AIR IN SPACE to blow the damn thing up.

[leftie]

The ship may be inflatable, but thay have to HAUL THE AIR TO INFLATE AN INFLATABLE SHIP TO SPACE. Comressed air may not weigh a whole lot itself, but the big ass metal bottle you have to put air into to haul it anywhere has a whole lot of weight. This concept might have value as an emergency vehicle of last resort, when it doesn't matter if you transfer the air out of a station because you're evacuating it. That's about the only circumstance I can see use for the concept.

it can be made to be more resistant than Aluminium

[Murphy(c)]

I know we are talking only about a heat shield in this design, but the TransHab module (wiki, Howstuffworks) is even more resistant to puncture than the actual "skin" of the ISS.

For the little story, TransHab was really a great project but got canned by congress because it was way over budget. NASA still decided to fund a research project on it and that time Congress actually forbad NASA any new research on an inflatable habitation module. So NASA gave it of the Italian contractor that was building parts for the ISS and had them continue the work on it.

Murphy

BZZZT! Re:How do we get back???

[StefanJ]

First, get your facts straight:

Mars' surface gravity is about 38% that of Earth.

Second . . . don't you think NASA guys think about this sort of thing?

I've seen lots of interesting proposals for making fuel for the return trip right on the surface, using a refueling station sent ahead of time. It would be fast, but such a station could turn CO2 into methane. (With enough energy, it could even cook up the LOX oxidizer.)

You don't need to bring your return trip fuel down to the surface with you. You can leave it (and all the supplies you need for the return trip) in orbit.

Stefan

Re:BZZZT! Re:How do we get back???

[bcarl314]

Holy Crap, I didn't realize I was off by that much.

Interesting link for those interested in the Mass / Volume / Diameter / Gravity information of the planets.

I'll got back to wearing my dunce cap now.

Re:BZZZT! Re:How do we get back???

[bcarl314]

And here's the link... http://amesnews.arc.nasa.gov/erc/HowBig/diameter.h tm

The Worst Case Scenerio

[ServeYourWorld]

*Pop*

The sound of catastrophic failure

[DeadVulcan]

Pfbfbbbpfpffpbfbfppffpfpfbbffbfbfff... splat.

Fictional Re-entry story

[Mostly Monkey]

This has been bothering me for some time since I can't seem to find the story anymore but a long time ago someone posted a story link about a sole survivor of an orbiting shuttle or space station accident who used an Apollo-esk reentry shield to return to Earth. I don't remember the details apart from him up curling into a ball behind the blast shield and using some form of propellent to decelerate it to reentry speed. He had a tough time keeping it balanced on the way down and I don't remember where he got the parachute for the final decent. Does anyone remember the details or better yet the link?

Re:There's NO AIR IN SPACE to blow the damn thing

[francisew]

rtfa

It also says that they will use a chemical reaction similar to the one in airbags to generate nitrogen from a solid powder. Considering the air pressure is much lower high in the atmosphere, it wouldn't take a huge amount of air to fully inflate the structure.

And yes, lower in the atmosphere the internal air pressure would be too low, hence using a second stage large parachute.

Interesting idea. Much better than a solid craft in some ways. I still can't wait to have a space elevator. That would be cooler.

The one thing I have trouble picturing is how they would be able to have astronoughts go down in one. It seems that the lack of control and relative danger of landing in one is much higher. (but it could be cool to be able to retrieve satellites for repair & re-launch)

Re:There's NO AIR IN SPACE to blow the damn thing

[Anonymous Coward]

But if it wasn't inflatable they would have to bring some solid material to fill that space. Bringing a bit of compressed gas is still a pretty big improvement...

Nitpick

[Daverd]

Ignition in T minus five ...

I know this is offtopic and somewhat anal, but I'm tired of people misusing the T-minus-X notation commonly associated with launches.

T refers to the expected time of launch. So, if you wanted to launch at 12:45, then that would be T. When you say T-minus-5 minutes, you are referring to the current time; that is, at 12:40 you would say that it is T-minus-5 minutes, because 12:45 (T) - 00:05 is 12:40.

Saying T-minus-5 minutes until something doesn't make any sense. You would just say 5 minutes until something.

Re:it can be made to be more resistant than Alumin

[uberdave]

Congress forbade NASA to research inflatable modules? Why? Inflatable structures seem ideally suited for space. Besides, what business does Congress have dictating what NASA researches? NASA has the experts, not Congress.

Re:There's NO AIR IN SPACE to blow the damn thing

[mbstone]

Since there is no air in space, you would only need a little bit of air to fully inflate the vehicle. By the time you fell sufficiently near to earth that you would need more air pressure to keep the vehicle fully inflated, who knows, maybe it would then be feasible to then scoop up and compress some air. If the vehicle was falling at a sufficient velocity, you might have a ready supply of high-velocity air that would be readily compressed. Maybe some rocket-science blowhard can reply and tell me whether this idea will float....

It might have been..

[Scott Francis[Mecham]

Allen Steele's "Orbital Decay". One of the main characters uses something similar to escape from a falling space station towards the end of the story.

Of course, as he's riding it down, he's got memories of his flight instructor sternly lecturing that they were meant as an absolute last-last resort, since only about one-in-ten of the dummy tests worked.

Re:There's NO AIR IN SPACE to blow the damn thing

[El]

Right... and it's not like they'd be bringing any air into space with them otherwise!

Re:There's NO AIR IN SPACE to blow the damn thing

[Carnildo]

You don't need canned air. Gunpowder doesn't need air to burn, and it produces plenty of exhaust gas. Similarly, nitroglycerine decomposes just fine without air, and produces even more gas. And what do you think they use to inflate the airbags in your car?

Re:There's NO AIR IN SPACE to blow the damn thing

[Anonymous Coward]

Due to the lack of air pressure, it might not take a whole lot of air at 1 atmosphere to fill it up.

Remember kids:
PV = nRT
P very verey small, so V can be very very large

If only we had this some time sooner...

[FusionDragon2099]

We'd have seven more astronauts and one less grounded space program.

They wouldn't install some escape system in the shuttle becuase it would make it too heavy, but THIS doesn't sound heavy, and that's why NASA should be putting it on every future space flight.

Re:There's NO AIR IN SPACE to blow the damn thing

[iamcf13]

Yes there is.

10 particles of air per cubic centimeter of space.

This is according to an old science book put out by the Time-Life guys years and years ago.

Problem is, there is so little air in space it is effectively a vacuum.