Future of Space Shuttles - How could the Space Shuttles be used?

Aaron Chester · 2002-03-15 11:12:07

Once NASA or someone else has built a newer, more reliable, and cheaper RLV, the space shuttles should be used in a different way. Instead of continuing to use them as RLV's, they possibly could be launched into space and be used as transporters between the moon, space stations, etc. They are already built to withstand much of the radiation. There might have to be a few modifications once they are in space, but they definitely would give us a boost in space vehicles.

At the very least, it is an idea that should be looked at.

Josh Cryer · 2002-03-15 12:39:48

You know, I agree, I think the next space shuttle should be designed so that it can go to the moon and back. Also, its design should be extremely scalable, so you could replace the engine easily, and so on and so forth.

Also, I think the plans for the next shuttle should be totally unclassified, and available online for scientific peer review. (As far as I know, you can't actually see the plans for the current space shuttle.)

The next space shuttle should be simple, and totally self contained. The space shuttle we have now is composed up of four different pieces that come apart with explosives. C'mon, this is ice age stuff we're talking about here.

Adrian · 2002-03-15 18:18:40

While it might be possible to use the Space Shuttle as a cislunar transporter (I don't know whether it is or not), I don't think it's a good idea to make a spacecraft that fulfills all possible human transportation roles.

This is simply because getting up into orbit is a much different task to getting from orbit to the Moon - you need a huge amount of delta-V, you need high heat resistance for re-entry, you need wings, you need undercarriage, etc etc. Whereas if you want to go from orbit to anywhere else, you don't really need any of that.

At our current status of technological prowess at making spacecraft, it is neither economical nor efficient to specialise too much.

That said, I do agree that in the future there will be a role for spacecraft that can get you from the ground to the Moon in one go, for purposes of speed and comfort, perhaps.

As for the next RLV, I think that what is most important is that it should be cheap, relatively safe and have a quick turnaround. These properties do not necessarily mean it should be totally self contained; if they manage to figure out some way of making a spacecraft in two parts that is significantly cheaper than a spacecraft in one part, I don't think many people would argue for the self-contained craft.

Finally, I remember reading about possible uses of the Space Shuttle when they get retired. I can't remember whether this was fiction or not, but one scenario had the Space Shuttle being used as an orbiting weapons platform (fill it full of nukes out of harm's way). I don't agree with the use, but I do think that throwing a Space Shuttle into orbit for its last trip could see it living the rest of its days as a temporary space station or some similar thing.

Phobos · 2002-03-17 21:35:32

Finally, I remember reading about possible uses of the Space Shuttle when they get retired. I can't remember whether this was fiction or not, but one scenario had the Space Shuttle being used as an orbiting weapons platform (fill it full of nukes out of harm's way). I don't agree with the use, but I do think that throwing a Space Shuttle into orbit for its last trip could see it living the rest of its days as a temporary space station or some similar thing.

It's funny that you mention the possibility of the Space Shuttle being used as a weapons delivery platform. I read in "Korolev" by James Harford that the Soviets believed the real purpose of the Space Shuttle was to toss hydrogen bombs at the Soviet Union. Apparently, according to this same book, the Soviets scrapped their plans to set up a permanent base on the moon to develop the Buran spaceshuttle so they to could sneak some hydrogen bombs
into orbit should they have to. They didn't have funds for
both programs. This seemed a little far fetched to me but
I suspect there's some truth to it.

Adrian · 2002-03-18 08:58:32

It's not too far off the truth. I seem to recall that the Space Shuttle's current design owes a lot to input from the military - it can carry out low orbital bombing runs over a large range of latitudes. Obviously that's not what it was made 'for' but I am sure that the possibility of using the Space Shuttle for offensive purposes was discussed at length.

Aaron Chester · 2002-03-18 10:42:28

I am not sure if I explained myself clearly. I did not mean that we should create a space shuttle that will take us from earth to moon. Rather, that once we have created the next RLV's, we should take the current Space Shuttles, launch them into space, and use them in space.

The current space shuttles would be perfect to keep in space and so that we could use them as utility vehicles. They could do maintenance work, serve as a platform for space research, and even serve as a shuttle between earth and the moon. Though I am sure that it would be somewhat difficult to keep them fueled, I don't think it would be impossible. They would not need a tremendous amount of fuel once they were in space to move around.

Shaun Barrett · 2002-03-21 05:38:17

I'm all in favour of any sort of lunar transportation system but I suppose you'd have to jettison quite a proportion of the present shuttle structure in order to make it economical.
As has been pointed out, there is much of the shuttle that, in space, would be dead-weight: Namely the undercarriage, those heat-resistant tiles, the stubby wings, the load-bearing struts, etc. In fact, the whole concept of the shuttle is probably wrong for Earth-Moon transportation. And it's no use trying to ignore the unwanted bits, either. Every unnecessary kilogram of weight will add to the fuel required to accelerate the shuttle out of Earth orbit and into cis-lunar mode.
In addition, the aerodynamic shape of the shuttle, though essential for atmospheric flight, will only serve to unnecessarily restrict the internal volume of this new space-tug. Perhaps a completely redesigned and purpose-built craft would actually be more economical in the long-run ( ? ).
I hope I'm not being a wet blanket but we do have to consider the practicalities of this proposal. And, because the shuttle is just so specific to the task for which it was designed, it may be hopeless to ask it to perform in an environment for which it was never intended.
???

Aaron Chester · 2002-03-21 09:43:18

I absolutely agree that the current space shuttle configuration is not efficient as a permanent space vehicle. However, I think these modifications could be done. I must admit that the thought of astronauts doing space walks to tear off ceramic tiles is a bit daunting. Perhaps making the space shuttles permanent space vehicles is not the best use of the current space shuttles. However, these shuttles are going to be around a long time, and I don't think we should just junk them when the next generation RLV comes along.

RobS · 2002-03-23 01:51:02

Actually, the heat shield probably is not one of the elements you'd want to eliminate, because a vehicle that returns to the earth from the moon encounters the atmosphere at 25,000 mph. A heat shield takes far less mass to slow you down than fuel.

There have been hundreds of studies of lunar transportation systems made in the last forty or so years, and they are getting more and more efficient all the time. Michael Duke et al. proposed this for an Earth-Moon transportation system. The details can be found at http://members.aol.com/dsfportee/ex97b.htm.

1. Solar-powered Electric Propulsion Vehicle (EPV) weighs about 8 tonnes and can haul a 16-tonne cargo to L2 (Lagrange beyond the moon) in six months. This means it can haul 16 tonnes to just short of escape velocity. [If you assume an Isp of 900 and an delta-v of 3.3 km/sec, the mass ratio is 0.45:1; thus a 16-tonne payload requires 7 tonnes fuel. A solar-thermal rocket could accomplish this as well. Adapted to a Mars transportation system, this element could accelerate a vehicle to 3.1 km/sec, just short of escape velocity.]

2. Lunar-based vehicle (LBV), weighing 8 tonnes with LOX/LH2 fuel and capable of carrying 8 tonnes to the lnar surface from L2. [If you assume an Isp of 475 and a delta-v of 2.3 km/sec, mass ratio is 0.62:1 and 16 tonnes of mass must burn 6.2 tonnes of fuel to land on the moon. By the way, this element could be used to push a Mars vehicle to Mars and return it from an elliptical Mars orbit.]

3. Processing plant weighing 8 tonnes with 25-kilowatt power supply (1-tonne nuclear or solar) capable of making 16 tonnes of propellant every six months from lunar polar ices. [This element probably could be modified to make return fuel on Phobos and Deimos or even on the Martian surface.]

4. Lunar surface habitat weighing 8 tonnes [This could be modified for the Martian surface, though it might be too small for an 18-month stay.]

5. Crew vehicle (CRV) based on X-38 lifting body weighing 8 tonnes. Can be landed on moon using lunar-based vehicle and launched back to Earth with same. [This is definitely too small to return from Mars.]

A space shuttle launches the first three (combined weight, 24 tonnes, which is just the shuttle's low earth orbit capacity) and EPV1 carries the other two (LBV1 and the processing plant) to L2; the LBV1 carries the processing plant to the lunar surface, where it is set up robotically. EPV1 returns to low earth orbit. LBV1 is refueled over a six month period and returns to L2 with 8 tonnes of fuel.

Then a second shuttle launches EPV2 and LBV2 to carry the habitat to the lunar surface. LBV2 refuels and goes to L2. EPV2 returns to low earth orbit.

Then a third shuttle launches a CRV. A chemical stage carries it to L2 [which requires about 8 tonnes of LOX/LH2, minus fuel to carry the tank] where LBV1 carries it to the lunar surface. The crew stays 1 month.

LBV1 refuels, launches the CRV back to the Earth, returns to L2. I suppose it can be refueled there by LBV2 and return to lunar surface.

If EPV can haul 16 tonnes to L2, it could haul 16 tonnes back as well. This allows it to refuel low earth orbit with lunar propellant. Also, the LBV can launch 8 tonnes LOX/LH2 toward Earth as easily as toward L2; with aerobraking, it could refuel the chemical launch system in low earth orbit.

As you can see, a similar system could haul items to Mars or its moons; the delta-vee is very similar. But you can't send people to Mars with a mere eight tonnes of payload; the consumables alone would weigh more than that. But if you scale this system up by three, then you have 24 tonnes, which is the mass of a Mars Direct Hab. So something like this system could be used to send people to Mars. The authors of the presentation apparently scale this up by four to create a Mars transportation system.

-- RobS

VitaminJ · 2002-04-04 13:51:38

I had a similar thought years ago: that one of the shuttles could be retired as a part of the ISS, with a nice big lab in the back. a 4 billion dollar vehicle to replace 10 or 20 Billion worth of ISS...

I also seem to recall NASA considered a "space taxi" for use in earth orbit, as a moon taxi, could go to the Lagrange points, etc. It could be either a x38 ISS escape vehicle with a fuel pod and service module mounted aft, or a capsule design. I think this would be more sensible than refitting a shuttle. Maybe.

Somebody tell NASA to get on with the nexgen RLV and manned missions to mars. And if they GOTTA build the ISS, DON"T CUT THE CENTRIFUGE AND TRANSHAB!

The Mars Society rules. Put those mice up there!

Mark S · 2002-04-11 13:10:03

The current shuttle is not capable of the flight rates needed to support an outpost on the moon, let alone Mars. It could, however, be used as part of the first Mars mission, as it is in the Borowski nuclear-thermal plan that I am partial to.

However, Shuttle ETs could be boosted into orbit and used as habitats for cycler spacecraft on the way to Mars. Shuttle tanks and boosters can also be used to build a heavy-lift launcher for moon and Mars missions, as Dr. Zubrin suggests.

My suggestion to NASA is to design the next-generation RLV for a flight rate which is at least twice that of the existing shuttle (currently, a maximum of eight per year.) It should also be able to launch on time without all of the delays and maintenance associated with the space shuttle.

Aaron Chester · 2002-04-11 13:26:46

Actually, I think I am to the point where I believe that NASA should get out of the RLV business, and instead focus on building an interplanetary space craft. Private corporations should build the next RLV and then NASA could buy space on those flights. This would get the government out of Near Earth space and allow private businesses take over commerce, construction, and transportation in Near Earth space.

I know this seems to be a big step, but I think it is very plausible. If corporations know that they will not be competing with the government, and that the government will be buying space on their vehicles and paying for construction in Near Earth space, then it will give them an incentive for building the next RLV.

Not only would private companies have guaranteed income from the government, -in essence a subsidy- they would also have the ability to expand into tourism. These companies could become the gateways into space.

RobS · 2002-04-11 23:19:21

You might want to look at the articles on the web about the new Delta IV Heavy (search using Google). Basically, what you advocate is what is happening. Boeing is building the Delta IV heavy partly because the US Air Force has ordered a bunch of them; this guarantees a market. It is selling them for commercial launches as well.

But the big problem right now is that commercial launches rarely require more than 10-20 tonnes in low earth orbit. Geosynchronous satellites run 5-10 tonnes and require an equal weight of fuel to get to GEO, so the low earth orbit launch weight is 10-20 tonnes. The Delta IV Heavy can put about 25 tonnes in LEO for something like $7,000 per kilogram.

Mars and moon flights really need more tonnage. While one can go to the moon 25 tonnes at a time, Mars launches really need 50 to 80 tonne launches, and ideally more like 140 tonnes. There is currently no commercial demand for launches of this size, and there won't be such demand in the near future. This means that either the government builds a big booster exclusively for Mars flights or that it develops the ability to assemble a Mars vehicle in LEO from 25 tonne pieces. Both strategies are expensive. The third alternative is to go to the moon 25 tonnes at a time, using the shuttle or the Delta IV heavy or other equivalent rockets, then bring lunar fuel back to fuel a Mars flight. Both the Hab and the ERV in Mars Direct are in the 25 tonne range (though when you add the aerobrake and fuel for landing, they are more like 35 or 40 tonnes) and could be launched by a 25-tonne tonne lifter. A solar electric propulsion vehicle (ion engine) could push it to a geosynchronous transfer orbit or all the way to the Lagrange point between the Earth and moon, where lunar oxygen and hydrogen would be waiting to push the vehicle to Mars.

The aerospace companies are trying very hard to lower the cost of launching to low earth orbit, but the technology simply does not yet exist to permit cheap access to space.

-- RobS

Bill White · 2002-04-12 10:19:32

In my opinion, RobS has nailed the bullseye of the challenge facing Mars advocates:

<<While one can go to the moon 25 tonnes at a time, Mars launches really need 50 to 80 tonne launches, and ideally more like 140 tonnes. There is currently no commercial demand for launches of this size, and there won't be such demand in the near future. This means that either the government builds a big booster exclusively for Mars flights or that it develops the ability to assemble a Mars vehicle in LEO from 25 tonne pieces. Both strategies are expensive.>>

There is Energia, of course, which is not being built or used because there simply are no commercially viable payloads which require such a large rocket. Hopefully, however, the plans for Energia will not disappear like the plans and tooling for the Saturn V.

Mark S · 2002-04-12 13:02:44

Like Aaron, I believe in privatizing space transportation. However, I feel that the industry is too timid to challenge the NASA bureaucracy right now, and all of the small space startups like Beal Aerospace and Roton do not have the resources to go through with it.

On the subject of heavy lifters:
The Saturn V tooling is history, but NASA has the plans safely locked up. It would not be practical to build a new Saturn V, but an upgraded Saturn V would be feasible. NASA proposed the Saturn V-derived "Comet" for the First Lunar Outpost program. It would use uprated Saturn engines with stretched 1st and second stages, strap-on liquid boosters, and a 10m diameter third stage.

Our best bet for building a heavy lifter is the same method Lockheed and Boeing have used for their EELVs: just cluster more core booster stages together. With a new upper stage, a cluster of seven booster cores can probably do the job.

Phobos · 2002-04-12 18:07:33

Nasa had a Lunar Outpost program? If it did I hope the space shuttle isn't responsible for killing it. It would be a shame considering that the modified Saturn V you talked about could probably lift as much as the Space Shuttle into LEO and perhaps cheaper to, not to mention we could have a base on the moon.

Vishal · 2002-04-13 16:36:57

1. Energiya... seems to be the KEY to getting to MARS... to everyone but the POWERs that be...

What are the chances of a private consortium... getting the services of this launch vehicle... ? Is it feasible.... ? and ofcourse cost effective..... I'm thinking of the Energiya 200 tonne capacity configuration

I mean ... this thing could launch modules the size of SKYLAB into orbit... and hence slash the cost of the ISS construction process.... in one fail sweep.. if initially folks decided to design things sensibly.....

2. on a seperate note... Why is it that every European ATV is destined to burn up in the atmosphere.... ? It seems mighty waste of something that could effectively be a transfer vehicle between LEO stations... or indeed.... possibly linked together to form some sort of larger transfer vehicle... But its present post ferrying up supplies role would make it the worlds most expensive garbage truck.....

Adrian · 2002-04-13 17:16:29

More on the European ATV mentioned by Vishal. It sounds very cool to me, especially as it's a European project.

RobHazlewood · 2002-04-17 19:30:57

Everything that seems to have been mentioned here for lunar/mars missions seems VERY expensive.

Wouldn't it be better if no chemical propulsion was needed beyond LEO?

I'm sure this would be possible (for the moon at least).

I think the best option that is achievable in the near future would involve solar electric propulsion and a space elevator on the moon.

A conventional 2nd gen RLV could be used to transport the modules of the spacecraft into orbit, which would then travel from earth orbit to lunar orbit as much as required. (stopping at ISS for refueling)

The vehicle would only need to consist of a propulsion module (very scaleable as more propulsion modules could be added), and a human hab module that could be left at the ISS if not required in that particular mission. The mission payloads could simply be docked to the side of the propulsion module.

This craft would enter lunar orbit, move its payloads to the elevator, then the elevator would move the payload to the surface.

NO CHEMICAL PROPULSION NEEDED! (beyond LEO at least)

Once this basic infrastructure is in place, a moon base would be cheaper to maintain than the ISS currently is. (assuming shuttle for ISS, 2nd gen RLV for moon).

A space elevator on the moon would probably be quite cheap. People are considering using these on earth! (moon would be much easier/cheaper)
see:
http://www.space.com/busines....-1.html

thanks,
Rob

Phobos · 2002-04-18 19:39:47

How long do you think it would take a space elevator to deliver a payload from LEO to the moon? Anyway I think it's a great idea, you could build a very massive elevator on the moon and this would probably be a cost effective way of keeping a lunar colony supplied. I really think space elevators will prove to be the next big thing in delivering payloads to orbit.

RobHazlewood · 2002-04-19 06:08:48

The space elevator would not have much to do with the actual ammount of time it would take to get to the moon. If anything, an elevator would speed up the process (faster transit due to lower craft mass - less propellant)

The bit that might take a while is the solar electric ion engine part of my whole scheme. I figure if the space agencies manage to make craft self sufficient (growing own crops, etc), transit times won't matter too much (A 1 month journey to the moon would be acceptable). People stay 6 months on the ISS at a time, so I don't see how the moon should be any different. The whole solar electric thing is just my attempt to save money, as the whole craft would be *very* reusable. Also, no huge heavy lifter rockets would be needed on earth, as no where near as much propellant would be needed to get there & back. Propellant to the ion engine could just be bought up in re-usable modules in a shuttle cargo bay.

Does anyone know (or care to calculate) how far a lunar geostationary orbit is away from the suftace? Add 50% and thats probably how long the carbon nanotube cable would have to be.

What are other cheapish solutions?
What does everyone else think about this?

thanks,
Rob

Mark S · 2002-04-19 13:46:10

It's nigh-impossible to build a lunar elevator. Any space elevator would connect the earth's surface to a node in geosynchronous orbit. If you tried to construct a lunar elevator, the velocity of the moon would tear out the elevator cable.

RobHazlewood · 2002-04-19 20:29:11

It's nigh-impossible to build a lunar elevator. Any space elevator would connect the earth's surface to a node in geosynchronous orbit. If you tried to construct a lunar elevator, the velocity of the moon would tear out the elevator cable.

I never mentioned anything that involved a cable going from earth to the moon. You are right, that idea is pretty stupid. Maybe Phobos got abit confused with what I said, but i'm pretty sure the neither of us were talking about a cable from earth to the moon. (the whole solar electric propulsion thing is the means of getting to the top of the elevator on the moon).

The more I think about it, the more I like the concept. (provided people manage to make suitable cables).

thanks,
Rob

RobHazlewood · 2002-04-19 20:35:50

I forgot to mention that the reason why I used that example is that its a method of making moon/mars bases without needing something the size of Energiya. Something that huge would cost WAY too much to develop and use. I speak for myself when I say this, but I feel that the future of space travel is with RLV's delivering payloads into orbit (or possible space elevators), which are then transported to the required position by separate spacecraft that aren't designed to go into earths atmosphere. (ie no more big rockets like Delta, Titan, Saturn V, Ariane 4,5, etc)

And that leaves the shuttle for museums. Its too damned expensive to use for anything else.

thanks,
Rob

Vishal · 2002-04-20 12:25:01

we can keep hoping that the new RLV when it arrives will be the answer to all the problems...

However, my question is the costs banded about for launching all the present complement of vehicles are these actual costs or do they include. all the research costs (a proportion of) and the fixed costs for the training of the crew ground support teams .. general facilities etc etc...

i.e. are these actually the minimum costs or exagerrated because of the present climate and buisness models that exist... ?

Finally... space is presently prohibitively expensive because each country wants to develop its own facilities and technologies from scratch i.e. reinvent the wheel rather than try and build on each others frameworks.. ok this may be extremeley naive of me... however isn't there any way around this...

New Mars Forums

Announcement

#1 2002-03-15 11:12:07

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#2 2002-03-15 12:39:48

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#3 2002-03-15 18:18:40

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#4 2002-03-17 21:35:32

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#5 2002-03-18 08:58:32

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#6 2002-03-18 10:42:28

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#7 2002-03-21 05:38:17

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#8 2002-03-21 09:43:18

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#9 2002-03-23 01:51:02

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#10 2002-04-04 13:51:38

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#11 2002-04-11 13:10:03

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#12 2002-04-11 13:26:46

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#13 2002-04-11 23:19:21

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#14 2002-04-12 10:19:32

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#15 2002-04-12 13:02:44

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#16 2002-04-12 18:07:33

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#17 2002-04-13 16:36:57

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#18 2002-04-13 17:16:29

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#19 2002-04-17 19:30:57

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#20 2002-04-18 19:39:47

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#21 2002-04-19 06:08:48

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#22 2002-04-19 13:46:10

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#23 2002-04-19 20:29:11

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#24 2002-04-19 20:35:50

Re: Future of Space Shuttles - How could the Space Shuttles be used?

#25 2002-04-20 12:25:01

Re: Future of Space Shuttles - How could the Space Shuttles be used?

Board footer