Could a modified space shuttle get to the moon?

[FishInferno]

DISCLAIMER: I hate he shuttle. It was a waste of money. But that's another discussion for another time...

So, basically, I was thinking, what if you had the space shuttle used for a lunar mission. I am not asking if it would be cost-efficient, or logical to preform, just if it would be possible.

Here is how I think it would work:

The payload bay would have a Lander and extra fuel for the OMS(enough for getting to the Moon and back) as the payload.

The shuttle would have a crew of three rather than the usual five, to let the life support last longer.

Extra living space in the cargo bay if there is enough room for it with the lander and fuel, allowing for a crew of four or five

One problem that I can think of is that the shuttle would probably have to retrofire or areobrake into LEO coming back from the Moon before reentering the Earth's atmosphere. If i remember correctly, he Apollo capsule had a more robust heatsheild to combat the increased speeds that it was travelling coming straight back from the Moon. I just assume that the shuttle couldn't stand that kind of heating because that was not what the shuttle was built for. So you can either upgrade the shuttle's heat shield(which I assume means more weight) OR retrofire/areobrke into LEO.

another problem is that the shuttle has to land specifically at either Edwards or KSC, which would be harder to time right coming back from the Moon

[Reddragon]

This mission scenario you have said was impossible with the shuttle. They were 75t heavy vehicles. Maybe a lightweight fuel tank in the cargo bay could have been enough to perform a TLI but not for the deceleration burn and return.

[Kryten]

The shuttle orbiter has a mass of 70 tons empty, and the OMS has an ISP of 316 seconds. The delta-v required to enter lunar orbit and back is about 8.2km/s. Plug these into the rocket equation, and you come out needing about 1000 tons of fuel.

[acc]

Nope, not possible. Even with the cargo bay full of fuel.

See here: The Space Shuttle – Fly me to the moon? (PDF)

[Nuke]

it would be the most impractical moonship ever.

and the only way it would be possible is to swap out the oms engines with arcjets or perhaps vasmir engines, and you need a lot of solar area you can deploy from the cargo bay. im not sure if the propellant would fit in the remaining space. but the ship is designed to accept an external tank (which you would need to launch on another rocket). you might also swap the main engines with a nerva engine, and you might need more boosters to get that to orbit without irradiating the launch complex. you might also cook the crew while crossing the van allen belts, but im sure you can convince the astronauts its "worth the risk".

tldr: build a new ship.

Edited September 16, 2014 by Nuke

[Camacha]

Sure, with enough modifications, it could be done. Think larger of more (moar!) boosters or simply refuelling it in orbit. Though it is beyond me why you would want to use an aero capable craft to go to a moon without atmosphere.

[Rakaydos]

Nope, not possible. Even with the cargo bay full of fuel.

See here: The Space Shuttle – Fly me to the moon? (PDF)

They seen to be basing this on OMS. Does the SSME have a better ISP? That is, could you use an extra tank in the bay to extend the iniial launch burn out to LTO?

[Kryten]

Plugging in the ISP for the SSME (452s) into the same equation, you 'only' need about 380 metric tons of fuel for shuttle orbiter to LLO and back. Add a fueled Apollo LM (15 tons), and you need about 550.

[jwenting]

fit another stage in orbit after the big orange tank has been ejected, a stage including fuel and engines, and you could make it.

Launch another stage to the moon separate for it to dock to to return, and you could get back.

Of course it'd be extremely complex, risky, wasteful, but in theory you could do it.

Or just contract the Soviets for a few Soyuz capsules and launchers, they were designed initially to have the ability for a lunar return mission with 2 people on board, though not for a landing.

[Reddragon]

fit another stage in orbit after the big orange tank has been ejected, a stage including fuel and engines, and you could make it.

Launch another stage to the moon separate for it to dock to to return, and you could get back.

Of course it'd be extremely complex, risky, wasteful, but in theory you could do it.

Or just contract the Soviets for a few Soyuz capsules and launchers, they were designed initially to have the ability for a lunar return mission with 2 people on board, though not for a landing.

The shuttle couldn't do a TLI with a transfer stage. It would've been unbalanced.

[montyben101]

No chance, as other people have shown the OMS were very inefficient.

But why do you hate the shuttle so much? I know it was expensive...

[rpayne88]

They seen to be basing this on OMS. Does the SSME have a better ISP? That is, could you use an extra tank in the bay to extend the iniial launch burn out to LTO?

IIRC, the SSMEs couldn't be restarted during flight.

[Rakaydos]

IIRC, the SSMEs couldn't be restarted during flight.

And so they are only useful for the first half, to Lunar Transfer. But you can get to lunar transfer in a single burn from the ground.

Lunar capture and escape is a separate issue.

[Camacha]

Lunar capture and escape is a separate issue.

No one ever asked about getting back

[einsteiner]

See here: The Space Shuttle – Fly me to the moon? (PDF)

This is pure junk. Whoever wrote this did no research into how orbits or space propulsion works.

[peadar1987]

So say we modified the shuttle to use a NERVA, with an Isp of 850s. That's probably the best we'd realistically get with current/very near future technology.

This link here: http://i.imgur.com/SqdzxzF.png says you need about 7.9km/s to get to lunar orbit and back, call it 7, if you allow some bleeding off of speed by aerobraking.

The space shuttle has a dry mass of 78000kg and a payload to LEO of 24000kg (wikipedia)

Plug those numbers into this website, and you get a maximum delta-V of about 2300 m/s, so even if you filled the entire cargo bay with fuel, you couldn't get to the moon.

What you probably could have done was build a modular spacecraft in orbit that could have gotten to the moon and back, but even that would have been difficult, and horrifically expensive.

[Nibb31]

There was lunar plan in the 70's that involved the STS back in the days when they thought that it would be cheap to fly. They would have sent up an Apollo capsule and a LM on one Shuttle and a Centaur on a second Shuttle, docked the two in LEO, and flown to the Moon from there.

[Tech Support]

No chance, as other people have shown the OMS were very inefficient.

But why do you hate the shuttle so much? I know it was expensive...

I dont like it because it failed to do what it promised ie. lower costs for each Kilo and provide faster turnarounds. that being said, I think the Shuttle is one the most beautiful spacecraft ever made.

Edited September 16, 2014 by Tech Support

[rtxoff]

The only feasible way of doing an manned Earth to Moon mission is the way it's already done, an Apollo style mission.

All the other options are a wastage of resources. At least nobody else came up with an better concept yet. The space shuttle, even a modified one, is sure not suitable for this task.

Don't believe in things they show in movies like Armageddon, it's complete bulls**t.

Edited September 16, 2014 by gpisic

[peadar1987]

The only feasible way of doing an manned Earth to Moon mission is the way it's already done, an Apollo style mission.

All the other options are a wastage of resources. At least nobody else came up with an better concept yet. The space shuttle, even a modified one, is sure not suitable for this task.

Don't believe in things they show in movies like Armageddon, it's complete bulls**t.

Depends what you mean by "Apollo Style". If you mean single-launch, lunar orbit rendezvous, it's far from the only way.

Alternatives are generally two-launch solutions. Launch your CSM and your lander separately, and either rendezvous them in earth or lunar orbit. With modern computers and navigation, rendezvous in earth orbit is pretty trivial*, which it wasn't in the Apollo era.

I had a discussion about it with FCISuperGuy in this thread. It continues on with about four or five replies back and forth discussing mission architecture.

Basically the conclusion was that we couldn't do it with the current generation of rockets (25,000kg to LEO), but it wasn't far off, and with a bit more payload capacity, it could probably be done.

*Insofar as anything in space travel is ever trivial

[Godot]

So say we modified the shuttle to use a NERVA, with an Isp of 850s. That's probably the best we'd realistically get with current/very near future technology.

...

And I guess it is the one thing we probably won´t ever get, because of environmentalists/public opinion.

People would read the "Nuclear" in the abbreviation NERVA and will immediately be afraid of it, especially if it is planned to be built into a space shuttle (considering the fact that the number of space shuttle crashes is > 0)

[Camacha]

The only feasible way of doing an manned Earth to Moon mission is the way it's already done, an Apollo style mission.

Why on Earth would you say that? Just because it has been done in that manner does in no way mean it is the only or best way of handling things.

[Mr Shifty]

Stephen Baxter's book Moonseed imagines a trip to the moon with a combination of Shuttle, Soyuz, and Apollo technology. No one writes harder sci-fi than Mr. Baxter, so his conjecture is somewhat plausible. Specifically, he has 3 IUS's for the TLI burn, launched by two Shuttle missions and a Titan, assembled together in space and towed to the ISS, where a waiting Soyuz Block-D will serve as a command and service module. They use a reconfigured unmanned probe, with astronauts strapped to it in an open cockpit configuration for landing and ascent. The novel itself is a rip-roaring disaster novel with some very nice realistic space flight stuff thrown in. Check it out.

AND, in another of Baxter's novels, Titan, he imagines a trip to Titan using a shuttle orbiter retro-fitted with an ion-drive. That novel opens with a heart pounding and eerily prescient emergency during re-entry and landing of Columbia. It was published 6 years before the Columbia disaster.

Edited September 17, 2014 by Mr Shifty

[magnemoe]

Why on Earth would you say that? Just because it has been done in that manner does in no way mean it is the only or best way of handling things.

Lots of way to do it, apollo style, apollo style using two launches, an more advanced version would use an dedicated LEO to moon orbit craft with vasminr or nerva, then a moon lander, preferable with one stage so it can be refueled and reused. You would then use an space shuttle to dock with the moon craft and top it up with fuel.

This is pretty much the only plausible large ship to send to moon.

Sending an space shuttle to moon however is an bad idea, the space shuttle weight around 70 ton dry, lots of this weight is the huge engines and their support system needed for takeoff who would not be needed, an huge cargo hold and systems for working in space would probably also be redundant.

[cantab]

but the ship is designed to accept an external tank (which you would need to launch on another rocket).

Technically, you wouldn't. Though it was never done, the shuttle could have taken the external tank with it into orbit. There were ideas to use the tank for stuff like space stations, but nothing ever came of them.

If it were instead refuelled on-orbit and used as a drop tank, with an additional tank in the payload bay, you'd get something like:

Isp = 450 s (SSME)

Orbiter only:

m0 = 69 tonnes

m1 = 94 tonnes

dV = 1300 m/s

External tank:

m0 = 120 tonnes

m1 = 856 tonnes

dV = 8600 m/s

From a pure delta-V perspective, that could make a trip to lunar orbit and back. Indeed it might be possible to use the payload bay for a lander instead of extra fuel.

Of course there are other complications. The SSME's would need modifying to be restartable, and perhaps increased gimballing to propel the shuttle straight. I'm not sure how much of a problem fuel boiloff during the trip would be.

But worst of all, how are you going to get over 700 tonnes of fuel up there to refill the external tank!