Apollo-style or Earth Return Vehicle approach for future manned Moon missions?

[szputnyik]

If there are going to be future manned missions to the Moon in the next 10-15 years what do you think, which approach would be more practical and cheaper?

1.Doing the mission Apollo-style with a Lunar Orbit Rendezvous, and taking the LM and the CM with one single big launch.

OR

2. Sending an automated Earth Return Vehicle to the Moon, then with a separate launch, sending the astronauts to the Moon with a bigger LM-kind of capsule, and landing them near the Earth Return Vehicle. At the end of the mission, the astronauts would abandon the LM, board the Earth Return Vehicle and return to Earth.

Which method would be cheaper and more practical with modern technology and why?

[Canopus]

In the next 10-15 years? Apollo style, since there already is a spacecraft avaiable. Atleast i saw a concept which had the lander launched underneath the Orion mpcv.

Edited October 20, 2013 by Canopus

[Kryten]

In your second scheme, the 'earth return vehicle' is fully capable of both landing and returning the astronauts-so what would be the point of the 'LM-kind of capsule'?

[szputnyik]

The LM-kind of capsule would have no heatshield or parachutes, it wouldn't be capable of entering the atmosphere and landing on Earth. The Earth Return Vehicle would go to the moon automatically, thus the weight of the astronauts could be replaced by payloads on the way there.

[Nibb31]

Over the next 30 years, it will likely be Orion, which is designed for direct re-entry from lunar orbit.

However, I can't help thinking that we should stick to affordable LEO taxis for the launch and reentry role only and design spaceships for space only. Trying to perform both roles with a single vehicle is like designing an amphibious car. It's going to be designed around compromises which will make it impractical.

We could do with a reusable lunar shuttle/lander. It would refuel in LEO (or rather dock with an expendable stage) and rotate crew/supplies from a LEO Dragon. Then it would transfer to the Moon, to the lunar surface, and return to LEO again for another trip. This would allow a semi-permanent base on the lunar surface.

Not going to happen in the foreseeable future though.

[Dunbaratu]

I thought "Orion" was the name for the concept of a ship propelled by mini nuclear bombs. Are they seriously planning on using that for a moon mission? And putting the payload "under" the Orion sounds like it would arrive quite irradiated.

[dharak1]

Orion is the name of a capsule designed by NASA. I thought it was cancelled? I think the landers they were designing were called atlas or something.

[Nibb31]

Orion is the name of a capsule designed by NASA. I thought it was cancelled? I think the landers they were designing were called atlas or something.

If all you have to offer is "I think" in a forum where most of us follow these things pretty closely, then it might be better to refrain from posting. At least look up Google or wikipedia before posting nonsense.

Constellation was cancelled (the Ares rockets and the Altair lander), but work on the Orion MPCV continued and it is flying unmanned next year. It should be flying on SLS in 2017.

[Superluminaut]

The first method.

A moon lander is designed to be absolutely minimal. The Apollo landers actually had some walls as thin as foil. They are not more roomy than a command pod. The apollo style mission made use of maximum space by connecting the two. A reentry capable pod has a lot of extra equipment on it, such as a heat shield and parachutes resulting in a lot of mass you don't want to spend extra fuel trying to land. Landing a reentry pod would require much more fuel than a minimalist lander.

If you want to go really low on ÃŽâ€V you could try a third option. Send one reusable lander that stays at the moon for multiple moon crews to refuel and use.

[Krupski]

If there are going to be future manned missions to the Moon in the next 10-15 years what do you think, which approach would be more practical and cheaper?

1.Doing the mission Apollo-style with a Lunar Orbit Rendezvous, and taking the LM and the CM with one single big launch.

OR

2. Sending an automated Earth Return Vehicle to the Moon, then with a separate launch, sending the astronauts to the Moon with a bigger LM-kind of capsule, and landing them near the Earth Return Vehicle. At the end of the mission, the astronauts would abandon the LM, board the Earth Return Vehicle and return to Earth.

Which method would be cheaper and more practical with modern technology and why?

LOR is the most efficient way to do it, which is why Apollo used it. Mass is used, then discarded. Nothing "excess" is carried along as dead weight.

If they could successfully pull off LOR back then, with electronics in it's infancy, they can certainly do it now.

Funny thing is, everyone who tries to design something "better" for a manned lunar mission always seems to end up coming back to the "Apollo" method (a testament to how good the original engineering was).

[Spacewalking on Sunshine]

A bit off topic, but how does the SLS size up to the cancelled Ares?

[Nibb31]

A bit off topic, but how does the SLS size up to the cancelled Ares?

Wikipedia is your friend:

http://en.wikipedia.org/wiki/Ares_V

http://en.wikipedia.org/wiki/Space_Launch_System

[Drunkrobot]

LOR is the fastest way to get to the Moon. (It was picked during the Moon race so the huge, expensive Nova needed in Direct Ascent could be discarded, and Earth Orbit Rendezvous would need two Saturn Vs per mission-important considerations if you were in a race). When you don't mind the cost so much, and you want to spend more than a few days on the Moon, using two launches (twice the payload capacity) has a lot of merit.

Two launches would be far superior to one, in my opinion. One would be a manned mission like Apollo/Saturn-CSM/LEM/Earth escape stage-maybe a bit larger, heavier and better to best use the new launchers larger payload (Space Launch System Block ll, you little tease). The other would be unmanned, putting something like a base station module or a store of consumables on the Moon ahead of the astronauts, so they would be able to spend more time there, and have more equipment to use during that time.

[Whirligig Girl]

LOR, with a reusable LM kept in a high Lunar Orbit (So you would get less gravitational distortion). It would be launched alone.

Mission Profile:

RHLM (Reusable Heavy Lunar Module) launch from Ares V.

RHLM Is brought to the Moon, and is kept in a very high orbit to minimalize the Moon's uneven gravity.

It is left there.

HRCMPCV (Heavy Reusable Cargo Multipurpose Crew Vehicle) is launched on Ares IV-R (Reusable) with a (reusable) Lunar Transfer Stage.

It then does LOR with the RHLM.

Cargo/Crew to be taken to the Lunar Surface is taken from the HRCMPCV and moved to the HRLM. HRCMPCV Then tops off the HRLM's Fuel tanks.

HRLM Lands and does stuff. Most importantly, it takes water from rocks and then electrolyzes water into fuel with a special device called TDTMWARFOR.

HRLM Ascends to LOR with HRCMPCV in a lower Lunar Orbit.

HRCMPCV puts HRLM into a Hohmann transfer orbit to it's higher altitude, tops off the HRLM fuel, and then the HRCMPCV continues burning to escape the Moon and fall back to Earth.

HRLM Circularizes orbit.

HRCMPCV Lands on Earth.

Repeat HRCMPCV Launches, reuse all hardware.

The Spacecraft are designed to be fully reusable (Aside from the infrastructure used to launch the HRLM), and very large. the HCRMPCV is almost half the size of the Space Shuttle, and a remarkable portion of that size is fuel for the HRLM.

The HRLM is 25% bigger than the Altair, because 1: It's single stage; and 2: High orbits needed; and 3: More cargo.

[Spacewalking on Sunshine]

Wikipedia is your friend:

http://en.wikipedia.org/wiki/Ares_V

http://en.wikipedia.org/wiki/Space_Launch_System

So it has less lifting capacity than the Ares?

That's depressing. Though as long as NASA gets their hands on something better than the old Saturn V, i'll be happy.

[Nibb31]

Bigger is not necessarily better. Especially when you only have money for one launch every two years and it eats up all the money for developing payloads to put on top of the rocket.

One of the problems of NASA is to always focus on "bigger and better rockets" instead of on the actual mission. You could build a moon infrastructure on cheapo expendable rockets for a fraction of the cost of a single SLS launch.

[Spacewalking on Sunshine]

Robert Zubrin seems to think "We absolutely do need heavy-lift", and the whole Mars Direct scheme requires huge rockets with little to no loitering in orbit. Maybe a whole mess of smaller rockets would torment NASA's funding more than launching a few heavies and being done with it. Nobody really foresaw the shuttle program being as disappointing as it turned out.

I don't claim to be an expert, but Apollo was done by one solid and true heavy-lift rocket, and that's the greatest accomplishment in spaceflight.

[p331083]

Too many acronyms in this thread.