Private Moon Landing in the works?

[HappyMartian]

I'm thinking if this is going to more than a one-off stunt that doesn't go the way of Apollo, they're going to have to go with a reusable lander. At a billion USD a pop, they can't afford to be throwing those things away. That means they'll need an SSTO and refueling. Which also means they're going to need maximum Isp which in turn means LH2/LO2.

I would say go with something along the lines of the Masten Xeus lander in it's reusable form, which can have a 5 mT payload. Now, the Apollo LEM ascender module massed close to 5 mT, but more than half of that was propellant, so they could probably make a 4-man capsule and keep everything under 5 mT.

Then maybe some sort of reusable flying depot composed of 2 Centuar segments that could possibly double as space tug for the Dragon.

Basically, it would be a mini-version of the ULA architecture....


But of course there are many ways to skin this cat: any other ideas?

Find diverse sources of piles of money. When and wherever it is possible work with the Europeans, Russia, China, and Japan. Avoid NASA for the next four years. Focus on gaining initial hydrolox ISRU capability. Lean and mean.

[Nelson Bridwell]

An article in MIT Technology Review pointed to this recent essay by Alan Stern and Gerry Griffin:  US Needs Near-term Results in Human Space Exploration

http://www.spacenews.com/article/us-needs-near-term-results-human-space-exploration

[Mongo62]

The key portion of that essay (in my opinion):

Pragmatism means exchanging more perfect solutions for more practical ones by using existing systems, modified to the least extent practical, to accelerate the pace of exploration.

We therefore urge an approach that obtains near-term results — i.e., human exploration beyond LEO — as quickly and as pragmatically as possible. In an era when budgets are shrinking, as are both public and political attention spans, we believe this course is a must for human space exploration in the United States.

Specifically, what does this course imply? It means two things:

Establishing a commercial crew capability to LEO and the international space station as rapidly as possible, in order to expeditiously free up resources within the human spaceflight budget for exploration, rather than expensive Soyuz seats.

Using the savings accrued by adopting commercial crew to jump-start human exploration beyond LEO before SLS is ready. This can be accomplished by developing orbital refueling for and then human-rating one or more existing rockets to carry out simple exploration missions — such as lunar/near-Earth object flybys and orbiters — using the Multi-Purpose Crew Vehicle or other crewed spacecraft that can be ready by mid-decade.

So considering the drive to keep development and running costs down, basically Falcon Heavy and Dragon, with the Dragon mated to a lunar SSTO-capable "service module", and also utilizing propellant depots.

[ARD]

But of course there are many ways to skin this cat: any other ideas?

For minimum development, I've personally always favored a Falcon Upper Stage with four SuperDracos mounted in pretty much the same way the ULA DTAL has its hydrolox thrusters.  A one-off Falcon Heavy with an upper stage modified in such a way should, by my reckoning, be capable of delivering 4 metric tons to the lunar surface.  Refueled at EML-2, it should have a pretty significant single-stage-to-surface-and-back cargo capacity. 

A stretch on the kerosene tank would mean that such a stage could be refueled with LOX on the surface, and replacing the SuperDracos with Kestrels could mean simplification of propellant use in much the same way that ULA's DTAL would use LH2/LOX for final landing.  But that would mean reopening the Kestrel production line. 

I feel bad to throw away LH2 from the future ice-cracking plant, but I suppose it could be used in experiments in regolith reduction. 

Hydrolox might be more efficient, but until ULA starts flying ACES, the Delta 5m upper stage and Centaur might not offer enough of a performance increase to justify it.  It would still be the next logical step in development, but to reduce costs, commonality with an existing LEO and GTO system is a plus. 

That's just my amateur view--please, rip into it. 

[simonbp]

But of course there are many ways to skin this cat: any other ideas?

Personally, I've only ever skinned a cat once, so I wouldn't know.

We'll see tomorrow, but it sounds like small expendable depots might be their plan...

[daveklingler]

Lunar cycler.

[Nelson Bridwell]

We'll see tomorrow, but it sounds like small expendable depots might be their plan...

When the lowest cost per pound to orbit comes in units of 50+ mT, my non-expert guess is that propellant depots would be a non-essential complication for Lunar missions.

In order to hold down costs, which appears to be the main priority, they might choose to adopt a KISS (keep it simple), JIT (just in time), minimum launch mass strategy.

One approach might be to reuse everything that goes up and does not come back down, and deliver only the required fuel to spacecraft, refueling them only when and where they need it.  The last thing that they need is surplus fuel in their tanks, beyond reasonable safety margins.

[Warren Platts]

But of course there are many ways to skin this cat: any other ideas?

Personally, I've only ever skinned a cat once, so I wouldn't know.

Oh gross! I was being metaphorical! Poor kitty!

We'll see tomorrow, but it sounds like small expendable depots might be their plan...

The expensive chess piece is going to be that manned lander. To refuel it, I see what you're saying: What's the difference between a tanker and a depot anyways, really? There's no reason why one of those simple, single-launch, dual-Centaur depots that Goff and Kutter proposed couldn't also double as a LEO to LLO tanker, I guess. But once you get it to Lunar orbit, is it worth the propellant required to send it back?

And before people complain about how cryogenic fuel transfer has never been done before, not to mention the boiloff, allow me to point out that the Centaur/RL-10 system already exists. This commonality could extend to the lander itself, as well, just like Zegler et al. were talking about back in the good old days of 2009, thus radically reducing costs and speeding up delivery time.

To build a hypergolic 3rd-stage/EDS/depot/tanker/lander system, it's going to be basically from scratch, and that means a lot of money and a lot of time that we (meaning the people would like to see Lunar return before the 50th anniversary of Apollo 17) don't have. It would be extremely foolish to build from scratch a low-Isp system when the high Isp system already exists IMHO.

[A_M_Swallow]

I'm thinking if this is going to more than a one-off stunt that doesn't go the way of Apollo, they're going to have to go with a reusable lander. At a billion USD a pop, they can't afford to be throwing those things away. That means they'll need an SSTO and refueling. Which also means they're going to need maximum Isp which in turn means LH2/LO2.

Boiloff can be included in the rocket equation by modelling it as a stage with an Isp of 1 and a delta-v that increases with time.

I would say go with something along the lines of the Masten Xeus lander in it's reusable form, which can have a 5 mT payload. Now, the Apollo LEM ascender module massed close to 5 mT, but more than half of that was propellant, so they could probably make a 4-man capsule and keep everything under 5 mT.

{snip}

The MMSEV has a mass of ~5 mT including 2 man crew, consumables and wheels.

[HIP2BSQRE]

Did anyone see this link?  https://twitter.com/ikluft/statuses/190954016082108416

[Ben the Space Brit]

Did anyone see this link?  https://twitter.com/ikluft/statuses/190954016082108416

Does the tweeter in question speak for Masten or Golden Spike? Or is this just someone guessing aloud?

[apace]

Did anyone see this link?  https://twitter.com/ikluft/statuses/190954016082108416

Does the tweeter in question speak for Masten or Golden Spike? Or is this just someone guessing aloud?

Tweet is from 13 Apr 12

[dasmoth]

@GoldenSpikeCo have just changed their Twitter profile pic.  Now a railway track leading towards the moon -- guess logos can't get much more explicit than that!

[HappyMartian]

I've been wondering if their potential landing site is in a polar region. Why? If ice and volatiles are buried at the landing site or the Lander is a single stage, then there could be some of the same issues that were noted here:

"Introduction: It is unsafe or too risky to land human-class landers (>40 MT) on Martian soil without first constructing a mechanically competent surface, a landing pad."

And, "The need for landing pads is the consensus of the plume/soil research community after a decade of concentrated research, including experiments, physics-bases simulations, and mission analysis. This finding has not yet been communicated widely outside the community of researchers because the consensus has been achieved only recently, so both space architects and mission planners may be unaware of the seriousness of the problem."

And, "Prior missons to the Moon and Mars all successfully avoided the worst cratering regimes owing to their smaller size landers and/or environmental conditions where they were landing."

From: PRECURSOR ACTIVITIES TO SOLVE PLUME CRATERING PROBLEMS FOR HUMAN-CLASS MARS LANDERS.   By P. Metzger, P. Hintze and R. Mueller
At: http://www.lpi.usra.edu/meetings/marsconcepts2012/pdf/4359.pdf

[DLR]

That depends on the lander. A horizontal lander like ULA's DTAL or Masten's XEUS, with its main engine in the back, would land on small descent thrusters which wouldn't produce a large plume.

[apace]

That depends on the lander. A horizontal lander like ULA's DTAL or Masten's XEUS, with its main engine in the back, would land on small descent thrusters which wouldn't produce a large plume.

What's the idea of Xeus, where's the payload?

[Robert Thompson]

The payload of Xeus is the idea.

[Ben the Space Brit]

What's the idea of Xeus, where's the payload?

I'm presuming it's a crew lander and would carry the mission cargo (scientific instruments and an Apollo-style 'bed frame' rover) along with its crew.

[apace]

What's the idea of Xeus, where's the payload?

I'm presuming it's a crew lander and would carry the mission cargo (scientific instruments and an Apollo-style 'bed frame' rover) along with its crew.

On top of the Centaur?

[HappyMartian]

That depends on the lander. A horizontal lander like ULA's DTAL or Masten's XEUS, with its main engine in the back, would land on small descent thrusters which wouldn't produce a large plume.

An an open-cab lightweight horizontal Lander might work out. Ice and frozen volatiles do give one pause for thought about the impact results of even small rocket plumes.

A lightweight Skycrane stage landing process might work in polar regions, and then the landed ascent stage is used for the launch from the Lunar surface... Maybe that is too complicated.

Keep the Lander lightweight. Send two Landers, with the one carrying cargo going first, and the second one carrying the astronauts...


Note:

"The final Human Lunar Return study of 1996 was the ultimate cut-rate fasterbettercheaper manned lunar mission - requiring only two shuttle and three Proton launches, and landing two crew at Aristarchus in an open-cab lander. Total cost $2.5 billion; total time to achieve, five years."
From: Human Lunar Return  American manned lunar base. Study 1996.
At: http://www.astronautix.com/craft/humeturn.htm


And:

Comparison of Staging Strategies (assumes mid to high latitude landing) on Page 12 of:
Human Lunar Exploration Mission Architectures  LPI Lunar Knowledge Requirements Workshop    March 1-2, 2004
At: http://www.lpi.usra.edu/lunar_knowledge/connolly.pdf