cheaper lunar landings

[j05h]

I've been pondering the VSE lately, along w/ my usual interests in private space utilization. One thing that has caught my attention lately is Space Adventure's proposed lunar flyby mission. The flyby is priced at $100million and uses a Soyuz and BlockDM upper stage. At the same time, NASA is trying to organize itself to produce the Stick and SDHLV launchers and eventually land on the moon. <br /><br />Starting with Space Adventure's $100mil baseline, how do we go from a very wide lunar flyby into an commercial architecture that can land on Luna? I'm proposing the SA baseline flight with a second Blok DM (add say $50mil) and a custom lander based on Armadillo Aero's tech or similar for the lander. The second Blok DM is used for LLO capture and TEI burn. The Soyuz does direct entry at Earth. The lander could be an open frame, a lander-with-hab or connect to the Soyuz for the decent. Ideally it is reusable to create infrastructure. If the lander can be built and delivered for $100mil, this system could put customers on the moon for around $250million per flight. <br /><br />NASA's proposed $2+billion/flight seems awfully expensive by comparison, even if it places 4 people instead of 3 on the surface.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[barrykirk]

Minor point but Apollo only put 2 people on the moon. They left the 3rd guy in lunar orbit.<br /><br />He drove there, but he never got out of the car.

 

[rogers_buck]

Yeah, but Nasa is going back for him.

 

[rogers_buck]

Good thoughts, but I kind of like the idea of ion propulsion for unmanned lunar missions. That method worked well for the ESAs moon shot. No real hurry to get to the moon and multiple probes could be orbited with one launcher.<br /><br />Now here is a real screwy idea for landing on the moon. Buji jumping. Arrange for a really close approach to the lunar surface much like a fly-by but only a few hundred meters up. Prior to close approach release a "moon anchor" made of a dense alloy with a strong tether that is connected to the probe through a brake - or a long bungi chrod. The "moon anchor" will bury itself in the surface and the attached tether/brake will come under tension. At the point of maximum decel before you are slammed into the lunar surface, cut loose the tether and use braking rockets for a soft landing. Well, its different...

 

[j05h]

>Minor point but Apollo only put 2 people on the moon. They left the 3rd guy in lunar orbit. <br /><br />I was refering to the Soyuz+ arrangement, not Apollo.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[barrykirk]

Didn't realize that.

 

[j05h]

That's OK, maybe I wasn't clear on it. <br /><br />What do you think of the idea of integrating Soyuz with a custom lander? Could it make for affordable, commercial lunar missions? The goal is to find a way to beat NASA and China to the moon via commercial sourcing. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[tap_sa]

Sounds doable. Forget Armadillo though, I'd check Russia they might have some plans and even prototypes left from 60s moonrace. And they definitely have to knowhow to design a new lander, and it might not be prohibitely expensive.<br /><br />Light openframe lander would be coolest to start with, what a ride it would be <img src="/images/icons/smile.gif" />

 

[barrykirk]

I'd take it for a spin, even though I probably wouldn't survive the return re-entry to earth.

 

[formulaterp]

A few points:<br /><br />1) I thought the asking price was $100M per person. So $200M per flight.<br /><br />2) The current booster (BlockDM) can only send the Soyuz on a free return trajectory. Now you want it to send a Soyuz, a second booster, and a lander? I haven't bothered to look up the numbers, but I suspect you're going to need something more powerful.<br /><br />3) Develop a lunar lander for just $100 million? If the operating costs of the current mission are double that, do you really think you the development costs of a brand new lander are going to come in under that? <br /><br />4) Using current assets (Soyuz and Proton) you're going to need a minimum of 3 launches and a rather complex multiple LEO rendezvous.<br /><br />Could it be done? Sure, but it won't be cheap. If I had to just guess at a number, the first flight might cost in excess of $1 billion. If you're very lucky. I just don' think there are too many tourists out there with that kind of disposable income.

 

[rogers_buck]

I thought about lunar bungi landings some more, and I'm jazzed. Imagine a series of tower constructed on the lim of the moon. Sturdy towers a couple hundred meters high with an arrestor cable stretched between them. Spacecraft approach the moon unbreaked and grapple the arrestor wire. They are then slowed and settled to the surface like landing on an aircraft carrier. Wouldn't work for people, but it should be doable for resupply. A lot of energy would have to be gotten rid of, so materials would have to be strong and used in combination with elastic grapling lines.

 

[nexium]

Hi tigerbitten: Using your numbers for an aircraft carrier; 22 meters per second = 100 miles per hour stopping at 50 g average takes 0.044 seconds, and the stopping distance is 50 meters = 160 feet. Stopping distance is somewhat more than 160 feet, but average g is much less than 50 g, for aircraft landing on aircraft carriers. Cargo can possibly be landed at 50g average. Arithmetic error perhaps? A 5 Km "bungie" CNT cord may be reasonable. With an alternator/winch at both ends, most of the kinetic energy could charge batteries, and a constant g would be possible. Neil

 

[scottb50]

Might be an interesting Sport though.<br /><br />What we need is a reliable vehicle, that is based on the moon, to meet incoming cargo and passenger needs in lunar orbit. Using the same vehicles as surface transfer vehicles would also be possible. The same system would would work either at the moon or Mars. <div class="Discussion_UserSignature"> </div>

 

[rogers_buck]

I'm keenly aware of the energies involved. But it is hardly an impossible engineering problem. My over simplistic verbal schematic is just that - a tool to convey the basic components and identify the obvious problems.<br /><br />A grappling hook doesn't have to be a 100lb hook that will cut an arrestor made of CNT, for example. The elastic shock absorbing cable doesn't really have to be a rubber band, it is just there in recognition that there has to be an elastic element to oversome the shock of engaging the arrestor wire. Arrestor wire isn't a tight catch wire like on an aircraft carrier it is simply the main element for transfer of KE from the payload to the surface of the moon.<br /><br />If I had to take a WAG at the engineering that would actually be used, I would think a linear accelerator in reverse would be optimal. A multi-kilo tunnel of superconducting magnets on the dark side of the moon.<br /><br />The lowest tech version of what I'm proposing might actually be to use moon dust. Imagine a streth of primachord several kilo in length running directly beneath the trajectory of the cargo. You blow the primachord and the path of the payload is filled with ultra-fine moon dust. Your payload gets sand blasted, but it also gets slowed down.<br /><br />But I don't think direct mechanical capture would be out of the question either. Buzzing the moon a few meters above the surface is doable because there is no atmosphere on the moon. The earth has its atmosphere for aerobraking, why not an artificial equivalent for the moon? Be it linear accelerators, arrestor wires, or dust, it should be doable.<br />

 

[scottb50]

So, this is sort of a lunar sling shot? The same mechanism snags incoming payloads and also sends them into lunar orbit?<br /><br />This streth of primachord that is several kilo's long might require some more thinking, just my opinion.<br /><br />Absolutely, you could operate in as low an orbit as you wanted to, as long as you took terrain into consideration. The difference is the velocity change in either direction. <div class="Discussion_UserSignature"> </div>

 

[tomnackid]

Actually using a "moon dust landing strip" has been looked into. <br />The landing strip would be a long, shallow trench filled with fine moon dust. The spacecraft's orbit would intersect the moons surface at a shallow angle at the site of the landing strip. Wide skis on the underside of the craft would spread the load and the dust would absorb the impact. More of a "crash with style" than a landing, but the numbers apparently work. <br /><br />You would need a lunar infrastructure in place to prepare the landing strip so it won't work for early mission, though I do remember some proposals for landing spacecraft on the moon in this manner on unprepared surfaces! I think Stephen Baxter landed a Soyuze capsule on the moon in this manner in one of his books.

 

[rogers_buck]

Good point, just like a runway.<br /><br />Moon dust could be handy for soft landings in the absence of any infrastructure. If you had a big scoop on the front of your space craft you could fill it with tons of moon dust and thereby loose your energy. Getting the dust from the surface to directly in front of your spaceship would be the challenge.

 

[rogers_buck]

Interesting. One hell of a sled ride!

 

[scottb50]

Any landing you can walk away from. <div class="Discussion_UserSignature"> </div>