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Orbital stations going to 3rd generation. China starting its own program. Russians MIR (world) was flooded in the ocean. Humanity has lived in space for half of century. But there is still no moon base. What is the main problem of moon's base?

My vision of moon's base lay in more logically constructive way than earth's orbit base. There may be placed unbordered number of space modules. Move everything what need to be by some orbital catapult. Thereafter, all of this modules may stay on the moon for ages. No needs in normalization of orbit , no needs in fuel. Just sun batteries and portable nuclear generators.

And no needs to flooded that station as it was with Russians MIR.

What is the principle difference with trip to orbit or trip to moon? The radius of moon is 1.7 thousand meters and the radius of earth is 6 thousand meters. The range from earth to moon is 384.5 thousand meters. And there is no atmosphere in this 384 thousand meters, just little gravity maneuver and earth's force of gravity self move you to the moon.

I'd like to suggest that there is less need for fuel for this maneuver, than to get to the earth orbit, just precision equipment.

Curiosity rover mars.

Need less than order resources for setup the same station without chassis on the moon. There may be 10 such stations with full monitoring of moon.

There are 3 orbital stations, may be one on the moon instead.

Nathan Tuggy
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woodstack
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    Could you possibly clean up your question? It's difficult for me to understand what it is you're asking, especially when your question is written in the form of a poem! – JohnB Jul 23 '13 at 13:32
  • It is not a poem, what exactly do you misunderstood? Two answers at bottom is about theme. – woodstack Jul 23 '13 at 14:34
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    It looks like a poem because each sentence is on a new line and many of them are incomplete sentences. Two people have voted to close as "unclear what you're asking", so it would be a good idea to re-read your question and add some clarity if possible. – JohnB Jul 23 '13 at 14:38
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    Short answer: $. Long answer: $$$$$$$$$. – SF. Jul 23 '13 at 14:41
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    Note also you are using "meters" for radius and distance values where instead you should be using "kilometers" - there's a factor of 1000 in the difference. – FKEinternet Aug 04 '17 at 11:41

2 Answers2

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Distance

The moon is much further away. Just a hair shy of 385000km, versus a peak of about 450km for the planned LEO stations.

Distance within a gravity well is a major issue; the moon is still inside Earth's gravity well, roughly 0.0027 meters per second per second...

This means having to hit a velocity high enough to not stop until gravity of the moon captures it. That means more fuel per unit payload. That means bigger launchers and/or more launches.

The ISS - an LEO Station.

The ISS was assembled from over three dozen missions's efforts; over 2 dozen carried significant superstructure units. It can house at best a dozen people. It's not self sufficient. It is one of the most expensive habitation units ever built by mankind, and per capita, probably the single most expensive.

Oh, and it's about 450 tons. ①

So what portion of LEO mass can we expect for Delivery to the moon?

About 1/10th. Here's the math...

Let's look at the Saturn V. It was capable of delivering 118 tons to LEO, but only 47 tons to translunar orbit insertion (and the payload has to stop itself at the moon, at that).② The Apollo-Saturn missions were essentially 6 stages. The S-1C first stage, the S-II second stage, the S-IVB third stage, the Service Module as 4th stage, and the Lunar module is two (descent and ascent). Each of which is a rocket. Without the SM, figure the SIVB would launch even less to the moon. The actual payload to the moon was the command module and the lunar module; the service module is actually essential rocketry as well as essential support for the CM.

So... let's assume 7500kg the CM mass is the 4th stage to the moon, and calculate the mass to the moon of useful lunar payload.

Loaded Masses: LM Mass: 14,696 kg ③
SM Mass: 24,523 kg ④
CM Mass: 5,806 kg ⑤
Remove: -7500 kg (Fuel, engines on SM, estimate)
Total: 37525 kg to lunar orbit.

The Descent stage is about 10,500 kg ⑥, of that roughly 14,700 LM, or about 71% descent stage. So, using the same ratio upon that 37525... we get about 10700kg to surface... from a Saturn V. About 1/10 the payload to the moon as to LEO

The best current heavy lift launchers only get 23 tons to LEO; the Falcon Heavy is supposed to get 53 tons to leo. ⑦ Which means a mere 5 tons to the moon per launch.

Which means MANY launches to get a useful payload to a lunar base. Even assuming a railgun return launcher, it's going to be an insanely expensive project to build a moonbase with current launcher technology.

Which leads to the other issue. Return Mass. Figure an LM/CM combination unit for every crewing. It's just within reach of the Falcon Heavy... It's 5 tons, and two men, and not happy. And not carrying supplies. That's a second Falcon Heavy.

Conclusions

Without a mega-rocket like the Saturn V, it's just NOT practical to consider a station. And the political considerations of the Carter Administration basically sealed the doom of manned lunar spaceflight.

Note that SpaceX founder Elon Musk has stated categorically his goal is a manned colony on Mars in his lifetime. He's got the money, the brain-power, and the will. And the heaviest working launch vehicle in the approval process. The question becomes, "Can he get a working colonial craft into orbit, equipped, and staffed?" We can expect the Falcon 9 Heavy will not be the final stage in his ultra-heavy lift needs.

References

① http://en.wikipedia.org/wiki/International_Space_Station Wikipedia — International Space Station. Didn't need an exact figure, so Wiki's good enough.

http://www.nasa.gov/mission_pages/station/structure/iss_assembly.html NASA ISS Assembly Missions.

② http://www.astronautix.com/lvs/saturnv.htm#more Encyclopedia Astronautica - Saturn V

LEO Payload: 118,000 kg (260,000 lb) to a 185 km orbit at 28.00 degrees. Payload: 47,000 kg (103,000 lb) to a translunar trajectory. Success Rate: 100.00%. Launch data is: complete. Development Cost $: 7,439.600 million. Launch Price $: 431.000 million in 1967 dollars in 1966 dollars.

③ http://www.astronautix.com/craft/apollolm.htm Encyclopedia Astronautica - Lunar Module

④ http://www.astronautix.com/craft/apollosm.htm Encyclopedia Astronautica - Service Module

⑤ http://www.astronautix.com/craft/apollocm.htm Encyclopedia Astronautica - Command Module

⑥ http://www.braeunig.us/space/specs/lm.htm Lunar Module

⑦ http://www.spacex.com/falcon_heavy.php SpaceX Falcon Heavy page

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aramis
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  • Do you think ratio of placing a ton payload to orbit(450km) vs placing a ton payload to the moon is more than e.g. 1/10? – woodstack Jul 23 '13 at 14:32
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    @woodstack I'm not sure what you're asking. 10:1 is the ratio aramis computed for leo vs lunar surface. Using his numbers the ratio for leo to lunar orbit is 3:1. – Dan Is Fiddling By Firelight Jul 23 '13 at 15:12
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    @woodstack 1/10 is LEO:LunarSurface is the ratio from the apollo program; from LEO to Low Lunar Orbit (LLO) is 7/20 or so. LLO is irrelevant to lunar colonies except as a staging point for the landing phase, tho'. There's nothing useful that can be done in LLO that can't be done in LEO except mapping the moon for exploitation. Any LLO target is either for pure science of the moon, or supporting a landing, and the pure science missions can be done fine with unmanned probes. – aramis Jul 24 '13 at 08:00
  • This doesn't take in to account in situ utilization, which no doubt would improve the numbers a bit. Still... I absolutely agree, LLO is a horrible orbit for a space station... The L4 Earth-moon point might work, but not LLO... – PearsonArtPhoto Jul 27 '13 at 22:30
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MIR: Flooded is the wrong term. It was de-orbited and fell into the ocean. At the time, it was found to be damaged beyond repair. So it was a natural decision for avoiding any future collisions for preventing the generation of more space debris.

The current advantage of Earth's orbit is that you can easily conduct research in microgravity.

The Moon is certainly an interesting place to go, but much further away. It takes a lot more energy to carry any payload or module to the Moon. Compared to that, you first need to go into an orbit around Earth. You then leave this orbit and Earth and Earth's field of gravity (almost) and fly towards the Moon. Then you need to brake again to come into a Lunar orbit. Then you need to brake another time to land in powered flight. It is not about precision really, it is about fuel / energy. The whole process takes a lot. Therefore it is a hell of a lot more expensive.

Building modules and even space ships from Lunar material has been discussed, but it is still a far way to go, both from an engineering point of view and again the required funding - and it would require launching the machinery to do it (more mass to launch from Earth). The necessary materials however do exist on the Moon.

The question is, what you want to do on the Moon. Right now, most interesting is its exploration. On the contrary, it is the wrong place to conduct microgravity research. Microgravity is just interesting to a lot of people right now.

FKEinternet
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s-m-e
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