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The following section is based on some forum posts.
The lander is really a combination lunar lander and lunar base station, so there are a lot of components to consider.
- 1. Engine, without which it cannot land
- 2. Lunar Comm (WiFi?) to communicate with the rover
- 3. Earth Comm (10W radio transmitter / receiver + digital [en+de]coder + Ext. Antennae
- 4. Web, Mail, Ftp, Dns server (embedded, running off a flash array)
- 5. Network equipment (e.g. if more than two servers, we need a switch)
- 6. Environmental equipment (heater, cooler, radiator)
- 7. Hull, radiation shielding
- 8. Solar panels (NanoSolar? Probably won't survive the temps).
- 9. Mechanical Solar shade slats (Dan, you had some ideas for this)
- 10. Cargo Hold
- 11. Internal structure to hold all of the above in its proper place.
fjb
some more things we'll need:
- 12. Laser range finder
- 13. batteries for storing solar power
- 14. Star tracker (especially if we used phased array antenna)
- 15. Fuel storage and fuel pumps for lander engine
- 16. Accelerometers
- 17. On board computer or microcontroller for processing accelerometer and laser range finder data and controlling engine valves, servos, etc
im leaving something out but i cant think of it.
ryan
The only way, practical at this point, to land on the Moon is to use a rocket engine - solid fuel, liquid fuel or hybrid, because penetrators are really hard to do (about 2.5 km/s impact velocity), electric propulsion doesn't provide necessary thrust, and other means are even less real.
Consider liquid fuel engines, as an example. There is such a thing as thrust-to-weight ratio, and it goes down with the thrust. In other words, you can have 100 tons thrust engine with weight 1 ton, and TTW ratio of 100, but you can't have 100 kg thrust engine with weight 1 kg, you'll get probably 2 kg, and TTW ratio will be only 50. These are very crude numbers, of course.
You can improve TTW ratio, but at the expense of Isp. These two factors - one is possible TTW you can get, the other- possible Isp you can get - dictate, that the lander mass can't be arbitrarily small. And if you lander weights some 100 units of weight empty, and your payload is only 1 unit of weight, then total mass landing on the Moon is 101 unit. If you double th payload, the total mass becomes 102 unit - about 1% increase. It means, that it may make sense to balance the weight of the lander and weight of the payload - you may not need to make the latter as small as possible, because it won't make it much easier to land, if lander mass is fixed.
So, providing you can make payload small, the question looks like this: what is the smallest lander which you can land on the Moon? Likely the lander will have to brake from at least Moon orbital velocity, about 1700 m/s. How small can be system, which can provide such velocity change? What are the smallest weights of engines, tanks, plumbing like pipes, valves, pressurization gas for such a lander?
Jang
Landing seems easier than I thought.
It seems we can be precise enough to not have to prepare for much hard landing contingency.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660082318_1966082318.pdf
dennisdahl3
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