JohnHunt
07-22-2010, 07:58 PM
DATA
ISRO's Manned Lunar Mission (http://indianspaceweb.blogspot.com/2010_02_01_archive.html)
..6,000 kg - Crew Module
25,000 kg - Service Module
17,000 kg - Lunar Descent Module
67,000 kg - Earth Departure Stage
Apollo
14,696 kg - Lunar Module (http://en.wikipedia.org/wiki/Apollo_Lunar_Module) (total)
...-...4,547 kg - Ascent stage
...- 10,149 kg - Descent stage
Command & Service Modules (http://en.wikipedia.org/wiki/Apollo_Command/Service_Module)
...-...5,809 kg - Command module
...- 24,523 kg - Service module
Falcon 9 Heavy (http://www.spacex.com/falcon9_heavy.php)
32,000 kg - Mass to LEO
----------
DISCUSSION
There are a couple of very interesting things about India's proposed manned lunar mission plan. For starters, the Crew (CM) and Service (SM) modules are almost exactly the same size as Apollo's. Strangely the Lunar Module (LM) is about 2,500 kg more massive than Apollo's. (I presume that ISRO's LM includes an ascent stage).
The second interesting thing is that they will be launching not just one really huge rocket but two rockets. They are practically the same rocket with the same components but with different configurations. I think that that is pretty smart. An Ares V-class HLV has (as I understand) little to no commercial value. India's rockets will be pretty large but might be useful in scaled down versions for lifting large GEO sats and so could also be commercially valuable. I personally think that NASA should learn a lesson here.
NOW, here's where things get very interesting. India's EDS masses 67,000 kg which is close enough to what two F9H's could put up. Unfortunately, the remaining mass (CM, SM, & LM) comes to about 1.5 F9H launches. It would be nice if the total launches could be 3 or less.
Might it be possible to design either the CM, SM, or LM so that it stays in space permanently? In particular, if you put the service module in a cycler orbit then you would only need to launch it once. This would save on Earth to LEO fuel and so might be able to get us to just 3 F9H launches.
OK, taking it further. Does the LM really need to be discarded every trip? If it is to rendezvous with a cycling SM then does this mean that it will need to have enough fuel to gain enough delta-v to essentially make it back to Earth? Same for the CM?
If enough ROxygen were to be produced on the lunar surface for all space-based maneuvers then all that would need to be lifted from the Earth's surface would be the capsule and some fuel (not the oxidizer) for space-based maneuvers. How big a rocket would you need for just that? One F9H?
This seems to be too good to be true.
ISRO's Manned Lunar Mission (http://indianspaceweb.blogspot.com/2010_02_01_archive.html)
..6,000 kg - Crew Module
25,000 kg - Service Module
17,000 kg - Lunar Descent Module
67,000 kg - Earth Departure Stage
Apollo
14,696 kg - Lunar Module (http://en.wikipedia.org/wiki/Apollo_Lunar_Module) (total)
...-...4,547 kg - Ascent stage
...- 10,149 kg - Descent stage
Command & Service Modules (http://en.wikipedia.org/wiki/Apollo_Command/Service_Module)
...-...5,809 kg - Command module
...- 24,523 kg - Service module
Falcon 9 Heavy (http://www.spacex.com/falcon9_heavy.php)
32,000 kg - Mass to LEO
----------
DISCUSSION
There are a couple of very interesting things about India's proposed manned lunar mission plan. For starters, the Crew (CM) and Service (SM) modules are almost exactly the same size as Apollo's. Strangely the Lunar Module (LM) is about 2,500 kg more massive than Apollo's. (I presume that ISRO's LM includes an ascent stage).
The second interesting thing is that they will be launching not just one really huge rocket but two rockets. They are practically the same rocket with the same components but with different configurations. I think that that is pretty smart. An Ares V-class HLV has (as I understand) little to no commercial value. India's rockets will be pretty large but might be useful in scaled down versions for lifting large GEO sats and so could also be commercially valuable. I personally think that NASA should learn a lesson here.
NOW, here's where things get very interesting. India's EDS masses 67,000 kg which is close enough to what two F9H's could put up. Unfortunately, the remaining mass (CM, SM, & LM) comes to about 1.5 F9H launches. It would be nice if the total launches could be 3 or less.
Might it be possible to design either the CM, SM, or LM so that it stays in space permanently? In particular, if you put the service module in a cycler orbit then you would only need to launch it once. This would save on Earth to LEO fuel and so might be able to get us to just 3 F9H launches.
OK, taking it further. Does the LM really need to be discarded every trip? If it is to rendezvous with a cycling SM then does this mean that it will need to have enough fuel to gain enough delta-v to essentially make it back to Earth? Same for the CM?
If enough ROxygen were to be produced on the lunar surface for all space-based maneuvers then all that would need to be lifted from the Earth's surface would be the capsule and some fuel (not the oxidizer) for space-based maneuvers. How big a rocket would you need for just that? One F9H?
This seems to be too good to be true.