Re: NASA "LSAM" and where's sci.space.xx gone?



Alex Terrell wrote:
It seems like things like this aren't discussed anymore here.

http://www.aiaa-houston.org/cy0607/event-22feb07/Connolly_AIAA_2-20-07.pdf

Has all the serious discussion moved to NASAspaceflight.com?

There is the occasional good discussion here, and lots of nice
irreverence for NASA direction.

Anyway, the LSAM module is overly complex and the ascent module is too
massive. Despite having a design goal to minimise ascent mass they
still have it at over 10 tons, compared to 4.8 tons for Apollo.

I make 4 crew = 400kg, plus structure gives about 2 tons plus fuel
gives about 4 tons. A six ton saving on ascent mass gives about a 40
tons saving in LEO mass.

If you can decrease crew size, you can shrink overall RV capsule diameter by a foot or two, and that equals major savings in heatshield weight.
Even removing one crew member would generate major weight savings throughout the whole mission, when you start figuring out delta-v's for the whole mission.
Less crew space, less weight, less life support, less propellants, less propellant tankage mass, etc.
It's a domino effect.
Once you take a crew member off, things start getting a lot lighter for the whole mission.
Probably on a order of a couple of thousand pounds or more.

Pat
.

Relevant Pages

  • Re: NASA "LSAM" and wheres sci.space.xx gone?
    ... Despite having a design goal to minimise ascent mass they ... still have it at over 10 tons, compared to 4.8 tons for Apollo. ... A six ton saving on ascent mass gives about a 40 ... That's one major advantage the Chinese space program will have over ...
    (sci.space.policy)
  • NASA "LSAM" and wheres sci.space.xx gone?
    ... the LSAM module is overly complex and the ascent module is too ... Despite having a design goal to minimise ascent mass they ... still have it at over 10 tons, compared to 4.8 tons for Apollo. ... A six ton saving on ascent mass gives about a 40 ...
    (sci.space.policy)