[FPSPACE] Circumlunar issues

[DSFPortree at aol.com]

A few thoughts off the top of my head. Some of these may be non-issues - I 
don't know. Perhaps Chris or David can say something about these?

Radiation - A modest problem during a brief circumlunar flight, unless you 
get solar activity.  Is Soyuz beefy enough to ward off radiation in its current 
space station ferry form, or does it need augmentation?

Orientation/navigation - Soyuz uses Earth as a navigational reference. 
Presumably, if Earth is not available, then a new navigational system will be 
required.

Electrical power - do the Soyuz arrays require augmentation to support the 
"Logistics Module" proposed in the CSI scheme? In the (vague) November 2004 MIT 
presentation the logistic module seems to include no power supply of its own.

Heatshield - Obviously the current heatshield can't handle lunar return 
speed. Related issue - reentry profile. Are you planning to do a skip, or 
ballistic, or something else? Can the current Soyuz Descent Module handle a worst-case 
ballistic reentry from the moon?

Couches - are the Soyuz DM couches adequate for a worst-case ballistic 
reentry from the moon?

Main engine - Is the current propulsion system adequate? Is it rated to do 
the number/duration of maneuvers required?

Balance - There's probably a better word for this, but I'm drawing a blank. 
How will the Soyuz "handle" if it has bigger solar arrays, a more massive 
heatshield, the Logistics Module, and other modifications which change its center 
of gravity? Will thrusters have to be added/re-located? How will the main 
engine handle the changed CG?

Redundancy - Does Soyuz have enough backup capability for a flight lasting 
~three times longer than a flight to ISS?

Thermal - the thermal environment in cislunar space is not the same as in 
LEO. It'll be generally colder in between the Earth and moon and hotter near the 
moon. Can Soyuz systems handle that?

David

David S. F. Portree
Science writer & historian
dsfportree at aol.com
Flagstaff Arizona USA

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