Essential command module design criteria | Command module design | Forum

Post edited 7:09 am – November 20, 2009 by Luke Maurits

The following are essential design criteria for the command module.  Any proposed module shapes, materials, construction technologies, etc. which cannot not be shown by some principled argument or calculation to meet the following criteria are absolute non-starters.

• Ability to withstand high acceleration: The module must be able to withstand the high levels of acceleration involved in launch, reentry, and orbial maneuvers.
• Ability to withstand vacuum: The command module will remain pressurised for the majority of its use.  The pressure difference between the inside and outside of the module while in space will exert a force on the module structure.  The module must be able to withstand this force.
• Ability to withstand micrometeroid impact.
• Radiation shielding: The command module will pass through the Van Allen radiation belt. The level of exposure to radiation that the astronaut receives during this pass must be within reasonable safety limits.
• Heat shielding: The command module will reenter the Earth's atmosphere at significant velocity.  The module must be able to readily withstand the temperatures involved.
• Landing survivability: The command module structure must be strong enough to endure a parachute or rocket decelerated spashdown or ground landing to such an extent that the astronaut's health is not risked *or* the hatch/chair position and stable reentry orientation must be able to facilitate a safe parachute exit by the astronaut.

If anyone can think of other design criteria which are similarly essential and must be kept in mind during all key design decisions, post them in this thread.  Administrators/moderators may add criteria to this list when the new criteria are self-evidently valid or there is a general, informed consensus amongst the community.

Editing post to include something about micrometeroid impact survivability.