Stephenson_2012

Copyright © 2012 by Gary V. Stephenson. Published by The Mars Society with permission.

HUMAN RATING REQUIREMENTS FOR MARS MISSIONS

Gary V. Stephenson

Linquest Corporation, Los Angeles, CA

425-443-8651, gary.stephenson@linquest.com

ABSTRACT

Human rating requirements are explored for space systems associated with the transport of a human crew for missions to and from Mars. Human rating certification requirements guidance is given by NPR 8705.2B and broadly speaking consists of four steps: step 1, comply with human rating certification processes; step 2, develop and comply with a reference mission; step 3, comply with human rating technical requirements; and step 4, prepare and maintain a Human Rating Certification Package (HRCP) that demonstrates compliance with the first three steps.

The design challenges specific to a Missions to Mars (M2M) are described and include long endurance human habitation during interplanetary (IP) space travel, with higher than usual radiation exposure and lower than usual gravitation exposure, crew control requirements with expanded need for autonomous operations and control and operator situational awareness, and contingency operations for survivability. Due to the extreme physical isolation of the crew during missions to Mars there will be the need to trade lifeboat options with in situ survivability options in the case of contingency operations.

These human rating challenges are placed in the context of the design development of mission equipment needed for a Mission to Mars. It is assumed that the M2M equipment suite can be divided into four distinct systems, all of which will require human rating: a launch and LEO operations vehicle, a transhab vehicle for IP travel, a Martian orbital operations vehicle, and a Martian surface habitat. A methodology for flowing human rating requirements to each of these systems is identified and outlined.

KEYWORDS: Human, Rating, Requirements, Certification, NASA, Standards.