Standardization and high volume production of re-entry capsules. Accommodations on a variety of ELVs to carry standard capsules to orbit. With the possible exception of some space radiation missions, it generally appears that sample return systems currently exist, or will shortly exist, to provide needed capacity for the represented group of payload developers. However, current manifest plans show very few flight opportunities prior to IOC for ISS in 2004-5. No comprehensive systems apparently exist for processing and queuing up GAS, SEM, and other small carrier payloads that can be included as last minute additions to shuttle flights when final weight margins become clear just prior to launch.
Spartan systems appear to have distinct applications for a variety of laboratory science missions.
NASA shuttle and ISS payload project management is not customer driven. Paperwork, long lead times, and overlapping NASA office responsibilities impose a very high overhead on PIs. Only the shuttle, and perhaps the Russian Soyouz, can provide sample fly-back capability from ISS under current plans. ISS with overall 100 m2 size, is projected to require frequent debris collision-avoidance maneuvers at random intervals. Commercial space initiatives appear to be a means for alleviating access to space problems for science communities.