THE PHOBOS LIFE BIOMODULE: A RUGGED, MULTI-SEALED DESIGN FOR SPACE BIOLOGY EXPERIMENTS

摘要

The Planetary Society's Phobos LIFE (Living Interplanetary Flight Experiment) flew in the failed PhobosSample Return mission's sample return capsule. The Phobos LIFE experiment was contained in a speciallydeveloped, incredibly rugged, multiple sealed "biomodule" designed to safely hold a number of biological samples.This 88-gram biomodule can serve future biological space experiments or other applications where ruggedness andreliability are desired. Phobos LIFE was to have been a test of one aspect of the "transpermia" hypothesis: thepossibility that life can move between nearby planets inside rocks ejected into space by impact events. Thebiomodule acted as a simulated meteoroid in deep space for nearly three years and was to have experienced the highradiation and microgravity aspects of that trip, while ensuring separation of microbes and containment of microbeseven under harsh Earth return conditions. The Phobos LIFE "biomodule" consists of a titanium outer shell and useswebs and pockets to provide strength at low mass, and a strong, padded, multiple sealed design to provide structuralintegrity even under accelerations up to 4000 g's. It includes several types of redundant seals, and 31 individualDelrin sample containers. Phobos LIFE contained 10 different types of organisms, representing all three domains oflife, and one soil sample, but choices of materials could vary in future experiments. The LIFE biomodule iscompletely passive, allows sealing of individual sample tubes under Argon or other choices of gases, and canaccommodate passive temperature and radiation sensors. Many tests were carried out on biomodules to validate thedesign and performance. These included vibration tests using a shake table, and impact tests using an air cannonwhich produced impact conditions beyond 4000 g's. In multiple impact tests, no leaks in any seals occurred.