Suited for Spacewalking pdf - Virtual Astronaut

Mark C.Lee test flies the Simplified Aid for Extravehicular activity Rescue(SAFER) device during the STS-64 mission.41-B mission. Taking turns, the two astronautsflew the MMU out from the orbiter's payload bayto a distance of about 100 meters and tested complexmaneuvers. On STS-41C, the next Shuttlemission, James Van Hoften and George Nelsonused the MMU to capture the Solar Maximummission satellite and bring it into the orbiter's payloadbay for repairs and servicing. Their workincreased the life span of the satellite. The finalMMU mission was STS-51A that flew inNovember of 1984.The propulsion unit was used toretrieve two communication satellites that did notreach their proper orbit because of faulty propulsionmodules. Joseph Allen and Dale Gardner capturedthe two satellites and brought them into the orbiterpayload bay for stowage and return to Earth.M o re recent experiments with astron a u tm a n e u ve ring units took place on the 1994 STS-64m i s s i on . A new dev i c e, ca lled the Simplified Aidfor Extra vehicular activity Rescue (SAFER) wasf l own by Mark C. Lee and Carl J. Meade a fewmeters away from their orb i t e r. S A F ER is a smallerunit than the MMU and is designed as a selfrescuedevice for use on the Intern a t i onal Sp a c eSt a t i on . Although unlikely, an astronaut couldb e c ome separated from the station during an EVAand a Shuttle not be available to re t ri eve the crewm e m b e r. In that eve n t , the crew member would usethe pro p u l s i ve power of SAFER to re t u rn to thes t a t i on stru c t u re .SAFER fits over the portable life supportsystem of the Shuttle EMU. A control moduleconsisting of a joystick and display is stowed in thebottom of SAFER. During operation, the controlmodule is moved to the suit's front for easy access.With the controls the astronaut can expel nitrogengas through 24 nozzles that are fixed in differentorientations around the device. An autopilot systemis available to keep the astronaut at the same orientationfor a limited period of time. SAFER featuresthe same maneuverability as the MMU but becauseits nitrogen tank only holds 1.4 kilograms of nitrogengas, the total velocity change possible with theunit is 3.05 meters per second.3 6 • Suited for Spacewalking An Activity Guide for Technology Education, Mathematics, and Science, EG- 1 9 9 8 - 0 3 - 1 1 2 - H Q