MISSION CONTROL CENTER STATUS REPORT #9 STS-91 SATURDAY, JUNE 6, 1998 - 6 p.m. CDT Almost two and a half days into their planned four days of joint docked operations, the astronauts and cosmonauts aboard the Discovery-Mir complex are well into their transfer operations as they continue to move experiment hardware, logistical supplies and water between the two vehicles. With most of the Mir resupply items having been moved yesterday, the focus of today's work was on the U.S. and Russian return items. Earlier today, Mission Specialists Wendy Lawrence and Janet Kavandi successfully conducted a checkout of the shuttle's 50-foot-long robot arm to evaluate new electronics and software for use on upcoming assembly missions for the new International Space Station. Today's operations also tested the arm's dexterity to support future requirements in maneuvering around components of an orbiting space station. Mission Specialist Andy Thomas, now less than a week away from ending his four-month trip into space, spent part of his day collecting air and surface samples from the shuttle and the Mir as part of a study of the environment of the Russian complex. Early this afternoon, Lawrence, Kavandi and Thomas joined their colleagues -- STS-91Commander Charlie Precourt, Pilot Dom Gorie and Mission Specialists Franklin Chang-Diaz and Valery Ryumin and Mir 25 Commander Talgat Musabayev and Flight Engineer Nikolai Budarin -- in monitoring a leak test of Mir's depressurized Spektr module. During the test, a tracer gas comprised of acetone and biacetyl was released into the module in an effort to locate precisely a hull breach from last year's collision of a Progress resupply vehicle with the Russian station. Musabayev and the shuttle crew watched through windows at various viewing points on the shuttle and Mir as Budarin released about 14 pounds of the gas through a valve on the modified hatch leading into the Spektr module. The test was set up in the hope that as gas escaped out of the damaged module, the crew would see the colored substance and be able to identify the exact location of the leak source. Following the gas release, the crew aboard the Discovery-Mir complex reported they were unable to see any gas escape out of the Spektr module. Flight controllers were not surprised with the result since both sun and viewing angles to view the suspect damage area were not optimal. The primary purpose of today's exercise was to verify the procedures that will be used on Monday when the gas release test is performed again during Discovery's flyaround of Mir following undocking. The Discovery-Mir complex is orbiting the Earth at an altitude of 207 nautical miles circling the Earth once every 92 minutes. The next STS-91 status report will be issued around 6 a.m. Central time Sunday.