MISSION CONTROL CENTER
STS-63 Status Report #5


Sunday, February 5, 1995, 10 a.m. CST

Flight control teams in Houston and Kaliningrad, Russia, are busy 
putting the final touches on plans for Monday's rendezvous of the Space 
Shuttle Discovery and the Space Station Mir.

Discovery is expected to catch up with the Russian space station Monday 
morning, but mission managers are still discussing how close the orbiter 
will come to the Mir. The original plan calls for Discovery to come 
within 33 feet of the Mir complex, but because of a leaking steering 
thruster, controllers also are looking at back-up plans for having the 
shuttle fly around Mir at a distance of 400 feet. Mission managers in 
both countries are continuing to work toward a consensus.

In an attempt to stop the leak, Commander Jim Wetherbee and Pilot Eileen 
Collins closed and reopened the manifold of the leaky thruster several 
times. The same procedure was used to clear a leak in a thruster on the 
nose of the orbiter earlier in the day, but the procedure was not as 
successful for this one. The crew will attempt to stop the leak one more 
time later today. 

Meanwhile in the Spacehab module, activities with its 20 experiments are 
progressing smoothly.  Among those activities, crew members tested a 
small robot called Charlotte. Designed by McDonnell Douglas Aerospace, 
Charlotte is designed to service other experiments in the absence of the 
crew. The robot moves along cables and has the capability to change 
experiment samples and perform many routine procedures.
 
The crew also activated an experiment that studies how materials burn in 
weightlessness. In this instance, the Solid Surface Combustion 
Experiment is examining how Plexiglas burns.

Discovery, which is in a 200 by 182 nautical mile orbit, is less than 
2,000 nautical miles behind Mir and is closing that distance by about 
190 nautical miles per orbit.