STS-80
Report # 12 
 November 24, 1996 6 p.m. CST 
 
 Columbia's crew enjoyed a half-day off this afternoon as ground
controllers closely monitored the two satellites trailing the shuttle,
evaluating whether one satellite may need to be retrieved tonight, a
day earlier than first planned.

  The crew awakened at 12:56 p.m. CST today to news from Mission
Control that the ORFEUS-SPAS astronomy satellite may be closing in on
the Wake Shield Facility satellite slightly faster than originally
predicted.  The faster closing rate could dictate the need for a
rendezvous and retrieval of the satellite tonight.

  Currently, flight controllers are gathering additional tracking data
on each orbit.  They will decide if the situation requires an early
retrieval of the WSF by about 10 p.m.  If a retrieval is required
tonight, the shuttle would fire its engines at 9:58 p.m., when
Columbia is at a point about 15 nautical miles ahead of the WSF, to
set the stage for a rendezvous.  Then, at about 11:28 p.m., the
shuttle would reach a point about 8 nautical miles behind the WSF, and
it would fire its engines for the terminal initiation burn, setting a
direct course to intercept the satellite. The WSF would be captured
using the mechanical arm at 1:45 a.m. Monday.

  Meanwhile, the WSF already has completed five growths of thin film
semiconductor material, surpassing its major objectives for the
mission.  The satellite has a maximum capacity to grow a total of
seven films, but if it must be picked up by the shuttle tonight, it
may only complete six. Scientists with the satellite say it has
functioned extremely well and are delighted with the results obtained
thus far. If it is not retrieved until tomorrow, seven film growths
are expected to be completed.

  ORFEUS-SPAS continued to perform scientific observations overnight,
although its science work was interrupted for about five hours while
it was put in an orientation that encountered less resistance from the
sparse atmosphere in low orbit, thus slowing the rate it is closing on
the WSF.  At present, the ORFEUS-SPAS is again in a low-resistance
orientation that could temporarily interrupt observations.  This
orientation, or attitude, assists ground controllers with accurately
tracking the spacecraft's trajectory.  The astronomy satellite already
has made more than 100 observations since its release from Columbia
almost five days ago, and it is scheduled to continue flying free from
the shuttle, performing its astronomy work, for another nine days.

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