STS-88 MISSION CONTROL CENTER STATUS REPORT #23 
Sunday, December 13, 1998, 11 p.m. CST

  Endeavour's astronauts bid farewell to the International Space
Station this afternoon, undocking from the new complex which will fly
unpiloted for the next five months until the next shuttle assembly
flight in May 1999.

  Pilot Rick Sturckow separated Endeavour from the station at 2:25
p.m. Central time, firing the shuttle's jets to place the orbiter 450
feet above the outpost. Sturckow then initiated a nose-forward
flyaround of the station as shuttle TV cameras captured spectacular
views of the two station modules framed against the blue backdrop of
the Earth.

  Less than an hour and a half after undocking, at 3:49 p.m., Sturckow
fired Endeavour's jets one final time as the orbiter passed 450 feet
below the complex, separating for the final time as the station faded
from view along the horizon. More than six hours after undocking,
Endeavour trailed ISS by some 70 s.m., increasing its distance from
the station at about 19 s.m. every orbit.

  International Space Station flight controllers at Mission Control,
Houston and at the Russian Mission Control Center in Korolev, outside
Moscow, will now spend the next five months monitoring the station's
systems and awaiting the launch of Discovery on the STS-96
mission. STS-96 will see a multinational crew of seven astronauts
return to the station in a logistics resupply flight which will
include at least one spacewalk to attach additional hardware to the
new orbiting facility.

  Late Sunday, flight controllers commanded the station into a new
orientation to point the Zarya Control Module toward deep space and
the Unity Module toward the Earth. Commands were then sent to place
the station into a slow spin of about one revolution every 30 minutes
to keep the station within proper thermal conditions as it orbits the
Earth. Zarya's motion control system will be reactivated about once a
week over the next few months to insure it is working properly and its
guidance system will be updated with the latest orbital parameters.

  Before beginning their presleep period, the astronauts deployed a
small 590-pound satellite called SAC-A for the Argentinean National
Committee of Space Activities.  Equipped with five technology
experiments, including one to track the movement of whales off the
coast of Argentina, SAC-A was ejected from a canister in Endeavour's
cargo bay at 10:31 p.m. Central time as the shuttle few over the
northern Indian Ocean. The satellite is expected to remain in orbit
from five to nine months sending back data to Argentine researchers
back on Earth.

  The astronauts will begin an eight-hour sleep period at 3:36
a.m. Central time Monday and will be awakened at 11:36 a.m. to begin
preparations for their scheduled landing at the Kennedy Space Center
Tuesday night. On Monday, the astronauts will conduct the routine
pre-landing check of Endeavour's flight control surfaces and steering
jets to insure that the shuttle is ready for its high-speed reentry
back to Earth.

  Endeavour and the International Space Station are currently orbiting
the Earth at an altitude of 246 statute miles with all of their
systems operating normally.

  The next STS-88 mission status report will be issued Monday after the
astronauts are awakened.