Columbia is flying smoothly on in an orbit 187 x 176 miles above the
Earth, circling the planet every 90 minutes with its systems operating
in excellent shape.
The next STS-93 status report will be issued at approximately 6
a.m. CDT Saturday.
On Saturday, July 24, 1999, 7:00 a.m. CDT, STS-93 MCC Status Report # 4
With the major objective of their mission successfully completed,
Columbia^“s astronauts spent a busy night conducting a variety of
secondary experiments on both the flight deck and the middeck of the
Commander Eileen Collins, Pilot Jeff Ashby and Mission Specialists
Cady Coleman, Steve Hawley and Michel Tognini worked on experiments
involving everything from astronomy to biomedicine to plant growth as
the shuttle continued to orbit the Earth every 90 minutes in excellent
Hawley, the resident astronomer on board, used the Southwest
Ultraviolet Imaging System, or SWUIS instrument, to collect imagery of
Mercury, Venus, Jupiter and the moon in this, its second flight into
space. Hawley reported that he could not see a new comet called Lynn,
but that the SWUIS may have captured imagery of the comet for
investigators on the ground. The telescopic instrument is mounted on
the side hatch window in the shuttle^“s middeck.
Coleman monitored several plant growth experiments while Tognini
collected data from a biological cell culture experiment. The two
astronauts collaborated on the smooth deployment of the Chandra X-Ray
Chandra is currently orbiting the Earth in a highly elliptical orbit
of about 200 statute miles by 44,000 statute miles, thanks to the
successful firing of its two-stage Inertial Upper Stage booster an
hour after it was spring-ejected from Columbia^“s cargo bay
cradle. The first of five scheduled firings of Chandra^“s thrusters
to refine its orbit is planned for 8:16 p.m. Central time tonight, a
five-minute firing of the telescope^“s liquid-fuel propulsion
system. That maneuver should leave Chandra in an orbit of about 774
statute miles by 44,600 miles. Four additional maneuvers are expected
over the next two weeks.
Collins and Ashby fired Columbia^“s large orbital maneuvering
system engines and primary reaction control system jets on several
occasions to provide data for researchers in a pair of experiments
designed to characterize jet thruster plumes in the space environment.
They also conducted a successful test of a procedure called the
^”flycast^‘ maneuver in a rehearsal for the STS-99 mission in
September, in which a 200-foot mast will be deployed from the cargo
bay of the shuttle Endeavour equipped with a sophisticated radar
system to study Earth^“s topographical features. The maneuver uses
multiple thruster firings and the shuttle^“s autopilot system to
maintain stability. The procedure will be crucial for the September
mission to minimize disturbances to the radar mast.
Coleman also conducted several tests of High Definition Television
equipment carried on board Columbia. HDTV gear is being tested for
future use on both the shuttle and the International Space Station to
conform to evolving broadcasting industry standards for television
The astronauts are scheduled to begin an eight-hour sleep period at
9:31 a.m. Central time this morning and will be awakened at 5:31 this
afternoon to begin their third day in space.
Columbia is currently orbiting at an altitude of 177 statute
miles. The next STS-93 status report will be issued early this evening
after crew wake up or as developments warrant.
Go to STS-93 Flight Day 3 Highlights: