ISS Status Report #99-47
2 p.m. CST, Thursday, December 2, 1999
Mission Control Center, Houston, Texas
The International Space Station’s altitude was raised by an average of 10 statute miles yesterday following
two thruster firings using jets on the Zarya module. The result of the orbit-raising burns placed the station in
a 245 by 238 statute mile orbit in preparation for the arrival of the Zvezda service module early next year.
The altitude protects rendezvous options with Zvezda, which will rendezvous with the ISS and then become
the passive vehicle while the ISS is ground-commanded to remotely dock with Zvezda.
Zvezda’s date for launch atop a Proton rocket remains uncertain until an investigation into the most recent
failure of a Proton is completed, and until station managers conclude a General Design Review meeting in
Moscow, scheduled for later this month or January.
Flight controllers in Moscow elected to return battery number one to the set of batteries available for
electrical usage in an effort to evaluate its health. The battery had been offline for some time when
problems were noted in its ability to charge and discharge properly.
Once brought online Sunday, the battery performed normally and has been in use since that time with no
problems seen to date. Battery number two remains disconnected from the electrical bus, leaving five
operational batteries at this time (a minimum of three are needed for adequate electrical power).
Complete battery ‘restoration’ – a procedure conducted on each battery every six months – is expected to
begin tomorrow with battery number four. The process for each battery takes about 5-7 days and is
designed to maximize the useful life of the batteries.
The orbit-raising burns yesterday occurred about 45 minutes apart with the first occurring at 4:57 p.m.
Central time. That burn lasted 27 seconds and changed the velocity of the station by 5.4 meters per second
(12 miles per hour). The second burn, designed to nearly circularize the orbit, occurred at 5:45 p.m. Central
time and lasted 23 seconds. The second burn changed the velocity of the ISS by 4.7 m/s (10 mph).
The complex continues to operate in excellent shape as it orbits the Earth once every 92 minutes. Since the
launch of Zarya a year ago Nov. 20, the ISS has completed more than 5,904 orbits. Space Station viewing
opportunities worldwide are available on the Internet at:
http://spaceflight.nasa.gov/realdata/sightings/
The next International Space Station status report will be issued Thursday, December 16. For further
information, please contact the NASA Public Affairs Office at the Johnson Space Center, Houston, Texas,
281-483-5111.
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