2 p.m. CST, Thursday, December 9, 1999

Mission Control Center, Houston, Texas

The International Space Station’s first two components are in good shape with only minor issues facing the
flight control teams in Houston and Moscow – none of which affect the operation of the complex. Since
raising the altitude of the Station last week, controllers continue to manage electrical power generated by
the Zarya module.

A Zarya software patch was uplinked yesterday from Russia’s Mission Control Center. This update allows 68
additional electrical power system parameters to be sent to the ground via Unity’s early communications
system. This data now can be viewed more frequently using NASA’s Tracking and Data Relay Satellite

Late last week, Zarya’s automatic docking system, called KURS, was tested and showed discrepancies in its
alternate system’s relative velocity readings seen on the ground. Russian flight controllers plan to re-run the
test in an attempt to determine if ‘noisy’ interference from the Station’s other systems is the culprit. KURS is
used during the final rendezvous and docking of the ISS with the Zvezda service module.

After operating without problem for a week and a half, battery 1 telemetry showed the unit no longer
discharging properly as designed and it was removed from the electrical bus of the Zarya module. Four
batteries remain available for electrical power to Station systems.

Battery “capacity restoration” is continuing with battery 4 completing its deep discharge yesterday. The
remaining batteries will undergo the same procedure over the course of the next three to four weeks.
Capacity restoration is a procedure conducted on each battery every six months to maximize the useful life
of the batteries. Batteries 1 and 2 remain disconnected from the electrical bus.

Meanwhile, at the Baikonur Cosmodrome in Kazakhstan, Zvezda is undergoing final testing and is basically
ready for launch. While awaiting the recommendations of the investigation team on the recent Proton failure,
Zvezda will undergo some repeat testing on equipment with the time available.

Station managers will travel to Moscow in late January for the next General Designers Review and Joint
Program Review to assess the readiness of the module for flight. The meeting also will determine the most
probable launch date based on the recommendations of the Proton rocket failure investigation team. Its
report to the Russian Aviation and Space Agency is due later this month.

Zvezda, the Russian word for Star, will serve as the early living quarters for crews housed on the station
when the Shuttle is not present. It also will provide life support functions, and command and control
capability for the complex.

The International Space Station continues to operate in excellent shape as it orbits the Earth at an altitude
of 245 by 236 statute miles. Since the launch of Zarya in November 1998, the ISS has completed more
than 5,995 orbits. Space Station viewing opportunities worldwide are available on the Internet at:


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,