Commander Jim Halsell and pilot Scott Horowitz fired Atlantis' steering jets 27 times during almost an hour Tuesday evening to gently lift the 35-ton outpost about 10 miles higher. The same process will be repeated again tonight and on Thursday to boost the station by about 27 miles in total and leave it in an orbit with an average height of about 233 miles when Atlantis departs on Friday.
As has been the case through much of the mission, the crew completed most jobs ahead of schedule. Inside the Zarya module, Astronaut Susan Helms and Cosmonaut Yury Usachev completed the installation of a third fresh battery for the station. A fourth battery will be installed tonight. Meanwhile, station controllers in Moscow completed charging the first of two batteries installed in Zarya yesterday, and it is now operating perfectly. Controllers are charging the second new battery installed in the station, although the charging of that battery was interrupted briefly early this morning by an unforeseen conflict that prevents conducting charging and battery installation work simultaneously. The interruption halted the battery charging for about an hour and a half, but the process is now again under way with no problems. Controllers are confident the new battery is in good condition and are revising plans to ensure no similar conflict occurs as the crew is installing the final new battery tonight.
The crew also installed 10 new smoke detectors in Zarya, replacing detectors that had reached the end of the lifetime for which they were designed to operate. The astronauts replaced four cooling fans in Zarya for the same reason. In addition, they completed the installation of new cabling for the module's central computer that will allow that computer to be turned on and off via a United States-built backup station communications system. As the installation work progressed, the crew continued transferring items ranging from exercise equipment to computer printers to the station for use by future crews. Well over 1,200 pounds of gear have been moved from Atlantis to the station thus far.
Tonight, Helms and Usachev will install the final new battery in the station. Later, Halsell and Horowitz will fire Atlantis' jets to perform the second part of the three-part station reboost. Then the crew's attention will turn to unloading various supplies from Atlantis and stowing them aboard the station. The crew will take a short break from their work at 10:21 p.m. CDT for an interview with ABC radio news; KOIN-TV of Portland, OR; and a Department of Housing and Urban Development educational group.
Atlantis and the International Space Station are in an orbit with a high point of 219 miles and a low point of 212 miles, circling Earth every 91 minutes.