HOUSTON. -- Atlantis and crew lifted the International Space Station (ISS) into a higher orbit Thursday evening as a prelude to dock with the Russian service module in July.
At about 7:33 p.m. Eastern Daylight Time (23:33 GMT) Atlantis fired 26 pulses of its thrusters during a 54-minute period to gently nudge the station into a higher orbit.
An altitude boost was extremely critical because the station will have to maneuver to dock with the Russian Zvezda service module to be launched in mid July. Mission commander Jim Halsell and pilot Scott "Doc" Horowitz performed the last of three maneuvers that moved the station from about 224 miles (358 kilometers) up to a slightly elliptical orbit with a high point of about 237 miles (379 kilometers) and a low point around 229 miles (368 kilometers).
The station has also been dropping about 1.5 miles (2.4 kilometers) per week due to increased solar activity, which causes Earths atmosphere to expand. This adds more drag on the station, slowing it and causing gravity to pull it toward the planet at an increased rate.
Atlantis mission was also critical to swap out batteries and smoke detectors aboard the station. The reason: Zvezda, originally scheduled to launch in 1998, was slated to have taken over the batteries' duties as they ended their useful lives. It has been repeatedly delayed due to construction issues and Russian launch-vehicle problems.
Zvezda contains the stations living quarters and life-support systems -- without it the station cannot be occupied. Currently, a Russian module called Zarya and a U.S. module, Unity, are in orbit. Construction of the ISS calls for a total of almost 50 flights to the station by the U.S. and Russia before it is complete in 2005.
Station controllers in Moscow declared battery 3 operational after a night of charging. Mission managers were concerned after the battery developed voltage fluctuations and suspected it was not connected properly. According to the Moscow-based controllers, the errant readings may have been due to a communication glitch.
The battery installed Wednesday night will be charged before Atlantis undocking time Friday evening. Astronauts can reenter the station to perform troubleshooting tasks, though controllers expect the battery to charge and perform properly.
Mission Control also reported that the 10 smoke detectors replaced on the station are also functioning normally.
Earlier in the week, Jim Voss and Jeff Williams made a spacewalk to repair a U.S. crane and install a Russian one along with several other tasks.
Atlantis crew also finished moving and arranging the last of the supplies aboard the station. On this trip the crew delivered supplies that include an exercise treadmill, foodstuffs, water and even sewing kits.
"Were bringing up about 3,000 pounds (1,360 kilograms) of equipment and were stowing it all and putting it all into its nooks and crannies," said Mary Ellen Weber from the station Wednesday night. "Its going to be all set for the first crew to get here."
The first resident crew should arrive at the station this fall.
Susan Helms, along with Yuri Usachev and Jim Voss, will make the station their home early in 2001 as the second crew. Helms learned an interesting thing about her future residence.
"What often happens is that as we pass through the tunnels where we dont have any reference to whats up and whats down. As we go from module to module, sometimes you can end up turning about 90 degrees off from where you started," she said. "Then you have a little bit of fun because the module looks differently that you expected."
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