With five times more power than was available just two weeks ago, the Expedition One crew spent the week reconfiguring systems on the International Space Station (ISS) to route electricity being generated from the newly installed U.S. solar arrays on the orbiting complex to the Station’s modules.
Commander Bill Shepherd, Pilot Yuri Gidzenko and Flight Engineer Sergei Krikalev tidied up the ISS after last week’s departure of Endeavour’s astronauts who installed of the huge solar array truss structure on the Station. Around 50 kilowatts of power are being generated by the arrays, which span 240 feet from wing tip to wing tip.
The Expedition crew members worked to transfer electricity to the Zarya and Zvezda modules to augment the power being generated from the solar panels on the two Russian segments and have conducted tests with two radiators which were deployed from the U.S. solar array truss designed to dissipate heat from the truss itself.
Flight controllers in Houston at the Johnson Space Center conducted additional tests with the newly activated S-band communications system and report that the assembly, which is mounted at the top of the solar array truss, is providing 10-15 per cent greater coverage for low data rate telemetry than before Endeavour’s visit.
Engineers reported that the Floating Potential Probe device installed on the array truss has sent data to the ground indicating that the so-called Plasma Contactor Units located on the Station’s Z1 truss are discharging excess electricity from the ISS as it moves through low Earth orbit at a speed of about 5 miles a second.
The Expedition crew is preparing for the arrival of Atlantis in January on the STS-98 mission to deliver the U.S. Laboratory Destiny to the expanding facility. Atlantis may roll out to its launch pad at the Kennedy Space Center as early as this weekend pending a successful analysis of cabling associated with the system which detonates separation bolts on the Shuttle’s Solid Rocket Boosters. The analysis comes in the wake of the failure of one of those bolts to operate properly during Endeavour’s climb to orbit November 30.
Meanwhile, the Expedition crewmembers will spend two extra weeks in orbit due to the delay in the launch of their ride home --- Discovery --- on the STS-102 mission. Originally scheduled for launch on February 15 to bring the Expedition Two crew to the ISS to replace Shepherd, Gidzenko and Krikalev, Discovery is now targeted for launch March 1 due to additional time needed to replace 10 jet thrusters on the orbiter. The Expedition One crewmembers have plenty of supplies on board and the extra two weeks aloft will have no impact on their operations.
U.S. and Russian ISS managers continue discussions regarding the possible redocking of an unmanned Russian Progress resupply vehicle to the Station later this month. The Progress, which delivered food and supplies to the Expedition One crew in November, was undocked on December 1 and placed in a parking orbit several hundred miles away from the ISS. Russian flight controllers are interested in returning the Progress to the ISS to be used as a trash receptacle for the crewmembers prior to the launch of Atlantis to the Station next month. A window of December 24-28 is being discussed for the potential redocking because of good lighting conditions for the operation, which would be conducted by Gidzenko, using a manual navigation system at a control panel inside Zvezda.
The ISS is orbiting at an altitude of 230 statute miles in excellent shape with the Expedition One crew in its 44th day in space and its 42nd day on board the outpost.
A status briefing with Expedition One Lead Flight Director Jeff Hanley to discuss the progress of the mission will be held on Friday, December 15 at 3 p.m. CST (2100 GMT) at the Johnson Space Center and will be broadcast on NASA Television with multi-center question and answer capability. Another status briefing with Hanley will be held next week, on December 21, again at 3 p.m. CST from JSC and will again be broadcast on NASA TV.
The next written status report on the Expedition One crew and the International Space Station will be issued on Thursday, December 21, or earlier, if developments warrant.
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