A prettier ISS after the addition of a new segment to provide more power. (NASA photo)
CAPE CANAVERAL, Florida, June 11, 2007 - Satnews Daily - This month will see the International Space Station (ISS) receive more electrical power for future projects and look a whole lot “prettier”.
The U.S. space shuttle Atlantis recently docked with the ISS after a two-day chase carrying with it a new segment for the station that includes a third set of solar arrays to provide more power for additional modules. It was the first space shuttle flight this year. Atlantis was to have originally launched last March but dents to its main booster rocket from a sudden hailstorm caused a two-month delay to ensure the spacecraft’s safety.
Mission STS-117 and its seven astronauts have delivered and will install components to increase the station's electricity generating capability and prepare for the arrival of new laboratory modules from European Space Agency (ESA) and the Japanese Space Agency (JAXA). During its 11-day mission, Atlantis will attach to the ISS a new 35,000 lb. truss segment with a third pair of solar arrays. The $376 million segment will be attached to the station during the first space walk on June 11.
Attaching the new segment, however, will also make the station look “prettier. Mission launch package manager Floyd Booker said that with this flight, NASA hopes to see more symmetry in the station's shape. The ISS now resembles a letter “T.” Adding the new segment will give it the much more pleasant appearance of a letter “H.” The new shape has a practical advantage, however. It will make it easier for the station’s attitude-control system to keep the ISS properly oriented.
Astronauts James Reilly and Danny Olivas are scheduled to make the first of three space walks to add the new segment to the space station. During the first space walk, Reilly and Olivas will connect power cables from the truss and prepare the panels for deployment. The panels when unfurled will stretch 240 feet from tip to tip. It will take two more space walks to prepare the new solar panel to rotate so it can track the Sun as the station orbits. The astronauts will also install an external vent valve for the new oxygen-generating system delivered last July. This will be Reilly’s fourth space walk and Olivas’ first.
Each solar array is 35 meters long and 11.6 meters across. The total span of the arrays is just over 73 meters. The addition of these solar arrays will increase the station’s electricity generating capacity to about 60 kilowatts, enough to power 1,000 average domestic light bulbs. This increase in power generation is essential for the assembly of the ISS. Upon the arrival of Node 2 and Columbus, the ISS needs to be able to supply the additional power required by these two elements and those still to come
The coming STS-120 mission with ESA astronaut Paolo Nespoli, which will carry the Italian-built Node 2 connecting module into orbit, is scheduled to launch on October 20. Flight STS-122, which will carry ESA’s Columbus laboratory, is due for launch on December 6. The crew of the STS-122 mission will include ESA astronauts Hans Schlegel and Leopold Eyharts. Eyharts will fly to the ISS as a member of the Expedition 16 crew during the commissioning of the Columbus laboratory. He will return home with the STS-123 crew two months later.
A close watch is being kept on Atlantis, however, because of damage to a small area in its protective blanket located on a pod of engines near the shuttle's tail. NASA engineers are concerned about the safety margins of a piece of the blanket sticking out during re-entry into Earth's atmosphere when temperatures on the shuttle's heat shield can reach as high as 2,900 degree Fahrenheit. Engineers, however, are confident the loosened blanket was caused by aerodynamic forces during launch, and was not due to the shuttle being hit by a piece of debris during lift off.
