Courtesy photograph
In Sunnyvale, a Lockheed Martin employee works on one of the 107 by 19 foot solar arrays that astronauts on the space shuttle Endeavour installed at the International Space Station. The arrays willprovide enough solar energy to power the station for 15 years.
Shuttle Endeavour uses Lockheed product
Sunnyvale companies designed and built solar array blankets
By Daniel Hindin
Members of the Space Shuttle Endeavour installed a pair of solar panels, built at Lockheed Martin Space Systems in Sunnyvale, during their mission to the International Space Station (ISS) on Dec. 3.
When fully extended, the solar panels, called solar array blankets, each measure 107 feet by 19 feet.
"The solar arrays will provide power for the space station," says Lockheed spokesman Buddy Nelson. "And to collect a lot of power you need large arrays. The thing that's really special about the arrays is that they're deployable--something that big has to be able to be carried in the shuttle's cargo bay. The blankets are made of a durable plastic that folds along pleats. They fold like accordions, and the cells are so thin that they fit into a blanket box with a depth of only 20 inches."
Lockheed first entered into the $450 million contract with Boeing-Rocketdyne Division to build the solar array blankets in 1988, for delivery to the Boeing Company and NASA. According to Nelson, Boeing chose Lockheed to build the arrays because they conducted an array test as early as 1984, involving similar technology.
"Based on that," Nelson says, "they knew we could do it."
Lockheed touts these arrays as the largest deployable space structures ever built and by far the most powerful electricity-producing arrays ever put into orbit.
"Each solar cell is 3.5 inches square and delivers one watt of electricity," Nelson explains. "On each blanket, there are 16,400 cells."
Lockheed says they will produce a total of eight wings, each consisting of two solar array blankets. Together, the eight wings will accommodate a total of 262,400 solar cells and will encompass 32,528 square feet. They expect the arrays to provide power to the ISS for 15 years.
"It'll look like a bright star," Nelson says. "It won't be quite as bright as Venus, but close. It will be about the same brightness as Sirius, the dog-star."
In fact, the arrays will make the ISS one of the brightest objects in the night sky.
"When the space station passes over the Bay Area--a few times a month--you'll see a bright star-like thing that's moving in the sky," Nelson adds. "It takes it two minutes to get from horizon to horizon."
Lockheed also designed and built rotary joints that, when installed, will slowly rotate the arrays to keep them facing the sun as the ISS orbits every 90 minutes. This optimizes the production of energy.
According to Nelson, the astronauts successfully installed the first array to full extension. Although it began producing energy immediately, it didn't achieve the level of tension they hoped for. As a result, they waited until the next day to deploy the second array, which went off without a glitch.
Nelson reports, "As we speak, NASA is at Lockheed with a set of tools identical to those aboard Endeavour going through potential solutions to the tension problem."
Lockheed expects to install the next pair of arrays in December 2002, another in 2003 and the last in 2006.
Sunnyvale, California Since 1994
