Astronauts train with space station solar arrays
LOCKHEED MARTIN NEWS RELEASE
Posted: March 30, 2002

A group of 16 NASA astronauts, who will be flying to the International Space Station (ISS) in the next few years to install the remaining Lockheed Martin-built solar arrays, visited the Company's facility in Sunnyvale on Thursday. The visit allowed them the opportunity to observe at first hand the deployment of a massive solar array blanket, 107 feet long and 14 feet wide, and to carefully examine the intricate mechanisms with which they will be working on their visits to the Space Station.

In addition, the astronauts and their Extravehicular Activity (EVA) ground support team members, from the NASA Johnson Space Center in Houston, were able to consult with the Lockheed Martin Space Systems engineers and technicians who built and tested the solar arrays. NASA believes it important that astronauts and support teams have direct hands-on experience with the hardware that they will be taking into space.

Astronauts
The astronauts pose for a picture in front of a solar wing. Photo: NASA
 
The first of four pairs of massive solar arrays for the International Space Station, built at Lockheed Martin Space Systems in Sunnyvale, were launched aboard the space shuttle Endeavour to the International Space Station on Nov. 30, 2000. During a 12-day mission, astronauts connected the package of giant solar arrays and associated electronics, batteries, radiators, and support structure to the Station. Subsequent pairs of arrays, already delivered to NASA, will be carried on shuttle flights currently scheduled for 2003, 2004, and 2006.

The Space Systems ISS solar arrays are the largest deployable space structure ever built and will be by far, the most powerful electricity-producing arrays ever put into orbit. When the Station is completed a total of eight flexible, deployable solar array wings will generate the reliable, continuous power for the on-orbit operation of the ISS systems. The eight array wings were designed and built under a $450 million contract from the Boeing-Rocketdyne Division in Canoga Park, Calif., for delivery to the Boeing Company and NASA.

Each of the eight wings consists of a mast assembly and two solar array blankets. Each blanket has 84 panels, of which 82 are populated with solar cells. Each panel contains 200 solar cells. The eight photovoltaic arrays thus accommodate a total of 262,400 solar cells. When fully deployed in space, the active area of the eight wings, each 107 by 38-feet, will encompass an area of 32,528-sq. ft., and will provide power to the ISS for 15 years.

In addition to the arrays, Space Systems in Sunnyvale has also designed and built other elements for the Space Station that will be launched on future shuttle missions. Rotary mechanical joints for the ISS will move the solar arrays and thermal radiators into positions relative to the Sun that will optimize their individual functions. These mechanical joints are the largest mechanisms ever designed to operate in a space environment.

The two Solar Alpha Rotary Joints (SARJ) are each 10.5 ft diameter and 40 inches long. Their purpose is to maintain the solar arrays in an optimal orientation to the Sun while the entire Space Station orbits the Earth once every 90 minutes. Drive motors in each SARJ will move the arrays through 360 degrees of motion at four degrees per minute.

The Thermal Radiator Rotary Joints (TRRJ) are each five and a half feet long and three feet in diameter. Their purpose is to maintain the Space Station thermal radiators in an edge-on orientation to the sun that maximizes the dissipation of heat from the radiators.

Space Systems has also produced the Trace Contaminant Control System (TCCS). The TCCS is an integral part of the Space Station's Cabin Air Revitalization Subsystem (ARS). It is designed to ensure that the levels of airborne contaminants in the Space Station Laboratory and Habitation modules are safe for manned flight. The Space Station environment will be maintained at a level far cleaner than that in a modern office building. There will be TCCS units installed aboard equipment racks in two modules in the Space Station. The first was launched with the Destiny Laboratory Module in 2001. A second TCCS will be installed in U.S. Node 3, currently targeted for launch in 2005.

Lockheed Martin Space Systems Company is one of the major operating units of Lockheed Martin Corporation. Space Systems designs, develops, tests, manufactures, and operates a variety of advanced technology systems for military, civil and commercial customers. Chief products include a full-range of space launch systems, including heavy-lift capability, ground systems, remote sensing and communications satellites for commercial and government customers, advanced space observatories and interplanetary spacecraft, fleet ballistic missiles and missile defense systems.

Headquartered in Bethesda, Md., Lockheed Martin is a global enterprise principally engaged in the research, design, development, manufacture, and integration of advanced-technology systems, products, and services. The Corporation's core businesses are systems integration, space, aeronautics, and technology services. Employing more than 125,000 people worldwide, Lockheed Martin had 2001 sales surpassing $24 billion.