Search and Rescue

Commercial search and rescue missions to retrieve and repair valuable satellites may become commonplace in the twenty-first century. Telecommunications companies and other businesses typically spend between $50 million and $300 million to manufacture and launch a new satellite. If all goes well, the spacecraft may function reliably for ten to twenty years. In the harsh environment of space, however, satellites may fail prematurely because of mechanical breakdowns, damage from solar flares , or collisions with orbiting debris. Companies may reduce their economic losses from such perils by salvaging damaged or obsolete satellites at a cost lower than what they would pay for replacement spacecraft.

The National Aeronautics and Space Administration (NASA) successfully performed the first satellite search and rescue missions in 1984. In April of that year, astronauts on the space shuttle Challenger rendezvoused with the Solar Maximum satellite, walked in space, and replaced electronics and other parts on the damaged spacecraft. They then released it back into orbit to continue its scientific mission of solar flare observations. Six months later, the crew of the space shuttle Discovery captured two commercial communications satellites and stowed them in the shuttle's cargo bay for return to Earth. Equipment malfunctions in February 1984 had left these satellites, the American Westar-6 and the Indonesian Palapa-B2, in improper orbits. Technicians on the ground repaired both satellites and successfully launched them back into orbit in April 1990.

NASA reconsidered astronaut safety after the Challenger explosion on January 28, 1986. The agency decided to reduce the risk to astronauts by restricting most shuttle operations to scientific or military missions that required a human presence in space. In the fourteen-year period following the Challenger disaster, NASA rescued only one more commercial satellite, the International Telecommunication Satellite Organization's Intelsat VI F-3.

Despite NASA's successes, satellite salvage is not one of its primary missions. Furthermore, NASA does not have enough shuttles to meet the growing demand for search and rescue operations. The revenues generated by space commerce exceeded government expenditures for space exploration for the first time in 1996. Rapid growth of global telecommunications swelled space business revenues to about $80 billion by 2000, more than five times NASA's annual budget. That same year, about 200 commercial satellites were insured for more than $16 billion, and industry analysts predicted that space commerce would grow steadily, with about seventy new satellites launched annually.

Satellite owners and insurance companies are therefore motivated to find new and creative ways to safeguard their business assets. In 1998, for example, insurers declared a loss on the HGS-1 Asian television satellite, which had been stranded in a useless orbit after launch. Later, engineers at the Hughes Space and Communications Company found a way to boost the satellite on two looping orbits around the Moon, finally placing it in a useful parking orbit around Earth.

Because commercial salvage may be a profitable venture, several startup space businesses began offering new products and services to satellite owners by 1999. To be successful, however, these companies must find inexpensive solutions to the difficult challenge of search and rescue operations in space. For example, one company developed a wire tether that may be attached to a satellite prior to launch. If the tether is later extended in space like an antenna, an electric current will be generated as it passes through the Earth's magnetic field, and enough power may be produced to operate the spacecraft or to change its orbit. A valuable satellite that is stranded in space, or at risk of burning up in a premature reentry into Earth's atmosphere, may yet be saved by this simple and elegant solution.

see also Satellites, Types of (volume 1); Servicing and Repair (volume 1); Tethers (volume 4).

David A. Medek

Bibliography

American Institute of Aeronautics and Astronautics. "Space Commercialization: AnAIAA Position Paper Prepared by the Public Policy Committee." Reston, VA: Author, 1996.

Forward, Robert L., and Robert P. Hoyt. "Space Tethers." Scientific American 280, no. 2 (February 1999):86-87.

Lee, Wayne. To Rise from Earth: An Easy-to-Understand Guide to Spaceflight. New York:Facts on File, 1995.

Sellers, Jerry Jon. Understanding Space: An Introduction to Astronautics. New York: McGraw-Hill, 1994.