Developments in Brief : Pioneer 9 Dead After 18 Years in Space

A little 18-year-old satellite called Pioneer 9 has been declared dead after years of highly successful studies of interplanetary space, NASA officials reported last week.

The 148-pound spacecraft’s last radio signal was received in May, 1983. A last-ditch attempt to communicate with Pioneer 9 was made on Tuesday using transmitters and highly sensitive receivers at a National Aeronautics and Space Administration tracking center, according to project manager Richard Fimmel at NASA’s Ames Research Center in Mountain View, Calif.

Eighty command sequences were sent to Pioneer 9, he said. “The result was nothing. On the basis of that and many other attempts, we have decided we can no longer communicate with Pioneer 9.”

“Think of it as having been in a coma,” added NASA spokeswoman Linda Blum. “Now it’s officially dead.”

Pioneer 9, built by TRW Inc. of Redondo Beach, circled the sun 22 times and covered 11 billion miles of space, studying radiation from the sun along with magnetic and electric fields in interplanetary space.

Fimmel explained that Pioneer 9 has not been tracked regularly for years because NASA’s communications antennas are now concentrating on newer and more important missions.

Pioneer 9 was launched from Cape Canaveral, Fla., Nov. 11, 1968. Its solar cells, which degrade over time, apparently weakened to such an extent that they were unable to power the craft’s transmitter.