Meteor Storms

Satellites to be "Sandblasted" by Leonid Storm
The Aerospace Corporation, El Segundo, California
June 8, 1998

Dr. William H. "Bill" Ailor of The Aerospace Corporation told a congressional subcommittee in Washington May 21 that the estimated 500 satellites on orbit "will be sandblasted" by the Leonid meteoroid storm due November 17. But he said the effects on spacecraft are expected to be minimal, despite the fact the storm "will be the largest such threat ever experienced by our critical orbiting satellite constellations." Ailor, director of the Center for Orbital and Reentry Debris Studies established last year at The Aerospace Corporation, presented his testimony during a hearing titled "Asteroids: Perils and Opportunities." He was invited to appear before the Subcommittee on Space and Aeronautics, a panel of the House Committee on Science, by U.S. Rep. Dana Rohrabacher (R-Calif.), subcommittee chair.

"It is possible," Ailor told the subcommittee, "that some satellites will be damaged, but the most likely source of damage will not be from a rock blasting a hole in a satellite, but rather, from the creation of a plasma, or free electric charge on the spacecraft. The charge could cause damage to computers and other sensitive electronic circuits on board the spacecraft, and ultimately cause the spacecraft to fail. For example," Ailor said, "during the 1993 Perseid meteor shower, it was determined that the Olympus communications satellite was damaged by a meteor strike and went off the air shortly thereafter as a result of an electrical failure." Ailor pointed out that, "The latest information on the coming Leonid meteoroid storm was presented at the Leonid Meteoroid Storm and Satellite Threat Conference sponsored by Aerospace and the American Institute of Aeronautics and Astronautics in Manhattan Beach, California, on April 27 and 28.

"The primary recommendations from the conference," Ailor reported, "were that, while it is very unlikely that the storm will have any major effect on satellites, the 'A-team' of controllers should be on duty during the ... storm, and operators should check the state of health of their satellites frequently, looking primarily for electrical anomalies and glitches. It was also recommended that, if possible, satellites be oriented so that sensitive components are shielded from the oncoming stream of particles, and that recovery plans be in place should there be a spacecraft system failure during the storm." Ailor said Aerospace collected information on spacecraft anomalies experienced during the 1997 Leonid shower and will be collecting similar information for the 1998 and 1999 events. "This information will help us plan for the 1999 Leonid and future meteoroid storms. It may also help us to understand whether additional safeguards against the meteoroid impact threat should be included in future spacecraft designs," Ailor said.