Aug. 28, 1997 NASA's Earth-orbiting Lewis spacecraft has entered a spin that has disrupted the spacecraft's power-generating capability, raising the potential of the loss of the mission.
Lewis was launched successfully on Aug. 22 at 11:51 p.m. PDT from Vandenberg Air Force Base, CA, aboard a Lockheed Martin Launch Vehicle (LMLV-1). Built by TRW Space & Electronics Group, Redondo Beach, CA, Lewis is part of NASA's Small Spacecraft Technology Initiative.
Initial operations and check-out of Lewis were proceeding satisfactorily until telemetry received at 6 a.m. EDT today (Aug. 26) at the mission's Chantilly, VA, control center indicated that the spacecraft was spinning at approximately two revolutions per minute. Preliminary indications are that excessive thruster firing had occurred on one side of the spacecraft, causing it to spin when it should be stable on all three axes.
The solar arrays on Lewis were unable to generate full power due to the spinning motion, and the batteries were discharged below operational levels. Four subsequent attempts to contact the spacecraft were unsuccessful.
"The excellent performance of the launch vehicle put Lewis into an optimal circular parking orbit that provides us with a minimum of three weeks to try to resolve this anomaly," said Samuel Venneri, Chief Technologist at NASA Headquarters in Washington. "In addition, Lewis carries several autonomous systems onboard that raise the possibility that it can correct itself and recharge the batteries. NASA and TRW are working hard to assess and better understand the situation, in order to establish a recovery plan and try to resume the mission."
Outfitted with advanced technology Earth-imaging instruments and subsystems intended to push the state- of-the-art in scientific and commercial remote sensing, Lewis features remote sensing instruments designed to split up the spectrum of light energy reflected by Earth's land surfaces into as many as 384 distinct bands. Potential commercial applications include pollutant monitoring, analysis of endangered species habitats, estimation of forest and agricultural productivity, soil resources and crop residue mapping, and assessments of environmental impacts from energy pipelines.
The total cost to NASA of the Lewis mission, including its launch vehicle and one year of orbital operations, is $64.8 million. NASA incurred an additional cost of $6.2 million for storage and maintenance of the spacecraft during a one-year delay due to launch vehicle issues.
Lewis is part of NASA's Mission to Planet Earth enterprise, a long-term research program designed to study the Earth's land, oceans, air and life as a total system.
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