NEWS REPORTS



Douglas Isbell
Headquarters, Washington, DC             August 26, 1997
(Phone:  202/358-1753)

Sally Koris 
TRW Space & Electronics Group, Redondo Beach, CA
(Phone  310/812-4721)

RELEASE:  97-182

LEWIS SPACECRAFT ENCOUNTERS DIFFICULTIES

   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 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.

			-end-