| astronautix.com | Lewis |
Lewis was selected in the NASA SSTI (Small Spacecraft Technology Initiative) program, along with Clark, to demonstrate advanced spacecraft technologies. Contract start was July 11, 1994. Spacecraft: 3-Axis stabilised, zero momentum biased control system with 0.004 deg knowledge. Single solar array generates 600W power at 1 year. Hydrazine propulsion system with eight 1-lbf thrusters. System reliability is 0.86 at 5 years. Ground stations: primary at TRW, Chantilly VA, receive only at Univ. Alaska, Fairbanks, Stennis Space Centre, MS, HBCU network. Data archive by Stennis Space Centre, accessible on Internet, T1 line. Payload: Earth imaging Hyperspectral Imager (HSI) with 384 bands (0.4 - 2.5 �m, 30 m pixels, 7.7 km swath, panchromatic: 0.45 - 0.75 �m, 5 m pixels, 13 km swath). Linear Etalon Imaging Spectral Array (LEISA), from NASA GSFC (1.0 - 2.5 �m, 256 channels, 300 m pixels, 77 km swath). Ultraviolet Cosmic Background (UCB), from UC Berkeley (35 - 85 nm). In addition to the above instruments, several spacecraft systems technologies will be flown. A partial list of planned technology demonstrations is: pulse tube cryocooler, solid state recorder, fibre optic data bus, GPS attitude determination, wide FOV star tracker, magnetically suspended reaction wheel, lightweight structure with integrated thermal control, GFRP overwrapped propellant tank.
Financial/Operational:
Satellite cost was $ 65 million including the TRW hyperspectral sensor. Athena launch cost was $ 17 million. Launch was delayed from the original 1997.05.23 date due to launch vehicle delays. After launch, the satellite was spinning out of control. It lost power due to the solar panels not recharging the batteries. Failed August 25, 1997.
Design Life: 3 years (required life is 1 year). Total Length: 1.8 m. Maximum Diameter: 0.9 m. Electric system: 0.60 total average kW. Electrical System: Solar array.
Lewis was selected in the NASA SSTI (Small Spacecraft Technology Initiative) program, along with Clark, to demonstrate advanced spacecraft technologies.
Reentered Sep 28