FAST
Fast Auroral Snapshot Explorer
Part of the Small Explorer (SMEX) program

FAST will observe and measure rapidly varying electric and magnetic fields and the flow of electrons and ions above the aurora. FAST will correlate measurements of electrical and magnetic fields from other sensors and simultaneously correlate these forces with their effects on electrons and ions at altitudes of 350 to 4200 km. These observations will be complemented by data from other spacecraft at higher altitudes, which will be observing fields and particles and photographing the aurora from above, thus placing FAST observations in global context. At the same time, auroral observatories and geomagnetic stations on the ground will provide measurements on how the energetic processes FAST observes affect the Earth. Although prepared for mid-1994 launch date, FAST was placed into storage until a series of problems with the Pegasus launch vehicle could be corrected. The vehicle was finally placed into orbit on Aug 21, 1996.

Spacecraft
Spin stabilized (12 rpm) keeping spin axis aligned with orbit-normal. Body mounted GaAs solar cells. Aluminum structure. Dual 80C85 rad hard processors. S-Band transponder for command and telemetry. Passive thermal control.

Payload
Electric Field Experiment uses 3 orthoganal boom pairs to measure plasma density and electron temperature. Magnetic Field Experiment has 2 magnetometers 180 deg apart deployed on graphite booms. Time-of-Flight Energy Angle Mass Spectrograph (TEAMS) is a mass-resolving spectrometer designed to measure 3-dimension distribution functions of major ion species. Sixteen Electrostatic Analyzers (ESA) are used for electron and ion measurements from 3 eV to 30 KeV.

Country of Origin	United States
Customer/User	NASA, GSFC
Manufacturer(s)	NASA Goddard Space Flight Center
Size	1.2 m dia x 1.8 meter cylinder
Orbit	350 x 4200 km, 83 deg inclination
Design Life	1 year

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
FAST	1996-049A	8/21/96	WSMC	Pegasus XL	LEO	187
Fast Auroral Snapshot Explorer; investigated auroral phenomena