spase://SMWG/Observatory/ST5

The Space Technology 5 mission of the American (NASA) New Millennium Program consisted of three microsatellites. They were launched at 14:04 UT on 22 March 2006 by a Pegasus XL rocket that was released from the belly of a Lockheed L-1011 plane flying out of Vandenberg AFB. Each, with a mass of 25 kg and power 20 W, is octagon-shaped (53 cm x 48 cm). Each is called a "full service" satellite, capable of orbit/attitude maneuver and radio links. In all, about 10 innovative, miniaturized technology advances were tested during the 90-day operational span. Among them are variable emittance coatings (to heat when cold and cool when hot), metal oxide logic circuits that can operate at 0.5 volts, miniature magnetometers, and miniature, spinning Sun-sensors. They orbit in a "string of pearls" formation.

  Approximately 10 min after launch, ejected 3 min apart frisbee-style. Mission duration was 90 days, 7 day launch and early orbit period, mission completed June 20, 2006. The orbit was 105.6 deg inclination (full sun orbit), ~300 km perigee, ~4500 km apogee, 136 minute period.
 
 Spacecraft-induced magnetic field effects as measured at the magnetometer

sensor location less than 10 nT (d.c.), 5 nT (a.c.). The spacecraft carried a science demonstration instrument, a high-resolution, high-precission, three-axis flux-gate magnetometer.

  The ST5 constellation returned unprecedented data on the Earth's auroral currents as well as on the crustal magnetic field. ST5 provided for the first time simultaneous multi-point measurements of auroral electric currents at low altitudes, which allow us to separate temporal and spatial variations of these currents. ST5 provided a unique data set on the Earth's crustal magnetic field, which is a consequence of both the constellation flying, and the enhanced resolution from the low perigee, lower than any previous geomagnetism mission.