STRV-1
Space Technology Research Vehicle 1

STRV-1a and -1b are a pair of microsatellites designed to test new space technologies and make measurements of the space environment and its effect on spacecraft systems. The emphasis of the project is on low-cost, short timescale access to space and the rapid dissemination of experimental data. Although built and operated by the UK's Defence Research Agency, many experiments are collaborative, involving the Ballistic Missile Defense Organization, the European Space Agency and Universities. After 2.5 years of operation the spacecraft has been turned over to NASA and the University of Colorado for communications experiments.

Spacecraft
Each spacecraft has a cubic structure based on carbon/PEEK thermosplastic skinned aluminum honeycomb panels. Four GaAs solar panels provide 31-33W (BoL) to a 28V power distribution bus and 16 NiCd batteries. Platform requirements are approximately 19W, leaving 13W for payload operations. On-board data handling uses a GEC Plessey MIL-STD-1750 processor emplying radiation tolerant SOS technology. ESA CCSDS telemetry and telecommand standards are observed. Communications are through the S-band (2.2GHz); 125bps uplink and 1kbps downlink through a 1W omni-direction antenna. Both STRVs are spin-stablised at approximately 5rpm with attitude determination achieved via V-slit Sun and Earth sensors and analogue Sun sensors. Control is through magnetorquers and a cold gas thruster system.

Payload
Both spacecraft carry a variety of space technology and environment experiments. In fact, even the spacecrafts' carbon/PEEK structures are experimental. Specific payloads on -1a are the Atomic Oxygen Experiment, Battery Recharge, Cold Ion Detector, Cosmic Ray & Dosimetry Monitor, Langmuir Probe, Radiation Dose Rate Sensor, Surface Charge Detector and the Xenon Plasma Charge Neutraliser. On-board -1b are the Cryocooler/Vibration Suppression Experiment, Infrared Detectors, Neural Network Microprocessors, Radiation Environment Monitor, Single Event Upset & Radiation Monitor and the Solar Cell Technology Experiment.

Country of Origin	United Kingdom
Customer/User	UK, BMDO
Manufacturer(s)	UK Defence Reseach Agency, JPL
Size	45cm x 45cm x 40cm
Orbit	36,000km x 280km, i=7 deg., elliptical geostationary transfer orbit
Design Life	1 year
Related Sites	STRV-1 Page @ DRA Description of JPL cryocooler

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
STRV 1A	1994-034B	6/17/94	Kourou	Ariane 44LP	HEO	50
45 cm cube; Space Technology and Research Vehicle; included solar cell tests
STRV 1B	1994-034C	6/17/94	Kourou	Ariane 44LP	HEO	53
45 cm cube; Space Technology and Research Vehicle; included solar cell tests