Surrey Satellite Centre is well known for building mini satellites (100 - 500kg.), microsatellites (10 - 100kg) and nanosatellites (1 - 10kg). Now there are picosatellites that weigh less than 1kg! Find out more about six of our satellites...

Not many people realize there are now over 10,000 objects orbiting our planet.

They are used for looking at the Earth, looking out into space and communicating across the globe.

Some satellites were launched on old ballistic missiles, left over from the Cold War.

Nanosatellites like SNAP-1 are only the size of a football yet they can be monitored and controlled as they orbit 700 km above the Earth.

Mission Control at Surrey Space centre deals with an average of 160 satellite passes every day, each one lasting 10 - 20 minutes.

Because the Earth wobbles as it spins, the position of a satellite will seem to draw out a figure 8 in the sky.

In October 2000 the SNAP-1 nanosatellite used its innovative "machine vision system" of four micro-miniature single-chip video cameras (each smaller than a 2 pence/50 cent piece) to take images of other satellites as it flew past. Satellites can now be robotic 'eyes-in-the-sky' to allow astronauts and ground controllers to examine the outside of their space vehicles. News of SNAP's success is spreading.


Launched on the Ariane in 1990

900 km


Earth Imaging System (EIS)
One imager has a wide field of view with 2km ground resolution; the second narrow field imager provides 200m ground resolution.

Star Sensor
Images the faint light from stars for use as part of the spacecraft's attitude determination system.

GPS Navigation Experiment
The received data is decoded and filtered by the Transputer Data Processing Experiment to provide the satellites' position and velocity as well as an accurate on-board time reference.

Cosmic Ray Experiment (CRE)
The CRE monitors the space radiation environment experienced in orbit by the satellite and enables analysis of its effect on spacecraft semiconductor electronics.

Digital Signal Processing Experiment (DSPE)
The DSPE can be used as a programmable communications modem thus enabling experiments with new modulation techniques.

Messages from Space home | Introducing the satellites