Micro valves key to miniature satellite propulsion system
The UK's thriving space sector is exemplified by companies such as SSTL (Surrey Satellite Technology Ltd) and the Surrey Space Centre. An interesting project here is the PalmSat Pico-satellite, one of a number of developments in small satellites that aim to reduce weight and ticket price without compromising on capability.
PalmSat applies a COTS design philosophy and is intended for missions where the satellites are launched en-masse and are deployed in a swarm, for example for multipoint sensing for Earth observation or space science. Such missions require cooperation between the vehicles, so technologies such as inter-satellite linking will be essential.
Another key aspect of the design is the propulsion system. An earlier design used small solenoid valves to vent butane as a propellant. For PalmSat, engineers turned to Lee Products, which recommended the EPSV (Extended Performance Solenoid Valve) which is 6mm in diameter and 33mm long, has a mass of less than 6g, and an average draw power of 0.75W. This solenoid valve forms the basis of an ultra-miniature propulsion system, based on water as a propellant. Just 8g of water would give PalmSat around 3m/sec delta-vee.
A feature of the valves is their long inlet and outlet pipes, enabling them to be welded into position for ultimate reliability. Other features include a fast operating speed of up to 500Hz, suitability for use at high temperatures and the ability to function at high pressures. They are especially designed for use in applications where size and light weight are critical factors.
SSTL has already successfully test fired an experimental version of this thruster in order on the UK-DMC micro satellite.
Other News from Lee Products
Latest news about Valves & cylinders