The amateur radio STRaND-1 smartphone CubeSat is a joint project between SSTL and the Surrey Space Centre (SSC). It’s not only its smartphone that makes it exceptional. Engineers at the Surrey Space Centre have also developed a unique mass and power saving plasma propulsion system to fly on the satellite. This system will be the first propulsive technology to provide very precise attitude control and pointing.
STRaND-1 will carry both a Resistojet and a Pulsed Plasma Thruster (PPT) module on board. The PPT will consist of eight micro thrusters; four located at the top of the satellite stack and four located at the bottom. The micro thrusters operate by discharging a discrete train of pulses. Each pulse is a plasma discharge that forms between two metal electrodes, much like a small lightning bolt or electrical spark. The spark erodes the metal from the electrodes and electromagnetics accelerate the eroded mass out of the nozzle, which produces thrust. This is known as the Lorentz force.
Surrey Space Centre has developed two ways of minimising mass and volume. Firstly, the electrodes which form the plasma discharge also function as the propellant. As metal is highly dense, more propellant can be stored in a smaller volume than that of conventional chemical propulsion systems. The total weight of the propellant for the whole STRaND-1 PPT system is just 10g.
Secondly, Surrey Space Centre’s novel discharge initiation system uses a mechanical contact trigger built out of a tiny piezoelectric motor only 5mm in length. This takes up less space than the conventional spark plug system which requires volume intensive circuitry.
Matthias, DD1US, would like to draw your attention to a collection of audio recordings, the ‘Sounds From Space‘ collection on his website at http://www.dd1us.de. This features a collection which has also a section dedicated to recordings of amateur radio satellite signals.
Please have a look at it. The idea is to give older radio amateurs the chance, to listen to signals of satellites which are already gone and the might have worked in the past, and to younger people interested in ham radio, to get them more excited in satellite communication.
In spite of the fact that the collection now has close to 1000 recordings he is still missing recordings from some amateur radio satellites.
If anyone of you would be willing to contribute recordings to these satellite he would highly appreciate it. He has and always will give full credit to the source of the recordings. Please have a look in your older tapes and recordings!
Here is a list of the most wanted missing satellites:
Amsat Oscar 8
UOSAT OSCAR 15
WEBER OSCAR 18
UOSAT OSCAR 22
POSAT OSCAR 28
TMSAT OSCAR 31
PANSAT OSCAR 34
UOSAT OSCAR 36
ASUSAT OSCAR 37
WEBER OSCAR 39
SAUDI OSCAR 42
STARSHINE OSCAR 43
MYSAT OSCAR 46
Source: Amsat, Matthias, DD1US and The Sounds From Space website
The original TV news reports about the United Kingdom’s first Amateur Radio satellites, UOSAT-1 (OSCAR-9) and UOSAT-2 (OSCAR-11), can now be seen on the web.
In ‘Talking Satellite’, made February 15, 1983, Martin Sweeting G3YJO talks about OSCAR-9 and its speech synthesizer.
The ITN description reads: “The World’s first talking satellite begins to speak. It was launched 18 months ago in America for the University of Surrey and one of its purposes is to encourage interest among school children in space technology.”
Watch it at http://www.itnsource.com/shotlist//ITN/1983/02/15/AS150283008/
In ‘British Satellite’, made February 7, 1984, Martin Sweeting G3YJO talks about OSCAR-11 due to be launched the following month.
The ITN description reads: “Staff at the University of Surrey have designed and built a spacecraft in 5 months after being challenged by NASA. Intvw Dr Martin Sweeting, University of Surrey.”
Watch it at http://www.itnsource.com/shotlist//ITN/1984/02/07/AS070284011/
The International Amateur Radio Union satellite frequency coordination panel has agreed a frequency of 437.575 MHz for the UK satellite STRaND-1.
Some of the SSTL STRaND-1 Project Team, from Left to Right: Bob Dyer, Nick Holt, Dale Mellor, Mark Brenchley, Shaun Kenyon, Jonathan Gebbie, Rupert Taylor, Rosie Linehan, James Parsons, Andy Schofield
STRaND-1 will carry an Android Smartphone and plans to use data rates of 9k6 or 19k2 bps for the AX.25 packet radio downlink. A software-based speech synthesiser will be included to pay homage to the UOSAT family of satellites.
The 3U CubeSat measures 30 by 10 by 10 cm and weighs 4 kg. Unlike previous CubeSats it will feature full 3-axis control with the attitude an orbit control system comprising a nano-magnetorquer, nano-reaction wheels, GPS receiver, 8 pulse plasma thrusters and a butane thruster.
STRaND stands for Surrey Training, Research and Nanosatellite Demonstration and the programme is intended to be a long-term arrangement between the space company SSTL and academic researchers at the Surrey Space Centre (SSC), with STRaND-1 the first of a long line of STRaND nanosatellites.