The UK’s space technology demonstration satellite, TechDemoSat-1, is one step closer to completion. SSTL has received several of the eight payloads that will fly on the pioneering small satellite and the project team is busy integrating them.

TechDemoSat-1, which is roughly the same size as a dishwasher, will trial new space technologies in orbit giving them much sought after flight time and encouraging the commercialisation of British technologies.

Announced before Christmas, the first payload to be integrated is the Mullard Space Science Laboratory’s Charged Particle Spectrometer (ChaPS) that will detect electrons and ions simultaneously. ChaPS is a miniaturised instrument that offers a feasible alternative for future missions in which mass and power are at a premium.

Since ChaPS, SSTL has also taken delivery of some of the other payloads:

• MuREM: a miniaturised payload for radiation alarm and diagnostics that could enhance the safety of future space missions, developed by the nearby Surrey Space Centre.


• CMS: a low cost modular infrared remote sensing radiometer designed by Oxford University’s Planetary Group and Rutherford Appleton Laboratory (RAL).


• CubeSAT AOCS: a complete 3-axes attitude determination and control subsystem designed for Cubesats, supplied by SSBV.

SSTL also successfully completed early integration activities with the LUCID payload in December. This payload was developed by sixth form students to characterise the energy, type, intensity and directionality of high-energy particles and early tests have gone well. Full integration of LUCID will take place shortly after some final software development. The final payload, SSTL’s own earth observation payload to measure the state of the ocean, will progress to assembly, integration and test with the satellite over the next few weeks.

Funded by the Technology Strategy Board and South East Economic Development Agency (SEEDA), TechDemoSat-1 is the first-ever collaborative UK Space Agency mission. As reported by the BBC last week, TechDemoSat-1 is part of a broader programme to promote the UK’s skills and expertise as a high-tech engineering and services provider in space.

The payloads are being tested and integrated in SSTL’s new Kepler building in preparation for a launch in late 2012 or early 2013.

A group of students from Royal Grammar School, Guildford is exploring the possibilities of a scientific phenomenon to evaluate its potential for propelling a Tumbleweed Rover through the hills and valleys of Martian terrain.

The project is SSTL’s contribution to this year’s Engineering Education Scheme. EES is an annual event run by The Engineering Development Trust, the largest provider of STEM (science, technology, engineering and mathematics) enrichment activities for British young people. The EES links teams of Year 12 pupils with local companies to provide students with first-hand experience in science, engineering and technology that will enable them to make informed decisions about their future.

This isn’t the first time SSTL has sponsored the scheme. Two years ago SSTL supported a team from Farnborough college on a study to "Investigate possible ways of detecting earthquake precursor signals using satellites, to help us move from disaster monitoring to disaster mitigation". The constructive results of the study have been fed into the Mission Concepts team that evaluates new ideas in the innovation underbelly of SSTL.

This year, Sahand Ghanoun from the Flight Software Team is mentoring four students from Royal Grammar School, Guildford to study a "Low cost propulsion system utilising the Crookes radiometer effect". Their study will look into the possibility of using the Crookes radiometer effect as a supplementary source of propulsion for the NASA Tumbleweed Rover.

The spherical Tumbleweed Rovers could be used to explore the valleys of Mars that wheeled probes are unable to reach, relying on the Martian wind to move them around, see this video. SSTL’s Mission Concepts would like to know if the Crookes radiometer effect could provide an alternative means of propulsion when the Martian wind is insufficient to move the Rovers.


The Crookes Radiometer Effect can be observed when metal vanes in a partial vacuum (like the Martian atmosphere) move when exposed to light. The vanes are painted white on one side and black on the other. When exposed to light or infrared radiation the vanes move because the black side of the vane becomes hotter than the white and transfers more heat energy (and therefore, kinetic energy) to the air molecules behind the vane resulting in a new torque in that direction. In addition, another force is exerted by the flow of the gas molecules from the cooler side to the hotter side in an effect known as thermal transpiration.

A combination of wind power and the photo-thermally induced principle on which the Crookes radiometer works would cost less than solar panel powered propulsion and might make the tumbleweed rover concept viable in a shorter timeframe.

The project kicked off on Friday, 4th November, when Sahand presented to the four RGS students and their teachers and gave them a tour of SSTL facilities. The programme will run until April 2012 when the team will show off their work and a report to a team of assessors.

A Channel 4 news report on Sunday 9th October 2011 covered SSTL’s work towards the creation of an Interplanetary Internet (IPN) system that could change the way space exploration is conducted.

The development of the Internet originally aimed to connect the world, now one of its founders, Vint Cerf (Google Chief Internet Evangelist) is pioneering something much bigger: a network whose reach could extend further than our solar system and potentially allow transfer of data to and from spacecraft travelling to stars 30 trillion miles, or 4 light years, away.

Our terrestrial Internet requires few resends between nodes and data can be quickly resent end-to-end. This works well on Earth where everyone is significantly less than a light second apart and where a constant connection can be provided. However, the bigger the distances involved in space travel, the longer the data takes and the harder it is to guarantee a connection as it can be blocked by the sun and planets. This means that there can be delays of hours, or even days in the transfer of data.

The use of delay tolerant networking rectifies this. Under this system, each node stores data until it can be forwarded to the next node allowing greater use of available contact periods, greater accuracy in the transfer of data, and shorter overall delays in data delivery.

In SSTL’s current work, delay tolerant networking could be used to ensure maximum contact between Low Earth Orbit (LEO) satellites and Earth. In constellations of satellites, each individual acts as a node, and can communicate with each other using Inter-Satellite Links (ISLs) to send data via the quickest route. Data might be sent to a geostationary satellite that has contact with a ground station, providing more opportunities to get data downlinked. This system is faster and much more cost effective if cost is considered as data per pound or euro - it’s more science for your money. Also, the network can be fully automated, reducing operation costs.

Using delay tolerant networking to send and receive data reliably, and as soon as possible, could be particularly useful for defence and disaster monitoring, by reducing the delay between the satellite acquiring data and then waiting for its orbit to bring it within contact with its groundstation so that the data can be downlinked.

In 2003, CLEO, a Cisco router on a LEO satellite was launched onboard SSTL’s UK–DMC-1 satellite and is still in use after eight years in orbit. Working together and using Internet technology to prototype the future Interplanetary Internet, NASA Glenn Research Center, SSTL and Cisco Systems were the first to evaluate the delay-tolerant networking bundle protocol in space. CLEO was a prototype for the concept of IPN, and was followed by the launch of Intelsat’s IRIS geostationary satellite in 2009.

Despite discussions as early as 1998, IPN is only now becoming a reality. A prototype node is already on the International Space Station and an interplanetary Internet system could potentially be in operation for interplanetary exploration by 2018/2020.

Cloud cover is one of the main challenges of satellite imaging, because there’s always a risk that the view of an area is disrupted. This is especially true when an area needs to be imaged at regular intervals to detect changes, or when it needs to be imaged rapidly, for example in the event of a disaster. With this in mind, engineers at SSTL have developed a new innovative Synthetic Aperture Radar (SAR) system called NovaSAR-S which was unveiled this week at the International Astronautical Congress (IAC) in Cape Town.

Rather than follow a traditional development process, the SSTL approach was to design a baseline mission which addressed the question “what imaging performance can we achieve with a spacecraft that can be built and operated at low cost, and is compatible with low cost launches?”

NovaSAR-S complements much larger, complex and power-hungry radar satellites with a small and lower priced mission that delivers imagery in all weather during both day and night. One of the biggest technical challenges was managing energy use onboard, which was solved in part by using new highly efficient S-band solid-state amplifier technology. By combining a modified SSTL-300 platform (used by NigeriaSat-2 satellite) with an innovative S-band SAR payload, that was developed in partnership with Astrium, NovaSAR-S offers radar capability for the cost of an earth observation satellite – a capability otherwise not considered economically possible.

So what’s SAR good at?

Imaging through clouds means that NovaSAR is ideal for providing rapid-response imagery for disaster relief operations and aid disaster assessment, for example in the event of a flooding.

Its cloud-piercing imaging also offers new possibilities for crop monitoring, mapping agricultural land and assessing crop condition, as these applications demand imaging on a strictly regular basis – come rain or shine.

Many of the world's forests are found in tropical areas where cloud cover is dominant, which means that NovaSAR also is well suited for detailed forestry assessments.

This baseline SAR is also ideally suited to maritime and coastal applications such as ship and oil spill monitoring, or detecting shifts in ice formations and other environmental phenomena.

Of course, it doesn’t stop there – and we’re looking forward to exploring the possibilities of this new technology. In this recent article on BBC News online, SSTL’s head of Earth observation, Luis Gomes said: "It's nice to have the technology but we want people to engage in terms of services - to come up with uses for this sort of data for the scientific community and commercial world. These discussions are on-going."