Stars in his eyes

Cape Canaveral, Houston and Baikonur are all locations that readily trip off the tongue of any self-respecting armchair astronaut. Guildford almost certainly isn’t.

But while the leafy surrey town is perhaps more redolent of middle-England curtain-twitching than cosmic exploration, this quiet corner of the UK also happens to be home to a company that has made a name for itself as a leading member of the global space science community: Surrey Satellite Technology (SSTL).

Spun out of Surrey University in 1985 to commercialise the results of its small satellite engineering research programme, SSTL is headed by Prof Sir Martin Sweeting, a passionate advocate for the UK space industry whose 1970s PhD work at Surrey was the catalyst for SSTL’s commercial success. For instance, in the late 1970s he designed and built UoSat-1, a small 50kg satellite that he managed to get launched and communicating through amateur radio bands back to a ground station at the Surrey campus.

Thirty years and 23 satellite launches later, SSTL, which now employs more than 200 staff, is widely regarded as the world’s leading developer of micro satellites, priding itself on an ability to develop small, low-cost satellites in super-fast time. Indeed, thanks to the company’s speedy work, the first element of the Galileo system, Europe’s answer to GPS, is now in orbit around the earth.

Launched on 28 December from Kazakhstan’s Baikonur Cosmodrome, this satellite, known as GioveA, is essentially a testing device, primarily designed to validate the transmission frequencies that will be used by Galileo.

These frequencies, allocated by the International Telecommunications Union (ITU), must be secured before June this year and Sweeting claims that SSTL’s ability to build and deploy satellites so rapidly could be central to Galileo getting off to a good start.

To Sweeting’s obvious delight, the 660kg satellite — which was designed and built in just 30 months at a cost of e28m (£19m) — began transmitting its first Galileo navigation signals on 12 January. These signals were received and analysed by the Galileo receivers using the 25m-diameter dish of the Chilbolton Observatory Facilities for Atmospheric and Radio Research (UK) and ESA’s station in Redu, Belgium.

Sweeting said that the satellite will now sequentially generate the other Galileo signal modes and will also carry out measurements to assess the medium earth orbit radiation environment, characterise the performance of the on-board clocks and perform signal-in-space experimentation.

The extent to which SSTL’s approach differs from the traditional method of developing satellites is exemplified perfectly by the current status of Galileo’s second test satellite , GioveB. This system, which will be designed and built by Galileo Industries (a consortium of industry giants including Thales, EADS Astrium and Alcatel), is unlikely to be ready before the middle of this year and, although it will have a slightly more advanced payload, will still be dramatically more expensive than its hastily deployed forebear.

SSTL could develop GioveA so rapidly, explained Sweeting, because of the company’s ability to do everything in-house, bar some extremely high-level vibration and thermal vacuum testing. He said that, while this approach doesn’t sit particularly easily with the traditionally risk-averse space agencies such as ESA and NASA, it has enabled the company to punch well above its weight.

Sweeting suggested that the impressively speedy development, relatively low cost and consequent success of the GioveA satellite could even have a knock-on effect on the way the big space agencies work. With the e1.2bn (£0.8bn) contract for the remaining satellites already awarded to the Galileo consortium, SSTL doesn’t at present have any role in the next stages of the Galileo project, but Sweeting is optimistic that GioveA could lead to a re-evaluation.

‘We sincerely hope that the success of GioveA will cause the EC and ESA to rethink and take advantage of our approach, to the significant benefit of the European taxpayer,’ he said.

Other recent triumphs for the company include Topsat, a small earth-imaging satellite built with Qinetiq and launched in October, and the Chinese Beijing-1, the latest addition to the international disaster-monitoring constellation (DMC).

This international network of satellites and ground stations was used to help aid agencies co-ordinate the relief effort in the aftermath of the 2004 tsunami.

The system consists of a number of satellites, each weighing 80kg, that can give high-resolution images over a 384,000km2 swathe of land and zoom down to a 32m2 area.

In addition to their intended purpose, Sweeting explained that the DMC satellites have also provided the opportunity to test out some interesting new technology. For instance, on the UK-operated DMC satellite, which was launched in October 2003, the team experimented with the use of an innovative steam-propulsion system to induce small changes in the orbit of the satellite.

While conventional satellites don’t need propulsion systems, tiny satellites designed to operate in constellations require some form of propulsion to position them correctly, explained Sweeting. He added that while the system showed promise, there are obvious problems with using water as a propellant in the freezing vacuum of space. So on the recently launched Chinese Beijing-1 DMC satellite the team has installed a similar device that uses the gas xenon.

SSTL’s customer base is diverse, ranging from the US Air force to China’s Tsinghua University. The latter, tellingly, chose SSTL over its own nation’s much-vaunted technology industry to develop its Tsinghua-1 microsatellite, launched in 2000.

But while satellites are often perceived as high-cost scientific instruments, Sweeting believes that space technology can help humanity in all kinds of ways. So a large part of the company’s work is training scientists from nations that are taking their first steps into space.

For instance, an SSTL satellite operated by the SSTL-trained Algerian space agency is currently being used to monitor locust plagues. From this information it will go on to predict locust migration.

Nigeria also operates its own SSTL-built satellite, and Sweeting is effusive on the potential it creates for a developing country. ‘people say what does Nigeria need a satellite for when it doesn’t even have decent roads? The answer is that a satellite can help you build decent roads,’ he said.

Away from the commercial side of the business, SSTL’s R&D is carried out, by and large, through the University of Surrey’s space centre which is also headed by Sweeting. Here a range of PhD projects are looking at longer-term concepts, such as solar thermal propulsion and the use of control moment gyros to adjust the position of satellites precisely and rapidly.

One particularly exciting area of research is the development of picosatellites — tiny credit card-sized systems on chip devices that would be capable of working together like a colony of ants. Sweeting’s group is investigating the possibility of using such technology to create ‘morphing’ satellites that would be able switch roles from, for instance, mapping to telecommunications.

But while Sweeting’s researchers have their thoughts in the future, there are also plenty of interesting projects in the shorter term. The team is currently working with the Los Alamos Laboratory in the US on the Cibola Flight Experiment Satellite (CFESat), a system to be launched later this year for studying the ionosphere and lightning.

SSTL is also developing five microsatellites that will form the so-called RapidEye constellation. Due to be launched in spring 2007, it will be used mainly for agricultural and cartographic information services. Sweeting claims it will be the world’s first commercial earth observation constellation.

It will also herald a couple more very busy years for surrey’s satellite specialists.