During the Farnborough Airshow, a contract was signed for the provision of the Passive Hydrogen MASER (PHM) atomic clocks that will provide an essential timekeeper reference for the navigation payloads that SSTL is building for the Galileo navigation system, a programme of and funded by the European Union.

The PHM atomic clocks will be provided by SELEX Galileo, a Finmeccanica Company, for installation on each of the 14 satellites in the Galileo system, under a contract of more than 30m Euros.

The Passive Hydrogen MASER is the most stable clock ever produced for space applications with a frequency stability better than 10-14 day, and is currently demonstrating outstanding performance on board the Galileo GIOVE-B satellite. It is used as reference timekeeper to measure distance and positions in navigation systems. Its stability is better than 0,00000036 seconds in one year, equivalent to 1 second every 3 million years.

Timing is fundamental to Galileo and is essential for all services. It is best illustrated in positioning calculations, where a timing deviation of 1ns could result in a positioning error of 30cm on Earth.

Continue reading "Super accurate atomic clocks for Galileo"

Sir Martin Sweeting :

So President Obama has scrapped the US plans for a manned return to the Moon. As the world claws it way out of recession, many might see this decision as being financially prudent. However, the exploration of the lunar surface is still very much on the agenda. But it won’t be man making one small step next time, it will be a robot!

Several nations are planning robotic lunar missions including India, China, Korea and interestingly, the USA. And when you think about it, this makes perfect sense because robotic lunar missions are much more cost effective than manned missions, although not so emotive. Of course, robotic exploration is nothing new with NASA and ESA both utilising this technology, but it’s still very expensive. The price tag for the European ExoMars programme is around €1Bn which is a lot of money in any currency. But does robotic exploration have to be this expensive?

At SSTL we don’t think so. We think it is possible to knock a “0” off the cost of mounting lunar robotic exploration mission by simply employing the same, well founded, production techniques that SSTL use to reduce the cost of designing and building Earth-orbiting small satellites.

Currently, there is enormous interest in the moon, particularly with the prospect of finding water, the key perhaps to a permanent manned lunar base in the future. The LRO and LCROSS missions are currently surveying the lunar surface to identify future landing sites. Now is the time to mount a low cost robotic mission to Moon in order to prove the technology and its suitability for other more distant planetary missions.

Today at 12:30 in Brussels, the EC announced that the SSTL and OHB-System team has been selected by ESA to supply 14 navigation satellites for the deployment phase of the Galileo satellite navigation system in a deal worth 560m Euro.

The two companies agreed to work together as a “core team” on Galileo at the end of 2007, with OHB taking the role of prime contractor and builder of the spacecraft “bus” and SSTL taking full responsibility for the navigation payloads onboard the satellite that will form the heart of the Galileo navigation system.

SSTL Group CEO Dr Matt Perkins is delighted with the news:

The award of this contract is an important step for SSTL. Our satellites are already providing operational services for many government and commercial customers and we are pleased to have a major role within Europe’s flagship Galileo programme. The experience gained on GIOVE-A will help us to ensure the contract will be a success for the EC and ESA. This programme will also help to establish SSTL as a provider of communications and navigation satellites into other markets.

It was champagne all round at SSTL in Guildford as the news was announced, warming spirits despite worst snow for 30 years affecting the local area.

A jubilant SSTL’s Executive Chairman, Sir Martin Sweeting, added

This award is great news for the UK space industry and once again confirms SSTL as a world leader in sophisticated satellites and payloads, building on its 25-year history pioneering small satellites with 34 already launched, truly changing the economics of space.

The first Galileo satellites produced under this contract will be launched from 2013. To help improve the overall schedule the team was authorised by the EC and ESA to initiate the procurement of long lead items for the full system during 2009 which will enable the team to make a quick start towards an operational Galileo constellation.

Continue reading "Green light for Galileo satellites"

The European Space Agency (ESA) Proba-2 mission has entered its 2 month commissioning period following a successful launch. SSTL’s Microsatellite Gas Propulsion System is on-board the 137kg small satellite and was integrated by the satellite’s manufacturer Verhaert Space Systems.

The Microsatellite Gas Propulsion System is based upon SSTL’s heritage xenon resistojet propulsion system. Its highly cost effective design provides an enhancement over conventional cold gas propulsion.

By using the resistojet thruster to heat the exhaust gas to over 300ºC a 30% increase in efficiency is gained. The electronically controlled pressure regulation improves thrust control compared to conventional mechanically regulated propulsion systems for greater positioning control in orbit.

The warm gas propulsion system is simpler, safer and cleaner than chemical propulsion systems. This makes them ideal for launcher injection correction, constellation station keeping and acquisition and orbit height maintenance for small, low cost spacecraft.

Proba-2 is the follow-on to the highly successful Proba-1 satellite launched in 2001 that carried the Compact High Resolution Imaging Sensor (CHRIS) payload manufactured by SSTL’s Optical Payloads Group. Proba-2 will demonstrate 17 advanced satellite technologies – such as miniaturised sensors for ESA's future space probes and a highly sophisticated CCD camera with a wide angle view of about 120 degrees – while carrying a set of four science instruments to observe the Sun and study the plasma environment in orbit.

A datasheet for the SSTL Microsatellite Gas Propulsion System is available on the SSTL Website.