Professor Sir Martin Sweeting is the Chairman of SSTL

SIMON LEVY talks to PROFESSOR SIR MARTIN SWEETING OBE FRS FRAeS FREng FIET, Chairman of SSTL on 'CubeSats', space launchers, STEM outreach, and the effect of any Brexit on Britain's space industry..

1. What got you into the industry?

I am a child of the Apollo era and watched the Moon landings as a teenager – that inspired me to apply my fascination with radio communications to space and satellites. This then coincided with the emergence of microelectronics and microcomputers that made it possible for me to propose building a ‘microsatellite’ – on a micro-budget. After building two successful microsatellites at the University of Surrey that were launched in 1981 & 1984 respectively, the cancellation of the UK national space programme gave me no alternative other than starting a commercial company to fund the continuation of small satellites and their applications.

Gene Cernan on the Moon in 1972. (NASA)

2. With the likes of upcoming low cost laboratories in orbit such as Twinkle satellite with spectrograph telescopes generating exoplanet data, could he see an alignment with low cost platform in orbit to process the data rather than send raw data to earth?

This is a question that has been around for the last two decades as computing power and storage on-board satellites has increased dramatically! However, except for some specific applications, investigators still prefer to download all the ‘raw’ data to storage on the ground as they never can predict what new information might be extracted in the future from this ‘old’ data as new processing techniques and technologies appear. Processing the data on the satellite would lose this ability to re-examine the original data – unless we stored it all in the cloud in space of course!

3. For a long time the UK’s space industry has ’flown under the radar’ and built up an enviable track record. Now that politicians and decision-makers are aware of the success of the sector – does that cause new pressures to meet these expectations? 

Indeed the vibrant UK space industry has been very much hidden under a bushel until recently brought out into the daylight by the (catchily-titled) UK Innovation and Growth Strategy for Space that quantified the sectors contributions to the national economy, security and well-being. Awareness in Government of the value of the space sector and its associated increase in tangible support is very welcome indeed and, of course, the sector now has to deliver its side of the deal and live up to those expectations of economic growth and employment – but these are challenges that we welcome! 

4.  Are we still on track to deliver a £40bn UK space industry by 2030 and what initiatives are happening to reach this target?

Overall yes, based on a 2013 study by Oxford Economics the space industry in the UK is growing at an average of 8.8% per annum since 2008/09 (Oxford Economics is currently updating the study to include 2014/15 results). There are some 65 companies now at the Harwell Space Hub and in 2015 the UK launched the largest number of sub-500kg satellites  after the US and China.

5. How do we keep the level of interest and engagement of our space industry, particularly amongst the next generation going when Tim Peake returns from the ISS?

The STEM educational outreach campaign has been the biggest yet for an ESA astronaut, according to the UK Space Agency. (ESA)

Tim Peake has done wonders during his mission to raise awareness and enthusiasm for space (but also wider technology) amongst schoolchildren and students – after he returns to Earth, we need to build on his impetus by continuing to show how fascinating, challenging and important a career in any aspect of space is to young people – I might suggest that continued interest and informed leadership by the media will be crucial in achieving this.

6. You have warned of a cubesat ‘bubble’ – can you explain a bit more what this means?

So-called ‘CubeSats’ are a particularly effective format of the more generic ‘nanosatellite’ – typically the size of a beach ball and weighing  between 1-10kg. These tiny satellites are extremely valuable for stimulating interest in and educating your students through direct participation and access to space – what could be more inspiring?  However the laws of physics remain intact and very small satellites have very limited power and aperture for instruments that restricts their usefulness in meeting many demanding applications.  There are some specific applications to which they are well-suited but I fear that there has been a certain amount of ‘froth’ generated in investment circles that might find the expectation on the return on their investments rather difficult to realise – and this might lead to disillusionment that could tarnish the whole small (Micro & mini) satellite business.  Just a note of caution…

7. What is your opinion of the proposed UK Spaceport? Does Britain even need one, being so far from the equator where you get a gravity assist into orbit? 

I believe that Britain should have a spaceport – both for space tourism (and perhaps later for hyper-velocity intercontinental passenger travel) and for launching the growing number of small satellites; especially those for our own sovereign interests into high inclination orbits (not geostationary) that are needed for Earth observation missions.


The RAeS recently held a conference on Spaceports in the UK (image Copyright: DfT & HMG Crown)

8. How dangerous do you think the threat of space debris is to future satellite and space operations? Do you think this particularly a concern for smaller satellites – given the limited space for de-orbiting fuel or other technology? 

Space debris is a real threat – one of our satellites (built for the French government) was hit by rocket debris in 1996 but fortunately survived.  With some 18 operational satellites controlled or monitored  by our groundstation in Guildford, we receive ‘close encounter’ warnings once every couple of weeks where debris or other satellites come closer that a few hundred metres – and once or twice a year it may be close enough to require us to manoeuvre out of the way. The greatest danger is from debris spent rockets debris and satellites that fragment in orbit due to pressure vessels or hypergolic fuels. There is now a code of conduct that encourages depletion of unused propellants at the end of service life of a satellite – preferably also being used to reduce the orbit height to increase aerodynamic drag and thus bring the satellite down to burn up in the Earth’s atmosphere as early as possible thus reducing the debris population. Many very small satellites (nano-satellites) are launched into low, short-lived orbits, however small satellites launched into orbits above 600km may have lifetimes of many decades and thus mechanisms for reducing this are being proposed and tested in orbit at present (e.g. deployable ‘sails’ like parachutes).

9. Many launch companies (SpaceX, ULA, Arianespace, Virgin Galactic) are striving to bring down launch costs. Which do you think will be successful and what are the implications?

Satellite design techniques and costs are driven by the costs of launch, so reducing the cost to orbit is key. Streamlining production and re-usable stages should reduce launch costs – but probably by only 15-20%: whilst very welcome, this will not dramatically change the satellite industry. A new technology for launch is needed – perhaps something like the air-breathing SABRE engine being developed in the UK.

10. Your business has primarily been for civil applications and science. Do you see any interest from UK MoD in rapidly deployable cubesats, say to give a sovereign imaging capability? 

The majority of our small satellites launched over the last 35 years have been for civil communications or Earth observation– or demonstrators for military applications. The combination of the increased capabilities of small satellites coupled with dramatically reduced costs has made them an attractive proposition for a sensibly affordable sovereign space imaging capability – both for downwards for Earth observation and upwards for space situational awareness – however these are likely to be based around micro- and mini-satellite platforms as cubesats have a very limited payload capability.

11.  We have seen two ‘global internet from space’ initiatives – OneWeb and Elon Musk’s constellation. Can both be successful? 

Only time will tell – in fact there are a number of other similar constellations being proposed by countries in Asia. I suspect that the success of multiple systems may depend on interoperability to provide a better service coverage – perhaps learning from the cell phone business?

12. Over the past 30 years – SSTL has carved a niche as the leading supplier of small and low-cost satellites – what has been the secret to its success?

I often get asked this question – there is no one, simple ingredient but rather an overall philosophy that combines the innovative application of industrial/consumer electronics (‘COTS’), a reconfigurable and resilient system design, a carefully-balanced approach to PA/QA and risk, a management approach that is more akin to the IT industry rather than a conventional aerospace organisation and a business model that is based upon open partnership with our customer – wherever possible.


Sir Martin was recently awarded Honorary Fellowship from the Royal Aeronautical.

13.  What is next for SSTL? Do you plan to stay mainly in small satellites or are there adjacent sectors that you are looking to enter?

We plan to remain focussed on small satellites – but that means different sizes depending on the application!  At one end of our product range we have a 4kg nanosatellite and at the other end a 4000kg geostationary satellite that is still small when compared to the prevailing geo communications industry satellites!  All of these have a largely common suite of avionics housed in different structures to carry different sized payloads. We have been steadily moving from low Earth orbit for observation to medium Earth orbit for navigation missions and now to geostationary orbit. We plan to keep moving and taking our small satellites further out to lunar and Mars orbits to be ready to support commercial services there in support of sustained human habitation in future decades.

14. Should Britain leave the EU, what effect do you think this would this have on Britain’s space industry?

The arguments for and against are difficult to disentangle. In fact, most of our business is outside the EU (except the Galileo payloads), but for the UK space industry in general that are heavily reliant on institutional projects and for the UK’s involvement in important ESA projects,  it would be better to stay in the EU.  SSTL employs a significant number of EU citizens to meet its skills needs and leaving the EU would most likely make this more difficult.

15. And finally, what do you do outside of work to relax?

I enjoy cycling and experimenting with HF amateur radio – where it all started!

Simon Levy
17 May 2016