When Europe’s first solo mission to the Moon, Smart-1, was launched last week it carried the hopes of planetary scientists eager to unlock more of the secrets of our nearest neighbour in space.
But with all due respect to the data it will collect on the lunar surface, Pedro Cordero Perez, head of technology research and development at the European Space Agency (ESA), will be more interested in how the spacecraft’s engine performs on its journey than the pictures and information it sends back.
Smart-1 is demonstrating electric propulsion in which power from the spacecraft’s solar panels drives an ion engine. Within the engine atoms of xenon gas are ionised and accelerate away from the spacecraft at high speed, propelling it forward.
ESA plans to use ion drives on a number of its future missions – including BepiColombo, scheduled to travel to Mercury in 2009 – but first it has to prove that the technology works. That is why Smart-1 is so significant. ‘Smart-1 is a very relevant mission for technology. Electric propulsion, which the UK has been a very active participant in developing, is something we intend to continue with. It is a very promising technology,’ said Perez.
ESA is a procurement agency, and as such does not develop technologies in-house. So Perez’s role within the technology programmes department is to ensure the agency has access to the right technologies as and when they are needed by each space mission.
‘We have to anticipate what technology will be needed in 10-15 years from now. We have a series of scientific missions, such as BepiColombo and Lisa [a mission designed to detect the gravitational waves created by black holes] that are now under study, so we are introducing new technology plans for the work we deem to be necessary,’ said Perez.
To this end, the agency decided five years ago to work with the European Commission and Europe’s space industry to set out a strategy for future R&D work.
The resulting European Space Technology Master Plan was discussed with Commission officials at this year’s Paris Air Show.
With an annual budget of e250m (£175m) to spend on technology, the master plan is ESA’s attempt to ensure there are no duplications or gaps within its R&D programme. Research by the agency and its suppliers is carried out according to technology themes – science; earth observation; robotic planetary exploration; human space flight and planetary exploration; space transportation; telecommunications and navigation; and technologies that may have an application across a range of different missions.
Until now ESA’s main strengths have been in science, earth observation and telecommunications and navigation, while its human space flight activities are limited to its participation in the International Space Station. This has already led to the development of health-monitoring technologies for astronauts, and ESA is now investigating the creation of a mobile phone-sized device capable of sensing, recording and transmitting all the astronauts’ health data back to Earth.
ESA also plans to carry out microgravity research on its Columbus laboratory. This was due to be delivered to the ISS by the shuttle next year, although it is now likely to be delayed as a result of the Columbia disaster.
But despite all this useful scientific research Perez admitted that there remains a substantial gap in ESA’s repertoire. ‘The ISS is the core of our participation in human space, but it is more investigation in space than investigation of space. There is a very broad gap that, for a number of reasons, we have not covered before. That is the exploration of space.’
The Aurora programme has been designed to change all that. The programme involves a number of missions to explore the solar system and the universe, and is likely to stimulate the development of a range of new technologies, said Perez. ‘This will be one of the major drivers of new space technologies in the coming 15-20 years. There will be new technologies needed in navigation, propulsion and power.’
Solar-electric propulsion is likely to play a major role in these future Aurora missions, but ESA is also looking at issues such as securing food supplies, recycling water and oxygen and the detection and suppression of contaminants to enable astronauts to survive for months on the long journey to Mars. ‘One person needs three to five litres of water a day on average. Multiplied by the number of crew members, that means you would need to bring more or less a whole tanker with you unless you can find ways to recycle,’ said Perez.
As NASA struggles post-Columbia disaster with what it should do about the ageing shuttle, and what design to go for in its Orbital Space Plane (OSP) programme, ESA will also be exploring new space transportation technologies over the next few years. It will attempt to find the most technically feasible and cost-effective method of launching spacecraft into orbit. The team will investigate whether a recoverable, partly recoverable or completely expendable launcher system would be the best option for the future.
However, unlike NASA, ESA is unlikely to go back to a capsule design for its future spacecraft. Aerospace firms Boeing and Lockheed Martin recently indicated that a capsule, based on the Apollo, is now the most likely design for NASA’s OSP. But Perez dismissed this idea as ‘only half a solution. It is a short-term response to a minor part of the problem,’ he claimed. ‘NASA’s plans were to maintain and upgrade the shuttle for at least the next 15 years while another launcher-and-recovery system is set in place. The idea of the capsule is to use it as an emergency crew return vehicle for the ISS. It is not a whole solution, so in my opinion the US will continue to refurbish and upgrade the shuttle until it has another option.’
As well as carrying out research based on these main themes, the team also investigates innovative technologies it believes may be important in the future, but as yet do not have a particular application or mission in mind for. These include giant solar sails for propelling spacecraft to far-off planets, and inflatable re-entry vehicles.
ESA is also involved in a project to develop a laser camera for use on future mini-rovers capable of providing accurate mapping of the planet from ground level. And it is investigating the simplification and miniaturisation of the electronics within satellites by removing the wiring between devices and allowing systems to communicate using radio frequency antennas inside the satellite.
‘There is a big drive to miniaturise but eventually you reach the point where you have miniaturised the box itself but not the connector. So one possibility is to have wireless communication inside the satellite,’ said Perez. ‘This is important as one spacecraft could resemble the medium-sized telecoms switchboard of a big city.’
On the flip side, ESA hopes to increase the ‘size’ and capability of its satellites through interferometry, the method used to improve the imaging strength of telescopes by combining a number of the devices. Weight constraints in launching satellites into orbit mean there is a limit to how large they can become. So the team is studying the possibility of using electric propulsion to move a number of satellites into a constellation where they could then act as one large telescope with more powerful observation capabilities.
The Darwin mission, due for flight after 2013, will be based around six free-flying interferometric telescopes transmitting their light to a central beam-combining spacecraft, to allow it to see much further and search for other Earth-like planets.
‘The Darwin mission will be driven by these technology plans. But there are still a series of things to prove, because you have to ensure very accurate and tight positioning of these spacecraft with respect to each other,’ said Perez.
So by demonstrating that electric propulsion works the little spacecraft already on its way to the Moon could one day help us to find an answer to the question of whether there is life on other planets.