Unmanned Systems Technology 016 | Hydromea Vertex AUV | Power management systems | Unmanned Space Vehicles | Continental CD-155 turbodiesel | Swift 020 UAV | ECUs | DSEI 2017 Show report

47 Unmanned space vehicles | Insight autonomous satellite. Called the ELSA-d, it is due to be launched in the first half of 2019. Another approach to the debris problem is the Daedalus experiment at the UK’s Defence Science and Technology Laboratory, which is looking at using sails made of 25 micron-thick aluminium-coated Kapton, a high heat- resistant polyimide film. These would be added to satellites so that when they are deployed at the end of the satellite’s life, they create drag, causing a controlled descent into the Earth’s atmosphere where the satellite will burn up. The first Daedalus trial began in May 2017 on a Canadian satellite called the CanX-7, which is expected to burn up in the Earth’s atmosphere in around two years’ time. Two other satellites, TechDemoSat-1 and Carbonite-1, have also been fitted with de-orbit sails and are expected to start their descents later this year. Exploration Researchers at JPL are looking at designs of autonomous rovers that can operate in extremely hostile environments that have high temperatures or high pressure or both, such as the surface of Mercury or Venus. “Generally, the most environmentally sensitive components of a rover or spacecraft are the electronics, which will fail in heat, stop operating in extreme cold or experience upsets when bombarded with radiation. We are therefore exploring operations using a long-duration in-situ extreme environment rover on the surface of Venus,” says Jonathan Sauder at JPL. This is to be called the Automaton Rover for Extreme Environments, or AREE. Venus has a surface temperature of about 460 C, hot enough to melt lead, and pressures that would crush the hull of a nuclear submarine. Some researchers have been looking at cooling systems powered by radioisotope thermoelectric generators, which are expensive, or high-temperature electronics, which don’t have the necessary levels of integration. Instead Sauder and his team are proposing more of an automaton that is designed to reduce the requirements on the electronics while also requiring only minimal human interaction. The first phase of the project has identified a hybrid rover as the best approach. This combines a mechanical traction system and control system with limited high-temperature electronics, mainly for comms. This phase showed that passive signalling is possible, that the power budget balances out and that the rover fits within current entry, descent and landing systems so that it would be practical to transport. The team is now moving to finalise the design of the traction and comms systems before developing a complete rover design and testing a prototype in conditions similar to the surface of Venus. Another project is also looking at how autonomous systems could be used to explore the surface of Europa, one of Jupiter’s moons. The Europa Clipper mission is planned for launch in the 2020s, arriving in the Jupiter system after a journey of several years. The craft would orbit Jupiter as frequently as every two weeks, providing 40 to 45 flybys of Europa. This would identify sites for an autonomous lander with the primary goal to search for evidence of life. Even though the mission won’t be for another ten years at least, the lander’s specifications are coming together. Primary batteries would provide 45 kWh of energy, supporting operations for 20 to 40 days on Europa’s surface. This short operational time is a result of the radiation levels at the surface, so the lander would capture only five samples from 10 cm below the surface, which would be processed and analysed, and the data then transmitted back to Earth. Interstellar Even interstellar exploration is under development. Breakthrough Starshot, a $100m programme to develop and launch practical interstellar space missions, successfully flew its first spacecraft earlier this year – the smallest ever launched. Several prototype ‘Sprites’ were launched into LEO for testing, piggybacking on two satellites. The Sprites measure just 3.5 x 3.5 cm and weigh 4 g but contain solar panels, Unmanned Systems Technology | October/November 2017 The Automaton Rover for Extreme Environments is designed to survive on the surface of Venus (Photo: Jonathan Sauder)