ESR Technology awarded ESA contract to develop ‘Lunar dust resilient louvered radiators’
ESR Technology, supported by sub-contractor Almatech (of Switzerland), have been awarded a key contract to develop a radiator solution that is resilient to lunar dust, with the intent that these are used for dissipating heat on a future European Lunar Lander or Rover applications, such as the EL3. The contract, which kicks-off on 06-Sep-2021 involves development of rapid prototype mock-ups, critical prototypes of components and a system prototype that is planned to be characterised in vacuum and subsequently demonstrated to operate in a simulated dusty environment. The programme has a duration of 2 years.
The challenge of developing mechanisms for the harsh lunar environment is a formidable one. The temperature on the surface of the Moon ranges from 30 K in permanently shadowed craters at the poles to about 395 K at the sub-solar point on the lunar equator. Add to this the harsh abrasive nature of the dust, which can have considerable iron content, being magnetic, and can also be electrostatically charged. The dust can not only affect mechanism reliability by getting into to critical areas but it can seriously affect the thermal balance by changing sensitive thermo-optical properties, particularly for surfaces intended to have low emissivity or high solar reflectivity. Further, the IR loading from the lunar surface can be a challenge in some cases, so the thermal control strategies must be very resilient.
According to ESR’s Head of Mechanisms, Andrew Gibson, “We have recognised the challenges to be significant and have put together a team that is capable of taking on the challenge. We are pleased to have Almatech on board, who are highly experienced in design of long-life flexure devices and drive systems. They are also well-suited to lead the advanced thermal and structural analyses required. We have also included Spacemech Ltd, who retain a great depth of experience including having led work on similar mechanisms dating from ESA’s first deep space mission, Giotto. To deal with the challenges of lunar dust we have enlisted support of the Dr. Simeon Barber of Space Science Solutions Limited, who brings plenty of experience in dealing with the challenges related to dusty conditions of the moon and Mars. Combined with ESR’s experience in long-life mechanism design and lubrication at extreme temperatures, our team is ready for the challenge. We are keen to apply our tribology and mechanism design capabilities, with ESR leading the development of this active thermal solution for the lunar environment.”
In fact, this type of thermal control device is right in line with a recently acquired technology. The original design was targeted for cube-sats, but it is readily scalable for other applications and very attractive in terms of simple interfaces and being slim in terms of volume required. ESR are looking to offer this technology to new partners, for adaptation to suit various size cube-sats as well as for other needs. ESR completed the acquisition of the cubesat thermal shutter mechanism IP from Spacemech Limited in 2020, with Spacemech continuing to support further developments, such as the one described above which will be tailored for lunar applications.
