Lunar rovers could be engulfed by dust
Space agencies around the world have plans to continue the exploration of the Moon in the next two decades, with ever more sophisticated robots paving the way for astronauts to walk on the lunar surface once again. One major issue for these projects is the dust found on the lunar surface, material that is abrasive, sticky and unhealthy to breathe. Now an Anglo-French team of scientists have modelled how this dust will affect any rover vehicles travelling across the surface. They find a serious risk that rovers that move around sunrise and sunset could be engulfed in dust. Professor Farideh Honary of the University of Lancaster will present the new work at the RAS National Astronomy Meeting in St Andrews on Wednesday 3 July.
In the 1960s and 1970s the United States and Soviet Union sent a series of robotic (Surveyor and Luna) and crewed missions (Apollo) to land on the Moon. These give contemporary scientists a bank of data on the lunar environment including dust. The major issues associated with it are abrasiveness, adherence to clothing and equipment, visibility reduction particularly during landing and the effect on human health of breathing in the dust particles. Astronauts found that the dust stuck to all materials, something that could be fatal if it compromised life support systems.
Farideh will present a study of the simulated motion of lunar dust near a rover, part of a joint project with ONERA in France to study dusty environments where electrical charging has a strong effect.
Simulations were made for two different lunar regions, the boundary between night and day (terminator) where the sun would either be rising or setting and the region experiencing full daylight. The rover vehicle was modelled as a 3m x 1.5m x 2m rectangular box located in the middle of the simulation domain and placed 1 metre above the lunar surface.
The scientists simulated an area of on the Moon, 30 m long x 30 m wide and 20 m high. Dust particles were introduced into the simulation over a period of time, when both the surface and the rover were in electrical equilibrium.
In both the test cases, dust particles travel upwards above the height of the rover, but results suggest that they move in different directions. On the dayside the particles are pushed outwards and on the terminator the dust travels upwards and inwards above the rover, regrouping in the vacuum above it. The terminator simulation began with a region void of dust which was later filled by lunar dust particles.
The results suggest that a structure such as a rover might collect a significant quantity of dust over time and that this would happen more quickly around sunrise and sunset.
Prof. Honary believes this has implications for rover design: "On most of the lunar surface a rover would experience roughly 14 days of sunlight followed by 14 days of darkness, so the transition between the two would last a long time by terrestrial standards. Engineers really do need to think about this – one solution might be to build a dome-shaped rover so the dust simply falls to the ground."
Prof. Farideh Honary
Dr Robert Massey
Ms Emma Shea
Landline numbers in NAM 2013 press room (available from 9 a.m. to 5 p.m. from 1-4 July, 9 a.m. to 3 p.m. 5 July):
Tel: +44 (0)1334 462231, +44 (0)1334 46 2232
Image and caption
The Apollo 15 Lunar Rover on the surface of the Moon with astronaut Jim Irwin alongside. Tracks in the dusty lunar soil are clearly visible. Credit: NASA
Notes for editors
Bringing together more than 600 astronomers and space scientists, the RAS National Astronomy Meeting (NAM 2013) will take place from 1-5 July 2013 at the University of St Andrews, Scotland. The conference is held in conjunction with the UK Solar Physics (UKSP: www.uksolphys.org) and Magnetosphere Ionosphere Solar Terrestrial (MIST: www.mist.ac.uk) meetings. NAM 2013 is principally sponsored by the RAS, STFC and the University of St Andrews and will form part of the ongoing programme to celebrate the University's 600th anniversary.
Meeting arrangements and a full and up to date schedule of the scientific programme can be found on the official website at http://www.nam2013.co.uk
The Royal Astronomical Society (RAS: www.ras.org.uk, Twitter: @royalastrosoc), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3500 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The Science and Technology Facilities Council (STFC: www.stfc.ac.uk, Twitter: @stfc_matters) is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security. The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. It enables UK researchers to access leading international science facilities for example in the area of astronomy, the European Southern Observatory.
Founded in the 15th century, St Andrews is Scotland's first university and the third oldest in the English speaking world. Teaching began in the community of St Andrews in 1410 and the University was formally constituted by the issue of Papal Bull in 1413. The University is now one of Europe's most research intensive seats of learning – over a quarter of its turnover comes from research grants and contracts. It is one of the top rated universities in Europe for research, teaching quality and student satisfaction and is consistently ranked among the UK's top five in leading independent league tables produced by The Times, The Guardian and the Sunday Times.
The University is currently celebrating its 600th anniversary and pursuing a £100 million fundraising campaign, launched by Patron and alumnus HRH Prince William Duke of Cambridge, including £4 million to fund the creation of an 'Other Worlds' Think Tank and Observatory. The new think tank and Observatory project will extend the University of St Andrews' flagship work on extra-solar planets, and provide a creative environment for problem-focused research, education and continuing public engagement.
For further information go to: www.st-andrews.ac.uk/600/