Lead Instrument Scientist, Professor Neil Bowles, with the Lunar Thermal Mapper.
No bigger than a shoebox, the Lunar Thermal Mapper, a thermal imaging camera built by researchers at the University of Oxford’s Department of Physics will blast off to the Moon as part of NASA’s Lunar Trailblazer mission on Wednesday 26 February. This aims to map sources of water on the Moon to shed light on the lunar water cycle and to guide future robotic and human missions.
Once in orbit, the spacecraft – weighing 200kg and about the size of a washing machine- will map the surface temperature and composition of the lunar surface 12 times a day, at a resolution of 50 metres. Using cutting-edge instruments, it will examine features including the permanently shadowed craters at the Moon's South Pole, which could contain significant quantities (potentially 600 million metric tons) of water ice. This could be used in various ways, from purifying it as drinking water to processing it for fuel and breathable oxygen for future human Moon landings.
One of the two principal instruments, the Lunar Thermal Mapper (LTM), was constructed by researchers in the Planetary Experiments Group at the University of Oxford’s Department of Physics. This will measure the surface temperature and the various minerals that make up the lunar landscape, to help confirm the presence and location of water. The instrument will work in tandem with NASA/JPL’s High-resolution Volatiles and Minerals Moon Mapper (HVM3) to produce the most detailed maps of water on the Moon's surface to date.
Lunar Trailblazer was a NASA's Small Innovative Missions for Planetary Exploration (SIMPLEx) selection in 2019, which provides opportunities for low-cost science spacecraft to ride-share with selected primary missions. The spacecraft will launch as a secondary payload on a planned lunar lander mission led by Intuitive Machines, effectively hitchhiking on the larger spacecraft, which will attempt a soft landing on the Moon.
Since the spacecraft has a relatively small engine, its planned trajectory will use the gravity of the Sun, Earth, and Moon to guide it to the final orbit — a technique called low-energy transfer. The momentum provided by the rocket booster will propel the spacecraft past the Moon and into deep space before it is pulled back by gravity. The spacecraft will then use small thruster bursts to slowly correct its orbit until it is about 60 miles (100 kilometres) above the Moon’s surface. In all, Lunar Trailblazer should take between four and seven months to arrive in its final orbit.
The LTM was constructed by the Planetary Experiments Group at the University of Oxford’s Department of Physics, with £3.1 million funding from the UK Space Agency and the Department for Science, Innovation and Technology (DSIT). For the group, building the LTM is the latest achievement in a 50-year history of developing components for spaceflight and infrared thermal mapping cameras, including for missions to Mars, Saturn, and the Moon. With the LTM’s components being produced by various UK academic institutes and companies (details below), this collective effort highlights the nation's leading role in space exploration and scientific research.
Professor Neil Bowles is Instrument Scientist for LTM at the University of Oxford’s Department of Physics: ‘The Lunar Thermal Mapper was designed, built and tested here in Oxford and the launch is an important moment for the whole of our team. The measurements of temperature will help confirm the presence of the water signal in HVM3’s measurements and the two instruments will work together to map the composition of the Moon, showing us details that have only been hinted at previously.’
The mission could also reveal why the Moon has water in the first place. Possible reasons include comets and ‘wet asteroids’ crashing into the Moon; ancient volcanic eruptions disgorging water vapor from the Moon’s interior; or hydrogen within the solar wind combining with oxygen on the Moon. Lunar Trailblazer's findings will shed light on which hypothesis is more likely.
Lauren Taylor, Major Projects Lead from UK Space Agency adds: ‘The UK Space Agency is thrilled to be a part of NASA's Lunar Trailblazer mission. Our work with the University of Oxford to develop the Lunar Thermal Mapper showcases the UK's leading role in space exploration and scientific research. This mission will provide invaluable data on the Moon's water resources, supporting future human missions and enhancing our understanding of the lunar environment.’