Birkbeck research project heads for the Moon

A sophisticated X-ray camera developed by a team including Birkbeck scientists will be launched into space in the early hours of Wednesday 22 October, aboard India’s first mission to the Moon. C1XS is an X-ray Spectrometer that will map the surface composition of the Moon, helping scientists to understand its origin and geological evolution.

Dr Ian Crawford from Birkbeck, who chairs the C1XS Science Team, said: "There is still a lot we don’t know about the Moon. Accurate maps of the surface composition will help us unravel its internal structure and geological history. Among other things this will help us to understand better the origin of the Earth-Moon system. We will also be able to learn more about what happened on the Moon since it formed and how and when it cooled. By examining material ejected by meteorite craters, we will also be able to see below its surface to deeper crustal materials."

Dr Katherine Joy, C1XS co-investigator from the Birkbeck/UCL School of Earth Sciences said "C1XS will detect previously un-mapped elements such as magnesium, aluminium and silica, giving us a far clearer picture of the compositional diversity of the Moon’s surface, helping us to understand its complex geological past."

Chandrayaan-1 is the first lunar mission from the Indian Space Research Organisation (ISRO). It is designed to orbit the Moon and carries radar and particle detectors as well as instruments that will make observations in the visible, near infrared and X-ray part of the electromagnetic spectrum. C1XS was designed and built by a team of scientists and engineers from the UK’s Science and Technology Facilities Council in the Rutherford Appleton Library (RAL), in conjunction with the ISRO. It employs new technology to make a compact, lightweight, sensitive instrument that can measure the abundances of chemical elements in the lunar surface, by detecting the X-rays they absorb and re-emit. The spectrometer builds on a successful technology demonstration called D-CIXS, which was launched aboard the European Space Agency’s (ESA) Smart-1 mission to the Moon.

Prof Manuel Grande, C1XS Principal Investigator, Aberystwyth University, said, "In the UK we are rapidly becoming the world's leading maker of planetary X-ray instruments. C1XS will cement this position, and paves the way for UK leadership of similar instruments at Mercury and elsewhere in the Solar System."

Dr Ian Crawford concluded, "There is currently a renaissance in lunar exploration, with many international lunar missions either underway or planned for the next few years, leading up to the planned return of astronauts to the lunar surface by 2020. Through its involvement in C1XS, the UK is playing an important role in this international activity."

• Click here to download an animation about C1XS
• Credit: The animation was produced by Doug Ellison
• Click here for an image of the flight model C1XS instrument in the vibration testing facility with RAL engineers.(Credit: RAL)

C1XS X-ray Spectrometer

C1XS will work by looking at X-rays from the Sun which have been absorbed by atoms in the lunar soil, then re-emitted in such a way as to reveal the chemistry of the surface. The spectrometer is sensitive to magnesium, aluminium and silicon X-rays. When the solar X-ray illumination is bright, for example during a solar flare, it may also be able to make measurements of other elements such as iron, titanium and calcium. To make accurate measurements of the surface elements it is essential to measure the X-rays being produced by the Sun. C1XS has an additional detector system to measure these X-rays called the X-ray Solar Monitor (XSM) which is provided by the University of Helsinki Observatory, Finland.

C1XS uses an advanced version of conventional CCD sensors such as you might find in a digital camera, called swept charge devices. These are mounted behind a gold/copper ‘collimator’, which limits the field of view of the X-ray detectors to a narrow beam. Together these two innovations form an X-ray camera that has high resolution allowing identification of the surface elements, yet is far more compact and lower mass than other spacecraft’s X-ray spectrometers.

C1XS is a joint UK-Indian instrument with a diverse range of national and international collaborators from both research and academic institutions. View the full list of participating institutions and C1XS investigators here. Those participating in the UK are STFC Rutherford Appleton Laboratory, Aberystwyth University, Birkbeck College, Brunel University, University College London. Industrial partners include Oxford Instruments Analytical (Finland); who have provided the XSM, and e2V for the provision of Swept Charge Devices.

Facts about Chandrayaan-1

• Chandrayaan-1 is expected to launch from Satish Dhawan Space Centre at Sriharikota (SHAR), India.
• The launch is expected to take place at around 1:58 am on Wednesday 22 October. Follow the launch at http://www.isro.org/
• Within 18 days from launch Chandrayaan-1 will reach the Moon.
• Chandrayaan-1 will orbit the Moon at a height of 100 km.