What will all the instruments do?
Multinational teams of scientists and engineers will conduct ten different investigations coordinated by a Science and Technology Operations Centre. Instrument teams are led by principal investigators from Finland, Germany, Italy, Switzerland and the United Kingdom. All ESA member countries are taking part, providing coinvestigators for various experiments.
Testing new techniques
EPDP and SPEDE. Designers of future solar-electric spacecraft want to know how SMART-1's ion engine performs, what side effects it has, and whether the spacecraft interacts with natural electric and magnetic phenomena in the space around it. Possible problems include deflection of the ion engine's drive direction, erosion of surfaces, short-circuits by sparks, interference with radio signals, and accumulating dust. The main onboard instruments monitoring these effects are EPDP and SPEDE.
KaTE and RSIS. Small changes in SMART-1's motion will reveal the precise drive delivered by the ion engine. Similarly to police radars used to catch speeding motorists, RSIS will employ the Doppler effect to see how the speed alters the wavelength of radio pulses. It will use the very short radio waves of KaTE. The primary purpose of KaTE is to demonstrate the next generation of radio links between the Earth and far-flung spacecraft. Microwaves of the Ka band, around 9 millimetres in wavelength, can be focused into relatively narrow beams by the small dish antennas available on spacecraft.
Laser Link is another communications experiment. ESA already has laser links with telecom satellites from an optical ground station on Tenerife in Spain's Canary Islands. Aiming the beam becomes much more difficult if, like SMART-1, the spacecraft is far away and moving rapidly. The hope is that the onboard camera AMIE will see Tenerife illuminated with laser light.
OBAN. Future spacecraft will be more self-reliant in guiding themselves along predefined paths towards distant destinations. OBAN will evaluate a computer technique for on-board autonomous navigation. It will use the bearings of stars seen by SMART-1's star trackers, and the Earth, Moon and possibly asteroids seen by the AMIE camera.
AMIE, SIR and D-CIXS. Different kinds of visible and invisible light coming from the lunar surface will provide clues about its chemical composition and geological history. The ultracompact electronic camera, AMIE, will survey the terrain using visible and near-infrared light. An infrared spectrometer, SIR, will chart the Moon's minerals. An X-ray spectrometer, D-CIXS, will identify key chemical elements in the lunar surface.
XSM. The D-CIXS measurements can be confusing because of variations in solar X-ray emissions, which depend on how stormy the Sun is on that day. For this reason, SMART-1 monitors the solar X-rays with its XSM instrument. XSM will also make its own independent study of solar variability.
SPEDE. Similarly to a ship at sea, the Moon leaves a wake in the solar wind - the non-stop stream of charged particles and associated magnetic fields coming from the Sun. The SPEDE electrical experiment will observe this effect from close by.
RSIS. Using the KaTE microwave system and the AMIE camera, the RSIS radio experiment will demonstrate a new way of measuring the rotations of planets and their moons. It should be able to detect a well-known nodding of the Moon, which slightly tilts first its north pole and then its south pole, towards the Earth.
These instruments and techniques that will be tested when SMART-1 examines the Moon will later help ESA's BepiColombo spacecraft to investigate the planet Mercury.