What is EuroMoon 2000?

The EuroMoon 2000 mission consists of a Lander and an Orbiter with a total mass in lunar transfer orbit of at least 2900 kg. The composite spacecraft would be placed into a circular polar orbit of 200 km altitude with a dedicated Ariane-4 launch. After about one month of observations, mainly for establishing preliminary gravitational data, the composite's altitude would be lowered to 100 km, where the Orbiter (weighing about 300 kg) would be separated from the Lander.

The Orbiter's task would be to make a detailed topographic map using a stereoscopic camera and to establish the lunar gravitational potential more accurately with the help of a small subsatellite, in order to assist the subsequent landing operation. The Orbiter's payload (approx. 50 kg) would also address a large proportion of the MORO mission's objectives, including geochemical science.

The Lander would set down (to within ±100 m) on the highest point of rim of the South Pole crater, in order to take advantage of the permanent sunlight there. The landed mass of 1000 kg would include more than 250 kg of payload, the primary objective of which would be to study the soil composition, heat flow and possibly seismic activity in the neighbourhood of the intended landing site, which lies inside the largest lunar crater, the Aitken Basin.

Overall configuration of the EuroMoon 2000 spacecraft

In addition to the ESA element, more than half of the Lander's payload capacity would be allocated to three or four 'Millennium Challenge' experiments. These would be the winners of a contest involving Universities and European Industry. Their 'challenge' would be to devise various robotic devices to investigate the inside of the South Pole crater (20 km in diameter and approximately 3000 m deep, with temperatures of the order of 200 deg C), hopefully reaching the South Pole itself.

The Lander on the lunar surface, prior to solar-array deployment

The EuroMoon 2000 mission re-uses most of the LEDA design, although because of (i) the short time available for development, (ii) the precise landing requirement (±100 m), and (iii) the availability of the Orbiter, some significant modifications are made. Moreover, the EuroMoon 2000 mission has a high potential public-relations value, with all of the operational phases being very visible to the general public (participation of contestants, real-time links with schools, scientists in the loop, etc.).

The Mini-Rover and Micro-Rover

A high probability of mission success is ensured by:

• taking most risk during the mission-development phase, with early prototyping, testing and simulations

• adopting an operational scenario similar to that of a manned mission, i.e. a man-in-the-loop approach with planned pauses for assessment ('plateaus'), and if necessary recovery actions, to provide the highest possible likelihood of mission success, the higher risk phases being started only after satisfactory completion of the preceding lower risk activities.

These considerations drive the need for the orbiting phase, during which a high-resolution camera (like that developed for Mars 96) would provide an accurate digital elevation map prior to making the landing. This map and accurate tracking of the Lander from the ground would allow near-real-time translation of terrain features to absolute coordinates (by ESOC). Following this initial phase, a small subsatellite would be released at an altitude of about 100 km to perform very accurate gravity measurements using satellite-to-satellite tracking (as was foreseen for MORO). A radar system would be available to obtain terrain altitude, and possibly velocity and slope information.

This approach already provides a good probability of success for a 'blind landing' (if no visual data were sent to ground). To enhance landing safety and accuracy, however, images from several Lander cameras will be used on the ground for attitude updates during the descending orbit, for navigation updates during the powered descent, and for hazard avoidance during the final landing phase. After landing, these cameras could be used to monitor the robotic surveying activities.

Key Features of EuroMoon 2000

• Launch in the year 2000, providing substantial cultural impact.

• Landing on the rim of a lunar South Pole crater and the exploitation of specific favourable landing-site features, including permanent sunlight, terrain recognition for approach and landing.

• Use of a dedicated Ariane-4 launcher, which provides sufficient mass margin and greater launch-time flexibility than a shared Ariane-5.

• Use of a small orbiter, which can provide unique scientific data, compatible with the MORO mission studies.

• A man in the loop mission-operations approach, which ensures both a high success probability and high public visibility.

courtesy of Clementine/BMDO