Lunar Lander (space mission)
Depiction of Lunar Lander on the Moon's surface
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| Mission type | Technology demonstration, Exploration |
|---|---|
| Operator | ESA |
| Mission duration | Transfer: ~2-4 months Surface operations: several months (proposed) |
| Spacecraft properties | |
| Manufacturer | Astrium |
| Launch mass | ~2,000 kg (4,400 lb) |
| Dry mass | 750 kg (1,650 lb) |
| Dimensions | height: 3.44 m (11.3 ft) diameter: 5.6 m (18 ft) |
| Start of mission | |
| Launch date | 2018 (proposed) |
| Rocket | Soyuz 2.1b |
| Launch site | Guiana Space Centre - ELS |
| Moon lander | |
| Landing date | 2018 (proposed) |
| Landing site | Lunar south pole |
The Lunar Lander was a robotic mission intended to send a lander vehicle to the Moon, led by ESA's Human Spaceflight and Operations directorate. The primary objective of the Lunar Lander mission was to demonstrate Europe’s ability to deliver payload safely and accurately to the Moon’s surface. More specifically the mission would have demonstrated the technologies required to achieve a soft and precise landing while autonomously avoiding surface hazards that can endanger landing and surface mission safety. These technologies will be an asset for future human and robotic exploration missions. However the project was put on hold at the 2012 ESA Ministerial Council.
Launching from Centre Spatial Guyanais, Kourou in late 2018 on a Soyuz launcher, the Lander is injected into a Highly Elliptical Orbit (HEO) by a Fregat-MT upper stage, through a series of intermediate orbits. Following Fregat separation, the lander uses its own propulsion to enter the final Lunar Transfer Orbit and, after an overall transfer time of several weeks, injects itself into a polar orbit around the Moon. After a series of Apolune and Perilune lowering manoeuvres, the Lander reaches its final Low Lunar Orbit (LLO) at 100 km altitude.
Once in low lunar orbit the Lunar Lander prepares for the final phase of the mission waiting for the correct constellation of orbit, Earth and Sun geometry and performing the checkout and calibration operations of the systems critical for landing. The time spent by the Lander in LLO before the start of the landing operations is expected to last from a number of weeks up to a maximum of 3 months.
The descent and landing phase of the mission starts when the Lander performs a de-orbit burn close to the lunar north pole. This burn decreases the orbit's perigee to about 15 km, some 500 km ahead of the lunar south pole, half an orbit later. During the coasting period, automatic visual recognition of landmarks on the lunar surface is used to determine the lander's precise location and to ensure correct positioning at the beginning of the final descent. Heading towards the south pole, the lander enters the final powered descent phase. Using its cluster of thrusters, the lander decelerates and descends. During this phase, a varying thrust needs to be applied as the lander approaches its landing site. Finer thrust levels are achieved using the ATV engines in pulse modulation, as shown in this video of the hot-firing tests on YouTube. At an altitude of few kilometres, the Hazard Detection and Avoidance system (HDA) is able to see the primary landing site and to evaluate it. If the primary site is deemed unsafe, due to the presence of surface hazards (like steep slopes, craters, boulders, shadows, etc.), the HDA has the opportunity to command re-targetings to a secondary landing site. When a safe landing site is found, the lander performs a soft touch down using its legs.
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Wikipedia