Lunar Reconnaissance Orbiter
Mission
LRO will orbit the moon for at least one year at a relatively low polar orbit at an altitude of 30 to 50 kilometers. As a starting rocket initially about 1,000 kilogram probe a Delta II should serve. In December 2005, the Agency revised their initial choice and decided whether to start the probe with a Delta IV or Atlas V, Delta II since only has a spin-stabilized upper stage, which does not meet the requirements for the launch of LRO. On 28 July 2006, NASA announced that the launch would take place on an Atlas V ( 401) rocket.
Since the Atlas V is much stronger than the originally planned Delta II, the probe could be interpreted heavier by about 1000 kg. It was thus possible additional payload, such as an impactor, a lander or a separate communication microsatellites to take to the moon. After NASA had received several proposals for additional payload, the impactor variant was announced in the form of the LCROSS mission as the final winner of this contest on April 10, 2006.
The Goddard Space Flight Center in Greenbelt (Maryland) built the probe, while the instruments were built by private companies. The budget of the overall mission, including LCROSS, is 583 million U.S. dollars.
Until 31 July 2008, it was possible to transmit his own name via the internet to NASA. The names were stored on a chip of the Lunar Reconnaissance Orbiter and thus were on the probe, as it orbited the moon.
50 goals on the lunar surface are recorded with special priority. This includes the landing sites of various missions. Images of Apollo landing sites to provide further knowledge of the geological environment in order to classify the results of the Apollo program more closely. The landing site of Lunokhod 1 was a target because you did not know exactly its final position after almost a year of driving the rover. The " impact points " of failures to be detected. Just in time for the anniversary of the Apollo 11 landing on July 20, 2009 Pictures of the landing site in Mare Tranquillitatis have been published. High-precision images of the landing sites were released in September 2011. The images of the landing site of Apollo 17 can also be paths of the astronauts, the lunar vehicle lanes and sites of scientific instruments recognize.
Instrumentation
With six different scientific equipment LRO studied the moon in more detail than this has ever been studied before. In addition, a technology demonstration payload is installed, which is a developed by the U.S. Department of Defense Synthetic Aperture Radar (cf. also Chandrayaan -1). For this purpose, a total of 685 watts of electrical power of the solar cells with 4.3 times 3.2 meters size and lithium -ion batteries with 80 Ah capacity available. Data transfer takes place in the Ka band ( high-speed downlink with 100 Mb / s) and S-band ( two-way ).
- LOLA ( Lunar Orbiter Laser Altimeter ) is a lidar with a very accurate topographic map of the moon to be created. Due to the high albedo of water ice is also possible to detect the ice surface in the polar regions.
- Created LROC ( Lunar Reconnaissance Orbiter Cameras ) both wide-angle shots (Wide Angle Camera, WAC) as well as detailed shots ( Narrow Angle Camerae NAC) of possible future landing sites. From the planned orbit altitude of 50 kilometers, the LROC has a resolution of 0.5 meters per pixel.
- LEND ( Lunar Exploration Neutron Detector ) is one of neutrons, which are emitted from the lunar surface. This is for the search of water, because water absorbs neutrons. Reduced radiation in a certain area so indicates water. LEND is developed by Igor Mitrofanov of the Institute for Space Research, Federal Space Agency in Moscow and is based on the BASIS - instrument of the Mars Odyssey probe.
- DLRE ( Diviner Lunar Radiometer Experiment) mapped the temperature of the lunar surface. This instrument is used to search for water.
- LAMP ( Lyman - Alpha Mapping Project ) is looking for ice deposits in the darkness of the permanently shadowed craters at the poles. It takes advantage of the reflection of starlight in the range of ultraviolet radiation.
- CRaTER (Cosmic Ray Telescope for the Effects of Radiation ) measures the potential biological effects of cosmic radiation.
- Mini -RF is a technology demonstration of a single aperture radars (SAR ) operating in X-band and S-band. Mini -RF is used to demonstrate the new lightweight SAR of communication technologies and locating potentially available water ice.
Mission History
LRO launched with LCROSS on June 18, 2009 at 21:32 UTC on an Atlas V rocket. This brought the probes in a temporary parking orbit around the Earth. After 24 minutes, there was a further ignition of the engines of the Centaur upper stage, which in a highly elliptical orbit brought the combined direction of the Moon. Shortly after the rocket has been rotated 180 degrees and dissolved LRO. On June 23, at 09:47 UTC, the engine was ignited for 40 minutes to slow the probe so that they einschwenkte into a polar lunar orbit. Four other thruster firings during the following five days changed the orbit of initially 220 km to 3100 km to 31 km ( south pole) to 199 kilometers. In this orbit, all the instruments were commissioned and calibrated. During this phase about 60 days, the height is reduced to approximately 50 kilometers. The probe mapped since the moon and collect data on resources and the radiation exposure on the moon. The mission should conclude with a targeted impact on the moon.
First pictures of the LROC were published on 2 July 2009. On 17 July 2009, NASA released images of five of the six landing sites of the Apollo program, on which the left on the Moon stages of the lunar modules are seen. Due to the low sun, the lower levels of the Lunar modules mainly by the long shadows over the images to detect.
In September 2011, NASA released a video showing the landing sites of Apollo 12, 14 and 17 in even higher resolution. In March 2012, the first photo of the landing site of Apollo 11 from the final orbit and an altitude of 24 km has been published. On him the footprints of the astronauts are visible next to the landing module and scientific equipment. The images could contribute to rebut conspiracy theories landing on the moon.
- LRO images of the landing sites
Apollo 12
Apollo 17
Luna 21
LRO continues to work until October 2014, and possibly two more years.