Lunar Reconnaissance Orbiter (LRO)
- The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit.
- Data collected by LRO has been described as essential for planning NASA's future human and robotic missions to the Moon. Its detailed mapping program is identifying safe landing sites, locating potential resources on the Moon, characterizing the radiation environment, and demonstrating new technologies.
- Launched on June 18, 2009, in conjunction with the Lunar Crater Observation and Sensing Satellite (LCROSS), as the vanguard of NASA's Lunar Precursor Robotic Program, LRO was the first United States mission to the Moon in over ten years.
- LRO and LCROSS were launched as part of the United States's Vision for Space Exploration program.
- The probe has made a 3-D map of the Moon's surface at 100-meter resolution and 98.2% coverage (excluding polar areas in deep shadow), including 0.5-meter resolution images of Apollo landing sites. The first images from LRO were published on July 2, 2009, showing a region in the lunar highlands south of Mare Nubium (Sea of Clouds).
- NASA’s Lunar Reconnaissance Orbiter (LRO) has observed water molecules moving around the dayside of Moon, an advance that could help us learn about the accessibility of water that can be used by humans in future lunar missions.
- Lyman Alpha Mapping Project (LAMP) — the instrument aboard LRO — measured sparse layer of molecules temporarily stuck to the Moon’s surface, which helped characterise lunar hydration changes over the course of a day.
Uses of lunar water:
Lunar water can potentially be used by humans to make fuel or to use for radiation shielding or thermal management; if these materials do not need to be launched from Earth, that makes these future missions more affordable.
Source of Moon’s surface water:
- Scientists had hypothesised that hydrogen ions in the solar wind may be the source of most of the moon’s surface water. As a result, when the moon passes behind the earth and is shielded from the solar wind, the ‘water spigot’ should essentially turn off.
- However, the water observed by LAMP does not decrease when the moon is shielded by the earth and the region influenced by its magnetic field, suggesting water builds up over time, rather than ‘raining’ down directly from the solar wind.
- Water molecules remain tightly bound to the regolith until surface temperatures peak near lunar noon. Molecules thermally desorb and can bounce to a nearby location that is cold enough for the molecule to stick or populate the moon’s extremely tenuous atmosphere or exosphere, until temperatures drop and the molecules return to the surface.
Objectives of LRO
- Identify potential lunar resources.
- Gather detailed maps of the lunar surface.
- Collect data on the moon’s radiation levels.
- Study the moons polar regions for resources that could be used in future manned missions or robotic sample return missions.
- Provide measurements to characterize future robotic explorers, human lunar landing sites and to derive measurements that can be used directly in support of future Lunar Human Exploration Systems.