NASA's Lunar Crater Observation and Sensing Satellite, the Lunar Reconnaissance Orbiter and India's Chandrayaan-1 lunar orbiters and other missions discovered in 2009 both water and hydroxyl deposits at high latitudes on the lunar surface, indicating the presence of trace amounts of adsorbed or bound water are present. These missions suggest that there might be enough ice water at polar regions to be used by future landed missions, but the distribution is difficult to reconcile with thermal maps. Lunar prospecting missions are intended to pave the way toward incorporating use of space resources into mission architectures. NASA's planning for eventual human missions to Mars depends on tapping the local natural resources to make oxygen and propellant for launching the return ship back to Earth, and a lunar precursor mission is a convenient location to test such in situ resource utilization technology. The mission concept was developed by a team from the Jet Propulsion Laboratory, the University of California, Los Angeles, and NASA Marshall Space Flight Center and proposed to NASA's FY2014 Advanced Exploration Systems call. The mission was selected for funding in early 2015. . In its original conception, the Lunar Flashlight spacecraft would have been a 6U CubeSat format or bus propelled by an 80 m2solar sail that would also function as reflector to illuminate some selected permanently shadowed areas on the Moon, while an onboard infrared spectrometer measured the reflected spectrum diagnostic of surface compositional mix among rock/dust, regolith, water ice, CO2, methane ice, and possibly ammonia ice. The illuminated spot would have been about in diameter, reflected from an altitude of.
Overview and objectives
The goal of Lunar Flashlight is to determine the presence or absence of exposed water ice and its physical state, and map its concentration at the 1-2 kilometer scale within the permanently shadowed regions of the lunar south pole. The mission will be the first CubeSat to reach the Moon, and the first mission to use lasers to look for water ice. Any polar volatile data collected by Lunar Flashlight could then ensure the most appropriate landing sites for a more expensive rover to perform in situ measurements and chemical analyses. The spacecraft will maneuver to its lunar polar orbit and use its near infrared lasers to shine light into the shaded polar regions, while the on-board spectrometer measures surface reflection and composition. Barbara Cohen from the NASA Marshall Space Flight Center is the Principal Investigator.
Scientific payload
The proposed payload on this nanosatellite is an infrared spectrometer, consisting of a lens, dichroic beam splitters and multiple single-element detectors. It occupies 2 of the 6 modules of the 6U CubeSat bus. The attitude control system, command and data handling, and power systems will occupy 1.5U; the Iris telecom system will occupy 0.5U. The Lunar Flashlight payload is derived from a few predecessor systems, including JPL's INSPIRE, MARCO and JPL's experience with spectrometers, including the Moon Mineralogy Mapper. The 6U CubeSat bus will utilize mostly commercial-off-the-shelf components such as the lithium ion batteries, the CPU board, HaWK solar panels produced by , star tracker and 3-axis reaction wheels for attitude control. The CPU is a 'Rad-Tol Dependable Multiprocessor'. JPL will provide the Iris transponder that provides timing, navigation and telecommunication in the X-band, which is to be monitored with the NASA Deep Space Network.
Launch
The spacecraft will be launched on the maiden flight of the Space Launch System, as a secondary payload of the 2021 Artemis 1 mission.
Proposed trajectory
The Lunar Flashlight spacecraft will be ejected from the Space Launch System during its translunar flight, and will use a Sun sensor and solar panels to power the 3-axes reaction wheels. It also features a chemical monopropellant propulsion and orientation system. The propulsion system occupies 3U of volume including 2 kg of monopropellant. The concept is that it will then begin a trajectory toward a multiple lunar, and possibly an Earth swingby transfer; it will be captured into a lunar polar orbit in one or two months after launch, depending on the selected trajectory.
