About Lunar Flashlight
Lunar Flashlight is an innovative, small NASA mission to be launched as a rideshare payload on the iSpace Hakuto-R mission launched by SpaceX aboard a Falcon 9 Rocket. This highly mass- and volume-constrained satellite will demonstrate several technologies for NASA, including the use of “green” propellant, the ability for a CubeSat-sized satellite to perform science measurements beyond low Earth orbit, and the first planetary mission to use multi-band active reflectometry from orbit. Lunar Flashlight will detect and map water ice in permanently shadowed regions of the lunar south pole by measuring surface reflectance at multiple wavelengths. Mapping and quantifying lunar water ice addresses one of NASA’s Strategic Knowledge Gaps to understand the lunar resource potential for future human exploration of the Moon.
Why search for water on the Moon?
One of the largest unanswered questions in planetary science is, "From where, and when did Earth acquire enough water to cover most of the surface after its formation?" It is hard to answer these questions using water on Earth because it is constantly changing, no longer carrying information about when it was deposited and how. But on the Moon, in its permanently shadowed regions, we believe the water ice that is known to exist at the poles may have retained this record over billions of years. Understanding the quantity and location of water ice on the Moon will be a first step in answering these questions. Water throughout the solar system will also be vital for future exploration, as it is needed for humans to exist for long periods of time away from Earth, but it can also be used as rocket fuel so we can explore further than ever before.
What are Permanently Shadowed Regions?
Because the Moon has a very low tilt/obliquity relative to the Sun, the interiors of deep craters near the Lunar poles have never experienced direct sunlight. These areas, known as Permanently Shadowed Regions or PSRs, have remained untouched by the radiation emanating from the Sun. Without direct sunlight these regions ae incredibly cold, potentially as low as -415 Fahrenheit (-250 Celsius). At such temperatures, even in the vacuum of space ice is able to remain stable for billions of years without being lost to space.
