April 18, 2014. Ground controllers at NASA’s Ames Research Center confirmed that the LADEE spacecraft impacted the surface of the moon, as planned, on Thursday, April 17. The impact was the conclusion of a highly successful 130-day mission for LADEE, which carried the LASP-built Lunar Dust Experiment (LDEX).
LDEX was the latest in a series of dust detectors designed and built at the Laboratory for Atmospheric and Space Physics in Boulder, Colorado. During the mission, the LDEX recorded more than 11,000 impacts from lunar dust particles in an effort to determine the size, charge, and spatial distribution of dust grains lofted above the moon’s surface.
The LADEE mission launched in early September 2013 and, after two months of orbital maneuvers and instrument commissioning, began investigating the tenuous atmosphere of the moon in order to characterize its density, composition, and variability.
A thorough understanding of the characteristics of our nearest celestial neighbor will help researchers understand other bodies in the solar system, such as large asteroids, Mercury and the moons of outer planets.
LASP scientist and CU-Boulder Physics professor Mihály Horányi is principal investigator for the LDEX instrument. “We have gotten beautiful data,” said Horányi. “We discovered that a cloud of dust permanently engulfs the moon, and that the dust density dramatically increases toward its surface.”
The LADEE mission completed its primary 100-day science objective in March, but NASA approved a 28-day mission extension, allowing the spacecraft to gather an additional full lunar cycle worth of data from very low altitudes. The additional data, collected from within a few miles above the lunar surface, has given mission scientists an opportunity to observe changes in particle density and size distribution at a wider variety of altitudes.
LADEE lacked fuel to maintain a long-term lunar orbit or continue science operations and was intentionally sent into the lunar surface. The spacecraft’s orbit naturally decayed following the mission’s final low-altitude science phase and an intentional crash was planned. LADEE ran its science instruments almost non-stop right up to impact.
During impact, engineers believe the LADEE spacecraft, the size of a vending machine, broke apart, with most of the spacecraft’s material heating up several hundred degrees – or even vaporizing – at the surface. Any material that remained is likely buried in shallow craters.
The impact took place on the far side of the moon, opposite our view from Earth, and far from any of the historic Apollo exploration locations.
Scientists will continue to study the data collected prior to impact and will publish papers in the coming months. To see updates, follow the LADEE mission page at: http://www.nasa.gov/mission_pages/ladee/main/index.html#.U1gb4I5tUr9