Dr. Butler Hine is the project manager of the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft. The vehicle, successfully launched in September, will characterize the dust environment of the moon.
NASA Tech Briefs: What is the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft?
Dr. Butler Hine: It’s a small robotic orbiter. We launched on September 6 on a Minotaur V rocket. We’re currently in phasing loops around the Earth. We’re on our way to the moon, and once we get there, we’re going to check out our science instruments and do an optical laser-com experiment. We’ll drop down into a very low orbit and do our science missions.
NTB: What instruments are on the LADEE spacecraft?
Hine: We have three science instruments. One is a neutral mass spectrometer from NASA Goddard. One is an ultraviolet visible spectrometer from NASA Ames, and the third instrument is an in situ dust detector that was built by the University of Colorado.
NTB: You’re testing the instruments at this point?
Hine: They haven’t been activated yet. We’re still in the cruise phase on the way to the moon. We’ll start doing early checkouts of the instruments a little later in the cruise phase, but after we do our capture burn to get us into lunar orbit and go into our commissioning orbit, that’s when the science instruments will be extensively checked out and prepared for their science phase.
NTB: What does LADEE do, and why is it important?
Hine: There is a leftover question from the early Surveyor and Apollo days. The astronauts saw evidence of streaks or glow as the terminator approached, and there are a lot of theories about what this is. One of the theories is that you have elevated dust that occurs when the terminator passes. This is a very interesting scientific question. It [relates] to the transport mechanisms around the moon, how material moves around the moon, and collects in various places.
LADEE will fly several times a day during the mission, and try to measure the dust levels and characterize the dust. We’re also looking at elements: atoms, molecules, and various elements around the lunar atmosphere. It’s actually an exosphere, a collisionless atmosphere. It’s of interest for scientific purposes in its own right, but it’s also of interest to determine how transport mechanisms can carry material around the moon.
The previous Lunar CRater Observation and Sensing Satellite (LCROSS) mission confirmed water ice at the permanently shadowed pole on the moon. One of the questions is: How does that material get there, so we’re trying to help answer the questions of transport material around the moon.
NTB: How does it collect the data? And how quickly does it collect the data?
Hine: We orbit the moon about 13 times every terrestrial day, so during that time, we fly into and out of the terminators on both sides: the dawn terminator and the dust terminator. At those points, at local midnight and local noon, the instruments are activated in various sequences to make their measurements. The neutral mass spectrometer is measuring the environment right around the spacecraft, trying to detect atoms and molecules. The dust detector is measuring the dust impacts as we fly through the environment. The ultraviolet visible spectrograph is a remote sensing instrument. We use that to watch for the absorption of spectrographic lines against the sun as the sun sets or rises behind the moon.
NTB: The spacecraft was successfully launched at 11:27 p.m. EDT Friday, Sept. 6. Can you talk about the launch? Did all go as expected?
Hine: We launched on a Minotaur V rocket out of Wallops, Virginia. That’s a lot of firsts; this is the first flight of a Minotaur V. It’s a five-stage derivative of a Peacekeeper ICBM [missile]. The first three stages are assets from the Air Force, which are repurposed for civilian use. Those three stages are an ICBM, and then Orbital Sciences, under contract with the Air Force, added a fourth stage to make it a Minotaur IV. We added a fifth stage to make it a Minotaur V, because we needed not only the capability of going into Earth orbit; we actually needed a kick stage to get us into trans-lunar injection trajectory.
So we launched out of Wallops. It’s one of the launch locations that you can use for peacekeeper missiles, and we wanted a spot that could launch us eastward. That’s a safe location from Wallops to launch us out over the ocean, and it was a spectacular launch. It achieved exactly the orbit we needed. In fact, it did not give us a hot or cold insertion. It gave us a pretty much perfect insertion on Sept 6. So we were really happy.