[meteorite-list] NASA Completes LADEE Mission with Planned Impact on Moon's Surface

[Ron Baalke]

April 18, 2014

NASA Completes LADEE Mission with Planned Impact on Moon's Surface

Ground controllers at NASA's Ames Research Center in Moffett Field, Calif., 
have confirmed that NASA's Lunar Atmosphere and Dust Environment Explorer 
(LADEE) spacecraft impacted the surface of the moon, as planned, between 
9:30 and 10:22 p.m. PDT Thursday, April 17.

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.

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.

"At the time of impact, LADEE was traveling at a speed of 3,600 miles 
per hour - about three times the speed of a high-powered rifle bullet," 
said Rick Elphic, LADEE project scientist at Ames. "There's nothing gentle 
about impact at these speeds - it's just a question of whether LADEE made 
a localized craterlet on a hillside or scattered debris across a flat 
area. It will be interesting to see what kind of feature LADEE has created."

In early April, the spacecraft was commanded to carry out maneuvers that 
would lower its closest approach to the lunar surface. The new orbit brought 
LADEE to altitudes below one mile (two kilometers) above the lunar surface. 
This is lower than most commercial airliners fly above Earth, enabling 
scientists to gather unprecedented science measurements.

On April 11, LADEE performed a final maneuver to ensure a trajectory that 
caused the spacecraft to impact the far side of the moon, which is not 
in view of Earth or near any previous lunar mission landings. LADEE also 
survived the total lunar eclipse on April 14 to 15. This demonstrated 
the spacecraft's ability to endure low temperatures and a drain on batteries 
as it, and the moon, passed through Earth's deep shadow.

In the coming months, mission controllers will determine the exact time 
and location of LADEE's impact and work with the agency's Lunar Reconnaissance 
Orbiter (LRO) team to possibly capture an image of the impact site. Launched 
in June 2009, LRO provides data and detailed images of the lunar surface.

"It's bittersweet knowing we have received the final transmission from 
the LADEE spacecraft after spending years building it in-house at Ames, 
and then being in constant contact as it circled the moon for the last 
several months," said Butler Hine, LADEE project manager at Ames.

Launched in September 2013 from NASA's Wallops Flight Facility in Virginia, 
LADEE began orbiting the moon Oct. 6 and gathering science data Nov. 10. 
The spacecraft entered its science orbit around the moon's equator on 
Nov. 20, and in March 2014, LADEE extended its mission operations following 
a highly successful 100-day primary science phase.

LADEE also hosted NASA's first dedicated system for two-way communication 
using laser instead of radio waves. The Lunar Laser Communication Demonstration 
(LLCD) made history using a pulsed laser beam to transmit data over the 
239,000 miles from the moon to the Earth at a record-breaking download 
rate of 622 megabits-per-second (Mbps). In addition, an error-free data 
upload rate of 20 Mbps was transmitted from the primary ground station 
in New Mexico to the Laser Communications Space Terminal aboard LADEE.

LADEE gathered detailed information about the structure and composition 
of the thin lunar atmosphere. In addition, scientists hope to use the 
data to address a long-standing question: Was lunar dust, electrically 
charged by sunlight, responsible for the pre-sunrise glow seen above the 
lunar horizon during several Apollo missions?

"LADEE was a mission of firsts, achieving yet another first by successfully 
flying more than 100 orbits at extremely low altitudes," said Joan Salute, 
LADEE program executive, at NASA Headquarters in Washington. "Although 
a risky decision, we're already seeing evidence that the risk was worth 
taking."

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.

NASA also included the public in the final chapter of the LADEE story. 
A "Take the Plunge" contest provided an opportunity for the public to 
guess the date and time of the spacecraft's impact via the internet. Thousands 
submitted predictions. NASA will provide winners a digital congratulatory 
certificate.

NASA's Science Mission Directorate in Washington funds the LADEE mission. 
Ames was responsible for spacecraft design, development, testing and mission 
operations, in addition to managing the overall mission. NASA's Goddard 
Space Flight Center in Greenbelt, Md., managed the science instruments, 
technology demonstration payload and science operations center, and provided 
mission support. Goddard also manages the LRO mission. Wallops was responsible 
for launch vehicle integration, launch services and operations. NASA's 
Marshall Space Flight Center in Huntsville, Ala., managed LADEE within 
the Lunar Quest Program Office.

For more information about the LADEE mission, visit:

http://www.nasa.gov/ladee

For more information about LLCD, visit:

http://llcd.gsfc.nasa.gov

-end-

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Rachel Hoover
Ames Research Center, Moffett Field, Calif.
650-930-6149
rachel.hoover at nasa.gov

Dewayne Washington
Goddard Space Flight Center, Greenbelt, Md.
301-286-0040
dewayne.a.washington at nasa.gov