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

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 18 Apr 2014 10:25:34 -0700 (PDT)
Message-ID: <201404181725.s3IHPY9s010921_at_zagami.jpl.nasa.gov>

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
Received on Fri 18 Apr 2014 01:25:34 PM PDT