Tonight at 7 p.m. (EST) NASA’s Deep Space Network antennas will pull down
their last Near Earth Asteroid Rendezvous (NEAR) mission data, bringing to a
close the first mission to extensively study an asteroid. NEAR, which was
the first mission in NASA’s Discovery Program of low-cost, scientifically
focused space missions, and the first to land on an asteroid, has delighted
astronomy neophytes and scientists alike.

“NEAR has raised the bar,” says Dr. Stamatios Krimigis, Space Department
head at The Johns Hopkins University Applied Physics Laboratory in Laurel,
Md., which built the spacecraft and managed the NEAR mission. “The
Laboratory is very proud to have managed such a successful mission and
worked with such a strong team of partners from industry, government and
other universities. The team had no weak links and the result was an
historic mission that surpassed everyone’s expectations.”

“This mission has been successful far beyond what was in the original
mission plan,” says NEAR Mission Director Dr. Robert Farquhar of APL. “We
got the first images of a C-class asteroid when we added a flyby of asteroid
Mathilde in 1997; we added two low altitude series of passes over the ends
of Eros this past October and January that gave us spectacular images from
2.7 kilometers above the surface; and we achieved the first landing of a
spacecraft on an asteroid on Feb. 12. All this at no extra cost. When you
talk about ‘ faster, cheaper, better,’ this is what ‘better’ means.”

On Feb. 12 at 3:01:52 p.m. (EST), NEAR Shoemaker made a gentle,
picture-perfect 3-point landing on the tips of two solar panels and the
bottom edge of the spacecraft body. But the mission wasn’t finished yet.
Much to the amazement of the mission team and millions of observers around
the world who were following the descent, the touchdown was so elegant that
the craft was still operating and sending a signal back to Earth even after
landing.

Jumping at the chance to get “bonus science” from the spacecraft, which had
already collected 10 times more data than originally planned, the mission
team asked for and got a 10-day extension and then four more days of DSN
antenna time, enabling NEAR Shoemaker to send back data through Feb. 28. The
extension was granted to allow the gamma-ray spectrometer to collect data
from an ideal vantage point about four inches from the surface. The
spectrometer team quickly redesigned software and uploaded it to the
spacecraft so they could begin collecting elemental composition readings.

The results were spectacular. “This is the first gamma-ray experiment that
has ever been done on the surface of a body other than Earth,” says Dr.
Jacob Trombka, of NASA’s Goddard Space Flight Center, in Greenbelt, Md., who
heads the gamma-ray spectrometer team. “In fact, we can say it’s the first
feasibility study of how to design an instrument to be used on a rover that
could select samples from the surface, look for the presence of water, or
map the surface for the purpose of future mining.”

The gamma-ray spectrometer team was able to retrieve data for a period of
seven days after the spacecraft landed. “Right now we know we have good data
with strong signatures,” Trombka says. “But it will take months to
scrutinize what we’ve collected. What we’re looking for is information that
will help us more precisely classify Eros and determine the relationship
between the asteroid and meteorites that have fallen to Earth.”

NEAR Shoemaker now rests silently just to the south of the saddle-shaped
feature Himeros as the asteroid twists more and more away from the sun with
each rotation, moving the southern hemisphere into its winter season and
temperatures as low as minus 238 degrees Fahrenheit (minus 150 centigrade).

Project Scientist Dr. Andrew Cheng of APL, says the glamorous part of the
mission is over but now scientists can get down to studying the data,
including the more than 160,000 detailed images taken by the spacecraft. “We
solved mysteries, we unveiled more mysteries. Now we’re sharing the amazing
amount of data that we collected with scientists all over the world, to sort
through and debate and hopefully to help us discover facts about Eros and
our solar system that no one knows today.”

For more information on the NEAR mission, including a gallery of images,
visit Web site:

http://near.jhuapl.edu
.

Helen Worth

Johns Hopkins University Applied Physics Laboratory

Johns Hopkins Rd.

Laurel, MD 20723

(240) 228-5113