MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
Contact: Martha J. Heil (818) 354-0850
FOR IMMEDIATE RELEASE
February 28, 2001
DEEP SPACE NETWORK TO HEAR LAST FROM FARAWAY NEAR
The last data from the overachieving Near Earth Asteroid
Rendezvous (NEAR Shoemaker) mission to asteroid Eros will be
received today via NASA's Deep Space Network telecommunications
A group of engineers at NASA's Jet Propulsion Laboratory
stands by, monitoring final telemetry from this successful
extended mission to map and understand the asteroid. NEAR
Shoemaker was directed to a successful landing on the asteroid on
Feb. 12. Today, the Deep Space Network, Earth's phone line to
Eros, will hang up, marking the probable conclusion to the
historic mission, which is managed by the Johns Hopkins
University's Applied Physics Laboratory in Laurel, Md, for NASA.
The Deep Space Network, managed by JPL for NASA, consists
of large antennas at three complexes located in Goldstone,
Calif., near Canberra, Australia, and near Madrid, Spain. Each
complex houses several radio antennas of different sizes,
including giant 70-meter (230-foot) telescopes, used to
communicate with interplanetary spacecraft.
Antennas at Goldstone today received science data from the
last NEAR experiment, spectrometry from the spacecraft's gamma
ray instrument. This data will tell scientists about the surface
and subsurface composition of asteroid Eros. NEAR's position on
the asteroid precludes it from using its largest communications
antenna, called the high-gain antenna. To receive the weaker
signal from the low-gain antenna, the Deep Space Network is using
its own largest antenna, the 70-meter dish.
"The pass is going fine, we're locked on to the spacecraft's
signal and we're getting good data back." said JPL's Allen
Berman, the telecommunications and mission systems manager for
NEAR. Telecommunications support of the mission were scheduled to
end at 4 p.m Pacific Standard Time today, he said.
Throughout NEAR's five-year mission, controllers at the Deep
Space Network have provided every link between the spacecraft and
Earth. The Deep Space Network has transferred information about
the size, shape and gravity of the asteroid from the spacecraft
to Earth, sent commands to make changes in the spacecraft's
course, and maintained the contact for the exciting landing on
"We're the vehicle of getting those commands from the
mission controllers at Applied Physics Lab to the spacecraft,"
said Berman. "Then we receive the science and engineering data
from the spacecraft to Earth. We also generate navigational data
-- the Deep Space Network continuously measures the velocity of
the spacecraft through the Doppler shift imprinted in the signal.
We extract that data, and send it to the JPL navigation team so
that they can determine the orbit and develop maneuvers."
The antennas rotate toward certain portions of the sky where
engineers predict the signal will come from the spacecraft. Data,
in the form of radio signals, is intercepted by the antennas, and
sent via data processing equipment at the facility to the Jet
Propulsion Laboratory, where navigators determine the exact
position of the spacecraft.
The Deep Space Network also provided all the ground
communications for the NEAR mission between the Applied Physics
Lab, JPL and worldwide Deep Space Network stations via voice and
The NEAR spacecraft spent the last year in a low-altitude
orbit of asteroid 433 Eros, a near-Earth asteroid that is
currently 316 million kilometers (196 million miles) from Earth.
During that time it collected 10 times more data than originally
planned and completed all its science goals before attempting its
descent to the asteroid.
The Deep Space Network is managed and operated for NASA by
the Jet Propulsion Laboratory. NEAR is managed by Applied
Physics Laboratory of the Johns Hopkins University for NASA. For
mission updates, images and other information, see
http://near.jhuapl.edu . JPL, a NASA center, is a division of the
California Institute of Technology in Pasadena.