Gravity Probe B Relativity mission achieves two major milestones
The NASA Gravity Probe B (GP-B) Relativity Mission has successfully
mated its science payload to its spacecraft and after successful
systems testing, the GP-B space vehicle was shipped to Sunnyvale,
Calif., on Feb. 9, 2002, to prepare for upcoming rigorous
environmental tests.
“These milestones are a huge accomplishment for this dedicated team,”
said Gravity Probe B program manager Rex Geveden, of NASA’s
Marshall Space Flight Center in Huntsville, Ala. “The Gravity
Probe B team is working hard to complete preparation and testing of
one of the most unique experiments ever attempted in the history of
science.”
Gravity Probe B, led by principal investigator Francis Everitt and
program manager Sasha Buchman of Stanford University in Stanford,
Calif., has been pushing the limits on many different technological
fronts, including gyroscope technology, materials science, metrology,
astrometry, and cryogenics.
Scheduled for launch in late 2002 and using highly advanced
technology, GP-B is expected to be the most precise test to-date of
two extraordinary predictions of Albert Einstein’s Theory of General
Relativity.
Using its space-bound gyroscopes in a drag-free polar orbit, GP-B will
measure how space and time are warped by the presence of the Earth,
and, more profoundly, how the Earth’s rotation drags space-time around
with it. These effects have far-reaching implications for the nature
of matter and the structure of the Universe and are considered among
the most profound enigmas of physics.
The mission’s science instrument and its components were developed,
designed, built and integrated in Stanford University’s Hansen
Experimental Physics Laboratory. The payload is made up of the
science instrument inside a probe integrated into one of the largest
flight dewars (thermally insulated containers) ever constructed. The
dewar provides the extremely low temperature environment needed for
proper operation of the experiment while in Earth orbit.
The team has spent the last eight months in payload testing,
successfully verifying all subsystems and the integrated payload at
Stanford University before transporting and then mating the payload to
the Lockheed Martin spacecraft at the corporation’s nearby facility in
Palo Alto. Systems testing was conducted there to begin preparations
for the series of acoustic and thermal-vacuum tests in Sunnyvale that
will qualify the GP-B space vehicle for its upcoming launch.
Development of the Gravity Probe B mission is the responsibility of
Stanford University, with major sub-contractor Lockheed Martin
Corporation.
GP-B is managed for NASA by the Marshall Space Flight Center.
For more information about Gravity Probe B, please visit
