Gravity Probe B Launch Status 17 Sep 2003

MISSION: Gravity Probe B (GP-B)

• LAUNCH VEHICLE: Delta II
• LAUNCH PAD: SLC-2, Vandenberg Air Force Base
• LAUNCH DATE: December 6, 2003
• LAUNCH TIME: 5:52:02 p.m. PST

Gravity Probe B is at NASA spacecraft processing hangar 1610 on North
Vandenberg Air Force Base. The pumping down of the dewar which is filled
with cryogenic liquid helium continues. This brings the environment within
the dewar to a near vacuum. It will then be refilled to the level necessary
to achieve and maintain superfluid conditions.

The first stage of the Boeing Delta II was erected on Space Launch Complex 2
on Monday, Sept. 15, as scheduled. Mating of the second stage atop the
first stage is planned for tomorrow, Sept. 18. Attachment of the nine
strap-on solid rocket boosters in sets of three is scheduled for Oct. 6-8.

Gravity Probe B will be transported from the spacecraft hangar to Space
Launch Complex 2 on Nov. 18 and hoisted atop the second stage. The Delta II
fairing will be installed around the spacecraft on Nov. 24 as part of final
preparations for launch. Gravity Probe B arrived at Vandenberg Air Force
Base on July 11 from the Lockheed Martin plant in Sunnyvale, Calif.

Gravity Probe B is a relativity experiment developed by NASA’s Marshall
Space Flight Center, Stanford University and Lockheed Martin. The
spacecraft will test two extraordinary predictions of Albert Einstein’s
general theory of relativity that he advanced in 1916. Gravity Probe B
consists of four sophisticated gyroscopes to be launched into a
400-mile-high orbit for a mission lasting 18 months.