The Gravity Probe B spacecraft and the mission were 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 that will provide an almost perfect space-time reference system.  The mission will look in a precise manner for tiny changes in the spin axis direction.  Gravity Probe B will be launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

ACCREDITATION

News media desiring accreditation for the launch of Gravity Probe B should fax their request on news organization letterhead to:

30th Space Wing Public Affairs Office

Vandenberg Air Force Base, Calif.

Attention:  Staff Sgt. Rebecca Danet

FAX:  805/606-8303

(Telephone: 805/606-3595)

PRELAUNCH PRESS CONFERENCE

The Gravity Probe B prelaunch press conference will be held at 2 p.m. EDT (11 a.m. PDT) on Sunday, April 18 in the main conference room of the NASA Vandenberg Resident Office, Building 840, Vandenberg Air Force Base, Calif.  Participants will be:

• Chuck Dovale, NASA Launch Director, John F. Kennedy Space Center, Fla.
• Kris Walsh, Boeing director for NASA programs, Boeing Expendable Launch Systems, Huntington Beach, Calif.
• Rex Geveden, Gravity Probe B Program Manager, NASA Marshall Space Flight Center, Huntsville, Ala.
• 1st  Lt. Breea Lemm, USAF Launch Weather Officer, 30th Weather Squadron, Vandenberg Air Force Base, Calif.

Immediately following the prelaunch press conference will be an abbreviated mission science briefing.  Participating will be:

• Dr. Michael Salamon, Gravity Probe B Program Scientist, NASA Headquarters
• Dr. Francis Everitt, Gravity Probe B Principal Investigator, Stanford University
• Brad Parkinson, Gravity Probe B Co-Principal Investigator, Stanford University

Two-way question and answer capability will be available from NASA field centers including KennedySpaceCenter, Marshall Space Flight Center and NASA Headquarters.

Media desiring to cover the prelaunch press conference should meet at the south gate of Vandenberg Air Force Base on California State Road 246 at10:30 a.m.  They will be escorted to the NASA Vandenberg Resident Office.                        

REMOTE CAMERAS

Following the prelaunch press conference, media desiring to establish sound-activated remote cameras at the launch pad will be escorted to Space Launch Complex 2.  Departure from the south gate of Vandenberg Air Force Base on California State Road 246 will be at 12:15 p.m.Sunday, Apr. 18.

LAUNCH DAY PRESS COVERAGE

            On launch day, Apr. 19, media covering the launch of Gravity Probe B should be at the main gate located on California State Road 1 at9 a.m.to be escorted to the press site on north Vandenberg Air Force Base.  After launch, media will be escorted back to the main gate.  A post-launch press conference will not be held.  Media desiring post-launch interviews will be escorted to Building 840 after spacecraft separation at approximately 11:15 a.m.

NASA TELEVISION, VOICE "V" CIRCUIT COVERAGE

            The prelaunch news conference will be carried starting at2 p.m. EDT (11 a.m. PDT) Sunday, April 18.  Remote question and answer capability from NASA field centers will be available.  On launch day, April 19, NASA TV coverage of the countdown will begin at 11 a.m. EDT (8 a.m. PDT).  Coverage will conclude at2:30 p.m. EDT (11:30 a.m. PDT) after Gravity Probe B spacecraft separation events have occurred. 

            NASA Television is carried on AMC 2, transponder 9C located at 85 degrees West longitude.  Audio only for the news media will be available on the “V” circuits that may be reached by dialing 321/867-1220, 1240, 1260, or 7135.

WEB COVERAGE

            NASA Television coverage will be simulcast on the Web and accessed via the NASA Home Page at:

Real Player - http://www.nasa.gov/ram/35037main_portal.ram

Windows player - http://www.nasa.gov/55644main_NASATV_Windows.asx

Live informational updates and post-event video will also be available through Kennedy Space Center's Virtual Launch Control Center at:

http://www.ksc.nasa.gov/elvnew/messenger/index.htm

Two special live webcasts are scheduled for April 17 at4 p.m. EDT (1 p.m. PDT) and April 18 at4:30 p.m. EDT (1:30 p.m. PDT).  For more information, go to the NASA Direct! Web site at: http://www.ksc.nasa.gov/nasadirect/index.htm

GRAVITY PROBE BNEWSCENTER

The Gravity Probe B News Center at the NASA Vandenberg Resident Office will be staffed beginning Thursday, April 15, and may be reached at 805/605-3051.  A recorded launch status will also be available starting at that time by dialing 805-734-2693.  The U.S. Air Force Public Affairs Office at Vandenberg Air Force Base may be reached at 805-606-3595.