Status Report

NASA Spacecraft and Expendable Vehicles Status Report 29 Apr 2004

By SpaceRef Editor
April 29, 2004
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MISSION: Gravity Probe B (GP-B)


LAUNCH PAD:  SLC-2, Vandenberg Air Force Base

LAUNCHED:  April 20, 2004

LAUNCH TIME:   9:57:24 a.m. PDT

NASA’s Gravity Probe B was launched successfully from Space Launch Complex 2 at Vandenberg Air Force Base on April 20 at 9:57:24 a.m. PDT.  The solar arrays had a nominal deployment while still attached to the Boeing Delta II second stage.  Once acquired by the tracking station in Kiruna, Sweden, onboard cameras confirmed that deployment of the four arrays had been completed 72 minutes after launch, followed by live video of spacecraft separation from the Delta II launch vehicle 75 minutes after liftoff.  Gravity Probe B was launched into a 400-nautical-mile-high polar orbit for a 16-month mission.

All four gyro systems have been activated and are undergoing checkout.  The full Initialization & Orbit Checkout phase of the Gravity Probe B mission is planned to last 45 to 60 days, after which the science data collection will begin.

The Gravity Probe B mission 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: the geodetic effect (how space and time are warped by the presence of the Earth) and frame dragging (how Earth’s rotation drags space and time around with it).  The spacecraft 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. 



LAUNCH PAD:  SLC-2,  Vandenberg Air Force Base

LAUNCH DATE:  June 17, 2004 NET Under Review

LAUNCH TIME:  6:01:50 a.m. – 9:04:50 a.m. EDT (3:01:50 – 3:04:50 a.m. PDT)

NASA’s Aura spacecraft, the latest in the Earth Observing System (EOS) series, is at the Astrotech payload processing facility located on North Vandenberg Air Force Base.   The Spacecraft Comprehensive Performance Test was successfully completed last week.  This was a test of Aura’s instruments and onboard systems.  This week, spacecraft propulsion system testing and preparations for fueling are underway.

The erection of the Boeing Delta II launch vehicle on Space Launch Complex 2, located on North Vandenberg Air Force Base, begins today with the erection of the first stage. The payload fairing will be hoisted into the tower tomorrow, April 30.  The second stage is planned for hoisting atop the first stage on May 1.  Erection of the nine solid rocket boosters will occur in sets of three on May 3 – 5.

Aura’s four state-of-the-art instruments will study the dynamics of chemistry occurring in the atmosphere.  The spacecraft will provide data to help scientists better understand the Earth ozone, air quality and climate change.

The EOS Aura satellite, instruments and science investigations are managed by NASA’s Goddard Space Flight Center in Greenbelt, Md.  Government oversight of launch preparations and the countdown management on launch day is the responsibility of the NASA Launch Services Program based at John F. Kennedy Space Center.  The launch service is provided to NASA by Boeing Launch Services.




LAUNCH DATE:  July 30, 2004

LAUNCH WINDOW:  2:17:44 a.m. – 2:17:56 a.m. EDT

MESSENGER is at the Astrotech Space Operations facilities near Kennedy Space Center, where it is undergoing prelaunch testing.

Testing of the spacecraft’s radio system uplink and downlinks through the KSC/JPL interface with the Deep Space Network (MIL-71) has been successfully completed.   Autonomy testing continues.  This verifies MESSENGER’s ability to operate on its own when not in direct contact with Earth.  Installation of thermal blankets has been completed as required on the schedule up to this time.

The erection of the Boeing Delta II launch vehicle on Pad 17-B is currently scheduled to begin on June 18 with the erection of the first stage.

The launch period for MESSENGER extends through Aug. 13.

MESSENGER was built for NASA by the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.

SpaceRef staff editor.