Status Report

NASA Spacecraft and Expendable Vehicles Status Report 18 August 2004

By SpaceRef Editor
August 18, 2004
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LAUNCH PAD: 17-ACape Canaveral
LAUNCH DATE: Oct. 7, 2004
LAUNCH WINDOW: 12:57 p.m. – 1:57 p.m. EDT

The Swift satellite, which will pinpoint the location of distant yet fleeting explosions that appear to signal the births of black holes, arrived at Kennedy Space Center on July 29 to begin preparations for launch.

The Observatory Integrated Systems Test was completed on Aug. 12.  This was an unabridged performance evaluation of the spacecraft’s on-board systems.

The spacecraft was powered down, secured and temporarily covered as part of predetermined hurricane procedures based on the threat of tropical storm conditions on Friday.  There were no issues with the spacecraft that occurred during Hurricane Charley.  With severe thunderstorms forecasted to occur over the next several days during the afternoon, the spacecraft will remain covered for the present time.  With a spacecraft cooling purge on the observatory, this will not prevent powered-up tests from continuing.

Fault protection system testing was completed on Aug. 10, followed by the software regression testing on Aug. 15.  These tested the overall software programming to evaluate performance since they were updated previously.  The installation of the flight blankets has been rescheduled for mid-September.

The stacking of the Boeing Delta II launch vehicle on Pad 17-A will begin on Sept. 1 with the hoisting of the first stage into the pad launcher mechanism.  Attachment of the nine strap-on solid rocket boosters, in sets of three, is scheduled for Sept. 2-6.  The second stage will be hoisted into position atop the first stage on Sept. 7.  The payload fairing will be lifted inside the clean room within the mobile service tower on Sept. 8.

Gamma-ray bursts are the most powerful explosions known in the universe, emitting more than 100 billion times the energy that the Sun does in a year.  Yet they last only from a few milliseconds to a few minutes, never to appear in the same spot again.

The Swift satellite is named for the nimble bird, because it can swiftly turn and point its instruments to catch a burst “on the fly” to study both the burst and its afterglow.  This afterglow phenomenon follows the initial gamma-ray flash in most bursts and it can linger in X-ray light, visible light and radio waves for hours or weeks, providing great detail for observations.

Swift, a medium-class explorer mission, is managed by NASA’s Goddard Space Flight Center inGreenbelt, Md., and built by Spectrum Astro, a division of General Dynamics.

MISSION: Demonstration of Autonomous Rendezvous Technology (DART)
LAUNCH SITE: Vandenberg Air Force Base,Calif.
LAUNCH DATE: Oct. 18, 2004(tentative)

Testing is complete on the Pegasus XL launch vehicle’s fourth stage.  This is a hydrazine fuel upper stage that will later be integrated with the satellite before the combination is mated with the Pegasus XL rocket.  This stage will perform DART’s maneuvering during the mission.   

In other work, the first Pegasus Simulated Flight test is underway today.  The aft skirt of the launch vehicle has been installed.  The fins are mechanically mated and the alignment continues.  The GPS and UHF antennas have also been installed.  Installation of fillet, material that acts as an interface between the first stage and the wing of the Pegasus, continues.

 The Demonstration of Autonomous Rendezvous Technology (DART) spacecraft was rotated from a horizontal to vertical position and lifted onto a test stand July 27 for current launch processing activities.  The DART spacecraft arrived at Vandenberg Air Force Base on July 13 to begin its final preparations for launch. 

The Advanced Guidance Sensor (AVGS) hardware, the primary technology demonstration experiment for the satellite, is completing final testing at the Marshall Space Flight Center inHuntsville,Ala.  The optical characterization testing and final performance verification test will be conducted this month.  The AVGS will be shipped to Vandenberg for installation aboard the satellite in early September.

DART was designed and built for NASA by Orbital Sciences Corporation as a flight demonstrator to locate and maneuver near an orbiting satellite.  The DART spacecraft weighs about 800 pounds and is nearly 6 feet long and 3 feet in diameter.  The Orbital Sciences Pegasus XL vehicle will launch DART into a circular polar orbit of approximately 475 miles.

The DART satellite is an advanced flight demonstrator that provides a key step in establishing autonomous rendezvous capabilities for the U.S. Space Program.  While previous rendezvous and docking efforts have been piloted by astronauts, the unmanned DART satellite will have computers and cameras to perform all of its rendezvous functions.

Once in orbit, DART will rendezvous with a target satellite, the Multiple Paths, Beyond-Line-of-Site Communications (MUBLCOM), also built by Orbital Sciences and launched in 1999.  DART will then perform several close-proximity operations, such as moving toward and away from the satellite using navigation data provided by onboard sensors.  The entire mission will last only 24 hours and will be accomplished without human intervention.  The DART flight computer will determine its own path to accomplish its mission objectives.

DART is designed to demonstrate technologies required for a spacecraft to locate and rendezvous, or maneuver close to, other craft in space.  Results from the DART mission will aid in the development of NASA’s Crew Exploration Vehicle and will also assist in vehicle development for crew transfer and crew rescue capability to and from the International Space Station.

SpaceRef staff editor.