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Expendable Launch Vehicle Status Report

George H. Diller
NASA Kennedy Space Center

MISSION: Demonstration of Autonomous Rendezvous Technology (DART)
LAUNCH SITE: Vandenberg Air Force Base, Calif.
LAUNCH DATE: Oct. 26, 2004 NET
LAUNCH WINDOW: 11:13:32 a.m. - 11:20:32 a.m. PDT

Due to a failed pressure transducer on the DART upper stage, launch aboard a Pegasus XL has been rescheduled to no earlier than Oct. 26. The upper stage is necessary to deliver DART to its rendezvous point and to conduct proximity operations with the Multiple Paths, Beyond-Line-of-Site Communications (MUBLCOM) satellite. Three strain gauges have been installed on the upper stage to derive hydrazine fuel tank pressure. Verification testing is now under way to validate this alternate method of monitoring. A final flight simulation is now scheduled to be conducted on Oct. 7.

Installation into the satellite of the Advanced Video Guidance Sensor hardware, the primary technology demonstration experiment, was completed Sept. 15 after arriving at Vandenberg Sept. 12.

DART was designed and built for NASA by Orbital Sciences Corporation as an advanced 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 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 its rendezvous functions.

Once in orbit, DART will make contact with a target satellite, the 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 on-board 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.

LAUNCH PAD: 17-A Cape Canaveral Air Force Station, Fla.
LAUNCH DATE: Nov. 2, 2004 NET
LAUNCH WINDOW: 12:02 p.m. - 1:02 p.m. EST

Due to Hurricane Jeanne, the launch of Swift has been retargeted to occur no earlier than Nov. 2. Integrated schedules involving the launch of Swift from Pad 17-A and the pending launch of an Air Force Global Positioning Satellite from Pad 17-B are now being developed. A firm launch date for Swift should be known next week.

Swift is in the clean room at NASA's Hangar AE on Cape Canaveral Air Force Station. The Observatory was covered in a protective double bag with a dry nitrogen purge during Hurricane Jeanne. The bag is being removed today in preparation for a resumption of testing.

The final installation flight blankets to provide thermal stability during the mission will occur on Sunday, Oct. 3. The two remaining Observatory Operational Simulations are scheduled Oct. 6 through 8.

The start of stacking of the Boeing Delta II first stage on Pad 17-A has been rescheduled for Friday, Oct. 1, due to Hurricane Jeanne. Attachment of the three strap-on solid rocket boosters is scheduled for Oct. 2. The payload fairing will be lifted into the clean room of the mobile service tower on Oct. 4. The second stage will be hoisted into position atop the first stage on Oct. 5.

The Swift observatory will pinpoint the location of distant yet fleeting explosions that appear to signal the births of black holes. 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 is a medium-class Explorer mission managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The observatory was built for NASA by Spectrum Astro, a division of General Dynamics. The Kennedy Space Center in Florida is responsible for Swift's integration with the Boeing Delta II rocket and the countdown management on launch day.

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