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RE: THEMIS spacecrafts

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Delta 2 rocket launch

Blobrana · L

RE: THEMIS spacecrafts

Blobrana · L

Launch of NASA's THEMIS spacecraft is scheduled for Thursday, Feb. 15 from Pad 17-B at Cape Canaveral Air Force Station, Fla. The launch window is 6:08 to 6:26 p.m. EST, a duration of 18 minutes. NASA's Launch Services Program at the Kennedy Space Centre is responsible for the launch of THEMIS aboard a Delta II rocket with the launch service being conducted by the United Launch Alliance. Should the launch be postponed for 24 hours for any reason, the launch window will extend from 6:05 to 6:23 p.m. EST. For a 48-hour postponement, the launch window will be from 6:01 to 6:19 p.m.

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Blobrana · L

They may seem small and boxy, but five new NASA probes have a lofty purpose: sifting through the Earth's magnetic field for the stormy beginnings of the planet's most dynamic auroras.
Set to launch in less than a month, NASA's THEMIS spacecraft are designed to hunt down the origin of substorm, tempests of high energy particles that accumulate somewhere in the Earth's magnetic field, then flow back to the planet and supercharge its aurora borealis, also known as the Northern Lights.

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A United Launch Alliance Delta 2 rocket in the 7925 vehicle configuration is set to launch five `Time History of Events and Macroscale Interactions during Substorms` (THEMIS) microsatellites, from SLC-17, Cape Canaveral Air Force Station, Florida, at 23:07-23:26 GMT on February 15th, 2007.

Blobrana · L

NASA's THEMIS, the Time History of Events and Macroscale Interactions during Substorms mission, is set to venture into space and help resolve the mystery of what triggers geomagnetic substorms. For the first time, scientists will get a comprehensive view of the substorm phenomena from Earth's upper atmosphere to far into space, pinpointing where and when each substorm begins.
Substorms are atmospheric events visible in the northern hemisphere as a sudden brightening of the Northern Lights. THEMIS also will provide clues about the role of substorms in severe space weather and identify where and when substorms begin.
THEMIS' five identical probes will be the largest number of scientific satellites NASA has ever launched into orbit aboard a single rocket. This unique constellation of satellites will line up along the sun-Earth line, collect coordinated measurements every four days, and be ready to observe more than 30 substorms during the two-year mission. Data collected from the five probes will pinpoint where and when substorms begin, a feat impossible with any previous single-satellite mission.

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Blobrana · L

THEMIS Arrives in Florida for Launch Preparations
NASA's Time History of Events and Macroscale Interactions During Substorms (THEMIS) spacecraft arrived in Florida today, to begin final testing and launch preparations. THEMIS is scheduled to lift off on Feb. 15 aboard a Delta II rocket from Launch Complex 17-B on Cape Canaveral Air Force Station, Florida.
THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalising mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. These lights are the visible manifestations of invisible energy releases, called geomagnetic substorms, in near-Earth space. THEMIS will not only seek to answer where and when substorms start, but will also provide clues as to how and why these space storms create havoc on satellites, terrestrial power grids, and communication systems.
THEMIS is the fifth medium-class mission under NASA's Explorer Program, which was conceived to provide frequent flight opportunities for world-class scientific investigations from space within the Heliophysics and Astrophysics science areas. The Explorers Program Office at Goddard Space Flight Center, Greenbelt, Md., manages this NASA-funded mission. The University of California, Berkeley's Space Sciences Laboratory and Swales Aerospace, Beltsville, Md., built the THEMIS probes.
Now that THEMIS has arrived at the Astrotech payload processing facility in Florida, each of the five probes will be removed from the shipping container in preparation for six weeks of testing and launch preparations. This includes a functional performance test to verify the state of health of each of the five probes, installation of bolt cutters that will separate each probe from the payload carrier, and pressurization and leak checks of the reaction control systems.
Each probe will then be moved to the hazardous processing facility and placed on a stand in preparation for fuelling operations. Once fuelling is complete, each probe will be weighed and individually mated to the payload carrier before pyrotechnics are installed. The fully integrated THEMIS payload is then ready for spin-balance testing and weighing. The final milestone is mating THEMIS to its upper stage booster. THEMIS will be transported to Pad 17-B for mating to the Delta II rocket on February 1.
The rocket that will launch THEMIS is a Delta II 7925-10. The first stage is scheduled to be erected on Pad 17-B the first week of January. The nine strap-on solid rocket boosters will be erected for attachment to the first stage during the second week of January. The second stage will be hoisted atop the first stage during the third week of January. Finally, that same week, the fairing which surrounds the spacecraft will be hoisted into the clean room of the mobile service tower.

Next, several tests of the Delta II will be performed. In the last week of January, as a leak check, the first stage will be loaded with liquid oxygen during a simulated countdown. The next day, a simulated flight test will be performed, simulating without fuel aboard, the vehicle's post-liftoff flight events. The electrical and mechanical systems of the entire Delta II will be exercised during this test. Once the THEMIS payload is atop the launch vehicle, a final major test will be conducted: an integrated test of the Delta II and THEMIS working together. This will be a combined minus count and plus count, simulating all events as they will occur on launch day, but without propellants aboard the vehicle.

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