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17-Feb-07 | Delta flight 323 – THEMIS

NASA’s THEMIS mission was successfully launched on a three-stage Delta II rocket on Saturday, 17 February 2007.

Thunderstorms delayed fuelling operations earlier in the week, and extreme wind shear between altitudes of 10,000 and 20,000 feet caused a scrub on Friday evening. For Saturday’s attempt, those upper-level winds continued to be a concern, but never exceeded parameters and the board remained green for weather all evening. An unspecified issue with the third stage was quickly resolved without affecting the countdown.

The Delta 7925 with a 10-foot composite fairing left SLC-17B at an official range liftoff time of 18:01:00.384 EST, the very opening of the window. First and second stage burns completed in 9 minutes 59 seconds, placing the spacecraft in a temporary, elliptical parking orbit of 100.0 nm perigee by 303.78 nm apogee, with an inclination of 28.5 degrees.

After a 53-minute coast phase, the Aerojet AJ10-118K second stage reignited for just under a minute, boosting the apogee to 825 nautical miles. It spun up the third stage and payload, then released the pair, having completed its task. With telemetry being received by a Big Crow tracking aircraft flying off the northeast coast of Australia, the third stage’s Thiokol Star 48B solid motor fired for 86.5 seconds to kick the apogee up to almost 50,000 nautical miles. About five minutes later, the custom carrier system deployed all five THEMIS spacecraft, successfully completing the launch about 73 minutes, 42 seconds after liftoff.

Over the next seven months, THEMIS will remain in an injection or “coast” phase while controllers check out the five satellites’ systems and assign them to their operational orbits. Transfer to those orbits will begin some time in September. All five probes have already been found to be in nominal orbits and in excellent health.

THEMIS, an acronym for Time History of Events and Macroscale Interactions during Substorms, will examine the Earth’s magnetosphere and its interaction with the solar wind from various points along the magnetotail. In particular, the mission hopes to shed light on “how Earth’s magnetosphere stores and releases energy from the sun.” It may help to explain why aurorae (the northern and southern lights) have such a wide variety of colours and appearances. The use of five smaller subsatellites will provide a broader understanding of the phenomena than would a single probe. (Spaceflight Now Mission Status Center, 17-Feb-07, NASA Press Release, 17-Feb-07)


16-Feb-07 | THEMIS scrubbed

THEMIS launch was scrubbed today. Upper level winds were found to be out of spec, and the hold was called moments before the terminal count was to resume at T-minus 4 minutes. A 24-hour turnaround is in work, with a Saturday launch slated between 23:01 and 23:19 UTC.


14-Feb-07 | THEMIS delayed by 24 hours

Launch of NASA’s THEMIS spacecraft has been pushed back by one day, to Friday 16 February. Thunderstorms at Cape Canaveral led to postponement of fuelling operations, preventing the second stage’s hypergolic propellants (Aerozine-50 and nitrogen tetroxide) from being loaded. The weather is expected to clear and forecasters are predicting an 80% chance of good conditions on Friday. (NASA ELV Status Report, 13-Feb-07, Spaceflight Now Mission Status Center, 13-Feb-07)


30-Jan-07 | STEREO completes lunar swing-by

NASA’s twin STEREO spacecraft have completed a delicate series of orbital manoeuvres, using the Moon’s gravity to send them into their operational orbits.  Both observatories passed the Moon on 15-Dec-06, which placed the “A” spacecraft into its orbit “ahead” of that of Earth.  The “B” spacecraft made a second lunar pass on 21-Jan-07 to enter its orbit “behind” Earth.  Controllers expect the craft to produce the first 3-D images of the Sun by April.  (JHU APL Press Release, 23-Jan-07)


25-Jan-07 | Mission schedule update

According to its mission website, NASA’s Widefield Infrared Survey Explorer (WISE) will fly on a Delta II after all, reversing an announcement from three years ago. Planned as MIDEX-6, WISE will be the fifth MIDEX mission to fly if it launches as planned in November 2009.

Meanwhile, the Geospace Electrodynamic Connections (GEC) mission has been cancelled (or “moved outside the near-term [5-year] budget planning window”) due to budget constraints. It was intended to fly on a Delta II in September 2009.


21-Jan-07 | Next launch

The next launch will be NASA’s Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft, due to launch from Cape Canaveral in mid-February. Using five identical satellites launched in the same flight, THEMIS will examine the Earth’s magnetosphere and its interaction with the solar wind from various points along the magnetotail.


21-Jan-07 | NRO L-21 may have failed

Reuters reports that a National Reconnaissance Office satellite, believed to be the one launched in December by the most recent Delta II, has suffered “a comprehensive failure” and is likely to be a complete loss. According to the article, “U.S. officials were working to reestablish contact with the satellite because of the importance of the new technology it was meant to test and demonstrate,” although what this new technology may be remains wholly unspecified. Because the Delta rocket delivered the spacecraft into its appropriate orbit, and the failure lies within the payload hardware, the launch is still considered a success.


21-Jan-07 | Mars Global Surveyor lost; mission ends

Having explored all possible options for regaining communications with the Mars Global Surveyor, NASA has conceded that the mission has been lost. (NASA Press Release, 21-Nov-06) Preliminary reports suggest that a combination of software and operator error allowed one solar panel to be turned against its hard stops, sending the spacecraft into safe mode. At that point it was oriented with its battery pointed toward the Sun; the battery overheated and expired. A formal review board has been convened to determine both the events and management processes that allowed this to occur. (NASA Press Release, 10-Jan-07)

Meanwhile, images from MGS continue to provide new discoveries, such as the annoucement that water still flows in brief spurts on Mars’ surface. (NASA Press Release, 06-Dec-06)


17-Jan-07 | Note from the editor

For 2007, the News page has been replaced with an RSS-active news feed. The news archives have been transferred into it.


15-Dec-06 | Delta flight 322 – NRO L-21

A two-stage Delta II launched from Vandenberg AFB on 14 December 2006, carrying a classified payload for the National Reconnaissance Office. This was the first Delta launch for NRO since 2001’s GeoLITE, and Jonathan McDowell sums up the public’s knowledge of L-21 thusly: “In contrast to most secret launches, analysts appear to have little clue as to what this payload may be.” (JSR 575) This marked the first launch to be managed by the new United Launch Alliance, a joint effort of Boeing and Lockheed Martin. Spaceflight Now filed a mission status report.


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