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07-Dec-01 | Delta flight 289 – TIMED/Jason-1

The 100th Delta II launched from Vandenberg AFB today, placing two Earth-observing satellites into their respective orbits.

Ground winds were a concern all morning, prompting the launch team to load the RP-1 fuel tank early in order to weigh down the vehicle, a practice that has become common of late. The winds trended favourably and were not an issue at launch time.

Liftoff of the two-stage Delta 7920-10C occurred at 1507:35.560 GMT. As usual for a Vanderberg launch, the 6 ground-lit solid booster motors were carried for an additional 22-23 seconds to allow them to be dropped into a safe zone, downrange of several offshore oil platforms. The first stage continued to burn until LOX depletion, about 4:23 into the flight.

Video from the on-board videoroc, the first from SLC-2W since May 1997, appeared to have some transmission issues and was not quite up to the lofty standards posed by recent flights from the east coast. It did at least show decent images during the sequence of first stage jettison, second stage ignition, and fairing jettison.

Following a pair of second stage burns, the first satellite was deployed at about T+55 minutes over the southern tip of Madagascar. This was Jason-1, a joint project between JPL and France’s CNES, the Centre National d’Études Spatiales. Jason-1, named for the mythological captain of the sailing ship Argo, will measure ocean surface topography. It is the first follow-on to TOPEX/Poseidon, a mission that enabled scientists to forecast the 1997-1998 El Niño, and improved understanding of ocean circulation and its effect on the global climate.

Soon afterward, the barrel-shaped Dual Payload Attach Fitting was ejected, exposing the second spacecraft. The clean jettison elicited an uncharacteristically excited “ooh — a very nice response from the vehicle” from telemetry manager and in-flight commentator Marc “Moose” Lavigne.

Another pair of burns, about 51 minutes apart, adjusted the vehicle’s orbit and enabled it to deploy the second spacecraft, TIMED, at about T+2 hours, 5 minutes. TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) will study the uppermost layers of Earth’s atmosphere, a region that as yet is the least explored and least understood. According to the website, TIMED “will be the first mission to obtain a global picture of [this region], and will establish a baseline against which future studies of changes within this region can be compared and analyzed.” At the time of separation, the ground station in Nuka Hiva, French Polynesia, was receiving a signal, but was unable to transmit it to the TM room at Vandenberg. This kept everyone on the edge of their seats, while sporadic, tentative applause broke out in the flight control room more than once before the official word came through.

Both spacecraft soon had successful acquisition from their mission teams and are responding to commands. It appears to have been yet another perfect flight of the Delta II rocket. With five firings of the second stage engine (including the depletion burn), and a total flight time of nearly 2 hours, 38 minutes, this was one of the longest Delta flights in recent history.

The missions, while important for study of Earth’s climate, are both highly focused (if not downright esoteric) in terms of their scope. Their potential obscurity was not aided today by NASA Television, which rather than airing the Jason/TIMED launch, cut away from its continual coverage of Endeavour’s mission to show technicians setting up equipment in preparation for the Senate confirmation hearings of Administrator-nominee Sean O’Keefe. Meanwhile, JPL provided a nice smooth webcast of the launch that streamed at a constant 350 Kbps.


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