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Archive for 2001

21-Dec-01 | NASA approves Dawn and Kepler missions

NASA has announced the selection of two new missions in the Discovery program.* Dawn will launch on a Delta 7925H and will visit the two largest-known asteroids, Vesta and Ceres. Kepler will launch on a Delta 7925-10 and seek out Earth-like planets that may be orbiting around stars beyond our solar system. Both are expected to launch in 2006. (NASA Press Release, 21-Dec-01)

18-Dec-01 | Deep Space 1 mission ends

On Tuesday, 18 December, the mission of Deep Space 1 (Delta 261) came to an end. (JPL Universe, 7-Dec-01)

15-Dec-01 | FUSE enters safe mode

FUSE, the Far Ultraviolet Spectroscopic Explorer (Delta 271) has been in safe mode since 10 December. The second of its four reaction wheels shut down that day, leaving FUSE without full three-axis stabilization. (Spaceflight Now, 15-Dec-01)

07-Dec-01 | Boeing numbering changes

Further information on Boeing’s re-worked Delta numbering system has come to light, as shown in this graphic from NASA/KSC’s Expendable Launch Vehicle web site. Many thanks to Gunter Krebs of Gunter’s Space Page for the link.

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.

31-Oct-01 | IMP-8, venerable solar wind Explorer, shut down

One of NASA’s oldest continuing missions has come to an end.

On Sunday, 28 October, the last commands were sent to the Interplanetary Monitoring Platform IMP-8, retiring the spacecraft from service. Launched in the evening of 25 October 1973 aboard a three-stage Delta rocket, IMP-8 spent the last 28 years measuring the magnetic fields, plasmas, and energetic charged particles of the solar wind as it interacts with Earth’s magnetotail and magnetosheath. It was the fiftieth mission in the long-running Explorer series.

Like EUVE earlier this year, NASA claims that IMP-8 has fallen behind the curve of diminishing science returns versus continuing funding. Its magnetometer failed in 2000, depriving scientists of its primary instrument, yet six of IMP-8’s original twelve instruments continue to function.

In its 28 years of service, IMP-8 has provided data for over 1,000 published scientific papers, several hundred in the last 5 years alone. It also was the impetus for a low-cost, ad hoc data collection system utilizing new technologies after the Spaceflight Tracking and Data Network, capable of receiving IMP-8’s now-obsolete VHF transmissions, was “largely disestablished.” (30-Oct-01 NASA Press Release)

26-Oct-01 | Mars Odyssey reaches orbit

On Tuesday, 23 October 2001, 2001 Mars Odyssey successfully entered orbit around the Red Planet.

At about 02:26 (UTC, 24 October; all times are Earth-received, not Mars local), MO lit up its main engine for a duration of about 19 minutes. Just over 10 minutes later the spacecraft passed behind Mars from Earth’s perspective, and all contact was lost as expected. The engine shut down on time, but it wasn’t until 02:56 that MO passed out of occultation and the Deep Space Network reacquired its signal. Controllers were relieved to discover that all events in the complicated manoeuvre occurred on time, and Mars Odyssey was found to be in a highly elliptic, 160 by 15,000 nautical mile orbit with a duration of 18 hours, 36 minutes.

Aerobraking will begin on Friday, 26 October, and is expected to take about 3 months to put MO in a circular, approximately 220 nautical mile orbit. Mapping operations will then commence and continue for an estimated 917 Earth days, around 1-1/3 Martian years.

With the announcement last week of NASA Administrator Daniel Goldin’s pending retirement, all eyes are on Mars Odyssey as it strives to vindicate the “Faster, Better, Cheaper” policy that Goldin championed during his tenure. NASA’s two previous Mars missions, Mars Climate Orbiter and Mars Polar Lander/Deep Space 2, were both lost on arrival at the Red Planet. “Danny G.” was on hand Tuesday at JPL to lead the post-arrival news conference regardless of outcome, and was obviously pleased to have good news to report. Tuesday’s encounter was the riskiest phase of its mission, but MO still has to survive its tricky aerobraking phase before it will return any substantial science. In addition, the flight team has yet to resolve issues with the navigational star tracker and one of the primary instruments, the Martian radiation environment experiment (MARIE).

20-Oct-01 | Delta flight 288 – QuickBird 2

On Thursday, 18 October, the 288th Delta launched QuickBird 2, an Earth imaging satellite owned by DigitalGlobe. The satellite, when it becomes operational in February, is expected to provide the highest-resolution images available on the commercial market.

The two-stage Delta 7320, sporting three booster motors and a 10-foot diameter composite fairing, left Vandenberg’s SLC-2W at 11:51:26.242 PDT after a problem-free terminal count. The Ball Aerospace-built spacecraft was deployed into a nominal 243 nautical mile circular orbit just over an hour later. Like most Delta launches from the west coast, QuickBird’s orbit is polar and sun-synchronous, which will allow maximum coverage of the Earth’s surface.

According to Spaceflight Now, the usual controller “ground loop” audio was unavailable for this flight, hindering that site’s ability to provide what is usually quite detailed play-by-play coverage. Whether this was merely a technical glitch or an intentional security measure by the Air Force has not been determined.

This was the third attempt for DigitalGlobe (formerly known as EarthWatch), which is based in Longmont, Colo. Their first satellite, EarlyBird — not to be confused with Intelsat 1 — suffered a power system malfunction four days after its launch in 1997. QuickBird 1 was lost in November 2000 when the second stage of its Russian-built Kosmos-3M launch vehicle failed to restart at apogee, possibly due to oxidizer contamination. Despite the substantially increased cost versus Russian rockets with similar capacity, DigitalGlobe chose Delta II for this flight thanks to the vehicle’s exceptional reliability. “We looked at it and said ‘here is the most reliable rocket in the U.S. inventory, in the kind of class we can fly in and it is just an outstanding rocket,'” said Herb Satterlee, DigitalGlobe president and CEO.

25-Sep-01 | Deep Space 1 gets up close and personal… with a comet

On Saturday, 22 September, Deep Space 1 became the second spacecraft ever to capture close-up images of a comet. DS-1 passed within 1,200 nautical miles of comet Borrelly at a relative speed of about 37,000 mph. The encounter occurred at 22:30 UTC, with the first data reaching Earth about 13 minutes later.

Amazingly, not only did the unshielded spacecraft survive the potential impacts of cometary dust as it passed through the coma — a mission for which it was never designed — it significantly expanded the state of comet observation. With perfect aim and using all four of its advanced technology (i.e. experimental) instruments, DS-1 captured the most detailed black-and-white photos yet of a comet’s nucleus; that same camera package (MICAS) carries an infrared imaging spectrometer. PEPE (Plasma Experiment for Planetary Exploration) collected ion and electron data from the coma and observed its interaction with the solar wind. Measurements of the magnetic field were also taken. Much of the data will continue to be downloaded over the next few days.

The preliminary results — showing a complex, elongated nucleus spouting asymmetric jets while not travelling at the center of its own coma — appear to have comet scientists perplexed, who apparently were expecting a neatly packed schoolyard snowball. The data from Deep Space 1 will beneficially influence several future comet rendezvous missions, including CONTOUR and Deep Impact, both of which will be launched on Delta II vehicles.

DS-1, which launched aboard Delta 261 on 24 October 1998, has already tripled its design lifetime and long ago successfully completed its primary mission of testing a dozen advanced technologies including a xenon ion engine and autonomous navigation system; in 1999 it survived the loss of its (off the shelf, non-experimental) star tracker thanks to the tireless efforts of the project team led by Marc Rayman. Saturday’s fly-by was considered little more than the stem on the cherry on top of the banana split that was an already-stellar mission; the fact that it succeeded beyond anyone’s wildest dreams is a testament both to the robustness of the hardware and the hard work of the team.

21-Aug-01 | Nasa approves CALIPSO and CloudSat missions

NASA has exercised another option on its 1996 Med-Lite launch contract with Boeing. ESSP-3 (Earth System Science Pathfinder, formerly known as Picasso-CENA), and CloudSat will launch in April 2004 to improve our ability to predict climatic changes. (NASA Press Release, 20-Aug-01) NASA has three options remaining on the Med-Lite contract of 14 flights, of which 9 have flown (all successfully).

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