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History of the Delta Launch Vehicle



Current Delta News

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16-May-05 | Delayed again

Another delay for NOAA-N, as a vent hose broke loose during Friday’s detanking operations, possibly contaminating the spacecraft with hydrocarbons, namely RP1 vapours. Inspections took place over the weekend and the results were expected to be discussed today. If all is well, a Launch Readiness Review on Tuesday will formally set a new launch date, which will occur no earlier than Thursday due to the proper orbital mechanics needed for launch.


13-May-05 | “Modernized” GPS delayed

The launch of the first NAVSTAR IIR-M for the Air Force’s Global Positioning System has been delayed indefinitely for unspecified reasons. In all, eight IIRs will be converted into IIR-Ms, which add a second signal for civilian use and two new encrypted signals for military use. The “M-Code” signals, scheduled to be fully operational by 2010, will have increased power and reduced vulnerability to signal jamming.


13-May-05 | Launch scrub

After two days of delays from high winds at Vandenberg AFB, launch of the National Oceanic and Atmospheric Administration’s newest weather satellite was again scrubbed on 13 May when the ground equipment that supplies the launch pad with cooling and sound-suppressing water suffered an electrical glitch. A 24-hour turnaround is in effect and the new launch time for NOAA-N is set for Saturday morning.


28-Apr-05 | News round-up

With a nearly-four-month gap between launches, Delta operations have been fairly quiet lately, with two routine vehicle stackings (one in Florida, the other in California) being not
particularly newsworthy. However, this is not quite the case for Delta-launched NASA missions. Here’s a round-up of the last couple months’ news…

The Spitzer Space Telescope (Delta 300) has returned images that appear to show, for the first time, an asteroid belt surrounding a distant star much like our sun. Two previous sightings of asteroid belts have surrounded younger, more massive stars, but this marks the first time that we have seen a star system with planetary formation that may be very similar to our own. Further observations are planned in order to confirm the suspected sighting. (20-Apr-05 NASA Press Release)

Mars Rovers Spirit and Opportunity keep on trucking along, and NASA has approved up to 18 more months of operations for the hardy explorers. This marks the third extension to the missions that have already completed more than 14 months of scientific endeavour, far exceeding the rovers’ design lifetime of three months. (05-Apr-05 NASA Press Release)

Nearly fifty years after the first Explorers discovered the Van Allen radiation belts, researchers at GSFC have found clues as to why the nested, toroidal belts have a radiation-free “safe zone” between them. A new theory states that lightning, occurring in the atmosphere hundreds of miles below the belts, generates radio waves that “clear the safe zone by interacting with the radiation belt particles, removing a little of their energy and changing their direction.” Data to support this theory were obtained by the Imager for Magnetopause to Aurora Global Exploration (IMAGE) spacecraft, launched aboard Delta 277 on 25 March 2000, combined with archival data from the Dynamics Explorer mission, which ran for more than nine years following its launch aboard Delta 155 in August 1981. (08-Mar-05 NASA Press Release)

IMAGE (Delta 277) and the venerable Polar spacecraft (Delta 233, launched in 1996) are allowing scientists to study both the northern and southern lights simultaneously, with the not-too-surprising result that Earth’s aurorae are not mirror images of each other and are much more complex than previously thought. (05-Apr-05 NASA Press Release)

This month the MESSENGER team completed checkout and commissioning of three of the components in the spacecraft’s Energetic Particle and Plasma Spectrometer (EPPS) instrument: the Fast Imaging Plasma Spectrometer (FIPS), the Energetic Particle Spectrometer, and the X-Ray Spectrometer. All are functioning normally, and FIPS has already spent some time observing the solar wind. MESSENGER was launched by Delta 307 in August 2004. (18-Apr-05 Status Report)

At an distance of 39.7 million miles, Deep Impact (Delta 311) spotted its quarry, Comet Tempel 1, on the very first attempt. This impressively early target acquisition will be a major aid in approach navigation. The high-speed impact of the spacecraft’s impactor module with the comet remains slated for 4 July. (27-Apr-05 NASA Press Release)


28-Apr-05 | NOAA-N repaired

NOAA-N has had its faulty S-band transmitter replaced and fully retested. The National Oceanic and Atmospheric Administration’s newest weather satellite was expected to be transferred to the pad at SLC-2W during the third week of April, and is on target for an 11 May launch.


12-Feb-05 | NOAA-N delayed indefinitely

The next Delta launch may turn out to be the first NAVSTAR IIR-M in May, as the launch of NOAA-N has been delayed indefinitely. During routine testing, one of the spacecraft’s four S-Band transmitters was found to have “an out-of-specification change” to its center frequency, which in operation would significantly hinder reception of the signal. Extensive diagnosis is now needed to determine the cause of the frequency shift. If the transmitter requires replacement, the delay will be lengthy, as “these units are not easily accessible.” (NASA ELV Status Report, 09-Feb-05)


18-Jan-05 | Phoenix

The folks at the University of Arizona’s Lunar and Planetary Laboratory have launched a newly-reorganized and informative web site for the Phoenix Mars Lander. Named for the mythical bird that is reborn from its own ashes, Phoenix is a retooled resurrection of the Mars Surveyor 2001 Lander, which was mothballed following the demise of Mars Polar Lander in 1999. It is the first mission in NASA’s Scout Program and is slated to fly aboard a Delta II-Heavy in mid-2007.


12-Jan-05 | Delta flight 311 – Deep Impact

The first launch from Planet Earth in 2005 was a Delta II, as flight 311 set Deep Impact on course to intercept Comet Tempel 1 later this year.

It was a picture-perfect launch as the Delta team threaded the needle of an instantaneous launch window at 13:47:08.574 EST on 12 January 2005. The three-stage Delta 7925, looking very much like a GPS satellite carrier with its standard 9.5-foot-diameter payload fairing, leapt from the pad at SLC-17B and rose into a clear Florida sky.

Upper level winds that had been a concern during the countdown had subsided, and the Delta second stage shut down after 9 minutes 46 seconds in a nearly-circular parking orbit of 89.95 by 90.28 nautical miles with an inclination of 29.735 degrees. The stage’s Aerojet AJ10-118K engine fired for a few seconds longer than planned to compensate for a first stage underperformance of unknown cause, but this too was well within flight parameters.

After about a fifteen minute coast phase, the second stage restarted for another burn, this one of about 1 minute 40 seconds, that raised the apogee of the orbit. This was followed by the third stage burn which sent Deep Impact into a hyperbolic escape orbit, on course for a comet.

Once again the telemetry downlink was spotty, a problem exacerbated by a flight apparently devoid of on-board cameras. The link with Ascension Island was lost toward the end of the second AJ10 burn, causing a swarm of people to crowd into the telemetry lab to attempt to read something that wasn’t there. The signal was restored by an Air Force tracking ship called OTTR near the west coast of Africa in time to see third stage spin-up and ignition, and telemetry was maintained through spacecraft separation.

The nail-biting wasn’t over for the Deep Impact team, however, as signals received at Canberra, Australia, were indeterminate as to whether its solar panels had deployed, an event that should have occurred soon after separation. Then, since no one had bothered to include Goldstone, California, in the tracking network, it was feared that controllers would have to wait until Deep Impact passed over Madrid, Spain, for further information — but a last-minute hook-up at Goldstone sent word that the panels were deployed and all was well, for the most part. It turns out that catalyst bed heaters in the spacecraft’s propulsion system briefly caused some temperature sensors to send an alert, which put the probe into safe mode until ground control could take a look at it. (The resulting shift to low-gain communication led to the difficulty in ascertaining the status of the craft.) Project managers suspect that the temperature limits were set a bit too low, and are confident that no hardware was damaged.

Deep Impact is the eighth mission* in NASA’s highly successful Discovery Program. Its principal investigators are with the University of Maryland, and the spacecraft was built by Ball Aerospace in Boulder, Colorado, under the management of the Jet Propulsion Laboratory. On 04 July 2005 it will send its “impactor” subassembly into a collision course with Comet Tempel 1, while the “flyby” module collects transmitted data and watches closely with sensors of its own. It is hoped that the impact will release ejecta that will provide clues to the composition of comets and, by extrapolation, the early solar system.


20-Nov-04 | Next launch

The next Delta II launch will be NASA’s Deep Impact, which will launch in late December to encounter — and assault — Comet Tempel 1 on 4 July, 2005. The spacecraft is going through pre-launch preparations at Astrotech, and work to stack its Delta 7925 rocket on Pad 17B will begin on Monday, 22 November, with hoisting of the first stage into the launch mount.


20-Nov-04 | Delta flight 309 – Swift

Swift arrived safely in orbit on Saturday, 20 November, thanks to the efforts of Delta 309.

The launch was delayed for a couple of days by an issue with the vehicle’s command receiver decoder, equipment that can receive self-destruct commands from Range Safety in the event of a malfunction. That resolved, a unique issue cropped up overnight prior to the launch. At liftoff, ground support umbilical connections disconnect from the launch vehicle and are quickly retracted to the fixed tower on the pad. A cable that measures tension in one of the pullaway bungee cords that retract the umbilicals snagged somehow and could not be trusted to ensure proper retraction. Prior to fuel loading, a crew was dispatched to Space Launch Complex 17A, where they were able to lasso the cable and free it. The resolution took very little time, but nevertheless the launch team played catch-up for the rest of the terminal countdown. During the T-minus 4 minute hold, it became clear that all tasks could not be completed in time, and so the hold was extended for six minutes. This presented no problem for a one-hour launch window.

The Delta 7320-10C leapt off the pad at 12:16:00.611 EST and roared into the bright Florida sky, dropping its three spent booster motors about 66 seconds into the flight. Following second stage ignition, a “videoroc” showed a static-free shot of a payload fairing separation Boeing’s Marc Lavigne called “crisp.” Unlike several recent NASA launches, which carried several cameras, inside and out and facing fore and aft, this was the sole on-board video camera. It was mounted on the second stage, facing forward inside the fairing, and was mainly intended to show spacecraft separation. (Cameras ride aboard flights at the cost of payload capacity, and are only begrudgingly added in the planning stages of a mission. But “come launch day,” NASA launch manager Chuck Dovale commented, “everybody loves the camera.”)

The flight included three second-stage burns to place the spacecraft in its proper orbit. The first burn lasted about 5.5 minutes and ended in a nearly-circular parking orbit, 99.88 by 100.161 nautical miles, with an inclination of 28.47 degrees. A 16-minute coast phase was followed by the second burn of only about 32 seconds. This burn raised the apogee to about 334 nautical miles, and lowered the inclination to about 26 degrees. A longer, 44-minute coast came next as Swift and its Aerojet-built impeller rose toward apogee. Finally, a 54-second burn circularized the orbit at 324 nautical miles and 20.5° inclination.

Tracking was somewhat different than other recent flights due to the flight profile. As usual, early tracking and telemetry was provided by the Cape Canaveral Range and the Air Force’s tracking station on Antigua. The second of the three Aerojet burns, off the west coast of Africa, was followed by a station at Libreville, Gamon, and a mobile site deployed by the USAF at the small island of Sao Tomé. However, for unknown reasons Kwajalein was not able to relay data of the third burn as expected, and for several minutes the fate of the spacecraft was unknown. But the Hawaii tracking station came through in time for separation, and clean data and video both showed the release as the spacecraft faded into darkness. The second stage slowly backed away using gentle venting from its helium pressurization system in anticipation of its propellant depletion burn, and the flight was complete.

Swift is a gamma-ray observer that will have the capability to turn itself rapidly and view the afterglow of bursts in that wavelength. It will spend two years in orbit, helping scientists study massive star explosions and the subsequent formation of black holes. By the end of the day, Swift had unfurled its solar panels and was reported to be in an excellent state of health.


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