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Archive for June, 2004

25-Jun-04 | Next launches

The next two Delta launches will carry NASA science missions. Aura is set to fly from Vandenberg AFB on the central California coast no earlier than 10 July. Aura will study the Earth’s ozone, air quality and climate.  In Florida, with Pad 17B recently vacated, stacking operations for the Delta II-Heavy of MESSENGER are expected to begin around 30 June. The first Mercury orbiter is hoped to launch on 30 July; its launch period closes on 13 August.

25-Jun-04 | Delta flight 305 – NAVSTAR IIR-12

On the evening of Wednesday, 23 June, the 305th Delta flight placed a NAVSTAR satellite into transfer orbit for the U.S. Air Force’s Global Positioning System.

The launch, previously slated for early June, slipped by nearly three weeks. At first a suspect hydraulic pump on the first stage of the Delta rocket was replaced, causing about a week of delay. This was followed by a wiring harness investigation, and then a faulty yaw actuator on one of the first stage vernier engines. A pad-clearing hazard alarm (which turned out to have been a false alarm) added a day to the pre-launch activities. And then Florida’s typical summer weather struck, and three straight attempts were scrubbed by fast-moving thunderstorms after tanking operations had completed.

Finally, though the launch weather officer was predicting a 70% chance of violating launch conditions at the start of the 150-minute Terminal Countdown, the Delta team tried again, and this time Mother Nature cooperated.

A smooth countdown procedure ended at exactly 18:54:00.693 EDT as the three-stage Delta 7925 lifted from Pad 17B. A quick, 25 minute 35 second flight followed, and NAVSTAR IIR-12 was released into a transfer orbit of 101.4 by 11,106 miles and 38.99 degrees of inclination.

The launch, the 58th consecutive success for Delta II, was dedicated to the memory of President Reagan. The latest addition to the GPS Space Segment, IIR-12 will soon boost itself into its operational orbit (Plane F, Slot 4), where it will replace the aging NAVSTAR IIA-16 spacecraft, which was launched aboard Delta 216 on 22 November 1992. IIA-16, having served long past its design lifetime, has begun to suffer from “degraded clock performance,” and will be retired into a nearby position in the same orbital plane to act as a backup satellite as needed.

06-Jun-04 | Tech troubles

My apologies for this site having been off-line for about 48 hours from 3 to 5 June. A bad week for my home technology saw a blowout of a brand-new television lemon, an unrecoverable in-box in my e-mail client, and a freaked-out power switch that put my web server into continuous-power-cycling mode. If I were superstitious I’d think the full moon had something to do with it. -ed.

06-Jun-04 | Delays

Both June launches have been pushed back by about a week due to concerns with their launch vehicles. A first stage hydraulic pump aboard the Delta II at Vandenberg (preparing to launch NASA’s Aura spacecraft) failed a pre-flight test and had to be swapped out. The pump aboard the Delta II at Canaveral (for NAVSTAR IIR-12) was from a similar production lot and thus was replaced as well. {I am looking for confirmation that this pump is part of the main engine steering system. -ed.}

This has delayed the launch of the Air Force GPS replenishment satellite until the evening of Friday, 11 June. Aura has further problems with its launch vehicle, however, with an unspecified issue in the second stage helium pressurization system. It is now slated to fly in the morning of 26 June.

Meanwhile, NASA’s Mercury orbiter MESSENGER waits patiently (at the Astrotech Space Operations facilities near KSC) for the pad at SLC-17B to clear. It is hoped that NAVSTAR IIR-12 can launch in time for stacking operations for MESSENGER’s Delta II-Heavy to begin on 21 June.

     

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