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Archive for July, 1999

29-Jul-99 | Deep Space 1 update

Deep Space 1 has been in excellent health since its launch on Delta 261 in October 1998, and has exceeded nearly every requirement in tests of its new technologies. On 29 July it flew within 10 miles of the newly-named asteroid 9969 Braille (formerly 1992 KD) using only its experimental AutoNav guidance system. Unfortunately, DS1 lost track of the mile-wide asteroid about 20 minutes before conjunction and was unable to take any images, no great surprise considering the relative speed of almost 35,000 mph. Controllers are hopeful that funding will allow them to extend DS1’s mission past a September end date, since two comet passes are available in 2000.

27-Jul-99 | Iridum flights cancelled

As Iridium struggles with financial difficulties, its “as-needed” 12th and 13th missions aboard Delta II have quietly slipped from the schedule. Apparently Iridium needs customers more than it needs orbiting satellites. Meanwhile, the U.S. State Department has bought 1,000 portable phones in a $1.4 million contract, but whether this is due to the security of Iridium’s non-reliance on terrestrial networks, or an attempt to help Motorola keep the company afloat, is uncertain.

27-Jul-99 | SIRTF at risk of cancellation

SIRTF, a NASA infrared telescope, may be in danger of cancellation, as the U.S. House Appropriations Committee has approved a FY2000 budget that eliminates the $100 million requested for this project. Future Mars missions, including the endangered Mars Surveyor 2001 Lander, also took a $75 million hit. (Meanwhile, the Boeing Launch Manifest has returned to stating that SIRTF will fly on a 7920-H, implying the use of higher-powered booster motors on a Delta II. That is, if it flies at all.)

27-Jul-99 | Landsat-7 enters service

Landsat-7 was placed successfully into its proper orbit by a Delta 7920 on Thursday, 15 April, and is in excellent health. The first few weeks were spent on systems checkout and calibration, along with taking a handful of images for public relations purposes. Then, a series of orbital manoeuvres placed Landsat 7 in proximity with Landsat 5, allowing controllers to make simultaneous observations and cross-calibrate the two satellites. In this way they may fully understand the imaging characteristics of the Enhanced Thematic Mapper Plus (ETM+) aboard the new spacecraft. Full-scale data distribution was expected to be available around 15 July, though no new announcements had been placed on the website as of 27 July. The Landsat program, frequently referred to as “the central pillar of the national remote sensing capability,” has been continuously providing Earth images in visible and infrared wavelengths since 1972.

26-Jul-99 | Delta flight 273 – Globalstar-5

Following a one-day postponement to allow the Shuttle to successfully deliver Chandra to orbit, Boeing’s fifth mission for Globalstar was performed on Sunday morning, 25 July, completing the system’s initial constellation of 32 satellites. The two-stage Delta with 4 solid booster motors lifted off from Cape Canaveral’s SLC-17B at an official range time of 03:46:03.329 EDT, in the first of two possible windows, and deployed its payload of 4 satellites nominally.

The next Delta launch will continue the summer spate of Globalstar missions. The first opportunity will be in less than 0 days.

22-Jul-99 | Delta flight 272 – Globalstar-4

Boeing’s fourth mission for Globalstar was successfully completed on Saturday morning, 10 July. The two-stage Delta with 4 solid booster motors lifted off from Cape Canaveral’s SLC-17B at an official range time of 04:45:37.185 EDT, the opening of the first of two possible windows. The launch had been scrubbed for two days previous due to high-altitude winds. The terminal countdown was free from holds and all four satellites were deployed into highly accurate orbits, par for the course for the Boeing team.

The next Delta launch will be another Globalstar mission, and will complete the initial constellation of 32 satellites. It will also carry a “videoroc” and is scheduled to launch in less that 0 days. It has been pushed back by one day to give the Shuttle one more chance to launch before August.

17-Jul-99 | Delta III failure investigation, preliminary results

Boeing has identified a probable cause for the premature second stage engine shutdown that caused the 4 May launch of Delta III to strand Orion F-3 in a lower than planned orbit.  “The most likely [scenario] appears to be a breach in the engine combustion chamber that resulted in an explosive-type event,” said Dr. Russell Reck, Chairman of the Investivative Board. (Boeing press release) The rupture has been traced to a new manufacturing process used by Pratt & Whitney; similar flaws have been found in other recently-built RL10 engines, variants of which are used in Delta III as well as the Centaur upper stage. A number of Atlas-Centaur flights have also been delayed. The next Delta III flight is expected in October, but may depend on the availability of a non-suspect engine and/or re-engineering of the process.

     

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