The Rocky Road To Space

As with the other Great Observatories, it was always intended that Chandra would be named after an eminent astrophysicist whose own research had helped to pave the way for the work it would perform. Hence, the Hubble Space Telescope was named in honour of Edwin Hubble, the Compton Gamma-Ray Observatory for Arthur Holly Compton and, in 2004, the Spitzer Space Telescope for Lyman Spitzer. Chandra honoured the Indian-born scientist Subrahmanyan Chandrasekhar, affectionately known as 'Chandra' to his friends, who has been widely labelled as the 'father' of modern astrophysics.

Chandra, who died in 1995 at the age of 85, was not only a Nobel Prize-winner for his contributions to astronomy, but also conducted valuable theoretical work on stellar evolution that established a basis for the existence of neutron stars and black holes - the very objects his mechanical namesake would be observing from its high orbit. ''Chandra thought black holes were the most beautiful objects in the Universe,'' said Lalitha Chandrasekhar, his 88-year-old widow, who attended Columbia's launch. ''I hear a lot of people say they are bizarre, they are exotic, but to Chandra they were just beautiful.''

It was not, however, only the redesign of the observatory and the troublesome IUS that kept the mechanical Chandra on the ground, but also technical glitches with the spacecraft itself. Problems completing its construction at prime contractor TRW's Redondo Beach facility in California had pushed the launch date from August to December 1998, then January of the following year, and ultimately April when a number of computer software errors arose. On 20 January, only days before Chandra was due to be shipped from California to Florida, NASA announced yet another delay.

It appeared, the agency stated in a hurriedly composed press release, that TRW needed to evaluate and correct a potential problem with several printed circuit boards in the observatory's command-and-data-management system. Several other, TRW-built satellites had turned up faulty copper circuitry, similar to that installed on board Chandra. Aware of its high-priority status and that its orbit would render it irreparable, the decision was taken to remove and replace the boards. ''This potentially was very critical to our mission,'' said Ken Ledbetter. ''We're very pleased we found this problem before we got any further along.''

Although the replacement of the circuit boards delayed Chandra's delivery to Florida by only a week, it pushed STS-93's launch back by five weeks to late May, because of a need to conduct weeks of testing of the newly fitted units at KSC. This target launch date, however, conflicted with that of STS-96, the first Shuttle mission to dock with the International Space Station and the decision was taken to slip Columbia until the second week of July. Then, with only two weeks to go, Chandra engineers were alerted to another problem: this time, with 20 electricity-storing capacitors on board the observatory.

Fortunately, at the eleventh hour, the capacitors were given the all-clear. It was another heart-stopping moment in the often tumultuous genesis of Chandra, but scientists remained confident and excited. ''I think we've done everything humanly possible to ensure a successful launching,'' said Ed Weiler, NASA's Associate Administrator for Space Science. ''Let me remind everybody this is not a trip to Grandma's on a Sunday afternoon! It's high-tech stuff. There are always risks.''

0 0

Post a comment