2008 Woodie Awards
NASA delays shuttle launch, fuel sensor problems are blamed
Joshua Johnson
Issue date: 3/31/06 Section: News
- Page 1 of 2 next >
|
The window for Discovery's launch has moved to July 1 through July 19 later this year due to continuing problems with sensors in the shuttle's external fuel tank. The same sensors proved problematic during the first return to flight mission for Discovery last year.
The operation of the fuel sensors is vital in the shuttle's mission. The sensors are responsible for monitoring the level of fuel in the tank, telling the shuttle's computers when the main engines can safely be shut down. If the sensors give a faulty reading, the engines may shut down too early, causing the shuttle to not reach its intended orbit. Alternately, the sensors may give a false reading causing the engines may burn too long, causing severe damage to the orbiter's engines.
NASA began an investigation on the sensors, and has concluded that the problem originated during the manufacture of the sensors. Upon removing sensors from external tanks used in past missions, engineers at the Marshal Space Flight Center discovered several with loose wiring.
"We hope to take the four sensors that we will take out of the external tank and put them in extensive tests," said Hale during the press conference. "We want to see if the one sensor … really has this problem that the engineering tests say could potentially have."
The sensors in question were all manufactured 10 years ago, according to Hale. Hale confirmed that potentially flawed sensors manufactured during the same time period have flown on shuttle missions in the past. A few of the sensors flew on missions in 1999, but those operated normally.
The technology used in the sensors, however, has been around since the space program's infancy. According to Hale, variations of the sensors have appeared in many different launch vehicles, including the Saturn and Delta rockets. Hale responded that he and other engineers at NASA are unsure whether it was a manufacturing error or a possible design flaw that has lead to the sensor problems.