spacetoday.net: Sensor glitch could delay shuttle launch

Posted: Wed, Mar 8, 2006, 6:52 AM ET (1152 GMT)
STS-114: launch (NASA)

A problem with an external tank fuel sensor could postpone May's scheduled launch of the STS-121 shuttle mission. Tests on the external tank that will be used for that launch revealed that one of the four emergency cutoff (ECO) sensors, used to measure when the tank has depleted its supply of liquid hydrogen, had an unexpected response that it on the border of what is acceptable. NASA has yet to decide whether the sensor needs to be replaced. If it does, it could delay the launch, perhaps beyond the end of the May 10-22 launch window; the next launch window opens at the beginning of July. The ECO sensor also caused problems with last year's STS-114 launch, although it's not clear those problems are related to the current issue.