Discovery Poised to Liftoff

NASA is poised to launch space shuttle Discovery on her last mission this Thursday at 4:50 p.m. EST. It seems with all recent attempts to get Discovery launched, NASA is working one minor leak issue. However the issue should not cause any delay.

According to Steve Payne, NASA Test Director “we’re working only one minor issue, we have a slight internal leakage on a reaction control system regulator, however we’ve seen this condition before, it is well within acceptable limits and we’re going to accept it for flight, it should be waived here shortly.”

The leak of helium, which is used to pressurize the propellant tanks is adding a little more pressure to the tanks than NASA prefers. The helium is fed through two separate legs, each of which has redundant regulators that can adjust the pressure. The issue, which also happened on STS-116, should be resolved shortly by isolating and shutting down the affected redundant regulator.

At this time weather does not appear to be an issue with only a 20% chance of weather prohibiting launch. There is a very slight concern for showers and low cloud ceiling. if the launch is delayed from Thursday to Friday then the weather starts to become more of a factor with 30% chance of weather prohibiting launch and if delayed two days to Saturday then there there is a 40% chance of weather prohibiting launch.