Live at KSC: NASA to hatch go-forward plan

NASA's Mission Management Team will convene at 9 a.m. to develop a course of action for shuttle Atlantis in the wake of a second launch scrub in four days. Options include another launch attempt Monday or more troubleshooting at Kennedy Space Center's launch pad 39A.

Today's launch attempt was scrubbed at 7:24 a.m. after one of four low-level fuel sensors failed a test during fuel-loading operations. Ground rules put in place for the attempt called for all four sensors to be operating properly before the shuttle and its seven astronauts were committed to flight.

NASA Launch Director Doug Lyons said the sensors appeared to be working as intended when they initially were immersed in supercold liquid hydrogen. The sensors are mounted on a bracket near the bottom of the liquid hydrogen section of the tank and go "wet" when the fuel reservoir is about five percent full.

About 10 minutes later, engineers performed a standard checkout of the sensors and all four were working properly.

"It looked like we had a good system and in the Firing Room, we were very excited. We felt like we had a good system and we were going to be ready to go fly today," Lyons said.

But a few minutes after the checkout, the No. 3 sensor failed, and NASA managers ultimately scrubbed the planned 3:21 p.m. launch attempt.

What amounts to a tanking test still is under way at the launch pad. Engineers drained all liquid oxygen from the tank and then lowered the level of liquid hydrogen to five percent -- the point at which the sensors initially are immersed in the supercold propellant.

Engineers at this point are continuing to monitor the sensors so data can be gathered in an attempt to determine the root cause of the problem. The liquid hydrogen tank will be drained later today and the launch pad will be secured.

NASA mission managers will hold a news conference later today to discuss their go-forward plan. The time is TBD.

You can watch it live here in The Flame Trench. Simply click the link below the image at the top of the page to launch our NASA TV viewer and refresh this page for periodic updates.