Fourth spacewalk not needed to fix valve

The crew of Discovery woke up at 12:21 a.m. Thursday and was informed by NASA officials that a fourth spacewalk would not be needed to fix a faulty valve.

Astronauts were on standby and ready to prepare for that possible fourth spacewalk, which would have taken place Friday.

However, engineers determined overnight that the stuck nitrogen valve on the International Space Station can operate for an extended period of time as is. Officials on the ground will continue looking at alternatives to fix it.

Engineers sent the valve a series of commands Wednesday and plan to continue trying to free the valve electronically today.

The valve controls the flow of nitrogen, which pressurizes the ammonia cooling system. Engineers are studying whether the cooling system can be effective with the valve closed.

Another option that's been discussed is having the ISS crew perform a spacewalk after Discovery departs.

Discovery is set to leave the ISS on Saturday morning, and return to Kennedy Space Center Monday morning.

Instead of preparing for that fourth spacewalk, the crew will spend the day stowing the Leonardo cargo module in Discovery's cargo bay for the trip home.

A Japanese song, "The Earth in the Color of Lapis Lazuli" by Seiko Matsuda, was the wake up song Thursday morning in honor of mission specialist Naoko Yamazaki.

Although, maybe the wake up song should have been "Happy Birthday." Two members of the six-person ISS crew are celebrating birthdays today.

Japanese astronaut Soichi Noguchi is 45 and Russian Mikhail Korniyenko is 50.