Latch on module creating problem for astronauts

Discovery astronauts encountered another minor problem this morning.

A latch on a robotic arm at the International Space Station is not transferring data properly.

The latch firmly connects the Leonardo cargo module and the ISS to provide an air-tight seal.

The crew was set to use the robotic arm about 7:30 a.m. today to grab the module and eventually stow it in Discovery for the trip home.

NASA engineers asked the astronauts to delay that task while they troubleshoot the problem.

Meanwhile, engineers also are busy trying to fix a stuck nitrogen valve on the station.

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.

They have been sending commands to the valve to try and free it electronically.

A fourth spacewalk for the Discovery astronauts was considered a possibility to fix the problem, but that option was ruled out overnight.