Discovery is carrying a multi-purpose logistics module filled with science racks for the laboratories aboard the station. The mission has three planned spacewalks, with work to include replacing an ammonia tank assembly, retrieving a Japanese experiment from the station’s exterior, and switching out a rate gyro assembly on the S0 segment of the station’s truss structure.
The Ku-Band system is one of several shuttle communications systems that can be used for transmission of voice and data to and from the ground. The other systems -- S-band and UHF -- are operating normally. Discovery also has multiple systems that provide backup capability for the rendezvous radar system. In addition, the station has a Ku-band system that also is used for transmission of television to the ground and can be used to transmit shuttle television views after docking.
STS-131 Flight controllers are continuing to troubleshoot the problem with Discovery's Ku-band antenna while also formulating plans to conduct the mission without use of the shuttle Ku system if necessary.
The Ku antenna is typically used by the crew and the ground teams during flight day 2's inspection using the OBSS. If the Ku still is not working tomorrow, the crew will record all of the inspection video and play it back after docking with the station, using the station's Ku antenna.