1.   In their most visible work, astronauts will let loose a retrievable satellite carrying a coffin-sized inflatable antenna.

2.   On this trip, Spartan will serve as a platform for unfurling the inflatable antenna.

3.   One of the experiments is scheduled to take place Monday, when the astronauts deploy a retrievable Spartan satellite that carries the inflatable antenna experiment.

4.   Space agency engineers hope the experiment proves the feasibility of launching spacecraft with inflatable antennas or other major parts.