As the last round-trip for the Leonardo Multi-Purpose Logistics Module, Discovery’s 13-day mission will provide the International Space Station with not only some 8 tons of science equipment and cargo, but also one last opportunity to send a large load of cargo back to the ground. Leonardo serves as basically a moving van for the space station, allowing the shuttle to, first of all, deliver shipments of equipment and supplies larger than any other vehicle could accommodate, and, second, to return science experiments, unneeded hardware and trash to the ground – all other cargo transfer vehicles burn up in the Earth’s atmosphere. And although Leonardo will return to the station once more on the last space shuttle mission later this year, this is scheduled to be its last round trip – Leonardo will remain permanently at the station after STS-133. So while it will deliver one more batch of goods, the cargo returning on STS-131 will be the last that it brings home.
And although there are only four shuttle missions left before the space shuttle fleet is retired, the program is still making some space “firsts” possible. With three female crew members arriving on board Discovery and one already at the station, the STS-131 mission will mark the first time that four women have been in space at one time. And as there is one Japan Aerospace Exploration Agency astronaut on each crew, the mission is also the first time for two JAXA astronauts to be in space at the same time.
Discovery, commanded by spaceflight veteran Alan G. Poindexter, is scheduled to lift off from Kennedy Space Center at 6:21 a.m. EDT on Monday, April 5, and arrive at the orbiting complex early on Wednesday, April 7. While docked to the station, Discovery’s crew will conduct three spacewalks and spend about 100 combined hours moving cargo in and out of Leonardo and the shuttle’s middeck.
Source: NASA STS-131 Press Kit