In Earth years, it is February 2076. Just 100 years ago, Viking made the first robotic landings on Mars. Since then, manned missions have successfully landed and settled on Mars.
This mission begins with a new crew of astronauts in Martian orbit. The crew has been sent to replace the existing crew that has manned Mars Control for the past two years.
Control of the incoming flight has been transferred from Mission Control at Houston to Mars Control at Chryse Station. Mars Control will have as its objective the selection of entry and departure trajectories before the landing and subsequent lift-off can occur.
The Mars spacecraft will have as its objective the launching of probes to study the Martian Moons, Phobos and Deimos. A probe will be launched to Phobos prior to the crew's landing on Mars, while a probe launch to Deimos will be the crew's last objective before they begin the journey back to Earth.