The viability of a trip to Mars is examined by researchers, scientists, and astronauts, with a focus on the logistical challenges and technical obstacles faced by the international space community in sending a manned mission that could come back.

Engineers tackle problems that they have just one opportunity to get right; the spacecraft set to take a crew to Mars is assembled -- in space.

In space, zero gravity depletes muscle and bone mass, while cosmic radiation can cause brain damage and cancer; for six astronauts in a confined and limited environment for up to three years, a voyage to Mars could be deadly for the human body.

Examining vehicle entry into the Martian atmosphere, the techniques required to slow and protect the capsule, and targeting a landing spot in just 90 seconds.

Scientists in North America are combing the most barren places on Earth to search for bacteria, amino acids, or carbonates that might offer clues to the question of whether there is life on Mars.