When Canadian Astronaut Chris Hadfield was in space, on the International Space Station (ISS), he stayed there for six months, the standard length of stay for an astronaut. On the ISS, three of the six-person crew are replaced every three months. After returning to Earth, Hadfield could barely walk. He had lost bone density and muscle mass, his immune system weakened, cardiovascular functions slowed, and he produced less red blood cells. The lack of gravity is bad for humans, The longest a human being has ever been in space was Russian cosmonaut Valeri Polyakov, who was in space for a staggering 437 days, and when he came back to Earth he opted to walk a few feet between the landing capsule and the transport, showing that long-term human space flight is possible. Was Polyakov a special case? Or can any person survive longer trips to other worlds such as Mars?
This is exactly what humanity hopes to find out with the launch of NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko yesterday, who will each spend one year living in weightlessness aboard the ISS. This will be a record for American space flight as the previous American record holder was Michael López-Alegría, who stayed in space for 215.4 days back in 2006.
Mars is not going to be an easy journey for future astronauts. The trip is 8 months one way at the limits of our current technology, and that’s when Mars is close to the orbit of Earth. It’s another 8 months back, and that’s if Mars and Earth are aligned, which they won’t be. So unless we develop technology to make the trip shorter (which is planned), we will be sending humans into space for record-breaking flights just to get to Mars for the first time.
Knowing this, the mission with Kelly and Kornienko is underway so that humanity can determine the true effects of long-term space flight on the human body, and determine what is needed to support astronauts on the long trip to Mars.
If there’s one thing we have going for us (and against us) it’s that Mars has gravity. When astronauts hope to land on Mars, the lower gravity will restore some of the normal body functions and lead to a partial replenishment of bone density and muscle mass. But launching from Mars poses a new problem – It’s much bigger than the Moon and it has an atmosphere, meaning a rocket lander has to have a lot more power to escape Mars when eventually heading back to orbit and then back to Earth. It’s no easy task.
Between our scouting of Mars by the Rovers and the Kelly / Kornienko mission, we are taking a big step toward human exploration of Mars. It’s coming, it just might be a while.