How did NASA astronauts launch the pod from Mars, though they were at millions of Kilometres away?

Question

I watched The Martian (2015) not long ago and it has finally dawned on me why it looked a bit weird:

When Mark was stranded on Mars because of a dust storm, back on Earth they hold a funeral for him. It is not until late in the movie that they discover he is still alive.

When NASA sends a rescue crew to Mars, they somehow get into contact with Mark via his communication device. Mark is then told to hold tight in the pod until NASA launches the pod off Mars.

What I want to know is how did NASA managed to connect to that very pod when it is of very little use and Mark had gutted it out so that he can use it for other purposes?

How did they connect to it from that far in space let alone launch it?

The pod would have had very little fuel left, if any at all because of the time that it has spent on Mars, and the signal frequency and mechanisms would have been knocked out from the storm.

Am I missing something? I really want to know.

Answer 1

It is not until late in the movie that they discover he is still alive.

It's not late at all that they discover that he is still alive. They discover this in a few weeks (Sol 54 - about 2 months) - when they see that stuff has been moving around on the base. By Sol 109 (just over 3 months) he has got Pathfinder and is communicating with Earth. This all happens fairly early in the movie.

The events of his rescue are a little different than you describe.

The pod would have had very little fuel left, if any at all because of the time that it has spent on Mars, and the signal frequency and mechanisms would have been knocked out from the storm.

The Mars Ascent Vehicle (MAV) for their Ares III mission has already been used when the remaining crew abort the mission and leave Mars. It's not that it 'would have very little fuel left' - that MAV was entirely gone.

Watney travels by the Rover to the Schiaparelli crater, thousands of kilometers away to find he MAV for the future Ares IV mission. The MAV (and presumably the as yet unassembled Ares IV HAB) have been delivered to the Mars surface awaiting that mission. The MAV when waiting for its crew to eventually fire it up and use it to depart Mars doesn't really use fuel.

The Ares IV MAV is therefore unused and fully fueled. All he has to do is to remove weight, since he needs to go higher and faster to match path with the flyby of the Hermes, which never enters orbit.

how did they connect to it from way out that far in space let alone launch it?

The launch of the MAV isn't controlled by NASA from Earth, as its light-minutes away and couldn't be realistically controlled at that distance. The MAV is controlled from the Hermes, and piloted by Martinez by instrument.