How do we control the Mars lander?

Question

I've always wondered about this because it's done by remote control right? But I learned from my physics teacher that it takes around 4 minutes for signals to actually reach Mars. How would you ever be able to control it?

Answer 1

Here's an example.

The (stopped) rover sends a picture from one of its several cameras. 4 to 14 minutes later (depends on where Mars is in its orbit, relative to where the Earth is in its orbit around the sun), NASA/JPL receives the picture. The scientists see an interesting rock 20 meters in the distance, and decide they want to investigate. The engineers send the necessary commands to drive in that direction and that distance, then take another picture. Then everyone waits. They wait for the time it takes the command to reach Mars, the time it takes for the rover to drive 20 meters (about 1-2 hours), and the time it takes to transmit the new picture back to Earth.

So now, if the Rover didn't automatically stop itself for any number of reasons related to safety, there should be a closeup picture of that interesting rock on the screens at JPL 2 hours later. Then they can decide what to do next (like use the sensors on the robotic arm to check out the rock).

The whole thing is a very slow process. The rovers have only travelled about 6 and 10 kilometers in just over 3 years (although that feat is a fantastic piece of science and engineering).

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Answer 2

Yes, it does take a long time for radio signals to reach Mars, but the lander(s) are controlled by carefully deciding what you want them to do based on the lander's current position and condition along with your goal. It's kind of like if you're driving down the highway and see a traffic jam up ahead you can make a decision about what to do before you get there. Also, the lander(s) have the capability of monitoring themselves to some extent. If they see that they're about to do something that they're programmed not to do, they simply refuse to do it.

Answer 3

Megan
the time delay on signals reaching the rover are figured into the programing that is a the center OF this operation--- it is very sophisticated stuff and the people doing all of the control operations have learned on another program that allowed them to "get the feel" of this type of operation for quite some time before the rover was ever even in place on the planet Mars !!!

Answer 4

Because of the time delay the lander has to be able to operate alone for many minutes at a time. Basically Earth tells the lander what to do and the computer does it without help from Earth for many minutes, or even hours, at a time.

Answer 5

planning is the key word, they make a software with all the data that the lander needs to land safely, from time to time when the mission control receives the telemetry (flight data) and makes any adjustment necessary to keep the ship on course. actually most of the mission data is loaded in the lander months before take off and leave NASA hangars. so yes it's controlled sometimes via remote control but not in real time. it's not like handling a PC game with a joystick it's more like planning a date, you make it in advance but you make extra adjustments to land successfully

Answer 6

No. It's not done by remote control 'cause there's a communication delay because of the distance between the planets even when they're as close as possible. The lander is programmed to think by itself.

Answer 7

A very good question. It would take a very well-thought out system of blocks and tackles.

Answer 8

They'll control it the same way as they controlled the original moon landing operations . . . . by some bloke in the studio - it's all a big hoax . . .