How to drive a rover

探测器在火星上我们把,就像汽车Curiosity rover - need to be controlled and steered from Earth. Some say it’s a bit like driving a multimillion-dollar-remote-controlled car you can’t see over an obstacle course viewed through a camera from 250 million kilometres away! So how do they do that? Adam Murphy’s been finding out from the world - or perhaps that should be Martian - record holder, Paolo Bellutta from NASA's Jet Propulsion Laboratory!

Adam - If we want to learn about our neighbors, we have to send robots there to visit them. We've sent plenty of robots to trundle around the Martian surface, but how do you control them? It must be like the most high stakes video game there is. And if it is, one man, Paolo Bellutta from the Jet Propulsion Laboratory at NASA has the high score having driven 17 kilometers on the Martian surface, which is a world record. He told me a little bit more about how you actually control a rover.

Paolo - So we receive images from the rovers, and we analyse the terrain around the rover, decide together with the geologists, the next destination for the rover. And then we prepare a list of commands, such as move forward by a certain distance, turn by a certain amount, we prepare this list of commands. They are supposed to be executed in a single day on Mars that we call Sol. Then we send all these commands in one chunk, the rover then receives these commands and executes the commands in total autonomy.

Adam - Imagine just seeing one single snapshot of a level in Call of Duty, then having to input every command to beat that level, then going to bed and seeing what happens in the morning.

Paolo - It's not easy because the only thing that we have are basically images, they are stereo images, so we can determine the distance, the size of the obstacles that you see in the images. Also, we have geologists that can help us in determining whether the terrain that we plan to move the vehicle is safe, in the sense that it can support the weight of the vehicle or if the obstacles might be too dangerous for the vehicle.

Adam - So if you're a pro like Paolo, you know what you're doing, and you don't crash a very expensive NASA Rover, but how have things changed since the early days

Paolo - I started driving vehicles on Mars in 2004. And at that time it was quite rudimentary, I would say, not only because the vehicles at that time, they were smaller, but also the software onboard was pretty simple, but mostly because we didn't know how to drive on Mars.

Adam - And what's it like to play what you might call a real life space invader?

Paolo - The best part of my work is that it's never boring, there is always new ideas, new problems everyday to solve. And therefore, it is always exciting. There hasn't been a boring day of Mars.