At Your Command simulates how vehicles can be operated remotely or autonomously. Two scenarios are provided to help illustrate the advantages (and disadvantages) of each method of operation. You likely found it fairly easy to operate the vehicle in the Earth-based scenario, but you probably found the moon-based scenario much more difficult due to the three-second delay. In 1970, the Russians faced similar difficulties operating a remote control vehicle called Lunakhod on the moon.

It might make sense to use an autonomous vehicle (or vehicles with limited autonomy) in situations where signal delays may occur. To operate a vehicle on Mars, you would have to wait about 10 minutes before commands would be received by a vehicle. That's how long it takes for radio signals to travel between Earth and Mars.

To control the Mars Sojourner Rover which was driven on the red planet in 1997, NASA "rehearsed" all the rover's moves in a computer simulation using a 3-D image of the Martian landscape. These commands were then sent to the rover and executed. In addition, the rover had the ability to identify and avoid some hazards automatically. Cameras and lasers mounted on the front of the rover scanned the rover's path looking for potential hazards.

NASA plans to send two rovers to Mars in 2003. It's likely that these rovers will operate in a similar manner, a combination of remote operation and autonomous control. NASA's Intelligent Robotics Program is currently working on improving autonomous navigation.

Luna 17/Lunokhod 1