Exomars Rover Challenge

Exomars, short for Exobiology on Mars, is a European Space Agency project which aims to look for signs of past life on Mars.

Another related objective is to study the atmosphere and geology of Mars.

The mission is made up of three spacecraft:

• Trace Gas Orbiter - a satellite orbiting Mars launched in 2016
• Schiaparelli - a Mars landing test module launched alongside the Trace Gas Orbiter.
• Rosalind Franklin - the Mars rover due to launch in 2028.

Aberystwyth's involvement

There are many companies and research institutes involved in making this happen.

Here, at Aberystwyth University, we are involved in two main projects, both on the top of Rosalind Franklin's mast.

1. PanCam:

   • Three cameras which can see 11 different colours (humans can only see three!)
   • A calibration target made of stained glass - so we will be able to see what known colours look like on Mars. This will allow us to correct any and all images produced by the camera.
   • The software to operate the cameras and calibrations.

2. Enfys: A laser spectrometer, built at Aberystwyth University, which can be pointed at a rock to tell us what it is made of.

Here is an image of the rig mounted on the Rosalind Franklin's mast:

Grid world:

This is the simulator for your program. Initially the robot starts in the top left corner square facing right. There is an L-shaped obstacle in the middle of the grid.

Each time the robot scans one of the grid squares, it will either show up as yellow (no life found), or green (alien life detected).

If your program is successful, all the grid squares should be coloured in either yellow or green.

Manual Controls:

Beneath the simulator, there are some blue buttons which will manually allow you to move the robot around the simulator and conduct scans.

This would be the same as using a remote control - which is not possible on Mars - however, we have included these to help with idea development.

Programmed Actions:

This is the programming area where you will need to write all your commands for the robot.

Add Actions:

These four buttons are likely to be the commands you will need to use the most in this challenge. They provide a quick way to add them to the program, rather than typing them every time.

Program Controls:

Where you can run, tidy, clear, or stop your program. There is also a Reset World button which will return the simulator back to its starting position and clear all scans.

Robot Output:

There is a text box at the bottom of the page that shows a log of the robot's actions.

If there is an error or mistake in your code it will show you the details here.

You can program your rover to 'print' or 'say' things, and they will also appear in this window.

forward - moves the rover forward one grid square.

left or turnleft - turns the robot left by 90°

right or turnright - turns the robot right by 90°

scan - scans for life-forms

print "text" - prints the message inside the quotation marks to the robot output

stop - terminates (ends/stops) the program

Below is an example program you can copy to help learn the basic controls.

            
  scan
  forward
  scan
  forward
  scan
  right
  forward
  scan
  forward
  scan
  right
  forward
  scan
  forward
  scan
  right
  forward
  scan
  forward
  print "I travelled in a square!"  
            
          

Your program is going to be very long if we write out every single instruction. Instead, we can use loops that allow us to repeat the same actions.

begin - starts an infinite loop.

begin 10 - start a 10-times loop (you can use any number here).

end - ends the loop.

leave - forces the program to leave the loop early.

Below is an example program you can copy to help learn about using loops in your program.

            
  begin 4    
    forward
    scan
    forward
    scan    
    right
  end
  print "I travelled in a square!"
  stop
            
          

As this program still repeats the same two lines twice, we could put a second loop inside the first:

            
  begin 4
    begin 2
      forward
      scan
    end
    right
  end
  print "I travelled in a square!"
  stop            
            
          

If statements are used to tell the robot to do something only if a condition is met

if condition - starts an if statement

endif - ends the if statement.

Here is an example of using an if statement for you to test. This is an infinite loop so you will need to use the 'Stop Program' button in the Program Control.

            
  begin
    scan
    if blocked
      turnright
    endif
    forward
  end
            
          

These are the recognised conditions for the if statements:

blocked - the square in front is either outside the grid or contains an obstacle.

facingscanned - the square in front has already been scanned.

onscanned - the square that the robot is in has already been scanned.

movingright - the robot is moving right on the grid.

movingleft - the robot is moving left on the grid.

movingup - the robot is moving up the grid.

movingdown - the robot is moving down the grid.

allscanned - all squares have been scanned.

An if-else statement allows us to command the robot to do one thing if it meets a condition and something else if it doesn't.

else - can be used in an if statement to give instructions if none of the other conditions are met.

Here is an example for you to test.

            
  begin
    if blocked
      right
    else
      forward
    endif
  end
            
          

not - can be used in an if statement to to give instructions if a condition is not met.

Here is an example for you to test.

          
  begin
    if not blocked
      right
    else
      forward
    endif
  end
          
        

else if condition - can be used in an if statement to check for different conditions

Here is an example for you to try:

            
  begin
    scan
    if blocked
      turnright
    else if facingscanned
      print "I've done the perimeter!"
      stop
    else
      forward
    endif    
  end
            
          

Sometimes we may want to randomise a program's output.

We have included two approaches for you:

1. cointoss - this is a condition that allows us to have two possible outcomes.

   Here is an example of how it can be used:

                   
     begin
       if cointoss
         turnleft
       else
         turnright
       endif
       forward
     end
                   
                 

2. roll - a command that will pick a random number between 1 and 6

   roll 20 - a command that will pick a random number between 1 and 20 (or whichever maximum number you choose)

   rolled 3 - a condition that is asking if the random number selected using roll is 3 (or whichever number you use)

   Here is an example you can use to test this:

                   
     begin
       roll 4
       if rolled 1
         forward
       else if rolled 2
         left
       else if rolled 3
         right
       else
         print "rolled a 4!"
       endif
     end
                   
                 

For more examples and some additional information on using this application, please use the Program Help button in the game's program controls.