and unzip to your Orbiter folder. Look at the readme file for info on other required addon for the launch mission, you can try mission 2 and 3 without other addons.

Simple to use contrary to MER ( Spirit and Opportunity)  addons, EDL is all automatic. All you have to do is get rid of cruise stage by presssing "J" , use some time accelaration "T" to get to 150km then "R" to get back to real time. Students can watch and note every step ( CTRL+P  to pause) and once landed they can open the instruments, turn on the Lidar and manipulate the arm. They can't really grab some soil,   but they will  be able to see the extent of the arm's range of motion.

Orbiter screenshot of Phoenix, excellent work by Brian Jones