Tcl was used in the Mars Rover Project. Which role did Tcl play?
http://zmbh.com/Tcl-Usage/Tcl_on_Pathfinder.pdf
ftp://ftp.procplace.com/pub/tcl/sorted/misc/Tcl_on_Pathfinder/
http://mars.netanya.ac.il/~opensys/RESOURCES/docs/papers/Tcl_on_Pathfinder.ps
So now I know why NASA keeps having difficulty with their Martian landings.