A GPX for the ride can be found
here.
For those getting to Luton Airport Parkway station by train from London, here's a money saving tip. Buy your ticket online beforehand by purchasing a return from Luton Airport Parkway to London St Pancras and pick it up from your local station. Then simply use the return portion first, and the outbound bit when you go back to London. This is because the price of a London to Luton Airport Parkway return ticket is £14.00 but a Luton Airport Parkway to London is only £9.50 (or just £6.25 with a Railcard). This is because for going into London, they offer a
Super Off Peak Return which is cheaper.
In fact an even better money saving tip is to register on Quidco, and then go via their web site onto Southern Railways, and buy the ticket through them and get 6% cashback.