For information the long awaited DART (automated guided people mover (light metro)) from Luton Airport Station to the airport has a soft opening on 10 March, and was fully opened on 27 March 2023 operating 24 hours a day, replacing a bus service for the link.
Luton is an airport, north of London, which is very useful for regional connections, including Inverness on Easyjet.
There is a 24 hour a day rail service from London St Pancras international, taking 45 minutes, which can sometimes be picked up on an advance fare for £2.50, more widely £8, walk on fare £16.50.
If you book to 'Luton Airport' rather than 'Luton Airport Parkway' your fare includes the DART/bus.
The DART fare alone will be £4.90.
It's a useful option anyway.
EDIT- Full opening date of today [27 March] substituted, and information on free senior citizens rides added below