The full-back is using a 'zero-gravity treadmill' designed by the American space agency to help astronauts acclimatise to walking on the moon.
He reveals the hi-tech fitness work he is doing to get ready for the demands of top-level rugby.
"You set it from zero to 100pc body weight and it means you can slowly reintroduce yourself into running on full body weight."
Kearney (pictured) also gives an unique insight into the mood inside the Leinster camp as they prepare to take on Clermont in this Sunday's crunch Heineken Cup tie.
The teams have become rivals on the European stage after a series of high octane matches. But Kearney says his team-mates are aware there is an "awesome" opportunity to end Clermont's imposing unbeaten home record of 50 games this weekend.
Read Rob Kearney's exclusive new column in today's Irish Independent print edition.