Spacewalking Astronauts John Grunsfeld, Mike Massimino, Michael Good and Andrew Feustel began their formal training for the fifth and final Space Shuttle mission to repair and upgrade the Hubble Space Telescope this past December.

Their underwater, neutral buoyancy training takes place at the Johnson Space Center's Neutral Buoyancy Laboratory in Houston, Texas. Mission design engineers from NASA's Goddard Space Flight Center in Greenbelt, Maryland document the crew's activities by filming the training.

All photos were taken using a Canon 5D camera in an Ikelite housing with DS-125 Substrobe.

The NASA team continues to use Ikelite products to document their astronauts' underwater activities, making for very unique "diver photos."

We have yet to hear of an Ikelite housing going into space, but stay tuned!