Longueuil, Quebec, October 4, 2004 – The Canadian Space Agency (CSA)
announced today that NEEMO 7 back-up crewmember Dr. Robert Thirsk, CSA
astronaut, will replace Dr. Dave Williams as commander of the mission. NASA
and CSA officials decided after discussions that Dr. Thirsk, a Canadian
astronaut and medical practitioner, will lead this important undersea
mission to test and evaluate telerobotic surgical applications and
telementoring.

Dr. Thirsk was called upon to assume this role after a review of a recent
medical condition of Dr. Dave Williams, also a Canadian astronaut. However,
Dr. Williams, who was instrumental in designing the mission, will continue
to be actively involved in the NEEMO 7 mission. Dr. Williams is expected to
be medically recertified for active duty as an astronaut and aquanaut in the
near future, and to return to training for Space Shuttle Mission STS-118.

The Canadian and U.S. team will be supporting a series of telesurgery and
telementoring initiatives planned for the 11-day undersea mission off the
coast of Key Largo, Florida, from October 11 to 21, 2004.

More information on the crew and the objectives of the NEEMO 7 mission are
available on the CSA Website, http://www.space.gc.ca