(07/17/1961) -- PROJECT MERCURY'S SECOND suborbital astronaut training flight will be attempted during the week of July 16 with McDonnell Aircraft Corporation's production spacecraft number 11, which has been named 'Liberty Bell 7.' The number seven stresses the team effort of the seven Mercury pilots necessary for conducting Mercury flights. Mission pilot for the MR-4 launch will be astronaut Virgil I. 'Gus' Grissom. His spacecraft is seen here undergoing systems checks in the National Aeronautics and Space Administration's Mercury Hangar at Cape Canaveral, Florida, weeks before the planned launch