Engineering and limited scientific results (for instance, air resistance at high altitude determined by the rocket's trajectory)[1]: 259 would be obtained from the 25 lb (11 kg) telemetry payload carried by the WAC Corporal second stage.[5] Though the Bumper program was not, itself, a secret, aspects of it were classified, particularly the way the WAC Corporal was fitted into the nose of the V-2.[6]