OSCAR 40

AMSAT-OSCAR-40, also known as AO-40 or simply OSCAR 40, was the on-orbit designation of an amateur radio satellite of the OSCAR series. Prior to launch, the spacecraft was known as Phase 3D or "P3D". AO-40 was built by AMSAT.

AO-40's project manager was Peter Guelzow of AMSAT-DL, the German AMSAT organization. Mr Guelzow holds amateur call sign DB2OS.