America's first ASAT system was Program 505, which used prototype Nike Zeus DM-15S anti-ballistic missiles, operated from Kwajalein Atoll by the U.S. Army. US Secretary of Defense McNamara approved the US Army request to proceed with development, under the code-name Mudflap, in May 1962. The extended range Nike Zeus was first tested in ASAT mode from White Sands against a point in space in December 1962. After several tests with good results, McNamara authorized the Army to complete the ASAT facility at Kwajalein Atoll, including storage of the system's nuclear warheads. The system remained operational until May 1966. Nike Zeus could reach satellites up to 560 km altitude, using its 1 megaton nuclear warhead to destroy them. It was replaced by the Program 437 ASAT.

• 1962 May 1 - Mudflap approved. -
  US Secretary of Defence McNamara approved the US Army request to proceed with development, under the code-name Mudflap. America's first ASAT system was later known as Program 505, which used prototype Nike Zeus DM-15S anti-ballistic missiles, operated from Kwajalein Atoll by the U.S. Army.

• 1962 December 1 - Nike Zeus ASAT test. -
  The extended range Nike Zeus was first tested in ASAT mode from White Sands against a point in space. After several tests with good results, McNamara authorised the Army to complete the ASAT facility at Kwajalein Atoll, including storage of the system's nuclear warheads.

• 1966 May 1 - Program 505 Nike Zeus ASAT retired -
  The ASAT facility at Kwajalein Atoll was replaced by the Program 437 ASAT.