The Earth is orbited by many satellites and it is very difficult to isolate one satellite that will attack the Earth. Apart from that, it will also violate the terms and conditions of Outer Space Treaty which foes not allow the use of weapons of mass destruction in the outer space or orbits.
In 1950s, the Unites States was working on its special project known as Project Thor, however, it was never accomplished because of the treaty constraints. Apart from that, other projects and satellites have been discussed and used that target the satellites present at the lower ground.
4. Almaz Space Station
The Almaz Space Station was formed by Soviet Union in 1960s for helping the search of sea-based targets of the enemies.
The idea behind the formation of this station was that the presence of humans in the space orbitals will be helpful in evaluating the change of battle targets and participants.
The first deployment of the Almaz was done in 1973 as due to the space race between the United States and Soviet Union was aiming at the race to moon. The station has been able to perform surveillance only once but due to the technological constraints, the mission has been interrupted afterwards.
5. Lenticular Reentry Vehicle
This was also one of the products of Cold war era that was developed by the United States and did not receive much limelight. It was a flying saucer like spacecraft that had the potential to start World War III.
The weapon was to be carried in the space on the top of Apollo rocket that contained four nuclear missiles. The weapon was designed to be brought back to the Earth after the completion of its mission on a strategically determined lakebed.