Apollo 18 (2011)

Two years after the Apollo 17 mission, the crew of the cancelled Apollo 18 mission—Commander Nathan Walker, Lieutenant Colonel John Grey, and Captain Ben Anderson—learn that it will proceed as a top-secret Department of Defense (DoD) mission to place an early warning detector on the Moon for ICBM attacks from the USSR.

Grey remains aboard Apollo command module Freedom, while Walker and Anderson land in Apollo Lunar Module Liberty to install the detector. Anderson collects rock samples before they return to Liberty. The samples cause minor disturbances, which Houston attributes to interference from the detector. The following day, Anderson discovers footprints leading to an abandoned but functioning Soviet LK lander. Nearby, they find a crater containing a dead cosmonaut, but Houston dismisses Walker's questions. That night, Walker is awakened by strange noises and an object striking the lander.

After completing their mission, Walker and Anderson prepare to leave, but Liberty's launch is aborted when the spacecraft begins shaking violently. They discover damaged foil nearby, along with non-human tracks and damaged equipment. Walker is horrified when a spider-like creature enters his spacesuit, but it disappears before Anderson finds him unconscious near Liberty; Walker later denies the incident. Anderson subsequently removes a Moon rock embedded in Walker. Walker smashes the rock, contaminating the spacecraft. An unknown source interferes with their communications, preventing contact with Houston or Grey.

Anderson theorises that the detector was intended to monitor the aliens and is responsible for the interference. They attempt to deactivate it, only to find that it has been destroyed. Walker becomes increasingly contentious and paranoid, while they discover that the aliens are camouflaged as Moon rocks. Attempting to destroy cameras inside Liberty, Walker damages other controls and causes the spacecraft to depressurise. While travelling to the Soviet LK lander for oxygen, Walker deliberately crashes the rover, believing that returning to Earth would spread the infection.

Anderson awakens to find Walker being dragged into a crater by the aliens. Unable to rescue him, Anderson escapes to the Soviet LK and uses its radio to contact USSR Mission Control, who connect him to the DoD. The Deputy Secretary reveals that the DoD is aware of the situation but will not allow Anderson to return to Earth, believing incorrectly that he is infected. Grey contacts Anderson, and they arrange for him to return to Freedom. As Anderson prepares to launch, Walker suddenly appears and demands entry, but the aliens swarm and kill him. Anderson launches, only for the DoD to order Grey to abort the rescue, threatening to prevent his own return if he refuses.

The LK reaches orbit, where the aliens attack and infect Anderson during free fall. Unable to control the spacecraft, Anderson collides with Freedom. The U.S. government subsequently claims that the astronauts were killed in separate jet accidents and that their bodies could not be recovered. It also notes that many Moon rocks given to dignitaries from previous Apollo missions are now missing.