Editing Ranger 3 (section)

===Equipment malfunctions and trajectory errors===
[[File:Launch of Ranger III with Agena.jpg|thumb|Launch of Ranger 3]]
Liftoff took place at 3:30&nbsp;PM EST on January&nbsp;26, an hour and 15&nbsp;minutes before the launch window closed, after which Ranger&nbsp;3 could not have been launched for another month.

At T+49&nbsp;seconds into launch, the pulse beacon on the Atlas guidance system ceased operating, which prevented the transmission of any steering or cutoff directions for the remainder of the launch. Backup commands from the missile programmer were used to perform booster jettison and Agena separation, but without the guidance program, it was impossible to perform the necessary fine-tuning maneuvers to put the Atlas on the correct flight path. Second engine cut-off occurred due to fuel running out, rather than a programmed cut-off command, causing the Agena and probe to be accelerated higher and faster than planned.

Even worse, equipment at a Florida tracking station malfunctioned and picked up Ranger&nbsp;3's orbital parameters 5&nbsp;minutes late. Meanwhile, the Agena restarted and sent the probe out of Earth orbit, but another error in its guidance program resulted in yet another trajectory error. As a consequence, the spacecraft reached the Moon 14&nbsp;hours early and on January&nbsp;28 missed striking the Moon by 36,793&nbsp;kilometers (22,862&nbsp;miles).

The trajectory errors made impact with the Moon impossible, but Ranger&nbsp;3 could still have been used for deep-space studies. So the flight controllers issued commands to unfurl the camera boom, and on January&nbsp;28 an amended computer program was uploaded. However, midway through the upload, the probe's signal strength began to weaken and the onboard computer system failed completely. Without a functioning computer, the spacecraft was not able keep its high-gain antenna aimed at the Earth, which impeded communication with controllers on the ground.