Editing Ranger 1 (section)

=== Launch ===
During the first half of 1961, Lockheed introduced the new Agena B stage which replaced the early test-model Agena A of 1959-60. Agena B was more powerful and had in-orbit restart capability. Its first flight with the launch of [[MIDAS (satellite)|Midas 3]] on July 24 was successful. Several frustrating delays in Ranger 1's launch occurred, including one episode where the spacecraft's timer inadvertently activated on the pad, causing the solar panels to be deployed inside the payload shroud. After removing Ranger 1 and repairing it, the launch was carried out at 6:04 AM EST on August 23. All went well up to orbital injection, but the planned Agena restart went awry when the engine shut down after only a few seconds, putting the probe in a 312x105 mile track. Subsequent investigation concluded that an electrical circuit in the Agena had overheated from exposure to the Sun. The unintended orbit made it difficult to operate Ranger 1's systems correctly, although ground controllers tried to work around it. The main problem they faced was with the solar panels; Ranger 1 would experience 90 minutes of darkness while passing around the nighttime side of the Earth. In addition, the antennas at NASA's various tracking stations had difficulty locking onto the probe due to its orbital plane. During this time, the computer system repeatedly fired the attitude control jets in a vain attempt to lock onto the Sun with the effect that only one day after launch, the probe ran out of attitude control gas. At this point, it could not be stabilized and the solar panels lost their lock on the Sun. Ranger 1 thus reverted to battery power and continued transmitting until the batteries ran down on August 27 and all signals from the probe ceased. It was not a total loss; the spacecraft systems had worked well and some data on cosmic rays and radiation was returned, however the low orbit precluded the use of the [[magnetometer]]. After four days and 111 orbits, Ranger 1 reentered and burned up over the [[Gulf of Mexico]].<ref name="nssdc1961-021A" />