Intended to be an uncrewed sub-orbital spaceflight, it was launched on November 21, 1960 from Cape Canaveral Air Force Station, Florida.

[3][4] The flight would also test the Mercury-Redstone's automatic inflight abort sensing system, which would be operating in "open-loop" mode.

[6][7] On that day, following a normal countdown, the Mercury-Redstone's engine ignited on schedule at 9:00 a.m. Eastern Standard Time (14:00 GMT).

Furthermore, the capsule's main and reserve parachutes were hanging down the side of the rocket, threatening to tip it over if they caught enough wind; this did not occur, however, as the weather conditions were favorable.

Amid the panicked atmosphere in the control room, the launch team was unable to come up with quick and viable options to rectify the situation.

Flight director Chris Kraft rejected several unsafe interventions, including using a rifle to shoot holes in the booster's propellant tanks to depressurize them.

[9] This early test failure and subsequent panic led Kraft to declare "That is the first rule of flight control.

[6][10] Investigation revealed that the Redstone's engine shutdown was caused by two of its electrical cables separating in the wrong order.

[8][14] The Redstone had suffered some minor damage from falling back on the pad, but it could still be used after refurbishment, so it was returned to Marshall Space Flight Center in Huntsville, Alabama, and was held in reserve.

[4][15][16] To prevent a failure like MR-1's from recurring, subsequent Mercury-Redstones added a grounding strap about 12 inches (30 cm) long to electrically connect the rocket to the launch pad.

Had MR-1 been a crewed mission, the normal contingency would have been a pad abort, lifting the Mercury capsule off the booster and to safety via the escape rocket.

This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.