Mercury-Redstone 1A (MR-1A) was launched on December 19, 1960 from LC-5 at Cape Canaveral, Florida. The mission objectives of this uncrewed suborbital flight were to qualify the spacecraft for space flight and qualify the system for an upcoming primate suborbital flight. The spacecraft tested its instrumentation, posigrade rockets, retrorockets and recovery system. The mission was completely successful. The Mercury capsule reached an altitude of 130 miles (210 km) and a range of 235 miles (378 km). The launch vehicle reached a slightly higher velocity than expected - 4,909 miles per hour (7,900 km/h). The Mercury spacecraft was recovered from the Atlantic Ocean by recovery helicopters about 15 minutes after landing. Serial numbers: Mercury Spacecraft #2 was reflown on MR-1A, together with the escape tower from Capsule #8 and the antenna fairing from Capsule #10. Redstone MRLV-3 was used. The flight time was 15 minutes and 45 seconds.
Mercury-Redstone suborbital flight events
MR-1A Launch
T+ Time
Event
Description
T+00:00:00
Liftoff
Mercury-Redstone lifts off, onboard clock starts.
T+00:00:16
Pitch Program
Redstone pitches over 2 deg/s from 90 deg to 45 deg.
T+00:00:40
End Pitch Program
Redstone reaches 45 deg pitch.
T+00:01:24
Max Q
Maximum dynamic pressure ~575 lb/sq ft (27,500 Pa)
Posigrade rockets fire for 1 s giving 15 ft/s (4.6 m/s) separation.
T+00:02:35
Turnaround Maneuver
Capsule (ASCS) system rotates capsule 180 degrees, to heat shield forward attitude. Nose is pitched down 34 degrees to retro fire position.
T+00:05:00
Apogee
Apogee of about 115 miles (185 km) reached at 150 miles (240 km) downrange from launch site.
T+00:05:15
Retrofire
Three retrorockets fire for 10 seconds each. They are started at 5 second intervals, firing overlaps. Delta V of 550 ft/s (170 m/s) is taken off forward velocity.
T+00:05:45
Retract Periscope
Periscope is automatically retracted in preparation for reentry.
T+00:06:15
Retro Pack Jettison
One minute after retrofire, retro pack is jettisoned, leaving heatshield clear.
T+00:06:20
Retro Attitude Maneuver
(ASCS) orients capsule in 34 degrees nose down pitch, 0 degrees roll, 0 degrees yaw.
T+00:07:15
.05 G Maneuver
(ASCS) detects beginning of reentry and rolls capsule at 10 deg/s to stabilize capsule during reentry.
T+00:09:38
Drogue Parachute Deploy
Drogue parachute deployed at 22,000 ft (6,700 m) slowing descent to 365 ft/s (111 m/s) and stabilizing capsule.
T+00:09:45
Snorkel Deploy
Fresh air snorkel deploys at 20,000 ft (6,100 m). (ECS) switches to emergency oxygen rate to cool cabin.
T+00:10:15
Main Parachute Deploy
Main parachute deploys at 10,000 ft (3,000 m). Descent rate slows to 30 ft/s (9.1 m/s).
T+00:10:20
Landing Bag Deploy
Landing Bag Deploys, dropping heat shield down 4 ft (1.2 m).
^This is the mass of the spacecraft after separation from the booster, including all spacecraft consumables. It excludes the escape tower, which was jettisoned before spacecraft separation, and the spacecraft-booster adapter, which remained attached to the booster. Note that Mercury spacecraft #2 lacked some of the equipment present in the spacecraft used on the crewed Mercury flights.
This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.
