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Sun May 5, 2019, 10:13 AM

58 Years Ago Today; "Light this candle!"

Last edited Sun May 5, 2019, 11:03 AM - Edit history (1)

https://en.wikipedia.org/wiki/Mercury-Redstone_3


Still frame of Alan Shepard taken by a motion picture camera aboard Freedom 7

Mercury-Redstone 3, or Freedom 7, was the first United States human spaceflight, on May 5, 1961, piloted by astronaut Alan Shepard. It was the first crewed flight of Project Mercury, the objective of which was to put an astronaut into orbit around the Earth and return him safely. Shepard's mission was a 15-minute suborbital flight with the primary objective of demonstrating his ability to withstand the high g-forces of launch and atmospheric re-entry.

Shepard named his space capsule Freedom 7, setting a precedent for the remaining six Mercury astronauts naming their spacecraft. The number 7 was included in all the crewed Mercury spacecraft names to honor NASA's first group of seven astronauts. His spacecraft reached an altitude of 101.2 nautical miles (116.5 statute miles, 187.5 km) and traveled a downrange distance of 263.1 nautical miles (302.8 statute miles, 487.3 km). It was the fourth Mercury flight launched with the Mercury-Redstone Launch Vehicle, from Cape Canaveral, Florida, close to the Atlantic Ocean.

During the flight, Shepard observed the Earth and tested the capsule's attitude control system, turning the capsule around to face its blunt heat shield forward for atmospheric re-entry. He also tested the retrorockets which would return later missions from orbit, though the capsule did not have enough energy to remain in orbit. After re-entry, the capsule landed by parachute on the North Atlantic Ocean off the Bahamas. Shepard and the capsule were picked up by helicopter and brought to U.S. Navy aircraft carrier USS Lake Champlain.

The mission was a technical success, though American pride in the accomplishment was dampened by the fact that just three weeks before, the Soviet Union had launched the first human in space, Yuri Gagarin, who completed one orbit on Vostok 1. In 2017 the first National Astronaut Day was held on May 5 to pay tribute to this first flight.

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Flight
The countdown began at 8:30 p.m. the previous night, with Shepard waking up and eating a breakfast of steak and eggs with toast, coffee, and orange juice (the steak and eggs breakfast would soon become a tradition for astronauts the morning of a launch). He entered the spacecraft at 5:15 am. ET, just over two hours before the planned 7:20 launch time. At 7:05 am, the launch was held for an hour to let cloud cover clear good visibility would be essential for photographs of the Earth and fix a power supply unit; shortly after the count restarted, another hold was called in order to reboot a computer at Goddard Space Flight Center. The count was eventually resumed, after slightly over two and a half hours of unplanned holds, and continued with no further faults. All of the delays resulted in Shepard lying on his back in the capsule for almost three hours, by which point he complained to the blockhouse crew that he had a severe need to urinate (because the mission would last under 20 minutes, nobody had thought to equip the Mercury with a urine collection device). The crew told him that this was impossible as they'd have to set the White Room back up and waste considerable amounts of time removing the Mercury's heavily bolted hatch. An irate Shepard then announced that if he couldn't get out for a bathroom trip, he'd simply urinate in his suit. When the blockhouse protested that that would short out the medical electrodes on his body, he told them to simply turn the power off. They complied, and Shepard emptied his bladder. Because of the position he was sitting in, the urine pooled somewhat underneath his back and with oxygen flowing through the spacesuit, he was soon dried out, and the countdown resumed.


Launch of MR-3 on May 5, 1961

Mercury-Redstone 3 finally lifted off at 9:34 am. ET, watched by an estimated 45 million television viewers in the United States. Shepard was subjected to a maximum acceleration of 6.3g just before the Redstone engine shut down, two minutes and 22 seconds after launch. Freedom 7's space-fixed velocity was 5,134 miles per hour (8,262 km/h), close to the planned value. Ten seconds later, the escape tower was jettisoned. At the three-minute mark, the automated attitude control system rotated Freedom 7 so the heat shield faced forward ready for re-entry.

Shepard was now able to take manual control of the spacecraft, and began testing whether he was able to adjust its orientation. The first thing he did was position the spacecraft to its retrofire attitude of 34 degrees pitch (nose of spacecraft pitched down 34 degrees). He then tested manual control of yaw, motion from left to right, and roll. When he took control of all three axes, he found that the spacecraft response was about the same as that of the Mercury simulator; however, he could not hear the jets firing, as he could on the ground, due to the levels of background noise.

The secondary objective was to make observations of the ground from the spacecraft; returning the spacecraft to automatic control, Shepard found that he was able to distinguish major land masses from clouds easily, and could make out coastlines, islands and major lakes, but had difficulty identifying cities. He had problems working with the spacecraft periscope early Mercury capsules had a small periscope rather than a viewing window and had to abandon an attempt to change optical filters on it after noticing that a pressure gauge on his wrist kept bumping the lever that would have activated the Launch Escape System. Although the escape tower was long gone and pressing on the lever probably wouldn't do anything, Shepard still didn't want to risk it in case something unexpected happened.

Under automatic control, the spacecraft had developed a slight movement as it passed through peak altitude; Shepard now switched into the "fly-by-wire" mode, where the pilot used a controller to order the automatic system to fire the rockets for the desired positioning, rather than manually controlling the individual jets. Adjusting roll and yaw, he found the pitch position was around ten degrees too shallow 25 degrees rather than the desired 35 for reentry and as he began to correct it, the timed retrorockets fired to send him into reentry. The retrorocket pack strapped atop the heatshield and so requiring release before reentry was successfully jettisoned, but the confirmation light failed, requiring Shepard to activate the manual override for the jettison system before it confirmed that the rockets were fully released.

Shepard resumed fly-by-wire control after retrofire, reporting that it felt smooth and gave the sensation of being fully in command of the craft,[24] before letting the automatic systems briefly take over to reorient the capsule for reentry. He then kept control until the g-forces peaked at 11.6g during re-entry; he held the capsule until it had stabilized and then relinquished control to the automated system. The descent was faster than anticipated, but the parachutes deployed as planned, a drogue at 21,000 ft (6.4 km) and a main parachute at 10,000 ft (3.0 km).

Splashdown occurred with an impact comparable to landing a jet aircraft on an aircraft carrier. Freedom 7 tilted over on its right side about 60 degrees from an upright position, but did not show any signs of leaking; it gently righted itself after a minute, and Shepard was able to report to the circling aircraft that he had landed safely and was ready to be recovered. A recovery helicopter arrived after a few minutes, and after a brief problem with the spacecraft antenna, the capsule was lifted partly out of the water in order to allow Shepard to leave by the main hatch. He squeezed out of the door and into a sling hoist, and was pulled into the helicopter, which flew both the astronaut and his spacecraft to a waiting aircraft carrier, USS Lake Champlain. The whole recovery process had taken only eleven minutes, from splashdown to arriving aboard.

The flight lasted 15 minutes, 22 seconds and the spacecraft traveled 302 miles (486 km) from its launch point, ascending to 116.5 miles (187.5 km). Freedom 7 landed at these coordinates: 27.23N 75.88W. It reached a speed of 5,180 mph (8,340 km/h).

Following the flight the spacecraft was examined by engineers and found to be in excellent shape, so much so that they decided it could have been safely used again in another launch. Given to the Smithsonian Institution by NASA, Freedom 7 was previously displayed at the U.S. Naval Academy in Annapolis, Maryland until 2012. Since 2012, it has been on display at the John F. Kennedy Library in Boston, Massachusetts.




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