Monday, February 27, 2012

Mercury Redstone 3

Here are some images of Dragon Models 1/72 scale Mercury - Redstone 3 Rocket.

From Wikipedia"

Mercury-Redstone 3 was the first manned space mission of the United States. Astronaut Alan Shepard piloted a 15-minute Project Mercury suborbital flight in the Freedom 7 spacecraft on May 5, 1961 to become the first American in space, three weeks after the Soviet cosmonaut Yuri Gagarin had carried out the first orbital spaceflight.

The capsule, launched on a Redstone rocket from Launch Complex 5 (LC-5) at Cape Canaveral, Florida, reached an altitude of 116.5 miles (187.5 km) before falling back on a ballistic trajectory and splashing down 303 miles (488 km) away from the launch pad, off the Bahamas. During the flight, Shepard observed the Earth and tested the reaction control system of the spacecraft. Earth photos were taken by an automatic camera mounted in the spacecraft's window.

The countdown began at 8:30 p.m. the previous night, with Shepard entering the spacecraft at 5:15 a.m. ET, just over two hours before the planned launch time. At 7:05 a.m., 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.

Mercury-Redstone 3 finally lifted off at 9:34 a.m. 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, turning it so the heatshield 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.

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, 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, the USS Lake Champlain. The whole recovery process had taken only eleven minutes, from splashdown to arriving aboard.

The flight lasted 15 minutes, 28 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: 27.23°N 75.88°W. 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. The Freedom 7 is now on display in the lobby of the Armel-Leftwich Visitor Center at the U.S. Naval Academy, Annapolis, MD. It was placed there after Shepard's death in 1998.