The Mercury Project - by Andrea
After the Soviet launch of Sputnik 1, and the information about their effort to launch a man in orbit, USA hurried up the study and construction of what had to be the USA response to USSR Space program, and this was named Mercury Project (1958-1963).
Its goal was to orbit a manned spacecraft around Earth, to investigate man's ability to function in space, to recover both man and spacecraft safely, following these directives:
- Spacecraft fitted with a reliable launch-escape system to separate the spacecraftand its crew from the launch vehicle in case of impending failure
- Pilot´s capability of manually controlling spacecraft attitude
- Spacecraft with a retrorocket system capable of reliably providing the necessaryimpulse to bring the spacecraft out of orbit
- A zero-lift body utilizing drag braking used for reentry
- Spacecraft design satisfying the requirements for a water landing
3 shots during manufacture of the Mercury capsules...
The Mercury capsule was a little bell-shaped spacecraft, to be launched on top of an existing rocket (Viking, Atlas), in order to bring a single astronaut in a suborbital flight (but higher than 100 miles, in order to gain the Space flight definition) and then on flights of one or more orbits. The Mercury capsule was very small, a kind of metal dress for the astronaut, but giving him the possibility to give a look out and to drive manually the capsule. Many Mercury capsules were built, and six of them went to space with one astronaut on board.
- FREEDOM 7 (MR3), May 5, 1961, Alan B. Shepard, Jr.15 minutes, 28 seconds of suborbital flight; the first American in space
- LIBERTY BELL 7 (MR4), July 21, 1961, Virgil I. Grissom15 minutes, 37 seconds, suborbital; successful but the spacecraft sank shortly after splashdown
- FRIENDSHIP 7 (MA6), February 20, 1962, John H. Glenn, Jr.04 hours, 55 minutes 23 seconds; three-orbit flight, the first American into orbit
- AURORA 7 AURORA 7 (MA7), May 24, 1962, M. Scott Carpenter04 hours, 56 minutes, 5 seconds; duplicating Friendship 7 flight
- SIGMA 7 (MA8), October 03, 1962, Walter M. Schirra, Jr.09 hours, 13 minutes, 11 seconds; six-orbit engineering test flight
- FAITH 7 (MA9), May 15-16, 1963, L. Gordon Cooper, Jr.34 hours, 19 minutes, 49 seconds; last Mercury mission; 22 orbits to evaluate effects of one day in space
Mercury Mission MR4: LIBERTY BELL 7
This spacecraft was designated to fly the second manned suborbital flight in October, 1961. Gus Grissom announced he would name it Liberty Bell 7, as this name was appropriate for the bell-shaped capsule. Moreover it was synonymous with "freedom".
The launch of Liberty Bell 7, was postponed from July 16, due to the clouds, to the morning of July 21, 1961. The launch was at 12:20:36 UTC, July 21, 1961.
The Mercury 4 mission was to reach an apogee of 116 miles (187 km). The planned range was 299 miles (481 km). Grissom would experience a maximum acceleration of 6.33 g (62 m/s) and deceleration of 10.96 g (107 m/s).
|Virgil I. "Gus" Grissom|
At the proper altitude, about 27,000 feet (8.2 km), he felt that the environmental control system was in good working order. The suit and cabin temperature, about 57.5 and 97 °F (14 and 36 °C), respectively, were quite comfortable. Grissom noticed a sudden change in the color of the horizon from light blue to jet black.
With turnaround accomplished, the Air Force jet pilot for the first time became a space pilot, assuming manual-proportional control. A constant urge to look out the window made concentrating on his control tasks difficult. Some land beneath the clouds (western Florida around the Apalachicola area) appeared in the hazy distance.
With Liberty Bell 7 at an altitude of 118.26 miles (190.32 km), Grissom initiated the retrorocket sequence. Reentry presented no problem. The drogue parachute deployed at 21,000 feet (6.4 km), and main parachute deployed at 12,300 feet (3.7 km). His rate of descent soon slowed to about 28 feet per second (9 m/s).
The landing bag had dropped in preparation for impact. Grissom removed his oxygen hose and opened his visor but deliberately left the suit ventilation hose attached. Impact was milder than expected, As the window cleared the water, Grissom jettisoned the reserve parachute and activated the rescue aids switch. Liberty Bell 7 appeared watertight, although it was rolling badly with the swells.
Preparing for recovery, he disconnected his helmet. When the recovery helicopters, which had taken to the air at launch time and visually followed the contrails and parachute descent, were still about two miles (3 km) from the impact point. Lieutenant James L. Lewis on the primary recovery helicopter, radioed Grissom to ask if he was ready for pickup. He replied that he wanted them to wait five minutes while he recorded his cockpit panel data. After logging the panel data, Grissom asked the helicopters to begin the approach for pickup. He removed the pin from the hatch-cover detonator and lay back in the dry couch. The hatch cover blew away, and salt water swished into the capsule as it bobbed in the ocean. The third man to return from space was faced with the first serious emergency; Liberty Bell 7 was shipping water and sinking fast.
Grissom doffed his helmet, and scurried out the sloshing hatchway. From the copter they saw Grissom's head appear, and the astronaut began climbing through the hatch. Once out, the pressure-suited spaceman swam away.
Instead of turning attention to Grissom, helicopters completed the approach to the sinking spacecraft, trying the capsule recovery, because the pilots had noted that the astronaut seemed at home in and to enjoy the water. So picked up the shepherd's hook recovery pole and carefully threaded the crook through the recovery loop on top of the capsule. The pickup pole twanged as the attached cable went taut, indicating to the helicopter pilots that they had made their catch.
Immediately they prepared to pass the floating astronaut the personnel hoist. But at that moment a detector light flashed on the instrument panel, indicating that metal chips were in the oil sump because of engine strain. Considering the implication of impending engine failure, they called the second chopper to retrieve the pilot.
Meanwhile Grissom, certain that he was not snared by any lines, noticed that the primary helicopter was having trouble raising the submerged spacecraft. Suddenly Grissom realized that he was not riding as high in the water as he had been. All the time he had been in the water he kept feeling air escape through the neck dam. The more air he lost, the less buoyancy he had. Moreover, he had forgotten to secure his suit inlet valve. Swimming was becoming difficult, and now with the second helicopter moving in he found the rotor wash between the two aircraft was making swimming more difficult. Bobbing under the waves, Grissom was scared, angry, and looking for a swimmer from one of the helicopters to help him tread water. From the copter they tossed the "horse-collar" lifeline straight to Grissom, who immediately wrapped himself into the sling backwards. Grissom had been swimming or floating for a period of only four or five minutes, "although it seemed like an eternity to me," as he said afterward.
|During the recovery attempt...|
Now the flooded Liberty Bell 7 weighed over 5,000 pounds (2,300 kg), a thousand pounds (450 kg) beyond the helicopter's lifting capacity. The pilot decided not to chance losing two craft in one day. He finally cast loose, allowing the spacecraft to sink swiftly. From the carrier was suggested to place a marker at the point so that the capsule might be recovered later. Substantial controversy ensued as Grissom reported that the hatch had blown prematurely without his authorization. Engineering teams concluded this was unlikely.
Mrs. Grissom was not invited to the White House as per the forming tradition with Shepherd's wife upon his successful mission completion. Subsequent independent technical review of the incident has raised doubts as to the veracity of the incident report conclusions that Grissom blew the hatch and was responsible for the loss of the spacecraft. There is strong evidence that the Astronaut Office didn't accept Grissom's guilt in the fact that he was chosen to command the first Gemini flight.
Several years later, during an interview on April 12, 1965, Grissom said he thought the hatch may have been triggered because the external release lanyard came loose. On Liberty Bell 7, the external release lanyard was only held in place by a single screw. It was better secured on later flights. Ironically, the inability to open a hatch swiftly contributed to the death of Grissom, as well as Ed White and Roger B. Chaffee, in the Apollo 1 launch-pad fire.
|Thirty years later...|
One day before of the 38th anniversary (July 20, 1999) of Mercury 4's suboribital flight, and exactly 30 years after the day after man first landed on the Moon, a team led by Curt Newport and financed by the Discovery Channel, lifted the Liberty Bell 7 capsule off the floor of the Atlantic Ocean and onto the deck of a recovery ship.
The capsule was found after a 14-year effort by Newport and his team at a depth of nearly 15,000 feet (4.5 km), 300 nautical miles (550 km) southeast of Cape Canaveral and was in surprisingly good condition. Some of the interior aluminium panels showed deterioration but some fabric pieces, including Grissom's personal parachute were perfectly intact. The recovery failed to answer some of the questions surrounding the prematurely blown hatch. The recovery team ran out of time and was not able to continue the search for the hatch itself.
A camera that was running during the flight was located but was found broken open and the film inside was damaged beyond repair. After Liberty Bell 7 was secured in the deck of the recovery ship, experts removed and disposed of an explosive device that was supposed to detonate in the event of the capsules sinking but which failed to explode. After the capsule was made safe, it was placed in a container filled with seawater to prevent further corrosion. The Kansas Cosmosphere and Space Center disassembled and cleaned the capsule and keeps it on display in their museum.