Saturday, July 23, 2011

50 YA - America's Second Space Flight!

MR-4 launch from Pad 5.

Mercury-Redstone 4 launched from Cape Canaveral on July 21, 1961. Perched atop the Redstone rocket was Mercury spacecraft #11, affectionately nicknamed "Liberty Bell 7" by its occupant, astronaut Virgil I. Grissom.

Air Force Captain Gus Grissom.

Captain Grissom was known to the world as Gus. He didn't like his name Virgil, and certainly didn't want to be known by his middle name, "Ivan" - especially during the Cold War with the Soviets! He had flown 100 combat missions flying the F86F Sabrejet fighter, and later became a test pilot. He was NASA's second choice to fly into space.

Technicians servicing Mercury spacecraft #11.

The capsule Gus would fly into space was modified from the one Captain Shepard flew on the first flight. This model had a centerline window and had an improved attitude control system for easier spacecraft maneuvering. Technicians painted a simulated crack on the exterior, after Gus had named the capsule "Liberty Bell 7."

Gus enters the capsule, a tight fit for anyone.

Backup astronaut for the mission was John Glenn, Jr. He was scheduled to fly the next mission. In the small preparation room surrounding the capsule at the top of the tower, John helped technicians squeeze Gus into the spacecraft and then sealed the hatch shut. At this time, the hatches were bolted shut with 70 small bolts. This would make exiting the capsule a difficult thing were it not for emergency explosive devices that when activated would disconnect the bolts and propel the hatch some 25 feet. Normal procedure would be for the astronaut to exit through the top hatch in the antenna compartment. During final preparations, one bolt on the hatch failed to line up properly, and after a 30 minute wait, technicians decided that 69 bolts wouold have to do the job.

Launch occurred a little after noon on July 21st. Because they were using the Redstone rocket, there was insufficient thrust to place the capsule into orbit, so the flight was only planned for a 15-minute suborbital journey over the Atlantic ocean. Gus experienced about 6 G's, or six times the force of gravity during the ascent into space. He noted that the blastoff was smoother than he expected, but some vibration increasing toward the end of acceleration.

The craft separated from the rocket and Gus had control of the craft. During tests of the control system Gus discovered that the controls were more sluggish in reality than he had experienced in the simulators. He activated the new rate control system, which then performed flawlessly.

Having reached an altitude of 118 miles, Gus prepared for re-entry and positioned the capsule so the heat shield faced forward. The retrorockets jettisoned on time and the craft decelerated at about 3 G's. Parachutes deployed fine and he landed the spacecraft in the ocean 486 miles from his launch site. The carrier USS Randolph stood by to recover astronaut and capsule.

Unexpectedly, the hatch explosive bolts activated and the hatch was thrown from the craft. Water began entering the hatch from wave action and the capsule began to sink. GUs had to preform his own emergency egress from the craft and enter the water as the helicopters arrived. At first his suit kept him floating fine in the water.

Attempting to hook up to the capsule.

The helicopters ignored the floating Gus and focused on attempts to hook up the capsule and lift it from the water. Unfortunately, the increasing weight of the capsule, now filling with seawater, put an increased strain on the helicopter engines and warning lights began to show in the cockpit. Metal chips from the engine were entering the oil system and the second helicopter had to be assigned to grab the capsule. Meanwhile, Gus noticed that his suit had a hole and was filling with water also. He was sinking too.

Gus is lifted from the water.

Additional attempts to lift the capsule were failing. Gus reached a "collar" lowered from the helicopter, slung one arm into it and was pulled to safety. The pilot of the second helicopter decided against further risk to his craft and cut the cable to the capsule. Liberty Bell 7 sank to an estimated depth of 28oo fathoms.

Last view of the Liberty Bell 7 before it takes the plunge.

Safely aboard the carrier, Gus went through an intense debriefing and medical examination. The mission was considered a failure because of the loss of the spacecraft. Engineers familiar with the explosive bolts system would blame Gus for the accident, claiming he must have deliberately or accidentally "blown" the hatch. Gus always insisted that the hatch detonated by itself without any reason. Later, Gus would be cleared of wrongdoing by an investigation court.

Gus escorted from the flight deck of the carrier.

For Gus, there would be no grand welcoming like that received by Alan Shepard. Rumors abounded about the reason of the hatch release. Eventually, astronaut Wally Schirra performed an experiment on his capsule after landing, to see how the explosive hatch reacted. His hand injury from the detonation was quite apparent. Gus received no such injury, indicating he had been correct and had not accidentally hit the explosive hatch release. Gus was vindicated by his fellow pilots. Gus would stay with the program and would later play an important part in the development of both the Gemini and Apollo programs.

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