The Journey of Gus Grissom's Mercury Helmet

art by: Ron Woods

story by: Steven Kovachevich © 2013

The Journey of Gus Grissom's Mercury Helmet

Many are already familiar with the story of Gus Grissom's flight on Liberty Bell 7. Designated MR-4 this was the second suborbital test flight of the Mercury Capsule using the Redstone Booster. On July 21, 1961, Grissom was launched from Pad 5 at Cape Canaveral, Florida, on a ballistic trajectory to a position down range in the Atlantic Ocean. However, at the end of the fifteen minute flight Grissom was forced to bail out of the capsule after a malfunction caused premature activation of the explosive side hatch. The capsule filled with water and sank. Grissom almost drown waiting to be recovered by one of the helicopters.

After the flight Grissom recalled his last moments in Liberty Bell 7: "I had unhooked the oxygen inlet hose by now and was lying flat on my back and minding my own business when suddenly the hatch blew off with a dull thud. All I could see was blue sky and sea water rushing in over the sill. I made just two moves, both instinctive. I tossed off my helmet and then grabbed the right edge of the instrument panel and hoisted myself right through the hatch." 1 Liberty Bell 7 sank to the bottom of the Atlantic where it sat for 38 years until recovered by Curt Newport in 1999, on amission funded by Discovery Communications, Inc., and the Kansas Cosmosphere. The hatch was not recovered.

Grissom's capsule was the first to carry the explosive side hatch designed for quick, emergency egress.2 An earlier version of the hatch on Alan Shepard's MR-3, Freedom 7, capsule was operated by means of a lever. The hatch on Liberty Bell 7 was opened by depressing a plunger located on the inside of the hatch. To operate the astronaut removed a cover that concealed the plunger and a locking pin that prevented premature activation of the hatch mechanism. The astronaut pulled the pin and then pushed the plunger to trigger an explosive charge that severed bolts securing the hatch to the capsule. To prevent the hatch from becoming a projectile possibly injuring recovery personnel it was attached to the capsule by means of two restraining wires. The wires were connected to the back of the hatch and to the capsule which restrained outward movement to a couple of feet. Once "blown" the hatch rested below the opening suspended by the wires. Film of Grissom's recovery does not show the hatch restraining wire connection but only an open hatchway, because on splashdown Grissom had "released the restraining wires at both ends and tossed them towards [his] feet." 3 Release of the restraining wires allowed the hatch to completely separate from the capsule and sink independently to a resting place on the bottom of the Atlantic. The only part of the hatch recovered was "the cover for the door detonation switch", removed prior to the hatch malfunction.4 In response to Grissom's experience remaining Mercury Astronauts waited for their capsules to be hoisted onto recovery ships prior to opening the hatch.

After being pulled from the water Grissom was transported to the recovery ship USS Randolph where he was later presented with his helmet. The helmet left behind in the sinking capsule managed to float out before it sank and remained afloat until spotted by a destroyer crew who made the recovery. Grissom found the helmet's recovery "interesting" but "small consolation." 5

The unlikely way in which Grissom's helmet survived for future generations to contemplate was inspiration for Artist and NASA Suit Technician, Ron Woods. Mercury Era helmets were routinely stored in dome shaped plastic cases when not in use. The cases afforded additional means of identification as helmets, like spacesuits, were tailored to each astronaut. Astronaut names were usually written on a piece of tape affixed to the top of the case. The helmets sat in the dish like base with domed top attached by a series of latches. The Ron Woods watercolor shows Grissom's helmet resting in its case before the historic land, air and sea journey ahead.

The helmet was formed from plastic contoured to fully enclose the astronaut's head with the exception of an opening on the bottom where it attached to the suit torso by means of a neck ring.6 A plexiglass visor provided visibility. Later visors were made of Lexan after Grissom's plexiglass visor was punctured by a knob on the control panel of the Molly Brown during the first manned Gemini Flight. Unlike the Mercury Capsule, the Gemini Spacecraft was rigged to snap from a vertical to forty-five degree landing attitude after main chute deploy. Grissom and John Young were both thrown against the windows of their Gemini 3 Spacecraft after their main chute filled with air. Young's visor was scratched. The Mercury visor was manually opened and closed by the astronaut with an airtight seal between the visor and helmet formed from a rubber membrane inflated by an oxygen hose attached to a port on the left side of the helmet. The helmet interior was cushioned for comfort, impact and noise deadening. Once the astronaut was suited-up and visor lowered communication was via a set of headphones and pair of microphones situated directly in front of the astronaut's mouth. An oxygen outlet located on the right sideof the helmet completed the life support system loop that sustained the astronaut during tests and flight.

The journey of Grissom's helmet is "interesting". How the helmet managed to float out of the capsule that was at one point "clear under water" and then remain afloat for a period of time sufficient for a destroyer crew to spot it "floating right next to a ten-foot shark" was fortuitous.7 Recovery imagery suggests the helmet contained an air bubble that kept it afloat; while, prop-wash and agitation from hovering helicopters did not submerge the helmet but rather drove it away from the sinking capsule. Appropriately, the helmet now sits atop Grissom's flight suit on display in the Astronaut Hall of Fame located at the Kennedy Space Center in Florida. The helmet and suit look no worse for the experience and like the Ron Woods watercolor provide a unique perspective on this first generation helmet and spacesuit.

1 Chappell, Carl L., Seven Minus One, The Story of Astronaut Gus Grissom, New Frontier Publishing Co. (1968), p.73

2 Manned Spacecraft Center National Aeronautics and Space Administration, Results Of The Second US Manned Suborbital Space Flight July 21, 1961, p.3

3 Results, p.55

4 Madaras, Eric I. & Smith, William L., Langley Research Center, Hamption, Virginia, Liberty Bell 7 Recovery Evaluation and Nondestructive Testing, NASA/TM-1999-209824 (Dec 1999), p. 9

5 Seven Minus One, at p.77

6 National Aeronautics And Space Administration, Manned Spacecraft Center, Houston 1, Texas, News Release, Fact Sheet MA-8, Pressure Suits For Project Mercury Astronauts, p.2

7 Seven Minus One, at p.77

The Journey of Gus Grissom's Mercury Helmet
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