April 1982:American manned spacecraft recovery

When the Space Shuttle Columbia returned to Earth after its maiden flight, the aircraft-like spacecraft made touchdown on a runway at Dcryden Flight Research Center in California. This was a major departure from previous American spacecraft landings: all of which have been by parachute at sea. This article is intended to summarise the thirty-one American manned splashdowns which took place in the Atlantic and Pacific Oceans during the period 1961-1975.

Mercury

It was in late 1958 that a study began on manned spacepraft recovery operations. It had already been decided that water recovery was more favourable than land recovery. Many felt that retrieval operations could prove to be difficult: but with' properly designed equipment, helicopter pickup could be used. However, two and a half years were.to pass before the first manned splashdown occurred.

On 5 May 1961 astronaut Alan Shepard became the first American to fly in space during the sub-orbital. flight of Mercury Redstone 3. Shepard drifted back to Earth under a 19m diameter Northrop ringsail parachute only 486km downrange from the Cape Canaveral launch site. The small capsule hit the water at 10 m/sec and the pilot compared this as "a little abrupt, but no more severe than a jolt a pilot gets when he is launched off the catapult of an aircraft carrier". The splashdown, as with all Mercury landings, was cushioned by a rubberised glass-fibre landing bag which was released when the heat shield was lowered. Seconds after hitting the water, the capsule flopped over on its side and it was only when the reserve parachute was jettisoned that the spacecraft began to right itself. Minutes later, one of the recovery helicopters hooked on to the capsule and raised it slightly above the water. Shepard then emerged, entered a sling and was then winched up to the helicopter which transferred the astronaut to the prime recovery ship, the USS Lake Champlain.

The recovery of the second sub-orbital mission. Mercury Redstone 4. was by no means as successful. The capsule. Liberty Bell, "hit the water with a good bump" and a few minutes later while pilot Virgil Grissom was checking over the capsule’s instruments the side hatch prematurely blew open, apparently due to a short circuit. Sea water came rushing in over the sill and Grissom, seeing what was happening, lunged out of the hatch into the sea. In the process of doing this the astronaut got entangled in the line which attaches the dye marker package to the spacecraft, but fortunately managed to free himself quickly. The helicopter crew, seeing the sinking spacecraft, hooked onto it to lift it clear of the water, hut as this was happening a red warning light appeared in the cockpit to indicate that the helicopter's engine was overheating. This later turned out to be a false signal. The capsule, however, was released and sank to a depth of 4570m. Grissom who had been swimming around for three or four minutes was then picked up. but not before being dragged along in the water by the helicopter before he was lifted up. tired and very wet. Thus. Liberty Bell went down in the history books as the only American manned spacecraft to be lost during a mission. Following the loss of Mercury Redstone 4,a number of new procedures came into being to prevent any recurrence of the incident. These included a stipulation that the firing plunger safety pin would be left in place until the helicopter hook was attached to the spacecraft. Grissom had removed the safety pin a short time before the hatch blew open. Also for future missions an inflatable flotation collar would be fixed in place by recovery swimmers.

John Glenn, in Mercury Atlas 6, was next to splashdown in the Atlantic after America's first orbital flight. The accuracy of this landing was not as good as the two previous landings, the capsule landing some 64.5 km uprange. Friendship 7 "hit with a good solid bump" and the capsule went far enough under to submerge both the periscope and window. Glenn reported later that he heard gurgling noises but no leaks were found. For this mission the astronaut remained in the capsule until "Steelhead". the code name for the recovery ship USS Noa. came alongside. Twenty-one minutes after splashdown the capsule with Glenn aboard was winched onto the deck where the astronaut blew the side hatch of the capsule and emerged none the worse for his three orbits of the Earth. A helicopter later transferred the astronaut to the prime recovery ship, the USS Randolph. It is interesting to note that the recovery forces during this mission totalled twenty-four ships and one hundred and twenty-six aircraft. the astronaut blew the side hatch of the capsule and emerged

When Mercury Atlas 7 splashed down on 24 May 1962 it was 412 km from its predicted impact point. The overshoot was traced to a 25 degree yaw error at the time the retrograde rockets were fired. The capsule listed 60 degrees to one side after splashdown and astronaut Carpenter noticed that some water had seeped into the cockpit. Rather than wait in the capsule Carpenter decided to exit the spacecraft via the top of the craft and wait in the survival raft for pickup. The astronaut got into the raft before realising that it was upside down! Later, when recovery aircraft reached the area, he signalled with a hand mirror and stxrn frogmen were in the water attaching a buoyancy collar to the capsule to keep it afloat. The astronaut was then picked up by helicopter and taken to the USS Intrepid after being in the water for two hours and fifty nine minutes. The capsule, Aurora 7, was picked up by the USS Pierce and was found to contain a considerable amount of sea water, the majority of which was believed to have entered through the small pressure bulkhead when the astronaut passed through the recovery compartment to get to the life raft.

The landing and the recovery of the penultimate Mercury mission, Mercury Atlas 8. went according to plan with the spacecraft being recovered in the Pacific for the first time only 7.2 km from the predicted impact point. The splashdown of Mercury Atlas 9. the last mission of the Mercury programme, also went without a hitch. During the recovery the capsule was sighted by the aircraft carrier USS Kearsarge and helicopters were deployed to circle the spacecraft during its final descent. After a flawless splashdown swimmers dropped from the helicopters to fix the flotation collar and then a motor whaleboat towed the spacecraft alongside the ship. Cooper did not egress from the spacecraft until it was hoisted aboard the ship, only 37 minutes after splashdown.

Gemini

In early 1961 NASA decided to adopt land landing as a major Gemini objective but the means to that end, the paraglider system, had yet to prove itself. The first active interest in this landing system was in 1959, before the Mercury missions took place. The paraglider was, as the word suggests, a gliding parachute able to guide a returning spacecraft to a preselected site on land. After ejection of the paraglider cannister at 15.000m the paraglider would automatically take shape as gas inflated the 10 m structure. The pilot could bank.or change his rate of descent and could glide his craft up to 32 km in any direction. Cables attaching the paraglider to Gemini would be severed at touchdown and Gemini would skid to a halt. However, problems occurred with the ejection and inflation of the paraglider from Gemini during tests and in early 1964 after a string of failures the paraglider was dropped. Gemini money was tight at this time and this may have been the immediate reason for the cancellation of the paraglider project.

All ten Gemini.missions, like Mercury, landed by parachute in the sea. The heavier capsule however was lowered to a splashdown at 9m/sec by a 26m diameter ringsail parachute. Another difference from the Mercury landings was that the Gemini spacecraft lay in the water horizontally rather than vertically.

Gemini 3, the first manned flight of the programme, landed 111 km short of the planned impact point due to insufficient lift during re-entry. Shortly before splashdown the two astronauts. Grissom and Young, suffered a severe jolt when the spacecraft assumed its landing attitude. After the main parachute deployed, the spacecraft hung from it vertically with its nose suspended at a single point. Just before landing, activation of a cabin switch shifted the spacecraft to a two point suspension with its front end forward and some 35 degrees above horizontal. When Grissom hit the switch the spacecraft dropped into place, pitching both men forward against the capsule, breaking Grissom's faceplate and scratching Young's. The actual landing was mild by comparison but the parachute, still attached, dragged the nose of the spacecraft down in the water. When released, the spacecraft bobbed to the surface. The plan was for the astronauts to stay in the craft until it was picked up by the USS Intrepid, Due to the inacurate landing, however, the crew were picked up by helicopter and taken to the recovery ship after a flotation collar was fixed in place hv Navy swimmers.

The Gemini 4 crew were also jolted when their spacecraft assumed the two point suspension position, but neither knocked their helmets against anything. The splashdown occurred 81,4km from the predicted impact point but recovery helicopters were close by to pick up the astronauts. Fifty-seven minutes after splashdown the crew were on the deck of the USS Wasp.

Gemini 5 landed 168.5 km short Of its predicted landing point due to erroneous information programmed into the on-board computer from the ground. As with the Gemini 3 and 4 crews, this crew was picked up by helicopter. They arrived on the deck of the USS Lake Champlain just over one and a half hours after splashdown.

After successfully completing the first space rendezvous, Gemini 6 splashed down 12.9 km from the predicted impact point in full view of live television beamed from the recovery ship USS Wasp via satellite transmission. For this mission the astronauts stayed aboard the capsule until it was hauled aboard the recovery vessel. The recovery crew greeted the astronauts with a large banner proclaiming ‘Seasons greetings from Wasp’. The USS Wasp was in action again only two days later when Gemini 7 landed 11.8 km from the predicted impact point. Thirty-two minutes after splashdown the crew were on the deck of the ship after being'picked up by helicopter. Schirra and Borman, the commanders of this rendezvous mission had a small bet on who would splashdown closer to the target point. After the Gemini 6 landing, Mission Control told Borman of the computer controlled re-entry procedures used by Schirra and the result of this information was that Gemini 7 landed 1.1 km closer to the predicted impact point than Gemini 6. Borman won his bet!

Gemini 8, with astronauts Armstrong and Scott aboard, had problems in orbit after docking with an Agena target vehicle. This caused the mission to be terminated earlier than planned and resulted in a contingency recovery area being used. Aided by a new on-board computer designed for the Apollo programme the spacecraft splashed down safely into the sea 1110 km south east of Okinawa in the Pacific. Even before it hit the water, the capsule was spotted by an HG-54 Rescuemaster aircraft from Okinawa. Pararescue men parachuted down to the spacecraft and hooked on a flotation collar forty-five minutes after landing. The astronauts then exited the spacecraft and awaited rescue in a life raft. After three hours the USS Mason, a destroyer, pulled alongside Gemini 8, fastened a line to the spacecraft and the astronauts climbed the Jacob’s ladder to be welcomed on deck by the crew. The recovery forces had reacted to this emergency landing as if it had been normal.

Stafford and Cernan aboard Gemini 9 splashed down so close to their recovery ship USS Wasp that they were able to open the spacecraft’s hatches, relax and even raise their arms and thumb a ride on the Wasp. The two astronauts stayed in their spacecraft until it was hoisted onto the ship’s deck fifty-three minutes after splashdown. The splashdown was the most accurate of all Gemini flights - only 0.7 km from the predicted impact point.

Both Gemini 10 and 11 splashed down safely. The crew of the USS Guadalcanal watched Gemini 10 hit the water and twenty-seven minutes later welcomed the astronauts on deck. Gemini 11 also landed close to its prime recovery ship, the USS Guam, a sea-going platform for helicopters. The astronauts arrived aboard the ship only twenty-four minutes after splashdown. Recovery of the astronauts in both cases was by helicopter.

Gemini 12 astronauts Lovell and Aldrin described their landing as ‘hard’, but the astronauts and capsule were picked up safely and were on the deck of the recovery vessel twenty-eight minutes after splashdown. Recovery of this mission was televised live throughout the USA via the Early Bird communications satellite.

Apollo

Apollo 7. the first manned mission of the Apollo programme was next to splashdown, nearly two years after Gemini 12. The spacecraft landed in the Stable 2 position (upside down) which was one of the ways the Command Module (CM) could float. Three righting bags in the nose of the CM were inflated to flip the spacecraft over, and seven minutes later the spacecraft became Stable 1. A flotation collar was fixed by Navy frogmen, thus providing insurance against swamping from water taken aboard through the open hatch. The three astronauts were picked up by helicopter and taken to the prime recovery ship the USS Essex. Unlike the Mercury and Gemini spacecraft. Apollo landed with three parachutes, each having a diameter of 25.3 m. Landing speed was 8.5 m/sec.

After Man's first trip to the vicinity of the Moon. Apollo 8 landed Stable 2 close to its predicted impact point only 11 seconds earlier than the time given in the Flight Plan. Splashdown came 30 minutes before dawn and the crew decided to remain in the CM until sunrise. A helicopter than trasferred the astronauts to the USS Yorktown.

A storm in the selected landing area for Apollo 9 forced Mission Control to move the landing area 86 km to the south. However, the spacecraft splashed down only 4.8km from the USS Guadalcanal,the prime recovery ship. The only accident during recovery operations was when the downdraft from a recovery helicopter overturned one of the life rafts. Apollo 9 was the last American spacecraft to splash down in the Atlantic Ocean.

Dawn was just breaking when Apollo 10 floated down to a faultless splashdown 635 km east of Pago Pago in the Pacific. The three astronauts were on the recovery carrier only 39 minutes after landing and the spacecraft arrived on hoard one hour later.

The crew of the first moon landing mission,Apollo 11.landed Stable 2 within 24 km of the USS Hornet on 24 July 1969. The CM,Columbia, righted itself with the aid of the three big flotation bags after eight minutes enabling Navy frogmen to attach the flotation collar. On completion of this task all but one of the frogmen withdrew to a raft 30m upwind of the spacecraft. The remaining swimmer. Lieutenant Clancy Hatleberg,opened the CM hatch and passed in three Biological Isolation Garments for the crew. As the astronauts were waiting in the CM Collins announced “our condition is excellent". One hour after splashdown the crew were winched one by one into a hovering helicopter and after a three minute flight reached the l/SS Hornet. The three astronauts entered the Mobile Quarantine Facility (MQFj and from there were able to speak to President Nixon aboard the recovery ship. This was the first time a returning crew had been greeted in person by a President.

Television viewers saw a 6m high splash when Apollo 12 splashed down in a choppy Pacific Ocean on 24 November 1969. The spacecraft hit hard, landing Stable 2. Once the craft was righted Conrad radioed the recovery forces, reporting "we're in fine shape". Before the landing, television viewers were able to see what appeared to be smoke billowing from the CM. This was actually RCS propellent being vented, an operation usually performed at a higher altitude. Once the flotation collar was attached the crew were transferred to the USS Hornet by helicopter. One hour after splashdown the astronauts were in the MQF, above which a sign proclaimed "Three more like before", a reference to the fact that Hornet had picked up the Apollo 11 crew.

Of all the American spacecraft landings one of the most publicised was that of Apollo 13. the lunar mission which was terminated early in the flight due. to an explosion in the spacecraft's oxygen tanks. British Forces joined in the recovery operations when R.A.F. Command brought its worldwide Shackleton search and rescue reconnaissance aircraft to a state of readiness to help the American authorities. Also, six Royal Navy ships ( Nubian. Phoebe. Vidal. Tideflow. Ennerdale and Tarbatness) sailed to the spacecraft’s standby splashdown area in the Indian Ocean 259km east of Mauritius. Two Soviet merchant ships (Akademician Rykachev and Novopolotsk) diverted to the prime splashdown area in the Pacific and Soviet trawlers and whaling ships were ordered to give all possible help in the recovery of Apollo 13. The splashdown came on 17 April 1970 only 6.5 km from the recovery carrier the USS two Jima. the spacecraft landing Stable I. Within three minutes a helicopter was overhead and Navy frogmen dropped into the sea to fit the flotation collar. The tension of the four day flight was broken for the astronauts by the first man they spoke to after splashdown. Navy frogman Ernest Jahnche. who opened the spacecraft hatch and told Swigert that an Internal Revenue Service agent was waiting aboard the recovery ship to see him. He was referring to Swigert's failure to file an income tax return before the launch! Forty-six minutes after splashdown the astronauts arrived by helicopter on the deck of the recovery carrier, a scene watched by millions of television viewers worldwide.

When Apollo 14 splashed down 1448 km south of Samoa on 9 February 1971 a line from the main parachute failed to detach and became entangled around the CM as it bobbed in a slight swell. Navy frogmen, however, cut it free and attached a sea anchor and flotation collar. Shepard, the commander, announced that "we’re in very good shape in here" and within a few minutes the crew were in a life raft awaiting helicopter pickup.

Apollo 15 landed with only two of its main parachutes at a speed of 9.5 m/sec compared to the normal 8.5 m/sec with three parachutes. Despite this harder-than-usual splashdown astronaut Scott reported "everyone's in fine shape". The CM submerged briefly and then bobbed up in the Stable 1 position. The astronauts were soon picked up by helicopter and taken to the USS Okinawa. NASA narrowed the parachute failure down to two possible faults. Firstly, and the most likely reason,routine expulsion of RCS fuel by the CM as it came down may have caused contamination of the parachute. Secondly, flaws were detected in steel harness links on the one parachute recovered .from Apollo 15. A new metal was used on later missions.

Casper, the Apollo 16 CM landed only 0.5 km from its predicted impact point to become the most accurate splashdown of the American manned spaceflight programme. The CM landed Stable 2, the fifth Apollo to do so, a position it remained in for four minutes. This was partly due to the fact that it was dragged by its three main parachutes after it hit the water. The three large flotation bags were inflated and this changed the buoyancy characteristics and righted the bobbing craft. The commander, John Young, radioed "we finally got this thing right side up and we're doing fine. The condition of the astronauts is outstanding, it's super". After splashdown, ten frogmen were in the water when usually only three or four are involved in this procedure. The reason — to retrieve the three main parachutes to allow scientists to inspect them for any clue to the Apollo 15 parachute failure. Forty-five mir.utes after splashdown the astronauts were on the recovery carrier.

The splashdown and recovery of Apollo 17. the final Apollo mission was flawless. The CM splashed down gently into calm seas only 6.4 km from the recovery carrier, the USS Ticonderoga. The accuracy of the splashdown enabled one of the recovery helicopters to position itself directly over the descending spacecraft during the last few metres before impact. The three astronauts were aboard the Ticonderoga 53 minutes after splashdown.

Skylab

When Skylab 2 returned to Earth after a 28 day stay in space, the three astronauts remained inside the CM until it was hoisted aboard the recovery carrier, the USS Ticonderoga. This was the first time this had happened since Gemini 9 in June 1966 and the reason for this procedure was to protect samples and experimental data onboard the CM from the warm moist sea air. Also, many doctors felt that after a long period of weightlessness the crew might not have been able to exit the CM safely for a helicopter pickup. Swimmers dropped from a helicopter with flotation gear as in the past but then the aircraft carrier itself manoeuvred up close to the capsule and hoisted it aboard. When the astronauts emerged from the spacecraft 40 minutes after splashdown onto the deck of the recovery ship they appeared unsteady but well.

Skylab 3 landed in the roughest sea encountered by returning astronauts. The spacecraft landed Stable 2 and even when the three flotation bags righted the spacecraft it nearly tipped over as Navy frogmen tried to secure the flotation collar. Despite the 2.4m high waves the flotation collar was fixed in position and the CM was then winched aboard the USS New Orleans, only 40 minutes after splashdown. Three minutes later the astronauts emerged from the CM. slightly unsteady, and were assisted by doctors as they were taken off for medical examinations.

The final Skylab mission, Skylab 4. also landed Stable 2. within 5 km of the IJSS New Orleans. Minutes before splashdown the crew had been warned to wear oxygen masks because of fears of toxic fumes seeping into the capsule from a thruster jet which began leaking as they started their return to Earth. The CM remained Stable 2 for five minutes as the flotation bags were inflated to right the craft. Within an hour the spacecraft was on the deck of the recovery carrier and as with Skylab 3. the astronauts had to be helped across the deck. This was the first splashdown since 1966 that had not been covered on live television. The television networks decided against live coverage because of public apathy!

ASTP

The landing of the last American Apollo spacecraft, the Apollo used during the joint Soviet-American mission, nearly ended in disaster. Following reentry, the Earth Landing System (ELS) was not activated. One of the ELS functions was to cut off the roll thrusters, used to provide roll stabilisation of the spacecraft during reentry', and so the RCS system was kept operating for a longer period than normal, causing the CM to oscillate during parachute descent. Stafford, the commander, noticed the thrusters firing and so.cut off the propellent flow. However, nitrogen tetroxide fumes continued to enter the cabin through the pressure relief assembly which equalised the pressures inside and outside of the spacecraft. As the ELS had not been activated the main parachutes had to be deployed manually, this being the first time that had happened. During the last four minutes of descent the three astronauts were hardly able to breathe due to the fumes and. because of a great deal of aerodynamic noise and communictions interference. Mission Control and the recovery forces were unaware of what was happening. The CM "hit the water like a ton of bricks" (Stafford later-said that the splashdown reminded him of Gemini 9) and capsized when some of the parachute shrouds caught on the CM's nose. As the spacecraft was Stable 2 Stafford struggled to get at the oxygen masks located behind the astronauts couches. Brand, meanwhile, had passed out and had to be revived with oxygen. Once the CM righted itself Stafford radioed "We're okay now. We are in Stable 1 position". He then opened the hatch slightly to let some fresh air in before Navy frogmen reached the craft. A flotation collar was soon in place and recovery was in Skylab fashion with the CM being winched aboard the USS New Orleans only 45 minutes after splashdown. All three astronauts had been affected by the nitrogen tetroxide fumes and were hospitalised for two weeks in Honolulu.