Clickety-Clack: Remembering the Misfortune of Gemini VI, OTD in 1965

Stafford (left) and Schirra walk down the Pad 19 ramp after the GATV-5002 failure, 55 years ago today. Photo Credit: NASA

“Everything’s going clickety-clack,” reported CBS news correspondent Charles von Fremd on the morning of 25 October 1965. “We should be launching on the hour.” But for Gemini VI astronauts Wally Schirra and Tom Stafford, their mission would not go well that day.

Wally Schirra (left) and Tom Stafford, pictured in the final days before launch. Photo Credit: NASA

As Fremd relayed his report to news anchor Walter Cronkite, camera views panned out to Pad 14 at Cape Kennedy, to reveal the first Gemini-Agena Target Vehicle (GATV), primed and ready for liftoff. It was an unusual sight: a workhorse Atlas SLV-3 booster would provide the first-stage muscle to get the vehicle off the ground, with Lockheed Aircraft’s Agena-D perched on top. The intention at 10 a.m. EDT was that the mighty Atlas would boost the 26-foot-long (7.9-meter) Agena-D into low-Earth orbit, where it would be used later that day by Gemini VI astronauts Wally Schirra and Tom Stafford as a rendezvous target.

The ambitious two-day flight would mark the first-ever controlled rendezvous between a manned orbiting vehicle and another object. It should have been a spectacular step forward as America strove to fulfil a presidential directive to land on the Moon before the decade’s end. Sadly, good fortune was not on anyone’s side that day.

Wally Schirra felt a rendezvous mission was of sufficient complexity that the added drama of a spacewalk was an unnecessary frivolity. Photo Credit: NASA

Rendezvous was one of the central requirements of Project Gemini, the ambitious program of ten manned missions by a series of two-seater spacecraft between March 1965 and November 1966. In addition to demonstrating that astronauts could survive the harsh environment of low-Earth orbit for up to two weeks, Gemini also sought to master the hazards of spacewalking and bringing two large vehicles together under controlled conditions to mimic the kind of maneuvers that an Apollo Command and Service Module (CSM) and Lunar Module (LM) would one day perform in lunar orbit.

To get that rendezvous done, in March 1962 Lockheed Aircraft had begun work on its Agena-D, which was capable of firing its large engine up to five times and featured a radar transponder, forward docking adapter to achieve a link-up with Gemini and an advanced attitude-control system. And in April 1965, when Schirra and Stafford finished their duties as the backup crew for the first manned Gemini flight, they were formally appointed to Gemini VI, planned for later that year.

Tom Stafford clambers out of a Gemini boilerplate capsule during water egress training in the Gulf of Mexico in August 1965. Photo Credit: NASA

Original plans called for Stafford to perform the first spacewalk, but when the Soviet Union beat them to it in March 1965, that objective was brought forward to an earlier mission. It was no great loss for Schirra. He was reluctant to complicate an already-complex rendezvous mission with the added danger of an Extravehicular Activity (EVA). In fact, wrote legendary NASA flight director Chris Kraft, one of Gemini’s main learning experiences was “being able to pick a point in space, seek it out and find it.” And that is what Gemini VI would do.

The first Gemini-Agena Target Vehicle (numbered “GATV-5001”) was shipped to Cape Kennedy in May 1965, as a non-flying test article, followed by GATV-5002 in August for the mission itself. But there were doubts about its reliability. Some engineers felt that its powerful engine could not be trusted to execute maneuvers with a docked Gemini and, although Schirra lobbied fiercely for it to go ahead, opposition within NASA to actually firing it on this first mission was too strong.

The GATV-5002 (left) and Gemini VI (right) undergo a ground-based exercise. Photo Credit: NASA

The plan was for GATV-5002 to launch from Cape Kennedy’s Pad 14 at 10 a.m. EDT into a 186-mile-high (300 km) orbit, after which Schirra and Stafford would launch 101 minutes later aboard Gemini VI atop a Titan II booster from Pad 19, just 6,000 feet (1,800 meters) to the south. In his CBS coverage on launch morning, Cronkite even remarked that this distance was far closer than the minimum 7,500 feet (2,300 meters) normally allowed.

Following their own liftoff at 11:41 a.m. EDT, Schirra and Stafford would fly a lower, “faster”, elliptical orbit. “Two hundred and seventy degrees behind the Agena,” wrote Stafford in his memoir, We Have Capture, “you’d make a series of maneuvers that would eventually raise the orbit of the Gemini to a circular one behind the Agena. Then you’d glide up below the Agena on the fourth revolution. At that time, the crew would make a series of maneuvers to an intercept trajectory, then break to station-keeping and docking.”

Pictured during Gemini VIII in March 1966, the Agena-D provided a rendezvous target for four later Gemini crews. Photo Credit: NASA

This docking would occur over the Indian Ocean, about six hours after launch. Gemini VI would remain linked to GATV-5002 for seven hours, before Schirra undocked and brought them back to Earth after two days. They would utilize the Hohmann Transfer, which Schirra described as “the most efficient, quickest and prettiest way” of pulling off a rendezvous, albeit very unforgiving of error. “If you blow the rendezvous,” he wrote in his autobiography, Schirra’s Space, “fuel and time constraints won’t permit another try.”

The Atlas booster, tipped by the Gemini-Agena Target Vehicle (GATV)-5002, is readied for launch on 25 October 1965. Photo Credit: NASA

During training, the astronauts practiced the maneuver again and again, completing more than 50 simulations in total. “Housed in a six-story building,” wrote Schirra, “it consisted of a full-scale Gemini cockpit and the docking adaptor of the Agena. They were two separate vehicles in an air-drive system that moved back and forth free of friction. We exerted control in the cockpit with small thrusters, identical to those on the spacecraft. We could go up and down, left and right, back and forth. The target could be maneuvered in those planes as well, though it was inert. It would move if we pushed against it, just as we assumed the Agena would do in space.”

On one occasion, Schirra hosted Vice President Hubert Humphrey in the pilot’s seat. Humphrey asked if their voices could be heard from outside the trainer. When Schirra replied that it was sound-proofed, Humphrey asked if Schirra minded him taking a nap. When Humphrey awoke, he asked Schirra to tell him what had happened so that he could tell the people outside. “I was a fan of Hubert Humphrey from that day on,” wrote Schirra.

Schirra and Stafford board Gemini VI on the morning of 25 October 1965. Photo Credit: NASA

Early on 25 October, teams at Pad 14 labored to get the Atlas-Agena ready to fly. In the meantime, Schirra—who was struggling to give up smoking—lit up a Marlboro during his own ride out to Pad 19. According to Stafford, the command pilot felt “he could survive a twenty-four-hour flight without getting the shakes.” At length, General Dynamics launch manager Thomas O’Malley pressed the firing button for the Atlas-Agena at 10:00 a.m., and the first half of the mission almost got underway. Three minutes later, at Pad 19, the hatches to Gemini VI were closed, sealing Schirra and Stafford inside their spacecraft.

There seemed little doubt that the Atlas would fly straight and true, with a heritage of 140 previous flights and a good record in terms of reliability. High above the Atlantic Ocean, the GATV-5002 would separate from the Atlas and fire its engine over Ascension Island to lift itself into orbit. Then Schirra and Stafford would launch to initiate the rendezvous. At first, all went well, with the Atlas’ Sustainer Engine Cutoff (SECO) announced at four minutes and 44 seconds after liftoff. “Conditions looked very nice,” came the clipped report from the NASA announcer.

The Atlas-Agena launches at 10 a.m. EDT on 25 October 1965. Photo Credit: NASA

But his words were premature.

Thirty seconds or so later, GATV-5002 was due to separate and ignite its engine. It would appear that the Agena-D did separate from the Atlas, but seemed to “wobble” a little, despite the sterling efforts of its attitude-control system to stabilize it. Right on time, the engine ignited…and nothing more was heard. Chamber pressures in the engine were recorded by telemetry as having begun to rise, and downrange radar measurements indicated that it had ignited, but then all data was lost. GATV-5002 was 150 miles (240 km) high and traveling about 500 miles (800 km) downrange of the Cape. Fourteen minutes after launch, radar specialists in Bermuda expected to establish tracking.

Personnel at the Manned Spacecraft Center (MSC) in Houston, Texas, watch the aftermath of the GATV-5002 failure. At center is Flight Director Chris Kraft. Photo Credit: NASA

They saw nothing, apart from five large fragments.

Out at Pad 19, Schirra and Stafford were listening to the updates and were puzzled. “Maybe it’s the tracking station,” Schirra speculated. “Let’s wait for Ascension Island.” Their countdown was held, but at length Ascension, too—in the mid-Atlantic—saw nothing. Later, the Carnarvon station in Australia also saw nothing, and the assumption had to be made that the target vehicle had been lost. At 10:54 a.m. EDT, NASA’s Paul Haney told his listeners the news and announced the Gemini VI had been scrubbed.

Jerome Hammack at the Pad 14 blockhouse was convinced something was not right only six minutes after launch; so too was the Air Force officer in charge of the mission. Subsequent investigation revealed that the Agena had exploded, due to a pre-launch change in the oxidizer feed sequence protocol. If it represented a programmatic failure with the vehicle, the issue spelled trouble for Project Gemini, which depended upon the Agena as its primary rendezvous target.

A good party? Chief Astronaut Al Shepard in conversation with Wally Schirra during preparations for Gemini V’s eventual launch in December 1965. Photo Credit: NASA

For a couple of days after 25 October 1965, there was talk about using the GATV-5001 test article, but such plans were abandoned as the problem behind the failure was not yet known. It was Gemini VII command pilot Frank Borman who overheard a conversation between McDonnell officials Walter Burke and John Yardley. The pair discussed using Gemini VII, then planned for launch in December, as a “new” rendezvous target.

Launching two manned vehicles within a couple of weeks of one another seemed, at first glance, to stretch the system too far. But others were convinced that it could be done. And over a few adrenaline-charged weeks in late 1965, it was.

In the meantime, 55 years ago today, their next launch date uncertain, Wally Schirra and Tom Stafford were plucked out of Gemini VI and headed off into town with Chief Astronaut Al Shepard and backup crewman John Young.

“Boys,” Shepard told them, “what we need is a good party!”

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2 comments to Clickety-Clack: Remembering the Misfortune of Gemini VI, OTD in 1965

  • Marilyn Lunney

    Thanks so much, it is great to hear from you….don’t know where all the ‘black’ hair went but we were a great lot of men doing a fine job for our country.

    Glad to hear from you, still going here in Houston…


  • Out of the ashes of failure, the world was treated to the wonderous Gemini 7/6 mission which effectively paved the way for Apollo 11.

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