he capsule. For 10 minutes, the two remained connected, with the unneeded instrument section trailing behind and causing the capsule to experience wild gyrations as high as 30 degrees per second. The incident, which was not revealed by the Soviets, but which Gagarin hinted at in his state-sanctioned report, was potentially disastrous. The capsule was weighted in such a way that it would naturally rotate to point the thickest part of its heat shield into the direction of travel. If the instrument section did not separate cleanly, the capsule could not assume its correct attitude and properly bear the brunt of re-entry heating. Gagarin could burn alive.
Fortunately, at 10:35 a.m., as the spacecraft’s meteoric descent path neared Egypt, the cable finally burned through and separated the instrument section. After slinging the capsule away with a spin so severe that Gagarin almost lost consciousness, it finally attained aerodynamic equilibrium with its heat shield positioned accurately. It was later revealed that the complications arose when a retrorocket valve failed to close properly, allowing some fuel to escape from the combustion chamber. As a result of this loss, the engine cut off a second too early, slowing Vostok at a less-than-expected rate and preventing a normal shutdown command from being issued. In the absence of this command, the engine’s propellant lines remained open and pressurised gas and oxidiser continued to escape through the nozzle and served to induce the wild gyrations. Although the engine was ultimately cut off by a timer, its lack of delivered thrust caused the spacecraft’s control system to scrub the primary sequence to separate the capsule from the instrument section. The notes of the cosmonauts’ physician, Yevgeni Karpov, auctioned by Sotheby’s in March 1996, revealed his concern, and, indeed, analysts have speculated that—had the world known of these problems—the ’60s space race might have slowed dramatically.
Gagarin himself made one brief reference to the incident. “The craft began to revolve and I told ground control about it,” he wrote. “The turning I had worried about soon stopped … ” Little else would be known or even suspected for almost three decades. However, in his testimony before the top-secret State Commission on 13 April, he described feeling the intensity of the capsule’s oscillations and an audible sound of “cracking,” possibly from the structure of Vostok itself or from the expansion of the thermal cladding material. He saw the bright crimson glow of ionised gases rushing past the capsule and would later estimate that the G forces exceeded 10 and “data on the control gauges started to look blurry … starting to turn grey in my eyes.”
Eventually, as he heard denser air whistling past the capsule and saw blue—not black—sky outside, he braced himself for ejection. By this point, Vostok had crossed back into Soviet territory, on the Black Sea coast, near Krasnodar. Gagarin’s ejection procedure was supposed to be fully automatic, triggered when the on-board sensors registered an outside atmospheric pressure consistent with an altitude of about four miles. He may have felt that the oscillations were too severe to risk it, and it would appear that he initiated the sequence manually. With a tremendous roar and rush of air, the hatch above his head blew away and the ejection seat’s rocket propelled him from the capsule at terrifying speed. Protected from the frigid high-altitude temperatures by his suit, Gagarin descended to Earth; his main parachute opened successfully, followed by its backup, and the First Cosmonaut hit the ground under two canopies.
A new era had begun.
The second part of this article will appear tomorrow.