At the Baikonur launch site, half an hour remained until the scheduled flight. The R-16 rocket was loaded and military personnel, engineers, and technicians were moving around it. At 6:45 p.m. local time on October 24, 1960, instead of a countdown, a fire broke out.
The second stage engine ignited prematurely while the rocket was still on the ground. The flame pierced the first stage tank, the fuel ignited, and within seconds the launch site was engulfed in flames. Some people tried to escape through the flames, while others were trapped in the service structures.
Among those present was Marshal Mitrofan Nedelin, commander of the Soviet Strategic Missile Forces. He observed the preparations closely, although his presence on the site with an armed and loaded missile violated basic safety rules. Boris Konoplyov, chief designer of the R-16 control system, test managers, and dozens of military personnel and workers from the missile industry also died.
A missile prepared under political pressure
The R-16 was conceived as the first Soviet intercontinental ballistic missile capable of carrying a nuclear warhead over a long distance. The test is part of Moscow's drive to quickly show that it has a reliable weapon in its race with the United States.
However, the preparations were accompanied by failures, leaks and recurring problems in the systems. Nevertheless, work continued. There were many more people on the site than were needed for the operation. Later, the commission found that in addition to the technical defect, serious violations of organization and safety were made.
The report indicated that the electrical system allowed the activation of a valve that turned on the second stage engine. The document concluded that the “direct cause of the accident“ was a flaw in the control scheme that allowed the premature activation of the valve.
Officially a plane crash
Initially, the commission reported 90 victims. Later, more bodies were found, and in a number of historical reconstructions, the number reached 92. Some of the wounded died in hospital, and the exact number remains controversial due to secrecy and different lists of the dead.
Chief designer Mikhail Yangel survived because he retreated into hiding shortly before the explosion. In his first message to Moscow, he described a “fire during the last pre-launch operation“ and indicated that there were dozens of dead and many burned by the fire and nitric acid.
However, the truth was hidden from the public. On October 26, the Soviet authorities announced that Nedelin had died in a plane crash. The other victims were almost never mentioned. Details only began to emerge publicly in 1989, when the Soviet press broke its long-standing silence.
The R-16 rocket did reach mass production and was adopted for service in 1963. But its name will forever be associated with that night at Baikonur, when a pre-launch procedure turned the symbol of Soviet rocket power into a fiery monument to the human cost of the race.
Sources: theguardian.com, pbs.org, latimes.com