On October 24, 1960, at 6:45 p.m., a prototype intercontinental ballistic missile on its launch pad at Baikonur burst into flames. The 1994 State Commission tallied 78 deaths: 74 at the site and four in hospital. The cause was not a fuel leak nor an order to fire. It was a sequence programmer left out of its zero position, a small electromechanical device that convinced the rocket that it was already in flight.
- A small electromechanical sequencer left in the wrong position sent a signal that opened the second-stage propellant valves on the ground.
- Political pressure to have the missile fly before November 7 led to neglect of safety instructions and to carrying out repairs and preparations in parallel.
- Marshal Nedelin and two other top Soviet space-program officials died in the explosion, taking with them a crucial share of the pioneers’ knowledge.
A Missile Pressed by the Political Calendar
The R-16, designed by Mikhaïl Yanguel’s design bureau, measured 30.4 meters in length and 3 meters in diameter, weighing 141 tons at launch. It burned a pair of hypergolic propellants, meaning they ignite on contact: asymmetrical dimethylhydrazine and nitrogen tetroxide, a mixture so toxic that it was nicknamed the “devil’s venom.” Stable at ambient temperature, it avoided the heavy cryogenic installations of liquid-oxygen rockets. In return, it self-ignites as soon as the two substances touch, without the slightest spark.
Marshal Mitrofan Nedelin, head of the Strategic Forces, wanted to see this missile fly before November 7, the 43rd anniversary of the Bolshevik Revolution. The program, however, was ahead of schedule: the test flight was planned for July 1961, ten months away. To meet the date, safety rules were neglected and the tests ended up overlapping with the firing preparations.
On October 23, an incident melted wiring and delayed the launch.
A Chair, a Programmer, a Flame
The next day, the decision was made to resume preparations on a rocket already filled with propellants. Instead of keeping his distance, Nedelin had his chair placed only tens of meters from the missile to push ahead with the repairs. Official guests arrived to witness the launch, and any further delay would be a loss of face. Dozens of technicians, engineers, and officers swarmed around the launch pad.
The culprit lay inside a housing. The program power distributor (PTR) energizes onboard systems in a precise order. It had been left on a faulty setting, feeding the batteries connected to the second-stage propellant valves. When an operator manipulated it at 6:45 p.m., the switch crossed a operating position and emitted a stray signal that opened those valves.
The rest took only a few seconds. The second stage ignited, its flame piercing through the still-full first stage. A survivor, standing about thirty meters from the base, described a thick jet of flame that appeared without warning and engulfed everyone. Many ran toward the perimeter, where the safety enclosure trapped them, and those spared by the flames inhaled toxic fumes.
Yanguel, for his part, had stepped aside to smoke.
Among the dead were Nedelin, Lev Grichine, vice-president of the State Committee for Defense Technologies, and Colonel Alexander Nossov, head of Baikonur’s launch command. Nossov had pressed the launch button for Sputnik three years earlier, and Ostachev had contributed to developing the Sputnik launcher. The accident took with it a portion of the experience accumulated by the Soviet pioneers.
The Marshal “Dead in an Airplane Accident”
On October 26, Soviet newspapers published a brief communiqué from the Central Committee and the Council of Ministers: Marshal of Artillery Nedelin had died in an airplane accident. No detail or name of other victims was given. The families of the engineers and military personnel who disappeared were left to cope with polished versions as well.
It took almost thirty years for the silence to crack. In 1989, Ogoniok, the voice of Gorbachev’s perestroika, published “Site 41” and revealed that Nedelin had died in the explosion of a ballistic missile at Tyuratam. Other testimonies and documents followed, enabling today a minute-by-minute reconstruction.
The final tally remains unclear. The figure of 78 comes from the 1994 commission, but some estimates range from 54 to 300 dead, and Britannica cites an official range of 60 to 120. Let us settle on 78: roughly half the seats of a full Airbus A320, lost in a few seconds at the foot of a single rocket. The event is regarded as the worst accident in the history of rocketry.
The R-16 program nevertheless survived, at the cost of several months of delays. The first flight occurred on February 2, 1961, and initial operational capability was reached on November 1, 1961. Deployment peaked in 1965 with 202 missiles. During the Cuban Missile Crisis in 1962, the Soviets had fewer than 50 in service.
An earlier fatal accident involving the R-9 missile, exactly three years later, turned October 24 into Baikonur’s “Black Day,” and no launch has been attempted on that date since.
Source: Britannica.com
