USSR-1 was a high-altitude balloon built in the USSR.
On September 30th, 1933 the high-altitude balloon USSR-1 reached an altitude of 19 km with Prokofyev, Godunov and Birnbaum aboard. In 1932, they formed a committee on exploring stratosphere. One of the goals of the committee was construction of another high-altitude balloon that could reach an altitude of 25 km with people aboard.
Prokofyev, Godunov and Birnbaum aboard USSR-1.
Prokofyev before takeoff in Moscow, September 30th, 1933. Prokofyev also managed the construction of the high-altitude balloon.
Prokofyev checks the equipment before takeoff in Moscow, September 30th, 1933.
USSR-1 was launched at 8.40 a.m. When the high-altitude balloon reached an altitude of 19 km, the balloon crew sent a radiotelegram to Stalin, Voroshilov and Molotov reporting on the flight and thier readiness to continue exploration of stratosphere.
Boarding the high-altitude balloon.
The high-altitude balloon landed the same day at around 5 p.m. A special committee registered the new record established. Participants and organizers of the flight received orders.
Another check of the high-altitude balloon.
In 1930, a group of talented engineers expressed their willingness to construct a stratosphere balloon but due to financial difficulties construction works started just two years later in 1932 with Vasenko as its design manager. Osoviakhim-1 (OAKh-1) was completed by June, 1933. A special committee examined the stratosphere balloon and it obtained a permit for a flight even though some defects in its hatch were found.
P. Fedosenko, 1933.
OAKh-1 featured best equipment but when its launch was put off until spring, 1934 the equipment was dismantled.
That fall, Prokofyev talking with reporters announced his plan to perform another flight to stratosphere in winter, not in spring.
However, they failed to prepare for the flight in 1933 and it was put off until January, 1934. Takeoff was to take place in Kuntsevo, Moscow, on January 30th, 1934. They planned to reach an altitude of 20,500 m.
Osaviakhim before takeoff, January 30th, 1934.
OAKh-1 took off with Fedoseenko, Vasenko and Usykin aboard. Fedoseenko, an experienced aeronaut, belived that they took a risk performing that flight in the wintertime.
OAKh-1 before takeoff, January 30th, 1934.
At 9.07 a.m. Osoaviakhim-1 lifted off and soon made radio contact with the airfield. By 9.56 the aircraft reached 15,000 m according to on-board altimeter; at around 17,700 m its envelope expanded into a nearly perfect sphere and eventually reached static equilibrium at 19,500 m, exactly as intended by design. The crew experienced problems with carbon dioxide absorbers, but it appeared to be manageable. Fedoseenko dumped 310 kilograms of ballast and by 10.50 the balloon passed its design altitude of 20,500 m. This moment was later marked as the point of no return: at 20,500 m Osoaviakhim-1 carried just enough ballast to stabilize descent speed. Further ascent and inevitable loss of hydrogen made this ballast insufficient; the only escape route was through bailing out on personal parachutes, provided that the crew could open the awkward hatch. After nearly an hour at 20,600 m Osoaviakhim-1 climbed again, reaching 22,000 m at 12.33 and hovered at this record altitude for 12 minutes.
The OAKh-1 team.
At 12.45 the crew opened gas release valve for three minutes to initiate descent; the hot balloon did not respond as planned and travel to 18,000 m took more than two hours. At this altitude vertical speed levelled at a safe and steady one meter per second. At around 14,000 m vertical speed increased, reaching two meters per second at 13,400 m. Lifting force of the remaining hydrogen reduced to 1,300–1,400 kilograms, while the balloon weighed an estimated 2,120 kilograms.
Between 4.05 p.m. and 16.10 p.m, when Osoaviakhim-1 descended to 12,000 m, vertical acceleration went out of control; the balloon began disintegrating before it reached 8,000 m. At about 2,000 m its gondola separated from the balloon and impacted ground between 4.21 and 4.23, near Potizh-Ostrov village in rural Insar district of Mordovia.
Examining the crashed hight-altitude balloon.
The bodies in the gondola were badly maimed; Fedoseenko’s skull had disintegrated, probably after impacting a tempered glass porthole. The balloon envelope fell 4 km from the gondola and its fabric was quickly looted by local villagers.
Three urns on Red Square, February 2nd, 1934.
The three crew members, probably incapacitated by high g-forces in a rapidly rotating gondola, failed to bail out and were killed by a high-speed ground impact.
Thousands of people came to the funeral held in Moscow on February 2nd, 1934.
According to public investigation reports, the crash was ultimately caused by a prolonged stay at record altitudes exceeding maximum design limits. The balloon, overheated by sunlight, lost too much lifting gas in upper atmosphere. As it descended past the 12,000 m mark, cooling down to ambient air temperature, quick loss of buoyancy caused downward acceleration that triggered structural failure of the suspension cables.The aircraft design was marked by numerous engineering flaws, notably insufficient ballast weight and faulty gondola suspension design, which all contributed to the loss of life.
Stalin and Molotov at the funeral of the OAKh-1 crew. February 2nd, 1934.
Fedoseenko, Vasenko and Usykin’s funeral. Moscow, February 2nd, 1934.