Today in 1970, the Soviet Tupolev Tu-144 became the first commercial transport to exceed Mach 2.
Development of the Tu-144 was kept secret until 1968, when Russia announced that it was entering the race to put the first supersonic transport to the air. Since then, work on the aircraft outside Moscow, moved quickly despite problems with the air intakes on the four NK-144 engines.
The Tu-144 was very similar to the Concorde. It could carry 120 passengers at a speed of 1.552 miles an hour.
Aeroflot, the Soviet State airline, was the sole customer and the Tu-144 was never offered on world markets in direct competition to Concorde.