Kosmos 419

Launch Date	May 10, 1971
Launch Site	Baikonur Cosmodrome, Kazakhstan, Russia
Destination	Mars
Type	Orbiter
Status	Unsuccessful
Nation	Soviet Union
Alternate Names	1971-042A, M-71S No.170, 05221

Goals

It is widely believed that the primary purpose was to overtake America's Mariner 8 (which, ironically, was unsuccessfully launched 2 days earlier) and become the first spacecraft to orbit Mars.

Accomplishments

None. Launch failure due to human programming error stranded the spacecraft in Earth orbit. It reentered Earth's atmosphere within two days of launch.

Key Dates

May 10, 1971: Launch

In Depth

Kosmos 419 was the first of the fifth-generation Soviet Mars probes (after those launched in 1960, 1962, 1963-64, and 1969). The original plan was to launch two orbiter-lander combinations known as M-71 during the 1971 Mars launch window.

But in order to preempt the American Mariner H/I vehicles (also known as Mariner 8 and 9), Soviet planners added a third mission, the M-71S, a simple orbiter that could become the first spacecraft to go into orbit around Mars. The orbiter could also collect data important for aiming the two landers at precise locations in the Martian system.

The spacecraft entered Earth orbit successfully, but the Blok D upper stage failed to fire the second time to send the spacecraft to Mars. Later investigation showed that there was human error in programming the firing time for the Blok D; an eight-digit code to fire the engine had been issued by an operator in reverse order. The stranded spacecraft, which was named Kosmos 419 by the Soviet press, reentered Earth's atmosphere within two days of launch.

The Soviets had promised the French that two of their Stereo instruments (instruments to measure solar radiation) would be sent to Mars. Since one was lost on Kosmos 419, Soviet officials were forced to lie about its ultimate fate to cover up the failure.