Mission Type: Orbiter
Launch Vehicle: Proton booster plus upper stage and escape stages; 8K82K + Blok D (Proton-K no. 253-01)
Launch Site: Tyuratam (Baikonur Cosmodrome), USSR; NIIP-5 / launch site 81L
Spacecraft Mass: 4,549 kg
Spacecraft Instruments: 1) fluxgate magnetometer; 2) infrared radiometer; 3) infrared photometer; 4) spectrometer; 5) photometer; 6) radiometer; 7) ultraviolet photometer; 8) cosmic-ray detector; 9) charged-particle spectrometer; 10) imaging system; and 11) Stereo antenna
Spacecraft Dimensions: Presumed to be similar to the orbiter section of the later Mars 2 mission, a cylinder-shaped spacecraft 3 meters high
References:
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

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.