Fast Facts: Kosmos 21
This mission was a technology test intended to fly into deep space and return to Earth as a precursor to future lunar and planetary missions.
- This spacecraft exploded in Earth orbit.
- With this mission, the Soviets began the practice of giving Kosmos designations to disguise the failure of lunar and planetary probes that remained stranded in Earth orbit.
|Nation||Union of Soviet Socialist Republics (USSr)|
|Objective(s)||Deep Space and Return to Earth|
|Spacecraft||3MV-1A (No. 2, also No. 1)|
|Spacecraft Mass||c. 1,764 Pounds (800 Kilograms)|
|Mission Design and Management||(OKB-1)|
|Launch Vehicle||Molniya + Blok L (8K78 no. G103-18, also G15000-17)|
|Launch Date and Time||Nov. 11, 1963 / 06:23:34 UT|
|Scientific Instruments||1. Radiation Detector
2. Charged Particle Detector
4. Piezoelectric Detector
5. LA-2 Atomic Hydrogen Detector
6. Kassiopeya Radio Telescope
7. RSK-2M Ultraviolet and Roentgen Solar Radiation Experiment
8. VIKT-2 Vapor Friction Technology Experiment
9. Plasma Engines
This was the first of the Soviet Union’s “third generation” deep space planetary probes of the 3MV series. Like the second generation, Soviet engineers planned four types of the 3MV: The 3MV-1 (for Venus impact), 3MV-2 (for Venus flyby), 3MV-3 (for Mars impact), and 3MV-4 (for Mars flyby).
The primary difference over the second generation was vastly improved (and in many cases doubled) orientation system elements as well as improved on board propulsion systems.
While these four versions were meant to study Mars and Venus, the Soviets conceived of two additional variants of the series, similar but not identical to the 3MV-1 and 3MV-4 versions, with the designations 3MV-1A and 3MV-4A.
These “Object-Probes” (ob’yekt-zond) were designed to verify key technological systems during simpler missions into deep space and back to Earth.
A government decree on March 21, 1963 had approved two to three such “object-probe” missions, one of which (a 3MV-1A) was designed to depart from Earth’s ecliptic (the orbital plane of Earth around the Sun) out to 7.4 million to 9.9 million miles (12–16 million kilometers) from Earth and then return back to Earth after about six months when its orbit intersected with that of Earth again, aided by two mid-course corrections using its S5.45 main engine.
The latter, capable of two firings, was a lighter version of that used on the 2MV model with higher specific impulse and a longer burn time. During this mission, the third and fourth stages separated abnormally, and after reaching Earth orbit, ground control lost telemetry (at about 06:45:44 UT) from the Blok L upper stage designed to send the vehicle past the Moon. As a result, the spacecraft remained stranded in Earth orbit. The stage’s main engine turbopump probably exploded upon ignition destroying the spacecraft.
With this mission, the Soviets began the practice of giving Kosmos designations to obscure the failure of lunar and planetary probes that remained stranded in Earth orbit. If the spacecraft had successfully departed from Earth orbit, it would probably have been called Zond 1.
Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.