Venera 1

Venera 1

Mockup of theVenera 1spacecraft
Mission type	Venusimpactor
Operator	OKB-1
Harvard designation	1961 Gamma 1
COSPAR ID	1961-003A
SATCATno.	80
Mission duration	7 days
Spacecraft properties
Spacecraft	1VA No.2
Manufacturer	OKB-1
Launch mass	6,424.0 kilograms (14,162.5 lb)
Dry mass	643.5 kilograms (1,419 lb)
Start of mission
Launch date	February 12, 1961, 00:34:36(1961-02-12UTC00:34:36Z)UTC
Rocket	Molniya 8K78
Launch site	Baikonur1/5
End of mission
Last contact	19 February 1961(1961-02-20)
Orbital parameters
Reference system	Heliocentric
Eccentricity	0.173
Perihelion altitude	0.718AU
Aphelion altitude	1.019 AU
Inclination	0.58°
Period	311 days
Flyby ofVenus
Closest approach	19 May 1961
Distance	100,000 km (62,000 mi)
Venera

Venera 1(Russian:Венера-1meaningVenus 1), also known asVenera-1VA No.2and occasionally in the West asSputnik 8was the first spacecraft to perform aninterplanetary flightand the first to fly pastVenus,as part of theSoviet Union'sVeneraprogramme.Launched in February 1961, it flew past Venus on 19 May of the same year; however, radio contact with theprobewas lost before theflyby,resulting in it returning no data.

Spacecraft

Venera 1was a 643.5-kilogram (1,419 lb) probe consisting of a cylindrical body 1.05 metres (3 ft 5 in) in diameter topped by a dome, totalling 2.035 metres (6 ft 8.1 in) in height. This was pressurized to 1.2 standard atmospheres (120 kPa) with dry nitrogen, with internal fans to maintain even distribution of heat.Two solar panels extended from the cylinder, charging a bank ofsilver-zinc batteries.A 2-metre (6 ft 7 in) parabolic wire-mesh antenna was designed to send data from Venus to Earth on a frequency of 922.8 MHz. A 2.4-metre (7 ft 10 in) antenna boom was used to transmit short-wave signals during the near-Earth phase of the mission. Semidirectionalquadrupoleantennas mounted on the solar panels provided routine telemetry and telecommand contact with Earth during the mission, on a circularly-polarized decimetre radio band.

The probe was equipped with scientific instruments including a flux-gatemagnetometerattached to the antenna boom, twoion trapsto measure solar wind,micrometeoritedetectors, andGeiger countertubes and a sodium iodidescintillatorfor measurement of cosmic radiation. An experiment attached to one solar panel measured temperatures of experimental coatings. Infrared and/or ultraviolet radiometers may have been included. The dome contained aKDU-414engine used for mid-course corrections. Temperature control was achieved by motorized thermal shutters.

During most of its flight,Venera 1was spin stabilized. It was the first spacecraft designed to perform mid-course corrections, by entering a mode of 3-axis stabilization, fi xing on the Sun and the starCanopus.Had it reached Venus, it would have entered another mode of 3-axis stabilization, fi xing on theSunandEarth,and using for the first time a parabolic antenna to relay data.

Launch

Route of Venera 1 on a Soviet stamp

Venera 1was the second of two attempts to launch a probe to Venus in February 1961, immediately following the launch of its sister shipVenera-1VA No.1,which failed to leave Earth orbit.Soviet experts launched Venera-1 using aMolniyacarrier rocket from theBaikonur Cosmodrome.The launch took place at 00:34:36 GMT on 12 February 1961.

The spacecraft, along with the rocket'sBlok-Lupper stage, was initially placed into a 229-by-282-kilometre (142 mi × 175 mi)low Earth orbit,before the upper stage fired to place "Venera 1" into aheliocentric orbit,directed towards Venus. The 11D33 engine was the world's first staged-combustion-cycle rocket engine, and also the first use of anullage engineto allow a liquid-fuel rocket engine to start in space.

Failure

Three successful telemetry sessions were conducted, gathering solar-wind and cosmic-ray data near Earth, at the Earth'sMagnetopause,and on February 19 at a distance of 1,900,000 km (1,200,000 mi). After discovering thesolar windwithLuna 2,Venera 1provided the first verification that this plasma was uniformly present in deep space. Seven days later, the next scheduled telemetry session failed to occur. On May 19, 1961,Venera 1passed within 100,000 km (62,000 mi) of Venus. With the help of the British radio telescope atJodrell Bank,some weak signals fromVenera 1may have been detected in June. Soviet engineers believed thatVenera 1failed due to the overheating of a solar-direction sensor.

See also

• List of missions to Venus
• Mariner 2
• Timeline of planetary exploration

External links

• The Soviet Exploration of Venus
• NSSDC Master Catalog –Venera 1