Luna 4

LunarOrbiter
Name=Luna 4


Organization=Soviet Union
Contractors=OKB-1
MissionType=Planetary Science
Lunar landing
LaunchDate=April 2, 1963 at 08:04:00 UTC
LaunchVehicle=Molniya 8K78 (4-Stage R-7 / SS-6)
MissionHighlight=Lunar flyby
April 5, 1963, 13:25 UTC
at distance of 8336.2 km
MissionDuration= > April 6, 1963
Mass=1,422 kg
NSSDC_ID=1963-008B
Web= [http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1963-008B NASA NSSDC Master Catalog]
SatelliteOf=Earth
SemiMajor=394,128 km
Eccentricity=0.772
Inclination=?°
Period=~28.365 d
Apo=698,455 km
Peri=89,801 km
Orbits=?
LunarLandingDate=
LunarLandingCoords=
LunarLiftoffDate=
Instruments=Close-Up Lunar Surface Photography

Luna 4 (E-6 series) was the USSR's first successful spacecraft of their "second generation" Luna program. The spacecraft, rather than being sent on a straight trajectory toward the Moon, was placed first in a low Earth orbit (167 to 182 km altitude) and then the rocket stage reignited to send it on a curving path towards the Moon.

Luna 4, the second attempt of this program, achieved the desired trajectory but a failure to make a required midcourse correction resulted in it missing the Moon by 8336.2 km at 13:25 UT on April 5, 1963. It then entered a barycentric 90,000 × 700,000 km Earth orbit. The intended mission of the probe is not known, it was speculated the probe was designed to land on the Moon with an instrument package based on the trajectory and on the later attempted landings of the Luna 5 and Luna 6 spacecraft and successful landing of Luna 9. (A lecture program entitled "Hitting the Moon" was scheduled to be broadcast on Radio Moscow at 7:45 p.m. the evening of April 5 but was cancelled.) The spacecraft transmitted at 183.6 MHz at least until April 6.

Lunar surface close-up photography

The purpose of this experiment was to obtain information on the characteristics of the lunar surface. These characteristics include the amount of cratering, structure and size of craters, the amount, distribution, and sizes of ejecta, mechanical properties of the surface such as bearing strength, cohesiveness, compaction, etc. Determination and recognition of processes operating to produce the lunar surface features also were among the objectives of this photographic experiment.

External links

* [http://www.zarya.info/Diaries/Luna/Luna.php Zarya - Luna programme chronology]

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