Mariner 8

Mariner-8 is an American Mars orbiter intended to observe mars and its atmosphere. It was launched on 9 May 1971 and it was carried by Atlas SLV-3C Centaur rocket from Cape Canaveral air force station. But the launch failure prevented the spacecraft to reach earth orbit. This mission resulted in launch failure and the spacecraft felt in Atlantic Ocean.

DUAL MISSION:

     The project (Mariner-8) was also called Mariner Mars 71 project. It consist of two American Spacecraft Mariner-H and Mariner-I. Both orbiters intended to orbit around mars for many objectives.

OBJECTIVES:

     1) To measure atmospheric Density

     2) To measure atmospheric Pressure

     3) To measure atmospheric Composition

     4) To measure Temperature

     5) To measure Topography of Martian Surface

INSTRUMENTS CARRIED:

     1) Wide-narrow angle Television Cameras

     2) Infrared Radiometer

     3) Ultra-voilet Spectrometer

     4) Infrared Inferometer Spectrometer  

TECHNICAL DETAILS:

     1) Spacecraft frame was made with Magnesium frame

     2) It had four solar panels which could produce a power of 500 watts

     3) Power was stored in 20-ampere Nickel-Cadmium Battery

     4) Propulsion was provided by Gimbaled-engine (1340 N of thrust)

     5) Propellant was monomethy hydrazine and nitrogen tetraoxide

     6) Attitude control was provided by Sun sensor, a Canopus tracker, Gyroscopes, inertial reference unit

     7) Command systems = 86 direct, 4 Quantitative and 5 Control commands

     8) Data was stored in Reel-reel tape recorder of 180 million bits

     9) Telecommunication done via dual S-band 10-20W transmitters through low,high and omni-directional            antenna 

RESULT:

     Spacecraft failed to orbit due to launch failure

REASON FOR FAILURE:

     Launch failure due to improper ignition of Centaur stage 365 seconds after launch due to starvation by tumbling.