Mariner 8

  1971-F04

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The Mariner Mars 71 program used a new design, with a large Mars orbit insertion motor added to the basic Mariner MM69 bus. Three craft were built, with MM71-3 as a proof test model.

The first launch, payload MM71-1, Mariner 71H (Mariner H) or Mariner VIII, left the pad at 0111 on 1971 May 9 on azimuth 102.0 deg. However, at Centaur ignition the guidance failed and the rocket tumbled. Centaur and spacecraft separated and both fell back into the atmosphere about 1660 km downrange, 550 km N of Puerto Rico.

The original mission plan called for two missions: Mission A (Mariner 8) in an 1800 x 17000 km x 50-80 deg orbit for a mapping mission, and Mission B (Mariner 9) in a <1800 x 41500 km x 50-60 deg orbit, to study time-variable atmospheric and surface features. Following the Mariner 8 failure, a new mission was defined for Mariner 9.

Mariner 8
Date	Time	Event	Orbit
1971 May 9	0111:02	Launch by Atlas Centaur AC-24
		BECO
		Atlas MECO
		Atlas sep
		Centaur MES1
	0115	MES1+4s guidance failed
		MES1+28s tumbling
	0115:32	Loss of guidance T+4:30
	0116	MES1+86s payload sep
		MES1+88s Centaur MECO, premature	-2500? x 160? x 28?
	0121:02?	Impact Atlantic, 1660 km range

Payload:

• TV camera

• IR spectrometer

• UV spectrometer

• IR radiometer