D.5.2 Thor and Thor-Boosted Failure Narratives
The following narratives provide information about flight failure of Thor weapons system
and Thor-boosted space vehicle launches beginning with the first Thor launch in January
1957. The narratives are numbered to match the flight-sequence numbers in Section D.5.1.
1.     101, 25 Jan 57, Response Mode 1, Flight Phase 1: Failure of fuel-system valve
       resulted in loss of thrust. Missile fell back on pad after reaching an altitude of
       only 9 inches.

2.     102, 19 Apr 57, Response Mode 4, Flight Phase 1: Missile was apparently
       performing normally until destroyed by the RSO at 34.7 seconds. Erroneous
       DOVAP beat-beat plot showed missile heading uprange.
3.     103, 21 May 57, Response Mode 1, Flight Phase 1: Missile was destroyed on the
       pad at T - 5 minutes. A faulty fuel-tank regulator and relief valve resulted in
       ov~r-pressurizing and bursting of fuel tank.
4.     104, 30 Aug 57, Response Mode 4T, Flight Phase 1: Spurious signals in the main-
       engine yaw fe~dback circuit resulted in missile breakup shortly after 92 seconds.
5.      105, 20 Sep 57, Response Mode 4, Flight Phase 1: Premature propellant depletion
      • resulted in impact some 400 miles short of target.
6.     107, 3 Oct 57, Response Mode 1, Flight Phase 1: Main fuel valve closed 1.25
       seconds after liftoff. Missile fell back on pad after reaching an altitude of about 17
       feet.
7.    .108, 11 Oct 57, Response Mode 4, Flight Phase 1: Due to a mechanical failure, an
       abnormal main-engine shutdown (one second early) resulted in loss of the vernier
       solo phase ..
9.     112, 7 Dec 57, Response Mode 5, Flight Phase 1: An electrical-system failure at 107
       seconds produced an abnormal loading on the missile converter.. The missile
       began deviating at 110 seconds and finally broke up at about 224 seconds (well
       after MECO at 156 seconds). Missile impacted 200 miles downrange and 40 miles
       left of flight line.
10.    113, 19 Dec 57, Response Mode 4, Flight Phase 1.5: Flight was regarded as
       successful although there was no vernier solo operation and impact was 6 miles
       from target.
11.    114, 28 Jan 58, Response Mode 5, Flight Phase 1: Guidance system failure at 95
       seconds resulted in erroneous steering commands causing the vehicle to yaw left
       and pitch down. Divergence began about 110 seconds and continued until the


9/10/96                                      167                                         RT!