New evidence that part of the right-hand solid- rocket booster (SRB) of the Space Shuttle STS 51L/Challenger was breached and caught fire at lift-off on 28 January, 1986, has been revealed by controversial aerospace engineer Ali AbuTaha. Seven crew were lost when the Shuttle broke apart at T+73s, in what is still the worst accident in space-exploration history.
A photograph, never seen in public, taken at about T+20s, as the Challenger was completing its roll programme, shows a flame, about 3.3m long, emanating from an area around the joint between the two lower SRB segments. Another photograph shows a white object, estimated to be about 2m long, being explosively separated from the frustum at the top of the same booster at about T+1s.
The two images were among hundreds taken by automatic cameras set up close to launch pad 39B at the Kennedy Space Center, Florida, by Ralph Morse of Time/Life. They were discovered by AbuTaha at Time/Life, New York, where he was permitted to examine all the STS 51L launch photographs and to retain some.
The fire appears to vindicate Abu Taha's controversial independent analysis of the Challenger accident and Space Shuttle launch dynamics, which was publicly discredited by NASA. AbuTaha had claimed that the booster caught fire at lift-off and was leaking continuously during the ascent.
Clearly, there was also a breach of the booster in the O-ring area later in the launch, the first flame from which appeared at T+58s. Black smoke was seen coming from this area at lift-off, but the leak mysteriously closed, not reappearing until T+58s.
When it reported in June 1986, the Rogers Commission, set up to investigate the accident, surmised that this O-ring anomaly caused the accident,.
Abu Taha, however, had drawn attention to misunderstood lift-off dynamic loads, which had damaged previous flights and breached an already-weakened SRB segment close to the SRB/ET attach ring. He pinpointed and explained several factors not addressed by the Rogers Commission.
NASA not only redesigned the SRB O ring segment joints but also significantly strengthened the booster, especially the SRB/ET attach ring, increasing the weight of the Shuttle system, and reducing its payload capability (Flight International, 24-30 January, 1996).
AbuTaha claims that Time planned to publish the pictures in August 1987 after his discovery, but this is denied by the magazine.
At the time, the photograph-office staff would not have realised "-what they were looking for" in the negatives, says the magazine.
NASA maintains that it has never seen the pictures, saying: "If you are looking for a categorical denial, then you have one."
The agency says that it examined all launch photographs and returned them to their owners.
The Time photographs were, therefore, either missed or disregarded. AbuTaha has only now decided to show the picture to a reporter. Copyright restrictions mean that we cannot publish the photograph.
The picture, which supports earlier evidence from a private video of the launch and an eyewitness report from a pilot, indicates that the booster was breached, was trailing a secondary contrail, and that the Shuttle had lost thrust and was lower than NASA had claimed, items which were also apparently disregarded by the Commission.
The video, revealing a massive booster leak, was made by Harold Sehnert of Ohio, from New Smryna Beach, north of the Kennedy Space Center. AbuTaha discovered that NASA had only shown the final 2s of the tape to the Commission.
United Airlines' first officer, David Lieppe, flying a Boeing 727, saw the breach in the booster and SRB separation motors firing to sever the SRBs from the ET just before the break-up. This occurred below his cruising altitude of 37,000ft (11,300m), rather than the 49,000ft claimed by NASA. Lieppe's reports to NASA at the time were disregarded.
Abu Taha's latest photographic analysis also reveals that the Challenger's crew compartment was misidentified by NASA at the time of the explosion, explaining why the agency took 40 days to find it. NASA had identified the empty shell of the lower forward fuselage, AbuTaha says.
From video footage of the accident, he located and photographed the actual, almost-spherical crew compartment to the right and below the main debris thousands of metres away, 18s after the explosion occurred. He says that the crew would have been killed instantly by the intense energy of the shock wave of the main explosion which hit the cabin. NASA says that it looked for, but could not find, a shockwave.
Source: Flight International
