| Title: | Space Exploration |
| Notice: | Shuttle launch schedules, see Note 6 |
| Moderator: | PRAGMA::GRIFFIN |
| Created: | Mon Feb 17 1986 |
| Last Modified: | Thu Jun 05 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 974 |
| Total number of notes: | 18843 |
Some interesting stuff in this weeks' AW&ST:
It appears wind shear may have been a bigger factor in the Challenger
accident than first believed. Recent research indicates the amount
of wind shear may have been much greater than originally believed,
possibly contributing to the accident by exceeding vehicle stress
limitations. According to some scientist who examined photographs
of con-trails and clouds after the accident, the Air Force didn't
detect the actual amount of wind shear present. Apparently their
methods/apparatus aren't the most accurate.
Also, in a chilling sentence, the article said the SRB attach rings
may have a "negative safety factor". Several of the recovered SRBs
had missing bolts in the attach ring-to-SRB mountings. Everyone
apparently thought this was due to damage on impact with the water,
but now there is some suspicion the attach ring can't hack the stresses
placed upon it during ascent. The original explanation for the
SRB rotating into the external tank was that the leak plume burned
through the attach ring. In fact, the attach ring may have failed,
causing the SRB rotation. If this *did* happen, who can guess if
the vehicle might have survived long enough for "normal" SRB jettison
to occur.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 261.1 | Lack of data not surprising | ALIEN::MCCARTHY | Tue Feb 24 1987 22:12 | 7 | |
The original info on the wind shear was extrapolated from the records of the SSME and SRB gimbal activity, so it's not surprising that the magnitude of the wind shear was unknown. -Brian | |||||
| 261.2 | More News ? | RDGENG::WILTSHIRE | Dave Wiltshire - ECSSE @REO2 | Thu Mar 05 1987 07:50 | 13 |
It was reported on the UK Channel four news last night that film
of the accident shows solid pieces falling off the boosters BEFORE the
explosion took place. These pieces were predicted to have
fallen into the sea in a place that NASA deemed not worth searching.
The report then went on to say that without ALL the evidence some
important fact may be missed and we could have a re-run of the
Challenger disaster.
Does anyone have any more info on this ? (I came in late and only
caught the tail end of the news report)
Dave.
| |||||
| 261.3 | RE: 261.2 | CHEV02::MARSH | Jeffrey Marsh, DTN 474-5739 | Fri Mar 06 1987 00:12 | 49 |
This is from "New Analysis Indicates Possible Early Breakup of Shuttle
Booster," Aviation Week & Space Technology, December 15, 1986, p. 16:
A new, independent analysis of videotapes of the space shuttle Chalenger
launch Jan. 28 indicates external components of the vehicle's right
solid rocket booster could have begun to break off early in the launch,
raising questions about whether an improperly designed joint was the
only factor in the accident.
...
The photographic analysis was performed by aerospace consultant Ali
F. Abutaha at his own expense. Abutaha previously had proposed other
Challenger accident theories that were assessed by NASA but later
discounted.
...
Aviation Week editors, who viewed Abutaha's analysis of Kennedy Space
Center tracking camera videotape imagery, agree that he has identified
what could be interpreted as two debris separations from the area of
the right solid rocket booster before the Challenger vehicle broke up.
Photo interpreters cautioned, however, that the features could be large
cinders expelled by the solid motor.
...
At about 55 sec. into the launch, a closeup view of the vehicle shows a
larger puff of smoke emerging from the area of the right solid rocket
booster and billowing to the side beyond the main exhaust plume. This is
followed immediately by the appearance of a reflective feature that
could be debris falling through the plume.
Abutaha believes the feature could be the booster's large pin retainer
band falling away, a theory several booster engineers said was plausible.
The retainer band was never found, and Abutaha believes it could be lying
closer to Cape Canaveral.
At 70 sec., Abutaha's analysis shows what could be interpreted as another
unusual puff of smoke to the side of the main exhaust plume, followed
immediately by another reflective feature tumbling through the vehicle's
exhaust pattern. The events were not highlighted by NASA or the Rogers
commission.
...
All of the engineers and officials agreed the new photographic data merit
additional analysis.
| |||||
| 261.4 | Update on SRB Attachment Failure? | SSDEVO::FAVA | Tom Fava | Tue Mar 31 1987 11:57 | 9 |
It has now been over a month since this note was originally posted. Does anybody have an update? Knowing how large organizations operate, the possibility of letting a design weakness in the SRB attachment mechanism slip through the cracks when everybody "knows" the whole problem is in the SRB field joint is very real and absolutely terrifying! Especially in light of the pressure to get the shuttle flying again and after the recent Atlas/Centaur launch. Is NASA reviewing this aspect of the Challenger disaster seriously? | |||||