Explosive bolts question

On Sat, 09 Sep 2006 17:04:43 -0700, Lobster Man
wrote:

This isn't a specific-Shuttle question, but since this group has a bit
more traffic than some of the other sci.space groups, and explosive
bolts are still used (I think...) on Shuttle, I'll ask it here.

Been watching some old NASA Mercury program footage that's available now
on DVD. Last night I was watching the Little Joe launches. Great stuff!
Some of the footage was of the manual build process for the boilerplate
Mercury capsules tested with the various Little Joe launches.

Anyway, at one point they showed a collar that held the boilerplate to
the booster. And the voice-over of the footage didn't really discuss how
the two separated. I assumed they used explosive bolts to hold the
collar together, and that got me to wondering about exactly how
explosive bolts work.

Are they standard bolts like in other industries, but with some quantity
of explosives attached to force them to fail at detonation? Or are they
perhaps hollowed out and the explosive material is inside? I would
figure that the first might not separate in all instances, and the
second might be too prone to detonate at times of stress.

So... all the experts that are he what's the exact nature of these
essential components?

[Rusty]

Article detailing the use of explosive bolts by NASA:
http://media.nasaexplores.com/lesson...ullarticle.pdf

[/Rusty]

OM
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OM wrote:
On Sat, 09 Sep 2006 17:04:43 -0700, Lobster Man
wrote:


This isn't a specific-Shuttle question, but since this group has a bit
more traffic than some of the other sci.space groups, and explosive
bolts are still used (I think...) on Shuttle, I'll ask it here.

Been watching some old NASA Mercury program footage that's available now
on DVD. Last night I was watching the Little Joe launches. Great stuff!
Some of the footage was of the manual build process for the boilerplate
Mercury capsules tested with the various Little Joe launches.

Anyway, at one point they showed a collar that held the boilerplate to
the booster. And the voice-over of the footage didn't really discuss how
the two separated. I assumed they used explosive bolts to hold the
collar together, and that got me to wondering about exactly how
explosive bolts work.

Are they standard bolts like in other industries, but with some quantity
of explosives attached to force them to fail at detonation? Or are they
perhaps hollowed out and the explosive material is inside? I would
figure that the first might not separate in all instances, and the
second might be too prone to detonate at times of stress.

So... all the experts that are he what's the exact nature of these
essential components?


[Rusty]

Article detailing the use of explosive bolts by NASA:
http://media.nasaexplores.com/lesson...ullarticle.pdf

[/Rusty]

OM

Thanks!

Lobster Man wrote:

Thanks!


For detailed info........

--------------------------------------------------------------------------------------------------------------
A Manual for Pyrotechnic Design, Development and Qualification

Bement, Laurence J.; Schimmel, Morry L.
NASA Langley Research Center

Although pyrotechnic devices have been singularly responsible for the
success of many of the critical mechanical functions in aerospace
programs for over 30 years, ground and in-flight failures continue to
occur. Subsequent investigations reveal that little or no quantitative
information is available on measuring the effects on performance of
system
variables or on determining functional margins. Pyrotechnics are
considered to be readily available; and, therefore, can be managed by
any subsystem in which they are applied, such as structure, propulsion,
electric power, or life support. The primary purpose of this manual is
to alter the concept that the use of pyrotechnics is an art and refute
'justifications' that applications do not need to be understood by
providing information on pyrotechnic design, development, and
qualification on an engineering basis. Included are approaches to
demonstrate functional reliability with less than 10 units, how to
manage pyrotechnic-unique requirements, and methods to assure that the
system isproperly assembled and will perform the required tasks.
NASA-TM-110172

http://ntrs.nasa.gov/archive/nasa/ca...1995124937.pdf

--------------------------------------------------------------------------

Report on Alternative Devices to Pyrotechnics on Spacecraft; 10th
Annual AIAA/USU Conference on Small Satellites

Lucy, M.; Hardy, R.; Kist, E.; Watson, J.; Wise, S.
NASA Langley Research Center
2005-04-29T17:17:46Z; 2005-04-29T17:17:46Z; 1996-09-16; 1996-09-16;
1996-09-19
Pyrotechnics accomplish many functions on today's spacecraft,
possessing minimum volume/weight, providing instantaneous operation on
demand, and requiring little input energy. However, functional shock,
safety, and overall system cost issues, combined with emergence and
availability of new technologies question their continued use of space
missions.

http://library-dspace.larc.nasa.gov/...-10css-mhl.pdf


--------------------------------------------------------------------------

Independent Orbiter Assessment (IOA): Assessment of the pyrotechnics
subsystem
Robinson, W. M.
NASA Center for AeroSpace Information (CASI)
NASA-CR-185531; NAS 1.26:185531; REPT-1.0-WP-VA88005-05 , 19880205; Feb
5, 1988 The results of the Independent Orbiter Assessment (IOA) of the
Failure Modes and Effects Analysis (FMEA) and Critical Items List
(CIL) are presented. The IOA effort first completed an analysis of the
Pyrotechnics (PYRO) hardware, generating draft failure modes and
potential critical items. To preserve independence, this analysis was
accomplished without reliance upon the results contained within the
NASA FMEA/CIL documentation. The IOA results were then compared to the
NASA FMEA/CIL baseline with proposed Post 51-L updates included. A
resolution of each discrepancy from the comparison is provided through
additional analysis as required. This report documents the results of
that comparison for the Orbiter Pyrotechnics hardware.
Accession ID: 90N10946
Document ID: 19900001630

http://ntrs.nasa.gov/archive/nasa/ca...1990001630.pdf


--------------------------------------------------------------------------


-Rusty

Rusty wrote:

The guy to get going on this matter is Mr. Richard Katz.
AKA- Mr. Stray Voltage. :-)

Pat