This viewgraph presentation reviews an X-38 laser pyro system standardization system designed for a new manned rated program. The plans to approve this laser initiation system and preliminary ideas for this system are also provided

Brown, Christopher W.

NASA Technical Reports Server

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Laser Pyro 
Standardization 
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Energy Systems Division 
Christopher W. Brown I April 2004 
Source of Acquisition 
NASA 10hnson Space Center 
Laser Pyro System Standardization anci Man Rating 
Christopher Brown 
03/03/2004 
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Pyrotechnic Office 
Energy Systems Division 
NASA Johnson Space Center 
Houston, Texas 
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https://ntrs.nasa.gov/search.jsp?R=20110002890 2019-08-30T14:16:00+00:00Z
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Agenda 
-Objective 
-What NASA Johnson Space Center is Doing 
-Future Pyro Specification 
-Laser Firing System. Requirements 
-Standardization of Laser Initiators and Detonators 
-Qual Plan - Laser Firing System 
-Lessons Learned 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Objective 
-To share ideas on a plan to approve a laser 
initiation system for man rated vehicles. 
-Plans presented will reflect the evolution of the X-
38 laser initiation system and beyond. 
-The following charts are only ideas and not firm 
requirements signed off by any program office. 
03/03/2004 3 
Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
What is NASA Johnson Space Center Doin'g? 
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03/03/2004 
-Preparing for a new manned rated program - Moon ... 
Mars .... 
-As of now, one concept is called the Crew Exploration 
Vehicle. 
-Other vehicles to complete final objectives are not yet 
defined . 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
What is NASA Johnson Space Center Doing? 
(Cont.) 
-The X-38 Program has been mothballed. 
-Vehicle V201, demonstration space vehicle, was 850/0 
complete. 
-All vehicles are stored at a JSC and open for display. 
03/03/2004 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Future Pyro Specification 
-The NSTS 08060 Space Shuttle System Pyrotechnic 
Specification was originally established for the Space Shuttle 
pyrotechnics. 
-The 08060 has been applied to other programs such as the 
X-38 and Orbital Space Plane. 
-Work has begun to create a pyro specification for future 
manned rated space vehicles. 
-The new spec will be open to new technology developed 
after the start of the Shuttle program. 
-The new spec will allow for the acceptance of "alternate 
ignition systems" upon approval of a man rating qualification 
plan. 
-Specifications pertaining a certain vehicle will be developed 
and follow the guidelines from the upper tier. 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Laser Firing System Requirements 
System requirements are in 3 parts that are based on the 
lessons learned and the evolution of the X-38 Program along 
with other laser initiation experience gathered throughout the 
1990's and early 2000's: 
• Firing Unit 
• Fiber optic lines 
• In itiators/Detonators. 
To date, no laser initiation system has been standardized. 
Designs and processes are to be owned by the U.S. Government 
and have a minimum amount of proprietary information to 
facilitate the qualification of multiple vendor sources. 
03/03/2004 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Laser Firing System Requirements 
Firing Unit 
-As technology is being enhanced, the idea of an ideal laser firing unit progresses. 
-Unlike the Shuttle's Pyro Initiator Controller, there is not a standard firing unit that has 
been developed. 
-Several sources of laser power exist, and each has pros and cons. 
Energy Source Pros Cons 
Laser Diode wi II High Power I) Single Strand 
Pigtail Efficiency Output 
• Low Efficiency of 
DiodelFiber 
Interface 
Laser Rods It High Energy Output • Low Power 
Ii Able to energize a Efficiency I , 
Bundle of Fibers • Difficult Optical 
• 1vIechanical Shutter Alignment 
I) Inconslstant Output 
Dio de/Bwldle 0 High Power • Do They Exist??? 
Efficiency • How Much Will 
,.. High Energy Outp ut They Cost? 
It Able to Ene rgize a • Optical Alignment 
Bundle of Fibers 
I) Mechanical Shutter 
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03/03/2004 
Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Laser Firing Unit (Cent.) 
Sequencer Block Diagram 
SAFlNG 
SOLID STA 11, 
RELAYS(SS~ LASER DIODES ROD ----B~l)CR (FC 1) 28V POWER 
CAP I BANK 
(FC 2, 4) 15\1 FIBI' • "FIRE LASER X" 
--e 
~ 
--e 
--e 
~ (FC 1) Ijl3 rill'" .1 ~I ~ilCRo- I (FC 1) +28Y FNA BI f • • TOSOLENOIO POll'ERBUS _ 
~III III III III II • ;g III II III II II • III III PJ D Sl III III III 11 III III III II 
1ll:iJ (6,-.--..... (FC 3) 2SV POWE 
(~C2;;) ;;;;: ~I MIRROR OF ABOVE 
(FC 3) + 28V EN WLE 
(Fe 2) 28\1 !?()WER 
(FC 3, 4) 155'3 FIRE 
(FC 2) 1553 ARM 
(FC 2) +78)1 EN ABI F SEQ 
(~~C3~~) -----. i30X#2--·----· .. · 
(FC 1) 
(FC 1) "". ClU!.../.!~LL::...-a.I L-______________ ~ 
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LASER PULSE TO INI'Il ATOR VIA 
TWO·INPUT FIBER OP'OC CABLE 
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Laser Pyro Energy Systenls Division 
Standardization Christopher W. Brown April 2004 
Laser Firing Unit (Cant.) 
Preferred Requirements. These are the basics: 
-A minimum of 6 fiber strands per initiator. Half of the strands shall come from 
one power source and the other half of the bundle shall be powered from a 
redundant source i.e. 
-Each output strand shall have at least 2 times the minimum all-fire level of 
the initiator/detonator. 
-Post mating built in test for every strand through all connections. Testing 
availability times vs. inhibit closure to be worked later. 
-Three independent inhibits for firing. Shall be monitored at all times. "Pre 
Arm", "Arm", and "Fire". A computer is considered to be one inhibit. 
-Wavelength to fit absorption levels of ignition mix. 
-Firing pulse less than 2 ms to avoid fiber tip burning. 
03/03/2004 10 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Laser Firing System Requirements 
Fibers 
Fiber optic lines from the firing source to the initiator have been the 
weakest link, and fiber bundles are no exception. 
Incorrect fiber selection and construction can lead to system failure. 
03/03/2004 
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Laser Pyro Energy Systenls Division 
Standardization Christopher W. Brown April 2004 
Fiber Lines Requirements (Cont.) 
-SMA 905 - Pinned or keyed to prevent incorrect connections. 
-Fiber Material - Radiation hardened. Low OH -- for best wavelength 
transmission. Core- Pure Silica; Clad - Doped Silica; Buffer - Polyimide. 
-Coating - Dry lubricant coating to prevent stress on strands while bending. 
Material to be vacuum stable. 
-Lining - To protect bundle from rubbing on inner jacket wall. Must keep 
strands loose from rubbing against each other. Material to be vacuum 
stable. 
-Jacket - SST spiral tubing - does not stretch in tension. Metallic strain 
releases swedged to the SMA's 
-Epoxy - High temp 
-Bend Radius - Two inch radius minimum. 
-Temperature limits TBD. 
-No Splicing or connectors between firing unit and initiator/detonator. 
03/03/2004 
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Standardization Christopher W. Brown April 2004 
SST Spiral 
Tubing 
Jacket 
Bundle 
Liner 
Fibers 
03/03/2004 
Fiber Lines Requirement (Cont.) 
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SMA 905 
Connector 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Standardization of Laser Initiat()rs and Detonators 
Many laser pyro systems have been developed but none 
have been narrowed down to a standard. 
The Plan: 
-NASA to control the design, development, fabrication, and 
distribution of a standard laser initiator the same way the 
NASA Standard Initiator is controlled!. 
-A standard must have minimal proprietary designs and 
processes to allow multiple vendors to fabricate. 
03/03/2004 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Standard laser Initiator Design 
SMA Connector Pinned or Keyed 
Lens - Originally GRIN. Could 
Change. 
Charge - Originally 114 mg 
ZPP. Could Change. 
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Laser Pyro Energy SystelTIs Division 
Standardization IChristopher W. Brown I April 2004 
Standard Laser Initiator Design (Cont.) 
-Latest design has used 3 mm dia. GRIN lenses sized over a third 
pitch to accept a bundle of 19 fiber strands that concentrate the 
image to almost half the diameter. 
-A lens system simpler than GRIN lenses could be considered. 
'i nput 1.8w:w:. c 5 
FOCRL LENGTH - 3.B09 NR - O. 5Q32 
L _. 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Standard Laser Initiator Design (Cant.) 
Lenses other that GRIN could be: 
Easier to Produce 
Less Expensive 
More Tolerant to Rad iation 
03/03/2004 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Standard laser Detonator Design 
The plan for a standard laser detonator will consist of the same 
mechanical/optical interface as the initiator and an output tip 
having the power equivalent to one grain of HNS. 
The middle section is to be determined. 
Optical 
Connector and 
Lens. Same as 
Initiator 
03/03/2004 
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Charge -
Originally 
One Grain 
HNS. Could 
Change. 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Standard Laser Detonator Design (Cont.) 
Deflagration to detonation (DDT) area not yet settled 
DDT Source Pros Cons 
BNCP IJII Low Sensitivity .. Pro p rietal'Y 
0 Safe to ltamUe Packing Process 
• Not available to 
many vendors 
• More qual testing 
required 
Lead Azide (41 Available to many • Sensitive to Slwck 
vendors • Hazardous to 
e Simple packing handle 
process 
lit Less qual testing 
due to sirnilarity. 
Desired IVlaterial Ci!! Low Sensitivity .. Does is exist? 
- $II Safe to handle II lVlore qual te sting 
~ Available to many required for 
vendors unfamiliar mixes. 
($ Simple packing 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Qualification Plan 
The qual plan for laser initiators and laser detonators will 
implement the MIL-STD-1576 as a foundation and will be tailored. 
Laser initiators and laser detonators will be excluded from 
electrical tests used for bridge wire initiators; however, other 
hazards that might come with laser systems will be considered. 
Even though laser initiators from other programs have been 
subjected to considerable testing, a new configuration or design 
will require full qualification testing. 
Sensitivity will follow the latest Likelihood Ratio approach. 
03/03/2004 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Qualification of the System 
The system, as a whole, shall be fully qualified at levels meeting or 
exceeding flight environments. 
System tests shall take place after component qualification test -
i.e. firing unit, fiber, initiators/detonators. 
System tests shall consist of a flight firing unit, fiber lines of the 
same length routed in a flight like matter, and initiators/detonators 
(with containment vessels) all in one setup with full functioning to 
be performed. 
03103/2004 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
aser Firing System Requirements - Acceptance 
Tests 
-An objective of the NSTS 08060 that "viii carryon will be the 
control of traceability and pedigree. 
-New processes will be implemented to assure all material, 
I.e. fiber, lenses, rods, diodes ... etc, will be thoroughly 
checked at the earliest stage before fabrication and 
assembly. 
-These processes will require 100% test and inspection 
points throughout the assembly process just like Shuttle 
pyrotechnic devices. 
03/03/2004 
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Laser Pyro Energy Systems Division 
Standardization Christopher W. Brown April 2004 
Conclusion 
-The evolution of the X-38 laser pyro systems created a large 
data base of lessons learned. 
-Special thanks to Indian Head's and other laser programs 
for a great deal of knowledge used to create what NASA has 
baselined today. 
-Before having a NASA vehicle with human crew and a laser 
pyrotechnic system, there is still lots of work to be 
completed. 
03/03/2004 23 
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Laser Pyro System Standardization and Man Rating

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