NASA MISSI 1 2 Report 7231TM Ther Mark White Paper

User Manual: 7231TM

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MARKING TESTS TO CERTIFY PART

IDENTIFICATION MARKING PROCESSES FOR USE IN

LOW EARTH ORBIT (LEO)

OCTOBER 11, 2005

Donald L. Roxby

ABSTRACT

Prior to the Space Shuttle Program, space-borne vehicles launched into space were

expended; consequently their part identifiers were applied using marking processes designed for

use in ground operations. With the advent of reusable space transportation vehicles and

retrievable satellites, NASA needed to rethink how part identification markings are applied to

their space borne vehicles. Markings applied to reusable spacecraft need to survive the extreme

environments encountered in space. To support this new requirement, NASA approached RVSI

(now Siemens) to assist with a marking program to certify marking(s) for use in Low Earth Orbit

(LEO).

An experiment was designed to identify

part identification methods and techniques that

might survive the rigors of space. The experiment

was to be designed to expose both human and

machine-readable markings to LEO environments.

These include, but are not limited to, vacuum,

solar UV radiation, micrometeoroids and space

debris, atomic oxygen (AO) and deep thermal

cycles. Two specimen packages were

assembled. The first package was incorporated

into MISSE 1 and 2 (one year orbital experiments)

and consisted of currently approved marking processes and number of newly developed Laser

Additive marking techniques deemed safe for use in safety critical applications. The second

package contained a series of more robust intrusive marking technique that utilized higher-

powered laser markers. These specimens were incorporated in MISSE 3 and 4, which was

scheduled to fly in orbit for three years. This report describes the results of the MISSE 1 and 2

marking experiments.

International Space Station In Low Earth Orbit

INTRODUCTION

Working with the Boeing Phantom Works, Siemens’s (formally RVSI) Symbology

Research Center applied markings to test coupons made of materials commonly utilized in the

construction of the external components used on space transportation vehicles, satellites and

space stations. The materials included structural components (anodized and painted aluminum),

thermal protection system (TPS) blankets (beta cloth) and glass (windows, mirrors, lenses).

TPS tile markings were not included, having been previously tested by an RVSI Researcher on a

previous space shuttle program. The test coupons incorporated into MISSE 1 and 2 consisted of

17 marked 0.995-inch diameter disks. These coupons were marked using currently approved

marking processes (Dot Peen and Electro-Chemical coloring) and new additive laser marking

processes. These included laser inducted vapor deposition (LIVD), Laser Bonding to both metal

and glass, Gas Assisted Laser Etch (GALE) and a Laser Coat and Remove process that involved

the use of Vacuum Arc Vapor Deposition (VAVD). Additional intrusive laser marking processes

designed for survivability on longer duration mission were incorporated into MISSE 3 and 4.

These included Direct Laser Etch, Laser Shot Peening and Laser Induced Surface Improvement

(LISI). MISSI 3 & 4 also include marking processes for thermal blankets and a 6-inch plate

marked with containing symbol of different sizes to be used to establish the minimum data cell

size to be used in LEO applications.

The marked material test coupons were affixed to spaces provided on test panels, which

were then installed onto trays identified as Material - International Space Station - Experiment

(MISSE). These experiments were then installed into two suitcase like structures, called Passive

Experiment Containers (PECs). MISSE 1 and 2 where were attached to the International Space

Station (ISS) by Astronaut Patrick G. Forrester during a space walk conducted during the STS-

105 Mission, which was launched on August 10, 2001.

PEC-1 was positioned on the lower portion of the ISS Airlock so that it would be exposed

to the maximum amount of ultra-violet (UV) radiation and atomic oxidation (AO). PEC-2 was

positioned on the side of the ISS Airlock to receive UV radiation, but minimal amount exposure

to atomic oxygen.

STS-105 (Discovery) Launch on

August 10, 2001

MISSE Positioned on Exterior of the International Space

Station by Mission Specialist Patrick Forrester on August

16, 2001

The original plan called for MISSE 1 and 2 to be retrieved after 1 year. After their

recovery, MISSE 3 and 4 were to be launched into LEO and retrieved after 3 years. The

Columbia incident, however, delayed retrieval of the MISSE 1 and 2 experiments until the

second mission following return to flight (STS-115). Both of these experiments were recovered

early during the STS-114 mission. Astronaut Stephen Robinson retrieved MISSE 1 and 2 on

July 30, 2005 when an opportunity presented itself during his record-breaking six hours 50

minutes space walk. The experiments were subjected to a total 1443 days of LEO exposure, or

just 17 days short of 4 years.

MISSE 1 and MISSE 2 were returned to earth on August 10, 2005. As a result of bad

weather (low cloud cover) at the Kennedy Space

Center (KSC), Discovery was forced to make a night

Landing at the Dryden Flight Research Center

(DFRC), Edwards Air Force Base (EAFB),

California. The orbiter touched down on Runway

22 at 5:11 a.m. (8:11 ET) and was towed to the

Mate/Demate facility where technicians performed

inspections, drained and purged the fuel systems

and loaded the orbiter onto NASA’s modified 747

carrier aircraft for the return flight to KSC.

The Orbiter arrived at KSC on August 20,2005 and was towed from the Shuttle Landing

Facility to the Orbiter Processing Facility August 22, 2005. The payload bay doors were opened

to offload the materials brought back from the International Space Station on August 23, 2005.

MISSE 1 and 2 were then packaged and returned to the Atmospheric Systems Development

Labortory at NASA's Langley Research Center (LARC), Hampton, Virginia, where the PEC’s

were inspected, disassembled and photographed. The marked coupons were then hand carried

back to the Siemens Symbology Research Center where mark quality was analyzed and decoding

tests conducted to qualify identification processes for future retrievable spacecraft and satellites.

Columbia Lands At EAFB at end of the

STS-114 Mission

Data from this in-orbit experiment has been

added to NASA-STD-6002 Revision C,

“Applying Data Matrix Identification Symbols

On Aerospace Parts” and NASA-HDBK-6003

Revision C, ” Application Of Data Matrix

Identification Symbols To Aerospace Parts

Using Direct Part Marking Methods/Techniques

“ The standard updates were also provided to

the USAF for possible inclusion into MIL-STD-

130, “Identification Marking Of U.S. Military

Property .”

MARKING PROCESSES TESTED

Six different marking processes were utilized in the MISSE 1 and 2 experiments. These

included Dot Peening, Electro-Chemical Coloring, Gas Assisted Laser Etch (GALE), Laser

Bonding, Laser Engraving used in conjunction with Vacuum Arc Vapor Deposition (VAVD)

coatings and Laser Inducted Vapor Deposition (LIVD). These processes are explained as follow:

Dot Peen - Dot peening is achieved by striking a carbide or diamond-tipped marker

stylus against the surface of the material being marked. Symbol size is controlled by the size and

tip angle of the stylus, dot spacing, or by altering the number of strikes per data cell. Single

strikes are used to create small symbols. Multiple strikes may be used to create larger symbols

Electro-Chemical Coloring - Electro-chemical coloring marks are produced using an

electro-chemical process used in conjunction with a stencil to form a marking. In this process,

metal is removed and replaced using an alternating current passed through a chemical that

oxidizes (discolors) the metal. No pigments are added in this process. The penetration of

coloration into the metal is controlled by the amplitude and frequency of the AC potential. The

resulting color is determined by the chemical properties of the metal and the electrolyte used.

PEC’s Prior to Disassembly

Laser Bonding - Laser bonding is an additive process that involves the bonding of a

material to the substrate surface using the heat generated by an Nd:YAG, YVO4, or carbon

dioxide (CO2) laser. The materials used in this process are commercially available, and generally

consist of a glass-frit powder or ground metal oxides mixed with inorganic pigment, and a liquid

carrier (usually water or mineral oil). The pigment can be painted or sprayed onto the surface to

be marked, or transferred via pad printer, screen printer, or coating roller. Adhesive-backed

tapes coated with an additive are also used in this process. Laser bonding can also be performed

using a CO2 laser and ink foils for less harsh environments. This is accomplished using heat

levels that have no noticeable effect on metal or glass substrates and are safe for use in safety-

critical applications. The markings produced using this technique (dependent on the material

used), are resistant to high heat, unaffected by salt fog/spray, and are extremely durable.

Laser Coat (VAVD) and Remove - Laser engraving is acceptable in safety-critical

applications when used in conjunction with a “coat and remove” process. This process

involves the coating of a part with a medium of contrasting color that is subsequently

removed by the laser to expose the underlying material. The coatings used in the MISSE 1

and 2 experiments were applied using a new Vacuum Arc Vapor Deposition (VAVD)

process developed by Siemens and Vacuum Arc Technologies (VAT) under a Space Act

Agreement with the Marshal Space Flight Center (MSFC) . In this process, a thin film is

produced by injecting a small amount of inert gas, such as argon, into the chamber to serve

as the ionization medium that allows an arc to be sustained in the vacuum environment.

After the flow of gas is released, a high-current, low voltage arc is produced between the

slightly separated coating material and an electrode to create a jet of fully ionized metal

vapor plasma at minute hot spots on the charge. The resulting plasma is accelerated onto

the item to be marked to form an amorphous film that can range in thickness from

angstroms to several thousandths of an inch, depending upon the length of the firing time.

Laser Inducted Vapor Deposition (LIVD) – The LIVD process, developed by Siemens, is used

to apply part identification markings, heating and defrosting strips, antennas, circuitry, and sun

shields to transparent materials. This is accomplished by vaporizing material from a marking

media trapped under a transparent part using heat generated from a visible spectrum laser. The

gaseous vapors and droplets resulting from the heat buildup condense on the cooler transparent

surface to form a hard uniform coating that is applied in a prescribed pattern. The process is

accomplished under normal office conditions without the need for high heat or seal gas/vacuum

chambers.

TEST COUPON CONFIGURATIONS

Data Matrix Symbols and line pattern test markings were applied to seventeen 0.995-

inch diameter coupons as illustrated below.

Table 1 defines the substrate materials used in the construction of the 0.995-inch disks. It

also includes the marking process, marking device, marking media and protective coatings used

in their identification. The table also includes the technical contacts associated with the marking

of each of the disks.

Sample 0.995-Inch Diameter Coupons Created To Test Marking

Processes

Table 1 - Part Identification Markings Generated for MISSE 1 through 4

Marking

Category Coupon

No. Marking

Method Marking Device Marking Media Substrate

Material Protective

Coating Technical Contacts

Disk 1 Laser Bonding CO2 Laser Cerdec LMM-6000

Metal Coating Anodized

AL None Don Roxby, CiMatrix - (256) 830-8123,

Andy Axtell, Cerdec - (724) 250-5501 &

Jennifer Bunis, Synrad - (800) 796-7231

Disk 2 Laser Bonding LVO4 Laser Cerdec LMM-6000

Metal Coating Anodized

AL None Don Roxby, CiMatrix - (256) 830-8123,

Andy Axtell, Cerdec - (724) 250-5501 &

Mark Villand, LMT - (303) 664-9000 ext 624

Disk 3 Laser Bonding Nd:YAG Laser Cerdec LMM-6000

Metal Coating Anodized

AL None Don Roxby, CiMatrix - (256) 830-8123 &

Andy Axtell, Cerdec - (724) 250-5501

Eva Tang, Rofin-Sinar Laser – (480) 777-1199

Disk 4 Laser Bonding CO2 Laser Ink – Markem 2700

Heat Cure (Black) Anodized

AL VAVD –

Aluminum

Oxide

Don Roxby, CiMatrix – (256) 830-8123 &

Lisa Siewierski, Markem – (603) 352-1130 Ext.

2219.

Dusk 5 Ink Jet Domino Ink Jet Ink – Domino

262BK & 211WT

(UV curable)

Anodized

AL VAVD –

AL Oxide Don Roxby, CiMatrix – (256) 830-8123 &

Lyle Zickuhr, Domino – (847) 244-2501 x1128

Disk 6 Stencil – Ink Intermec Silk

Screen Generator Ink –Standard Silk

Screen Ink Anodized

AL VAVD –

AL Oxide Don Roxby, CiMatrix – (256) 830-8123 &

Ron Pickman, Intermec – (203) 264-9476

Disk 7 Stencil –

VAVD Laser Cut Vinyl

Stencil Gold Anodized

None Don Roxby, CiMatrix – (256) 830-8123,

Leonard Adcock, UAH – (256) 890-6020 &

Jack L Weeks, VAT - (256) 582-5484

Disk 8 Laser Bonding CO2 Laser Cerdec LMM-6000

Metal Coating AZ93

Coating None Don Roxby, CiMatrix – (256) 830-8123,

Jennifer Bunis, Synrad – (800) 796-7231,

Andy Axtell, Cerdec - (724) 250-5501 &

Richard Mell, AZTek – (256) 837-9877, ext.

135

Additive

Marking

Disk 9 Laser Bonding LVO4 Laser Cerdec LMM-6000

Metal Coating AZ93

Coating None Don Roxby, CiMatrix – (256) 830-8123,

Andy Axtell, Cerdec - (724) 250-5501,

Mark Villand, LMT – (303) 664-9000 ext 624

Richard Mell, AZTek – (256) 837-9877, ext.

135

Table 1 - Part Identification Markings Generated for MISSE 1 Through 4 Continued

Marking

Category

Coupon

No. Marking

Method Marking Device Marking Media Substrate

Material Protective

Coating Technical Contacts

Disk 16 LIVD Nd:YAG laser Tin PPG Glass None Don Roxby, Acuity CiMatrix - (256) 830-8123,

Eva Tang, Rofin-Sinar Laser – (480) 777-1199

& Guy Griffith, PPG - (256) 859-2500 Ext.

2211

Disk 17 Laser Etch CO2 Laser VAVD - Material

Gold Anodized

AL None Don Roxby CiMatrix - (256) 830-8123,

Jack L Weeks, VAT - (256) 582-5484

Disk 18 Laser Etch LVO4 Laser VAVD - Material

Gold Anodized

AL None Don Roxby CiMatrix - (256) 830-8123,

Jennifer Bunis, Synrad, (800) 796-7231 &

Jack L Weeks, VAT - (256) 582-5484

Dusk 19 Laser Etch Nd:YAG Laser VAVD - Material

Gold Anodized

AL None Don Roxby, CiMatrix - (256) 830-8123 &

Jack L Weeks, VAT - (256) 582-5484

Coat &

Mark

Disk 20 Laser Etch Nd:YAG Laser VAVD - Material

Gold AZ93

Coating None Don Roxby, CiMatrix - (256) 830-8123 &

Jack L Weeks, VAT - (256) 582-5484

Disk 21 Laser Etch Nd:YAG Laser VAVD - Material

Gold Corning

Glass None Don Roxby, CiMatrix - (256) 830-8123,

Jack L Weeks, VAT - (256) 582-5484 &

Guy Griffith, PPG - (256) 859-2500 Ext. 2211

Disk 22 Dot Peen Dot Peen Marker Dot Peen Bare AL None Don Roxby, CiMatrix - (256) 830-8123 &

Richard Pentz, DAPRA - (800) 442-6275

Disk 23 Laser Etch Nd:YAG Laser None Bare AL None Don Roxby, CiMatrix - (256) 830-8123 & Eva

Tang, Rofin-Sinar Laser – (480) 777-1199

Disk 24 Electro-Chem

Etch Standard Pwr.

Unit Electrolyte Bare AL None Don Roxby, CiMatrix - (256) 830-8123 &

Sy Haeri, lectro-Chem Etch Metal Marking,

Inc. (714) 671-7744

Disk 25 GALE LVO4 Laser Marking Gas TBD Bare AL None Don Roxby, CiMatrix - (256) 830-8123,

Mary Helen McCay, UTSI - (931) 393-7473 &

Mark Villand, LMT - (303) 664-9000 ext 624

Direct

Part

Marking

Disk 26 LISI Nd:YAG Laser TBD Bare AL None Don Roxby, CiMatrix - (256) 830-8123,

Mary Helen McCay, UTSI - (931) 393-7473 &

Eva Tang, Rofin-Sinar Laser – (480) 777-1199

Table 1 - Part Identification Markings Generated for M-ISS-E 1 Through 4 Continued

Marking

Category Coupon

No. Marking

Method Marking Device Marking Media Substrate

Material Protective

Coating Technical Contacts

Laser Etch Nd:YAG Laser None Bare AL None Don Roxby, CiMatrix - (256) 830-8123 & Eva

Tang, Rofin-Sinar Laser – (480) 777-1199

Direct

Part

Marking

Bar 1

Laser Etch Nd:YAG Laser None Bare AL Clear

Anodize Don Roxby, CiMatrix - (256) 830-8123 & Eva

Tang, Rofin-Sinar Laser – (480) 777-1199

TEST COUPON POSTIONING ON THE EXPERIMENT TRAYS

The marked disks selected for flight were installed onto Experiment Holders EOIM 3 and

EOIM 4 on the top side of the Atomic Oxygen (AO) and Solar Tray 1, MISSE 1, PEC 1 and

onto Experiment Holders EOIM 10 and D2 on the top side of the Ultra Violet (UV) Tray 2,

MISSE 2, PEC 2.

MISSE 1, Tray 1, Top

EOIM 3 Holder

E3-31

E3-30

E3-29

E3-28

E3-27

EOIM 4 Holder

E4-42

E4-43

E4-45

E4-46

MISSE 2, Tray 2, Top

EOIM 10 Holder (Flipped Horizontally)

D2 Holder

E16-42

E16-43

E10-07

E10-06

E10

E10-04

E10-05

PRE-FLIGHT GRADING

Each marked coupon to be flown was photographed under using a normal lens and under

magnification prior to flight. These prints were stored to compare against samples after being

exposed to the LEO environments. The Data Matrix Symbols were read and graded using

RVSI’s mark quality verification system and all scored “A.” The Pre-flight grades follow:

Table 2 – Pre-Flight Marking Grades Continued – MISSE 1 And 2

Specimen

Number Base

Material Marking

Method Marking

Material Encoded

Info. Planned

Orbit

Duration

Color of

Mark Pre Flight

Grade Marking

Equipment

B-1-E10-06 Glass VAVD Copper Line

Pattern 1 yr. Dark

Gray Good

Contrast Rofin-Sinar

Nd:YAG Laser

B-1-E3-27 Glass LIVD Brass Line Pattern 1 yr. Dark

Brown Good

Contrast Rofin-Sinar

Nd:YAG Laser

B-1-E3-28 Glass LIVD Tin Line

Pattern 1 yr. Black Good

Contrast

Rofin-Sinar

Nd:YAG Laser

B-1-E3-29 Glass Laser

Bonding Cerdec

RD-6005 Line

Pattern 1 yr. Gray-

Black Excellent

Contrast Rofin-Sinar

Nd:YAG Laser

B-1-E3-30 Glass VAVD Copper Line

Pattern 1 yr. Dark

Gray Good

Contrast Rofin-Sinar

Nd:YAG Laser

B-1-E3-31 Glass LIVD Tin B1E331 1 yr. Black A Rofin-Sinar

Nd:YAG Laser

B-1-E4-42 Aluminum Laser

Bonding Cerdec RD-

6000 B1E442 1 yr. Black A Rofin-Sinar

Nd:YAG Laser

B-1-E4-43 Glass Laser

Bonding Cercec

RD-6005 B1E443 1 yr. Black A Rofin-Sinar

Nd:YAG Laser

B-1-E4-44 Aluminum VAVD Copper B1E444 1 yr. White A Rofin-Sinar

Nd:YAG Laser

B-1-E4-45 Aluminum GALE Argon Gas CiMatx 1 yr. Dark

Gray A LMT Diode-

Pumped Laser

B-1-E4-46 Aluminum Chemical

Etching SCE-4 B1E446 1 yr. Gray A Electo-Chem

Etch Machine

B-1-E10-03 Glass LIVD Brass Line

Pattern 1 yr. Dark

Brown Good

Contrast Rofin-Sinar

Nd:YAG Laser

B-1-E10-04 Glass LIVD Tin Line

Pattern 1 yr. Black Good

Contrast Rofin-Sinar

Nd:YAG Laser

B-1-E10-05 Glass Laser

Bonding Cerdec

RD-6005 Line

Pattern 1 yr. Gray-

Black Excellent

Contrast Rofin-Sinar

Nd:YAG Laser

B-1-E10-07 Glass LIVD Brass B1E107 1 yr. Dark

Brown A Rofin-Sinar

Nd:YAG Laser

Table 3- Pre-Flight Marking Grades – MISSE 3 And 4

Specimen

Number

Base

Material Marking

Method Marking

Material Encod

Info.

Planned

Orbit

Duration

Color of

Mark Pre Flight

Grade Marking

Equipment

B-1-B9 Aluminum

Plate Laser

Etching N/A 12345

6 3 yrs. Gray A Rofin-Sinar

Nd:YAG Laser

B-2-E16-42 Aluminum Dot Peen N/A 2E164

2 3 yrs. White A

Telesis TMP

6000 Pinstamp

B-2-E16-43 Aluminum Laser

Etching N/A 2E164

3 3 yrs. Dark Gray A Rofin-Sinar

Nd:YAG Laser

B-2-E16-44 Aluminum LISI Metallic

Powders 2E164

4 3 yrs. Dark Gray A Rofin-Sinar

Nd:YAG Laser

B-2-E16-45

Aluminum Laser Shot

Peening

N/A

2E164

3 yrs.

White

B Neodymium-Doped

glass laser

B-2-E16-46 7980 Glass

(Corning) LIVD Tin 2E164

6 3 yrs. Black A Rofin-Sinar

Nd:YAG Laser

IN ORBIT OBSERVATIONS

Shuttle Astronauts visited the MISSE experiments to make observations and to take photographs

while MISSE 1 and 2 were in orbit. These Extra Vehicular Activities (EVA’s) were made to the

experiments in September, October and December of 2001; February, April and October 2002;

and March, April and August of 2003. The part identification markings included in the MISSE

experiments were clearly visible in many of the photographs and appeared to be readable.

August 2003 EVA Photograph

Data Matrix Symbols Still Clearly

Visible

POST-FLIGHT GRADING

The flown MISSE 1 and 2 samples were evaluated under magnification and compared to the

preflight photographs. Attempts were made to read the machine-readable symbols and where

found to be readable, were graded in accordance with NASA-STD-6002 Revision A. The results

of these evaluations and reading tests are recorded in Table 3 and discussed in the summary

section.

Photographs Of Marked Coupons – After 4 Years in Low Earth Orbit

Elec. Chem Coloring

B-1-E4-46

Dot Peen

B-2-E16-42

Laser Bonding

B-1-E4-42

Laser Bonding on Glass

B-1-E4-43

Laser Coat & Remove

B-1-E4-44

GALE

B-1-E4-45

LIVD - Tin

B-1-E3-31

LIVD - Brass

B-1-E10-07

LIVD - Tin

B-2-E16-46

Table 3 – Pre-Flight/Post Flight Marking Comparison - MISSE 1 & 2

Marking Comparison Sample Number Pre Flight Mark Photograph Pre Fight

Verification Grade Post Flight Mark Photograph Post Fight

Verification Grade

B-1-E3-27

LIVD - Brass Line Pattern Good Contrast –

Excellent Line

Resolution

Sample being Evaluated by

Boeing Phantom Works

N/A

B-1-E3-28

LIVD - Tin Line Pattern Good Contrast –

Excellent Line

Resolution

Sample being Evaluated by

Boeing Phantom Works N/A

B-1-E3-29

Laser Bonding Line Pattern Good Contrast –

Excellent Line

Resolution

Sample being Evaluated by

Boeing Phantom Works N/A

B-1-E3-30

VAVD - Copper

Line Pattern Good Contrast –

Excellent Line

Resolution

Sample being Evaluated by

Boeing Phantom Works N/A

B-1-E3-31

LIVD - Tin

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-1-E4-42

Laser Bonding

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

Table 3 – Pre-Flight/Post Flight Marking Comparison - MISSE 1 & 2

Marking Comparison Sample Number Pre Flight Mark Photograph Pre Fight

Verification Grade Post Flight Mark Photograph Post Fight

Verification Grade

B-1-E4-43

Laser Bonding % Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast B

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade B

B-1-E4-44

Laser Coat &

Remove - VAVD

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-1-E4-45

GALE

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

Table 3 – Pre-Flight/Post Flight Marking Comparison - MISSE 1 & 2

Marking Comparison Sample Number Pre Flight Mark Photograph Pre Fight

Verification Grade Post Flight Mark Photograph Post Fight Verification

Grade

B-1-E4-46

Electro-Chemical

Coloring

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-1-E10-03

LIVD - Brass Line Pattern Good Contrast –

Excellent Line

Resolution

Sample being Evaluated by

Boeing Phantom Works N/A

B-1-E10-04

LIVD - Tin Line Pattern Good Contrast -

Excellent Line

Resolution

Sample being Evaluated by

Boeing Phantom Works N/A

B-1-E10-05

Laser Bonding Line Pattern Excellent Contrast

And Line Resolution Sample being Evaluated by

Boeing Phantom Works N/A

B-1-E10-06

VAVD - Copper Line Pattern Good Contrast –

Excellent Line

Resolution

Sample being Evaluated by

Boeing Phantom Works N/A

B-1-E10-07

LIVD - Brass

% Contrast A

Axial Uniformity A

Print Growth B

Error Correction A

Overall Grade B

% Contrast B

Axial Uniformity A

Print Growth B

Error Correction A

Overall Grade B

Table 3 – Pre-Flight/Post Flight Marking Comparison - MISSE 1 & 2

Marking Comparison Sample Number Pre Flight Mark Photograph Pre Fight

Verification Grade Post Flight Mark Photograph Post Fight Verification

Grade

B-2-E16-42

Dot Peen

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-2-E16-43

LIVD

Note: Position

reassigned after

marking. ID’s as

B-2-E16-46,

flown in position

B-2-E16-43

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

Table 4 – Pre-Flight/Post Flight Marking Comparison Continued – MISSE 3 and 4

Marking Comparison Sample Number Pre Flight Mark Photograph Pre Flight

Verification Grade Post Fight Mark Photograph Post Fight

Verification Grade

B-1-B9

Small - Bare

Laser Etch

Data Cell Size

Study

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-1-B9

Small - Anodized

Laser Etch

Data Cell Size

Study

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-9-B9

Large - Laser Etch

Data Cell Size

Study

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

Table 4 – Pre-Flight/Post Flight Marking Comparison Continued – MISSE 3 and 4

Marking Comparison Sample Number Pre Flight Mark Photograph Pre Flight

Verification Grade Post Fight Mark Photograph Post Fight

Verification Grade

B-1-B9

Large - Anodized

Laser Etch

Data Cell Size

Study

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-2-E16-43

Laser Etch

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

B-2-E16-44

LISI

% Contrast A

Axial Uniformity A

Print Growth A

Error Correction A

Overall Grade A

Table 4 – Pre-Flight/Post Flight Marking Comparison Continued – MISSE 3 and 4

Marking Comparison Sample Number Pre Flight Mark Photograph Pre Flight

Verification Grade Post Fight Mark Photograph Post Fight

Verification Grade

B-2-E16-45

Laser Shotpeen

% Contrast A

Axial Uniformity A

Print Growth B

Error Correction A

Overall Grade B

SUMMARY

Siemens personal at the SRC marked two sets of samples to support this program. One

set was retained at the SRC as control specimens and the second set was incorporated into

MISSE 1 and 2, which were subsequently flown in earth orbit for four (4) years. A detail

comparison was performed between these control specimens and flown specimens on October

11, 2005 and the following observations were made.

All of the Data Matrix symbols flown received passing grades as defined by International

Standard Organization (ISO) document ISO-15415 as amended by NASA-STD-6002B. Only

one (1) of the flown symbols showed signs of degradation. This was specimen number B-1-E4-

43 (Laser Bonding marking process), which showed a slight decrease in contrast, falling from an

A grade (≥0.50 percent) to a B grade (≥0.40 percent). This was attributed to a combination of

exposure to strong UV light and atomic oxidation. The B grade is acceptable per the standard,

which requires an A or B grade at point of manufacture and remarking in the field after the mark

quality verification grade levels fall to a C grade.

The mark quality of specimen number B-1-E4-44 (Laser Coat and Remove – VAVD)

improved over the 4 years in orbit. The contrast levels for this specimen increased as the copper

colored coating darken to a dark green as a result of oxidation. This specimen was the only

specimen to show signs of micro-partial impact during flight. The impact sites could only be

viewed under high magnification and did not have an affect on decoding. This specimen also

showed signs of discoloration outside of the marking area, which was attributed to marking

process deficiencies caused by contamination in the coating sprayed or on metal at time of

coating. This contamination resulted in coating discoloration after exposure to the LEO

environment.

The MISSE 1and 2 marking program exceeded all expectations and meet 100 percent of

the SRC’s Principle Investigators objectives.

RECOMMENDATIONS

Based on the results of this experiment, Siemens recommends the following ground rules

for in-orbit part identification marking:

1. Identify and test other Laser Coat and Discolor and Laser Coat and Remove materials and

complementing substrate coloring and clear coat materials.

2. Require the use of matt finished clear coats in conjunction with Laser Bonding and Laser Coat

and Remove marking processes.

3. Require that markings applied to glass substrates using Laser Inducted Vapor Deposition

(LIVD) process be applied to the interior (unexposed) side of the item.

4. Replace the electro-chemical coloring (AC current) process tested as part of this experiment

with a deep electro-chemical etch process (DC current) to form a recessed marking that is

enhanced using a coloring agent to improve contrast. This marking, protected with a matte

finished clear coat, will be more durable and easier to read.

5. Explore means to backfill dot peen markings to improve readability using hand-held readers.

6. Implement a Rocket Engine Marking Development and Test Program (high temperature

applications). Spin off from this program would benefit the automotive, aircraft, pipe,

catalytic converter and other commercial industries.

REFERENCES

1. D. L. Roxby, USAF Aging Landing Gear Life Extension Program Marking Test

Report, March 29, 2001

2. Robert M. Beggs , U.S. Army Aviation Parts Marking Demonstration Final Report,

September 7, 2001

3. Roxby, D. L.; USCG Flight Safety Critical Aircraft Parts Direct Part Marking (DPM)

Verification Program Report, January 15, 2004

4. Coates, J.; USAF Landing Gear Life Extension Program Reports GA-C23527, GA-

C24577, GA-C24578, GA-C24623, GA-C24624 and GA-C24688

5. Roxby, D. L.; National Center for Manufacturing Sciences (NCMS)/DoD Retrofit

Parts Marking Project Final Report, September 30, 2004

6. MIL-STD-130, Identification Marking Of U.S. Military Property

7. NASA-STD-6002, Applying Data Matrix Identification Symbols On Aerospace Parts

8. NASA-HDBK-6003, Application Of Data Matrix Identification Symbols To

Aerospace Parts Using Direct Part Marking Methods/Techniques

9. More information related to the MISSE 1 and 2 Experiments can be obtained on Web

Site: http://misseone.larc.nasa.gov/

NASA MISSI 1 2 Report 7231TM Ther Mark White Paper

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