“Survey of Dust Issues for Lunar Seals and the RESOLVE Project” By Margaret P. Proctor and Paula Dempsey Abstract Lunar dust poses a technical challenge for sealing applications on the moon. A survey of seals used in Apollo lunar missions is presented as well as lunar soil characteristics and a description of the lunar environment. Seal requirements and technical challenges for the volatiles characterization oven and hydrogen reduction reaction chamber of the RESOLVE project are discussed. The purpose of the RESOLVE project is to find water or ice in lunar soil and demonstrate the ability to produce water, and hence oxygen and hydrogen, from lunar regolith for life support and propellants.

1

Nat

iona

l Aer

onau

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and

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e Ad

min

istra

tion

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Surv

ey o

f Dus

t Iss

ues

for L

unar

Sea

lsan

d th

e R

ESO

LVE

Proj

ect

By

Mar

gare

t P. P

roct

or a

nd P

aula

Dem

psey

Sea

ls T

eam

of t

he M

echa

nica

l Com

pone

nts

Bra

nch

Mat

eria

ls a

nd S

truct

ures

Div

isio

nN

AS

A G

lenn

Res

earc

h C

ente

r

Pre

sent

ed a

t the

20

06 N

AS

A S

eal/S

econ

dary

Air

Sys

tem

Wor

ksho

pN

ovem

ber 1

4-15

, 200

6C

leve

land

, OH

2

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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w.n

asa.

gov

Cha

lleng

es o

f Fut

ure

Luna

r Exp

lora

tion

“Dus

t rep

rese

nts

the

sing

le la

rges

t tec

hnic

al c

halle

nge

to p

rolo

nged

hu

man

pre

senc

e on

the

Moo

n.”

Har

rison

Sch

mid

tt, A

pollo

17

Ast

rona

ut M

arch

200

5•

The

exte

nt a

nd d

urat

ion

of p

lann

ed lu

nar s

urfa

ce a

ctiv

ities

is m

uch

high

er th

an p

rior A

pollo

exp

erie

nces

. •

Sys

tem

s an

d co

mpo

nent

s w

ill be

exp

osed

to e

nviro

nmen

tal f

acto

rs

for p

erio

ds o

f tim

e or

ders

of m

agni

tude

long

er th

an th

ose

prev

ious

ly a

ddre

ssed

.

Dus

t miti

gatio

n st

rate

gies

:1.

Des

ign

syst

ems

tole

rant

of d

ust p

rope

rties

2.D

evel

op te

chni

ques

to c

lean

or r

emov

e du

st fr

om s

urfa

ces

3.A

ctiv

e ab

atem

ent m

etho

ds to

min

imiz

e or

elim

inat

e de

posi

tion

and/

or a

dhes

ion

of d

ust

3

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

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istra

tion

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gov

Apo

llo L

unar

Sam

ple

Ret

urn

Con

tain

ers

a.k.

a. “R

ock

Box

es”

•U

sed

to re

turn

luna

r re

golit

h sa

mpl

es to

ear

th

•Tr

iple

sea

ls d

esig

ned

to

prov

ide

a va

cuum

sea

l of

10-6

torr

•A

lum

inum

box

(707

5 A

A)

with

Kni

fe e

dge

seal

in s

oft

indi

um a

lloy

(90%

indi

um,

10%

silv

er),

150

cm lo

ng

Of t

he 1

2 R

ock

Boxe

s, 4

had

sub

stan

tial l

eaks

due

to b

ag

mat

eria

l or d

ust o

n se

alin

g su

rface

1

•Tef

lon

spac

er p

reve

nts

cont

act p

rior t

o us

e.•S

ingl

e us

e an

d pr

essu

re re

quire

dto

mai

ntai

n se

alin

g.•D

oubl

e O

-rin

gs (L

608-

6 flu

oros

ilico

ne) f

or a

dd’l

seal

ing.

4

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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w.n

asa.

gov

Apo

llo

Spe

cial

Env

ironm

enta

l Sam

ple

Con

tain

ers

•34

0L S

.S. w

ith k

nife

edg

e se

al in

to in

dium

allo

y•

18 c

m lo

ng•

At e

nd o

f Apo

llo m

issi

ons,

no

repo

rts o

f lea

kage

5

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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gov

Apo

llo S

pace

Sui

ts

Spac

e Su

its•

Des

igne

d to

ope

ratin

g pr

essu

re:

3.75

psig

(2

5.8

KP

a),

tem

pera

ture

: +

250

o F(+

394

o K),

max

imum

leak

rate

: 0.

0315

lb/h

r (1

80 s

cc/m

in)

•Le

akag

e in

crea

sed

with

use

.

Apo

llo H

elm

et A

ttach

ing

Nec

k R

ing

•M

anuf

actu

red

by A

ir-lo

ck In

c.

•Al

umin

um a

lloy

7070

-T6

treat

ed w

ith a

n an

odiz

ed c

oatin

g.

•H

elm

et d

isco

nnec

ts h

ave

inte

rior s

tain

less

ste

el b

earin

gs•

Sea

ls in

the

Ext

rave

hicu

lar M

obili

ty S

uits

(EM

S) w

ere

used

to

atta

ch th

e sp

ace

helm

ets

to th

e sp

aces

uit b

y a

pres

sure

-sea

ling

neck

ring

.•

Bet

wee

n E

xtra

-Veh

icul

ar A

ctiv

ities

(EV

As)

the

hel

met

di

scon

nect

sea

ls w

ere

clea

ned

and

re-lu

bric

ated

with

Kry

tox

oil

and

grea

se to

redu

ce le

akag

e.

6

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

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istra

tion

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Apo

llo H

elm

et A

ttach

ing

Nec

k R

ing

•A

ttach

ed to

sui

t by

a se

lf-la

tchi

ng s

elf-s

ealin

g qu

ick

disc

onne

ct c

oupl

ing

It ha

s….

•Nec

k rin

g ho

usin

g

•8 la

tch

asse

mbl

ies

•A ro

tatin

g lo

ck

ring

•Pus

h bu

tton

lock

as

sem

bly

on th

e lo

ckin

g rin

g.

Latc

h

Com

man

d M

odul

e Pi

lot (

CM

P) H

elm

et

7

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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w.n

asa.

gov

Apo

llo S

pace

Sui

ts

Glo

ve D

isco

nnec

t Ass

embl

y•

Man

ufac

ture

d by

Air-

lock

Inc.

•

Alum

inum

allo

y 20

24-T

4.

•H

ave

inte

rior s

tain

less

ste

el b

earin

gs.

•P

ress

ure-

seal

ing

disc

onne

cts

atta

ched

glo

ves

to s

pace

suit

•ar

ms

•W

rist b

earin

gs a

nd ro

tatio

nal h

ardw

are

conn

ecto

rs h

ad fa

bric

co

verin

gs to

kee

p ou

t the

dus

t.•

Bet

wee

n E

VA

sgl

ove

disc

onne

ct s

eals

wer

e cl

eane

d an

d re

-lu

bric

ated

with

Kry

tox

oil a

nd g

reas

e to

redu

ce le

akag

e.•

Air-

lock

has

a p

aten

t (45

9605

4)on

the

synt

hetic

resi

n lip

sea

l us

ed in

the

bear

ing

asse

mbl

y of

the

spac

e su

it at

the

rota

ry

mot

ion

loca

tions

, suc

h as

at t

he g

love

con

nect

ion.

•

The

suit

side

has

a m

anua

lly a

ctua

ted

lock

/unl

ock

mec

hani

sm.

•Th

e gl

ove

has

a se

aled

bea

ring

that

per

mits

360

ogl

ove

rota

tion.

8

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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w.n

asa.

gov

Apo

llo S

pace

Sui

ts-G

love

Dis

conn

ect A

ssem

bly

Ref

eren

ce: A

pollo

Ope

ratio

ns H

andb

ook

(197

1) E

xtra

vehi

cula

r Mob

ility

Uni

t. V

olum

e I.

CSD

-A-7

89-(1

)

9

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

ww

w.n

asa.

gov

Luna

r Soi

l Cha

ract

eris

tics

0.3

(com

pres

sion

inde

x)C

ompr

essi

bilit

y (lo

ose)

1.72

-2.9

5 x

10-4

W/c

m o K

(Apo

llo 1

7)Th

erm

al C

ondu

ctiv

ity<2

0 μm

hig

h fe

rrom

agne

tic su

scep

tibili

tyM

agne

ticH

ighl

y ch

arge

dEl

ectro

stat

icN

ot a

ctiv

e in

vac

uum

Cor

rosi

vene

ssPr

imar

ily n

on-to

xic

Toxi

city

0.52

KPa

(.005

3 kg

/cm

2; .0

754

psi)

Coh

esio

n (0

-15

cm)

52%

+2%

Poro

sity

(0-

15 c

m)

5-7

( M

ohss

cale

)H

ardn

ess

1.58

+g/

cm3

Bul

k D

ensi

ty (

0-30

cm

)A

ngul

ar/s

uban

gula

rsha

rpSh

ape

90%

< 1

000 μm

, 70%

< 1

00 μ

mSi

zeD

escr

iptio

nC

hara

cter

istic

Ref

eren

ce: F

uhs,

S., H

arris

, J.(1

992)

Dus

t Pro

tect

ion

for E

nviro

nmen

tal C

ontro

land

Life

Sup

port

Syst

ems i

n th

e Lu

nar E

nviro

nmen

t. Pr

ocee

ding

s of t

he L

unar

Mat

eria

ls T

echn

olog

y Sy

mpo

sium

.

10

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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w.n

asa.

gov

Luna

r Soi

l Com

posi

tion

Oxy

gen

Mag

nesi

um

Cal

cium

Alu

min

um Iron

Silic

onTita

nium

Oth

er

Sodi

um

0.2

%M

anga

nese

0.

2 %

Pota

ssiu

m

0.1

%C

hrom

ium

0

.1 %

Nic

kel

300

ppm

Hyd

roge

n 1

00 p

pmC

arbo

n

10

0 pp

mN

itrog

en

8

0 pp

m

Cop

per

5

ppm

Thor

ium

1

ppm

Oxy

gen

Mag

nesi

um

Cal

cium

Alu

min

um Iron

Silic

onTita

nium

Oth

er

Sodi

um

0.2

%M

anga

nese

0.

2 %

Pota

ssiu

m

0.1

%C

hrom

ium

0

.1 %

Nic

kel

300

ppm

Hyd

roge

n 1

00 p

pmC

arbo

n

10

0 pp

mN

itrog

en

8

0 pp

m

Cop

per

5

ppm

Thor

ium

1

ppm

Ref

eren

ce: M

cKay

, D.S

. and

Tay

lor,

L. (2

005)

Nat

ure

and

Evol

utio

n O

f Lun

ar S

oil.

42%

21%

13%

7%

8%

6%

2%+

Oth

er

11

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

ww

w.n

asa.

gov

Luna

r Env

ironm

ent

Hel

ium

(25

);Neo

n (2

5);H

ydro

gen(

23);A

rgon

(20)

; Tr

ace:

Met

hane

; Am

mon

ia; C

arbo

n D

ioxi

de

Atm

osph

ere

(%)

Gal

actic

cos

mic

rays

(GC

R)

Sola

r par

ticle

eve

nts (

SPE)

win

d, c

osm

ic ra

ys

Luna

r Rad

iatio

n So

urce

s

Min

-181

C (9

2 K

) Max

111

C (3

84 K

)M

easu

red

Surf

ace

Tem

ps.

(Apo

llo)

3 x

10-1

3 K

Pa(2

x 1

0-12

torr

) A

tmos

pher

ic P

ress

ure

27.3

2 Ea

rth d

ays

Orb

ital P

erio

d ar

ound

ear

th

1.63

m/s

ec2

Surf

ace

grav

ity

3.34

g/c

m3

Den

sity

7.35

x 1

0E22

kg

Mas

s

37.8

x 1

06 km

2Su

rfac

e ar

ea

1738

.1 k

mEq

uato

rial r

adiu

s

12

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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w.n

asa.

gov

The

RES

OLV

E pr

ojec

t

•Pu

rpos

e:–

find

wat

er o

r ice

in lu

nar s

oil

–de

mon

stra

te th

e ab

ility

to p

rodu

ce w

ater

and

hen

ce o

xyge

n an

d hy

drog

en fo

r life

sup

port

and

prop

ella

nts

from

luna

r re

golit

h.

•H

ow w

ill th

is b

e do

ne?

–C

ore

sam

ples

of l

unar

rego

lith

heat

ed in

a V

olat

iles

Cha

ract

eriz

atio

n O

ven

to 1

50 ºC

to lo

ok fo

r wat

er v

apor

or

othe

r vol

atile

s.–

Hyd

roge

n re

duct

ion

proc

ess

reac

ts h

ydro

gen

to th

e ox

ides

in

the

luna

r reg

olith

to fo

rm w

ater

, whi

ch c

an th

en b

e sp

lit in

to

H2

& O

2us

ing

elec

troly

sis.

Pro

cess

requ

ires

heat

ing

to

~900

ºC.

13

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

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w.n

asa.

gov

Con

cept

ual I

nteg

rate

d R

ESO

LVE

Uni

t1

H2

Ne

GC

Anh

ydro

us S

alt

Bed

Wat

er

Cap

ture

Ther

mal

Env

elop

e

Fill

Val

ve

Met

al H

ydrid

e H

2 C

aptu

re

Fill

Val

veS

V1

SV

2

Cru

sher

R2

R1

Sig

ht

Gla

ss

Com

bine

d R

VC

and

H

ydro

gen

Red

uctio

n R

OE

Hea

ting

Cha

mbe

r

MFC

1C

V1 C

V2

Rot

ary

Sel

ecto

rV

alve

28V

28V

28V

DD

PP TT

28V

28V

PP TT

28V

28V PP T

Cam

era

Ram

an

28V

D

Cam

era

Ram

anC

amer

aR

aman

28V 28V

DD

Cam

era

Ram

an

28V

D

Cam

era

Ram

anC

amer

aR

aman

28V 28V

DD

Ele

ctro

lysi

sO

2H

2

28V

PT

Ele

ctro

lysi

sO

2H

2

28V

28V

PPTT

28V

28V

PPTT

28V

28V

PPTT

28V

28V

28V

SV

4

28V

28V

SV

4

Dril

l

Orif

ice

SV

3

28V28V28V

CV

3P TPP TT

28V

SV

5

28V

28V

SV

5R

V1

28V

SV

5

28V

28V

SV

5Ta

nk

To L

unar

Vac

cum

1 S

ande

rs, G

eral

d B.

, et.

al.,

“Reg

olith

& E

nviro

nmen

t Sci

ence

, and

Oxy

gen

& Lu

nar V

olat

ile E

xtra

ctio

n (R

ESO

LVE)

for

Rob

otic

Lun

ar P

olar

Lan

der M

issi

on,”

Luna

r Int

erna

tiona

l Con

fere

nce

2005

.

Cru

sher

Dril

l

Ove

n &

Rea

ctio

nC

ham

ber

Anhy

drou

s sa

lt be

dW

ater

cap

ture

Met

al h

ydrid

e

H2

capt

ure

Elec

troly

sis

14

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

ww

w.n

asa.

gov

Seal

Req

uire

men

ts fo

r Vol

atile

s C

hara

cter

izat

ion

Ove

n (V

CO

)•

Cap

able

of -

233

to 1

50 ºC

•E

ffect

ive

for 0

-75

psid

iffer

entia

ls (m

ay b

e re

vise

d to

150

psi

d)•

Low

or n

o ou

t-gas

sing

in a

vac

uum

(lun

ar 1

0-14

atm

or 7

.6 x

10-

12to

rr)

•Le

akag

e ra

te le

ss th

an 0

.5 c

m3 /m

in d

urin

g 20

min

utes

pro

cess

ing

time

at 5

atm

diffe

rent

ial a

ssum

ing

H2

•C

ompa

tible

with

hyd

roge

n, o

xyge

n, w

ater

, wat

er v

apor

, oth

er v

olat

iles

•To

lera

nt o

f vib

ratio

ns u

p to

10g

at 8

0-10

0 H

z

•R

eusa

ble

up to

40

open

/clo

se c

ycle

s–

Res

ista

nt to

luna

r rad

iatio

n en

viro

nmen

t–

Res

ista

nt to

dam

age

from

luna

r dus

t–

Mat

eria

l rep

els

luna

r dus

t or h

as m

eans

to re

mov

e du

st fr

om s

eal*

–M

ater

ial f

low

s ar

ound

luna

r dus

t tra

pped

at s

eal i

nter

face

*

•Li

ght w

eigh

t S

mal

l loa

d to

ach

ieve

a s

eal

•In

expe

nsiv

e•

Hig

h re

liabi

lity

Lo

w n

umbe

r of c

ompo

nent

s•

Geo

met

rical

ly c

ompa

tible

with

inte

rface

requ

irem

ents

15

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

ww

w.n

asa.

gov

Cha

lleng

es o

f Sea

ling

Hyd

roge

n R

educ

tion

Rea

ctio

n C

ham

ber

•S

ame

requ

irem

ents

as

the

vola

tiles

cha

ract

eriz

atio

n ov

en e

xcep

t:–

900

ºC–

3 ba

tche

s pr

oces

sed

at 9

00 ºC

•In

itial

ben

ch te

stin

g al

low

s th

e vo

latil

es

char

acte

rizat

ion

oven

to b

e se

para

te fr

om th

e hy

drog

en re

duct

ion

cham

ber.

•W

ant t

he s

ame

cham

ber f

or b

oth

proc

esse

s to

re

duce

wei

ght .

16

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

ww

w.n

asa.

gov

Som

e O

ptio

ns fo

r Sea

ling

VC

O

•O

-Rin

gs–

Met

al–

Vito

nA

-–

Teflo

n –

cold

flow

s ar

ound

sin

gle

laye

r of d

ust p

artic

le

•Tu

ngst

en C

arbi

de K

nife

edg

e on

Tun

gste

n C

arbi

de–

Kni

fe is

ver

y ha

rd a

nd v

ery

shar

p fo

r cut

ting

any

parti

cles

be

twee

n it

and

the

hard

flat

sea

ling

surfa

ce

•K

nife

edg

e in

to In

dium

or o

ther

sof

t met

al th

at c

ould

be

re-m

elte

d af

ter e

ach

use

to re

stor

e th

e “g

aske

t”m

ater

ial.

Key:

Pro

tect

sea

ling

surfa

ce fr

om d

ust !

17

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

ww

w.n

asa.

gov

A V

olat

iles

Cha

ract

eriz

atio

n O

ven

Con

cept

Ove

n

Hea

ter

Seal

gro

ove

Fill

open

ing

18

Nat

iona

l Aer

onau

tics

and

Spac

e Ad

min

istra

tion

ww

w.n

asa.

gov

Sum

mar

y

•Lu

nar d

ust p

oses

a c

halle

nge

to lo

ng te

rm m

issi

ons

on th

e m

oon.

•A

sses

smen

t of m

ater

ial c

apab

ilitie

s in

the

luna

r en

viro

nmen

t is

need

ed.

•P

rote

ctin

g an

d/or

cle

anin

g se

alin

g su

rface

s of

luna

r du

st m

ust b

e ad

dres

sed

for r

e-us

able

sea

ls.

•Th

e R

ES

OLV

E p

roje

ct p

oses

a c

halle

ngin

g se

al

prob

lem

.