d2 d5
Atm
osph
ere
Sele
ctio
nfo
r Lon
g-du
ratio
nM
anne
d Sp
ace
Mis
sion
s
Dav
id B
. Hirs
chN
ASA
Joh
nson
Spa
ce C
ente
r Whi
te S
ands
Tes
t Fac
ility
NA
SA
/JA
XA
Tec
hnic
al In
terc
hang
e M
eetin
gTs
ukub
a, J
apan
June
4-8
, 200
7
https://ntrs.nasa.gov/search.jsp?R=20070021586 2018-05-17T01:08:19+00:00Z
Slid
e 1
d2
The
envi
ronm
ent
of s
pace
craf
t fo
r fu
ture
hum
an s
pace
exp
lora
tion
mis
sion
s w
ill p
lay
a cr
itica
l rol
e in
the
ulti
mat
e sa
fety
, pro
duct
ivity
, an
d co
st.
Ther
e ar
e a
mul
titud
e of
fac
tors
invo
lved
in s
elec
tion
of s
pace
craf
t en
viro
nmen
ts.
Dur
ing
my
pres
enta
tion
I w
ill r
evie
w s
ome
of t
he
fact
ors.
dhirs
ch, 1
/15/
2006
d5
Long
er m
issi
on d
urat
ion
driv
e re
use
and
recy
clin
g of
mat
eria
ls t
o re
duce
con
sum
able
s an
d ex
pand
eble
s su
pplie
s.Lo
ng d
urat
ion
will
req
uire
gre
ater
hou
seke
epin
g an
d su
ppor
t ac
tiviti
es, i
nclu
ding
coo
king
, lau
ndry
, and
tra
sh m
anag
emen
t. Reg
ular
m
aint
enan
ce o
pera
tions
on
equi
pmen
t an
d sp
aces
uits
, suc
h as
cle
anin
g an
d pa
rt r
epla
cem
ent
will
be
nece
ssar
y. Th
e ca
pabi
lity
for
loca
l par
t fa
bric
atio
n m
ay a
lso
be r
equi
red.
Adva
nced
life
sup
port
sys
tem
s w
il lin
clud
e fo
od p
rodu
ctio
n an
d w
aste
rec
yclin
g sy
stem
s. D
ryin
g pr
oces
ses
are
cons
ider
ed t
o re
cove
r w
ater
fro
m s
olid
was
te, a
nd h
igh
tem
pera
ture
pro
cess
es a
re c
onsi
dere
d to
dec
ompo
se w
ates
and
mic
robi
al s
tabi
lizat
ion.
Th
ese
oper
atio
ns w
ill in
evita
bly
invo
lve
incr
ease
d ha
ndlin
g an
d m
ater
ials
pro
cess
ing
that
cou
ld in
clud
e fla
mm
able
item
sdh
irsch
, 1/1
7/20
06
2
His
toric
al S
pace
craf
t Atm
osph
eric
Con
ditio
nsd1
Slid
e 2
d1
Mer
cury
/Gem
ini/A
pollo
100%
oxy
gen,
5 p
sia
Spac
e su
it 10
0% o
xyge
n, 3
.75
psia
No
EVA
preb
reat
he t
ime
requ
ired
but
prio
r to
lunc
h th
e as
tron
auts
wer
e ex
pose
d tp
100
% o
xyge
n fo
r 3
hrs
Skyl
ab 7
0 ox
ygen
, 5 p
sia,
sam
e su
it as
abo
veN
o EV
A pr
ebre
ath
requ
ired
Shut
tle/I
SS U
S 21
% o
xyge
n, 1
4.7
psia
; su
it at
4.3
psi
atw
o op
erat
ion
mod
es:
36 h
rs a
t 26
.5%
oxy
gen,
10.
2 ps
ia in
spa
cecr
aft
follo
wed
by
40 m
in 1
00%
oxy
gen
in s
uit
if no
36
hrs
prec
ondi
tioni
ng, t
han
4 hr
s in
100
% o
xyge
n in
the
sui
t (2
.5 h
rs o
n em
erge
ncy)
ISS/
Rus
sia
suit
at 5
.8 p
sia,
30
min
ute
100%
0xy
gen
in s
uit
dhirs
ch, 1
/15/
2006
3
Spa
cecr
aft E
nviro
nmen
t Sel
ectio
nd4
d6
•W
hat d
rives
spa
cecr
aft e
nviro
nmen
t sel
ectio
n?–
Cre
w H
ealth
and
Saf
ety
Req
uire
men
ts–
Mat
eria
ls R
equi
rem
ents
–P
rogr
am R
equi
rem
ents
–M
issi
on, V
ehic
le, a
nd S
pace
Sui
t Opt
imiz
atio
n
Slid
e 3
d4
Crew
hea
lth:
resp
irato
ry p
hysi
olog
y, d
ecom
pres
sion
sic
knes
s pr
even
tion
dire
ctly
aff
ect
atm
osph
ere
sele
ctio
nra
diat
ion
prot
ectio
n af
fect
s in
dire
ctly
dhirs
ch, 1
/15/
2006
d6
Prog
ram
and
mis
sion
req
uire
men
tsN
umbe
r of
EVA
pla
nned
- c
ompl
exity
of
spac
e ar
chite
ctur
e -
Capa
bilit
y fo
r em
erge
ncy
EVA
Rap
id c
abin
dep
ress
uriz
atio
n re
spon
sedh
irsch
, 1/1
7/20
06
4
Phy
siol
ogic
al R
espo
nse
d3
Phys
iolo
gica
l res
pons
e to
atm
osph
eres
of v
ario
us t
otal
pre
ssur
es a
nd
oxyg
en c
once
ntra
tions
Slid
e 4
d3
Prov
ide
suff
icie
nt t
otal
pre
ssur
e to
pre
vent
boi
ling
of b
ody
fluid
s (>
0.9
psia
)Pr
ovid
e su
ffic
ient
oxy
gen
part
ial p
ress
ure
to p
reve
nt h
ypox
ia b
ut n
ot s
o hi
gh t
o ca
use
oxyg
en t
oxic
ityPr
ovid
e a
neut
ral g
as t
o pr
even
t at
elec
tasi
sdh
irsch
, 1/1
7/20
06
5
Dec
ompr
essi
on S
ickn
ess
Pre
vent
ion
•C
ondi
tions
of o
ccur
renc
e•
Sym
ptom
s: P
ain,
cho
kes,
circ
ulat
ory
col
laps
e,
neur
olog
ical
dis
orde
rs; p
oten
tially
deb
ilita
ting
and
life-
thre
aten
ing
cond
ition
•Th
e oc
curr
ence
and
sev
erity
of D
CS
cor
rela
tes
with
R, t
he ra
tio o
f the
fina
l nitr
ogen
par
tial
pres
sure
in th
e bo
dy ti
ssue
to th
e fin
al a
mbi
ent
tota
l pre
ssur
e.
•M
axim
um p
rebr
eath
e tim
e
d8
Slid
e 5
d8
The
inte
rnal
pre
ssur
e in
spa
cesu
its is
low
(4.
3 ps
ia f
or c
urre
nt E
VA s
uits
). Th
e lo
wer
pre
ssur
e al
low
s in
crea
sed
glov
e m
obili
ty a
nd
redu
ces
phys
ical
eff
orts
. Red
uced
pre
ssur
es r
equi
re h
ighe
r ox
ygen
con
cent
ratio
ns f
or b
reat
hing
. Tr
ansi
tion
from
a h
ighe
r pr
essu
re t
o a
redu
ced
pres
sure
may
res
ult
in a
bsor
bed-
nitr
ogen
in t
issu
es g
oing
into
the
gas
pha
se.
Fina
l R v
alue
s of
at
leas
t 1.
65 a
re r
equi
red
in c
urre
nt s
pace
craf
t, b
ut in
fac
t w
e go
to
as lo
w a
s 1.
3D
CS in
cide
nce
is lo
wer
in m
icro
grav
ity t
han
fore
cast
ed.
Ther
e m
ay b
e in
crea
sed
phys
ical
eff
orts
in p
artia
l gra
vity
impo
sed
by
ambu
latio
n.dh
irsch
, 1/1
7/20
06
6
Mat
eria
ls S
elec
tion
•Tw
o m
ajor
issu
es:
–Fl
amm
abili
ty–
Offg
assi
ng
7
Influ
ence
s on
LO
I
Influ
ence
of p
olym
er h
ydro
gen
cont
ent a
nd te
st c
ondi
tions
on
the
LOI
8
Com
mon
ly U
sed
Pol
ymer
s
•Som
e po
lym
ers
com
mon
ly u
sed
in A
mer
ican
sp
acec
raft
and
thei
r fla
mm
abili
ty li
mits
:–
PTF
E–
Kap
ton
–N
omex
HT
9040
–G
raph
ite e
poxy
com
posi
te
–S
ilico
nes
–
Vito
n
–P
U a
nd P
E–
Sol
imid
e–
Kyn
ar
–P
olyc
arbo
nate
–N
ylon
–C
otto
n–
Pap
er–
PV
C a
nd A
BS
–D
elrin
–K
evla
r–
Epo
xy fi
berg
lass
with
PI
d7
Slid
e 8
d7
PTFE
(49
); K
apto
n (>
30);
Nom
ex (
aram
ide)
- s
tow
age
cont
aine
rs (
22.6
); N
omex
flig
ht s
uits
, nev
er u
sed
Gra
phite
epo
xy c
ompo
site
- I
SS r
acks
Silic
one
adhe
sive
s an
d se
alan
ts (
23.5
as
foam
)Vi
ton
(22.
5);
PU (
15.3
) an
d PE
(17
.5)
stow
age
foam
(us
ually
cov
ered
with
Nom
ex)
Solim
ide,
not
use
d m
uch
(55.
1);
Kyna
r (p
vdF)
;PC
(25
-30)
-cam
era
and
lapt
op c
ases
Nyl
on (
23)
hook
and
loop
fas
tene
rs;
runn
ing
shor
ts;
cott
on (
clot
hing
, tow
els)
; pa
per
PVC
(49.
3) a
nd A
BS (
16)
in o
ff-t
he-s
helf
hard
war
e; K
evla
r (a
ram
id f
abric
) (2
5.6)
, int
erna
l web
bing
dhirs
ch, 1
/16/
2006
9
Ach
ievi
ng L
ower
Cab
in O
xyge
n C
once
ntra
tion
•In
crea
sing
the
spac
esui
t pre
ssur
e•
Acc
eptin
g a
high
er v
alue
for R
and
the
asso
ciat
ed D
CS
risk
•A
ccep
ting
a lo
nger
pre
brea
the
time
•A
llow
ing
a m
ore
hypo
xic
atm
osph
ere
d9
Slid
e 9
d9
A va
riabl
e sp
acec
raft
env
ironm
ent
is c
onsi
dere
d. Fo
r tr
ansi
t ve
hicl
es w
ith f
ew E
VA's
, a
long
er p
rebr
eath
e tim
e m
ay b
e ac
cept
able
, al
low
ing
an E
arth
-nor
mal
spa
cecr
aft
atm
osph
ere.
Th
is in
clud
e ve
hicl
es t
hat
dock
with
the
ISS
. It
is d
esira
ble
to a
void
the
airl
ock
oper
atio
ns d
urin
g cr
ew t
rans
fer.
The
hypo
xic
boun
dary
is d
efin
ed b
y an
oxy
gen
part
ial p
ress
ure
equi
vale
nt t
o an
alti
tude
of
6000
ft.
A
bout
130
mill
ion
peop
le li
ve a
t al
titud
es f
rom
650
0 to
820
0 ft
, ind
icat
ing
that
hig
her
equi
vale
nt a
ltitu
des
are
acce
ptab
le f
or s
hort
dur
atio
n sp
ace
trav
el.
dhirs
ch, 1
/17/
2006
10
Eng
inee
ring
Fact
ors
•C
abin
stru
ctur
al m
ass
–D
river
s: th
ickn
ess
to c
onta
in in
tern
al p
ress
ure,
st
ruct
ural
inte
grity
to w
ithst
and
laun
ch a
nd re
-ent
ry
load
s, ra
diat
ion
shie
ldin
g, m
eteo
roid
pro
tect
ion
•Th
erm
al c
ontro
l sys
tem
s•
Life
sup
port
syst
ems
•A
irloc
ks fo
r EV
A
d10
Slid
e 1
0
d10
At
cab
in p
ress
ures
bel
ow 5
to
7 ps
ia la
unch
load
s de
term
ine
the
min
imum
wal
l thi
ckne
ss, w
here
as a
t hi
gher
pre
ssur
es t
han
7 ps
ia, t
he
inte
rnal
pre
ssur
e di
ctat
es t
he t
hick
ness
. Fo
r lu
nar
vehi
cles
, the
laun
ch lo
ads
dict
ate
the
wal
l thi
ckne
ss a
t pr
essu
res
up t
o 14
.7 p
sia.
TCSy
stem
s -
The
tota
l pre
ssur
e ha
s an
impa
ct o
n th
e du
ct a
nd f
an s
izin
g. Fo
r eq
uiva
lent
hea
t tr
ansf
er, w
hen
redu
cing
pre
ssur
es, t
he
mas
s flo
w r
ate
has
to s
tay
the
sam
e. Co
nseq
uent
ly, t
he v
olum
etric
flo
w r
ate
has
to in
crea
se.
The
pow
er p
enal
ty t
o th
e ai
r co
olin
g su
bsys
tem
due
to
redu
ced
pres
sure
s pu
ts a
pra
ctic
al m
inim
um o
n ca
bin
pres
sure
of
7.35
psi
a.LS
Syst
ems:
the
car
bon
diox
ide
and
trac
e co
ntam
inan
ts r
educ
tion
are
not
affe
cted
by
redu
ced
pres
sure
s. Th
e ae
orob
ic b
iolo
gica
l was
tepr
oces
sing
sys
tem
s m
ay h
ave
to b
e m
odifi
ed if
oxy
gen
conc
entr
atio
ns o
ther
tha
n ai
r ar
e us
ed.
Ther
e ar
e tw
o ty
pes
of a
irloc
ks:
vent
ing
to o
utsi
de a
nd p
umpi
ng t
he e
nviro
nmen
t ba
ck t
o th
e sp
acec
raft
. If
at
leas
t 6
EVA
are
cond
ucte
d, p
umpi
ng b
ack
pays
off
. Th
e po
wer
req
uire
d is
muc
h le
ss a
t hi
gher
pre
ssur
es.
dhirs
ch, 1
/17/
2006
