SUIT AND HELMET SESSION WITH (Sanitized) OF DAVID CLARK, 23 MARCH 1966

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP75B00285R000400130021-1
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 11
• Document Creation Date: December 12, 2016
• Document Release Date: February 28, 2002
• Sequence Number: 21
• Publication Date: March 31, 1966
• Content Type: MEMO

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31 March 1966
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coating. Electric face heat was not discussed in
time auxiliary sun shield usage defined below.
However, at the present state-of-the art, its
mirror effect would severely reduce visibility,
already a problem.
2. Shall be coated at both surfaces with anti-glare
this session.
3. Applying the antiglare coating to the existing
plastic faceplate is known to be difficult, but
efforts to have this accomplished shall be continued.
I
Subject: SUIT AND HELMET SESSION WITH
OF DAVID CLARK, 23 MARCH 196
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It was agreed betwee f David Clark and
and ADP that helmet thermal improvements are s
as o ows:
y" Phase I
Immediate. Aluminize the exterior in
place of the present white paint, to
provide a reflective rather than ab-
sorptive surface.
Development - After evaluating results
of other improvements. Insulate or
revise the shell to reduce its thermal
conductivity. This may require double
wall construction to reduce or eliminate
weight increase.
Visor Pressure Faceplace:
1. Shall not be provided with I. R. coating. Such
a coating would be the most desireable approach
C thermally, giving us full time attenuation of heat
build-up in the material as opposed to the part
r,,a or Rele see"2p ~/0 1 ''CIA=RDP75'B0028 R00040i3b
 For R er- 2/06 CI L$~ 9Bt 286OW0400130021-1
.IV 31 March 1966
t~ . 1,
The first anti-glare faceplates will therefore be
the laminated glass version made by Pittsburgh
Plate Glass Company. At least three of the glass
versions exist at the moment and
states that these are already coated on at least
one side with a triple layer of magnesium fluoride.
David Clark has four faceplates at Santa Rosa, California
at the moment for coating. was not ut L
aware as to whether these are plastic or glass or some
of each.
Sun Shields - Infra-Red Reflective:
It was concluded that a single panel I. R. shield with
a clear lower section and an upper sunshade section
would be unsatisfactory and should not be considered
further; the most apparent of several problems is
that when flying into the sun, the illuminated lower
face would cause very bad self-reflection in the sun-
shade portion.
The hardware problems of mounting and operating
multiple auxiliary shields have already been solved
on the Gemini helmet, so we felt no compunction
about specifying the double shields below. However,
having no feel for what we will be getting into, we
would like to have a sample to examine
will transmit to lour request to arrange
if possible for a two week loan of a typical two sun-
shield helmet.
dark green sunshade, except
for the coatings as stated.
The I. R. coating may turn
out to be a gold deposition,
but no where near the density
of the Gemini gold shield we
have been testing.
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Two separate sunshield configurations should be made
for test, each with I. R. reflective coating on the outer
surface and anti-glare coating on the inner surface.
A. Clear Sunshade This will be of a material
and thickness similar to
the existing dark green
sunshade, except clear.
B. Sunshade - This will be like our existing
 Approved For Reftwse 2002/0?&/ 8IA-RDP75B00285Rce400130021-1
31 March 1966
4. Without being familiar with the mechanics of the
Gemini hardware, we stated more or less conver-
sationally that the clear shield should be the one to
come down with the first manipulation of the knob,
and that it would be satisfactory, and possibly
desireable, to have both shields down if the sunshade
were needed. These ideas may or may not be
significant in terms of the actual hardware.
It is becoming obvious that the suit must reflect both solar
and I. R. wavelengths in the cockpit environment vs. tie,
solar only problem for Gemini. This means that the
aluminized suit will be better as shown in our SP-795 report
which you have. The final decision as to the use of aluminized
or white HT will be the result of flight usage and comparing
well worn and washed garments.
In further discussions with e stated that he
considers the following composite to be w at we will have in
the first partially insulated suits, and left us a sample of each
layer
Pilot's Body
Vent
Air
P7084 Underwear (cotton).
P729 Comfort Liner (Sage green
Oxford nylon).
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P1807A Gas Container (Neoprene
impregnated nylon; neoprene surface
toward body).
X. X\--\ X X \A X K XX 01,111 P5018 Restraint (HT Link Net).
"Super-Spacer", no number assigned.
(Dimple-formed nylon tricot, aluminized
on outer surface). Selected zones only.
m _-- 6 ACS 1440 C Coverall (Nylon, aluminized
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31 March 1966
Other samples left with us for interest are:
A. Mercerized Cotton - No number assigned as yet
(sample is dark blue). Being considered as
replacement for the nylon comfort liner (layer
#2 above) due to better air permeability and
insulation characteristics. David Clark does
not yet stock any of this material.
B. "Super-Spacer" sample aluminized by applying
a layer of aluminized mylar on a trial basis. For
various reasons, including stiffness, this is not
being considered for real use a Me moment.
Sample is very shiny, giving the appearance of
being covered with fresh aluminum foil.
C. Regarding the sample of 'Super -Spacer9I left with
us as representing layer #5 in the trial suit com-
posite defined above. This sample, aluminized
by vacuum deposition, is very dull in appearance,
especially when compared with the shiny sample
just described. This was made early in the learning
stage, however, and they expect considerable im-
provement in the actual material used.
D. "Super-Spacer" sample (pink) before being aluminized.
This and the aluminized samples are all approximately
six inch squares from the same tooling, stitched
to et r_ as_regi fixed. ?
E. Sample of present aluminized outer surface material
ACS 1440C coated with an abrasion resistant film.
No number has been assigned to this combination,
bu tates they are considering it as a
possible next step in outer surface improvement. To
the eye and by his test measurements it is considerably
less reflective than new bare ACS 1440C; however, a
comparison after accelerated wear tests shows the
coated version to be nearly as good as when new,
versus serious degradation of the present bare material.
We are not in full agreement as yet, however, that the
coated material should be the "next step" in improve-
ment of the surface. We do not have a copy of their
report, but from a cursory glance at his reflectance
curves during our session it appeared that the present
materials reflectance when new is so superior that
we should not too hurriedly discard it merely for the
sake of better wear.
Although the present bare material is still fairly new
to the program`It f-s ready known to far exceed the
previous surface in wear qualities. We should wait
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31 March 1966
for more experience in the time taken for it to
degrade to the level of the less reflective coated
material; if this time were fairly short, say a few
weeks, it would obviously be better to start out
with the coated material in the first place. It is
our impression fro however, that
the bare ACS 1440C may e goo - or a number of
months.
F. Sample of ACS 2246, the white cover-all material
before being aluminized.
G. Sample,. un-numbered, of one experimental outer
surface aluminized by applying 1/4 mil mylar which
has been aluminized on each side. Excessively stiff
for suit usage.
H. Sample of white P5995, Gemini's outer cover-all
material. ?
I. Sample of P7251, hite Dacron,`: from which for
some reason an ent retest cover-all was made and
tried in the Firewel chamber. Performance was said
to be very poor.
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Time did not permit more than a glance at most of David Clark's preliminary
report, of which they will send us a copy when complete. They have done a
considerable amount of valuable test work in determining the physical and
thermal characteristics of a number of possible suit materials and suit
composites.
One large area of disagreement became apparent, however, when we
noticed that their thermal conductivity values for the various hard cloths,
etc., were several times better than ordinary insulation materials. The
reason for this seeming paradox turned out to be that their tests were made
in an evacuated bell jar at a very low pressure. It is known that by far
the major portion of heat transfer through fibrous insulations at sea level
is contributed by air conduction, and researchers have found that reduction
of pressure gives only negligible improvement in insulation value until
about 1/10 of an atmosphere is reached, let alone the 1/3 atmosphere of
our cockpit.
Thus, we must consider that the absolute k values from their bell jar tests T -
are not directly applicable for suit calculation purposes at our conditions.
This does not, however, detract from the fact that their findings are 25X1A
extremely valuable from the standpoint of comparison if, for example, the
degree of improvement in the thermal performance of a given composite
can be predicted for a change in one or more of the layers.
assures us that he feels the information can indeed be so use , and ac
can be seen to work this way when the test results of various composites
are compared.
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31 March 1966
As regards pressure reduction's effect on k value, we have since for-
warded to 1 :1 reproduction of the following ASME Heat
Transfer Division paper:
"HEAT TRANSFER BY GAS CONDUCTION AND RADIATION IN
FIBROUS INSULATIONS", by Verschoor and Greebler, physicists
at Johns-Manville Research Center
This is a very definitive and practical reference paper on the matter, and
although it deals specifically with fiberglass insulations, the effects should
be parallel for any porous or semi-porous material, and especially fabrics.
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Best regards,
cc: J. Parangosky
D
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OF DA i TD CLARK, MARCH 23, 1966
HELMET DECISIONS:
It was agreed between ;v alter, and myself that ther:,.al
.mprovements shall be made as foil 'his:
Stage (1). (Immediate). Alurni ize the exterior in place of the
present white palm., to provide a reflective rather than
absorptive surface.
Stage (2). Insulate or revise the shell to reduce its thermal con-
ductivity. This nay require double wall construction to
reduce or eliminate weight ircrease.
VISOR (PRESSURE FACEPLATE) :
(1). Shall not be provided with I.R. costing. Such a coating would
be the most desirable approach thermally, giving us fall time
,,.ttenuation of heat build-up in thr ^aterial as opposed to the
art time auxiliary shield usage defined below. However, at
he present state-ot'-the-art, its mirror effect woaid severely
-educe visibility, already a protlem.
). .'hall be coated at both surfaces with anti-glare coating.
Electric face heat was not discussed in this session and I am
of personally _'emiliar with this aspect of the matter.)
Applying the anti.-glare coating to the existing plastic faceplate
is known to be difficult,- but efforts to have this accomplished
shall be continued.
(4). The first anti-glare faceplates will therefore be the laminated
g lass version made by Pittsburgh Plate Glass Company. It appears
.:;.at at least three of the glass versions exist at the moment,
and Walter states that these are already coated on at least one
side with a triple layer of magnesium fluoride.
(5). David Clark has four faceplates at Santa Rosa at the moment for
coating. Walter was not aware as to whether these are plastic
or glass or some of each.
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March 29, 1966
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AUXILIARY FACE SHIELDS (Infra-Red Reflective):
(1).
It was concluded that a single panel I.R. shield with a
clear lower section and an upper sunshade section would
be unsatisfactory and should not be considered further;
the most apparent of several problems is that when flying
into the sun, the illuminated face wcald cause very bad
self-reflection in the sunshade portion.
(2). The hardware problems ot';r_ounting and operating multiple
auxiliary shields have already been solved on the Gemini
helmet, so _e felt no co.r.punction about specifying the
double shields below. However, having no feel for what
we will be getting? we would like to have a sample to
examine; Walter will trar:smit to our request
to arrange if possible for a two-week loan o a typical
helmet.
(3).
Two separate auxiliary shields shall be provided, each with
I.R. reflective coating on the outer surface and anti-glare
coating on the inner surface.
CLEAR SHIELD - Ths will be of a material and thickness
sir.ilar to the existing dark green sun-
-hede. except clear.
SUNSHADE - This will be like our existing, dark green
sunshade except for the coatings as stated.
The I.R. coating may turn out to be a gold
iepo:;ition, but nowhere near the density of
the Gemini gold shield we have been testing.
(1). Without being familiar with the mechanics of the hardware, we
stated more or less conversationally that the clear shield should
be the one to come down with the f .r. t manipulation of the 'Knob,
r)ad that it would be satisfactory (and possibly desirable) to
have both shields down if the sunshade were needed. These stipu-
'ations may or may not be significant in terms of the actual
hardware.
SUIT OUTER SURFACE DECISION:
It was agreed between and myself that the outer
surfr.ce of the suit should remain aluminized, and that no further consideration
should be given to changing to a white surface. This is consistent with the
"real" cockpit environment, wherein the suit surface must efficiently reflect
not just solar but both solar and I.R. wavelengths, as pointed out in my
Suit Problem Report SP 79:.
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CT;i;R SUIT CONSIDERATIONS:
In further discussions between Walter arid aryself he stated that he
considers the following composite to be what we will have in the first
partially insulated suits, and left us a sasple of each layer:
L
P'7084 Underwear (Cotton).
i IT
AIR
P'7?9 Co' fort Liner (Sage green
Oxford nylon).
Pl`-'O' A =as Container (Neoprene
r" :ted nylon; neoprene surfac=
ody)
X x \,/\ X X `/ ,
P3018, Restraint (h'T Link Net).
"Suoe?-Spacerrr, no number assicned.
-for red nylon tricot, alus::inized
o/ o' ter surface). Selected zones onl--y.
ACS __-ct0 C Coverall (Nylon, alu:Tinized
., ou,er surface).
Other samples left with us for interest are:
Mercerized Cotton: No r:umter assig;a:ed as yet (sample is dark blue).
Being cons ide.'e i as replacement for he nylon ca.-r,fort liner (layer #S
above) due to better air ermcabii ty and insulation characteristic:;.
They do not yet stock any Lf thi n m.e.*,erial.
Super-Spacer sar:.;l(' aiws1._iZ2C'. by acn,iying a layer of ai'Lli;::.z@d
'-lar on a trial basis. Fcr var_our reasons, including stif?.:% as,
s is not being considerei for real .use at the moment. Sarrple
very shiny, giving the a.sveararce of being covered with =. ..._
-m4- num foil.
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(As regards the sample of "Super-Spacer" left with as as
representing layer 7#5 in the trial suit composite defined
above: This sample, aluminized by vacuum deposition, is
very dull in apoearance, especially when compared with the
shiny sample just. (Iescribed. This was made early in the
learning stacle, however, and Walter expects considerable
improvement in the actual mater is used.)
"Super-Spacer" sample (pi:.k) before-- being aluminized. This
and the aluminized seur.n'.es are a ."i rnnroximately 6" squares,
the size of Walter's devei.ce e''t
toolin-g. For _ the first
.,
light-trial. suits the "Saner-Srjcr" layer, where used, will
probably consist of t' ss,:ares from the same tooling, stitched
together as requ'red.
Sample of present aluminized outer surface material ACS 144OC
coated with'an abrasion rpFistant fiLn. No number has been
assigned to this combination, but Walter states they are con-
sidering it as a po:;s?bl: next step in outer surface imnrove-
ment. To the eye and by his test ::easurements it is considerably
less reflective than new bare ACS 144OC; however, a comparison
after accelerates wear tests shows the coated version to be nearly
as good as when new, versus serious 'iegradatior of the present
bare material. 1 em not in full a';reement as yet, however, that
the coated material should be the "next step" in improvement of
the surface. We do not have a copy of Waiter's report, but from
a cursory glance at his reflectance curves during our session it
appeared that the present material's reflectance when new is so
superior that we should not too hurriedly discard it merely for
the sake of better wear. Although the present bare material is
still fairly new to the ,.roe-ra,r, it is already known to far exceed
t'.: previous surface in wear auilit'es. We should wait for more
experience in the time taken for i`. to degrade to the level of
t_:e less refleetive -coated material; if this time were fairly
.short, say a few weeks, it. would obviously be better to start
out with the coot d n:r. jai in the first place, fray a monetary
:.'.andpoint if nothing else. It is my impression from Walter,
however, that the bare ACS 1440C may be good for a number of
months .
Sample of ACS 2246, the white coverall material before being
aluminized.
Sample (un-numbered) of one experimental outer surface aluminized
by applying mil mylar which has been aluminized on each side.
Excessively stiff for suit usage.
'.^. ,*~le of white P 995 , Gem'-'
is outer coverall material.
of P7251, white Dacron, fray which for some reason an
e--, re test coverall was m:cie and toled in the Firewel chamber.
P ormance was said to be very poor, as would be expected.
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Time did not permit more than a glance at most ofO report,
of which he will send us a copy when complete. .He has done a considerable
amount of valuable test wort: in determn`.ning the physical and thermal
characteristics of a number of oossib1: suit materials and suit composites.
One large area of di sak;reement ::ecrme apparent, however, when I
noticed that his thermal cc:duetivity values for the various hard cloths.
etc., were several'ti'es better than ordinary insulation materials. The
reason for this seemin; paradox ':reed out vo be that Walter's tests were
made in an evacuated bell ,inr very low pressure. It is known thaL by
far the major portion of hcn,.t traL f-r tbroudi fibrous insulations at sea
level is contributed by ar cn.iucti~r, an.i .?searchers have found that
reduction of pressure gives only ner iF*,iblee i-prover.,er_t in insulation value
until about 1%10 of an atr,,osre is rr cle ., let alone the 1/3 atmosphere
of our cockpit. Thus I must, ccusidt~?r that t21.e> absolute k values from Walter's
bell jar tests are not directly applicable for suit caiculat`on purposes at
our conditions. This zees not, howt-.ver, detract from the fact that his
findings are extremely froT the stat_ipoint of comparison ii, for
exar,:ple, the degree of .nprG",~c'P'. r. Lh' performance o ' a given
composite can be predicted for a or more of the layers. He
assures me that he feels the information can 'r-c'eed be so used, and in fact
can be seen to work this ' ._ when the 't.est? rE ::;ui is of various composites,
are compared.
As regards pressure re+.'fiction' e' cot o~ k value, I have since forwarded
Walter a reproduction of the follow-_'-? AS`:Heat Transfer Division pacer:
"HEAT TRANSFER BY t-AS. CONDUCTION ANT RJIDIATION IN FIBROUS
INSULATIONS", by Vcrschoor and Greebier, physicists at
Johns-Manville Research Center.
This is a very definitive and practical reference paper on the natter, and
although it deals specifically with ?'ibergiaoss insulations, the effects
ssouid be parallel for any r.crous or semi-porous material, and especially
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