NASA FOIA 21-HQ-F-00500

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...m
•
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011
~-'
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•
- , -
t.N:lA$!I'lID '1'.00. Notl: ~ 36
nloc1\1 is 0.995 of cin;ular orbit ltlcu:1:q, <1-1 to 10 1IIIude of 100000n.
'llMo terminal (light path angle is 90 , 1.114, with ~" 0.1 in the subsonic flow
repOll, tbc illpacrt vdodty b 2f!Ofi/• .
In Cltimatiollhc wall ~Wre risc fo r tbe $phcrc account is taken of tbe
IIJ;Dinu convective heat input IItId the lurfaee radiation output; tho udiant input
from tbe gas cap is .,laCMd(l). 'The Iphcro is USUIlIod to be rotltio& 4uriJIc the
rr1rrb7 period.•0 that the heat input is uniformly distributed over the lunaee,
likewilc the ent ire lurface is assumed to radilte . bi..IDuD and Ju:rnq(8) have
ahown tbal relatively low rotation raIn arc adequate to attain tho .wfaec
tcrnpcratun: reductiona which IICCOI!IpB[IY the rotation. Th•• pbere .hell is assumed
10 be tberma!!y thin'. thus radial temperature gradients an neglected. The tOlal
heat atored in the .hell is equated to tbe Telultlnt inward heat flow, giving:
( ,)
where c is the: specifie: heat of the spbere material. 'The Gpeelfic heat ot ABDI
1265/5&1' Grade V TIri.. <.3) with temperature; I coutant ·...111\ of t • 0.23 is
adopted here, tbh value: cOITesponds to a temperature of 20'00""P..
'The laminar convective beal transfer to aoy point on the spbere ~ be written :
It • [J ~
where ca.. is the convective: heat transfer at tbe uagnltioo poiot
<, is the factor wb.lcb takes into account tjI.8 v&riatlon in heat
input over the .phere surface.
Uling the expreuion developed in referenee ,,:
_ B.1;,u, /n ~ leO
eo," .,
.... hero q is. dimen.ionle.. funetion proportional \0 \he heltinl rate
• is the loc,l flight path qU,
1bc: v.ri,tion of 1(, adopted (oJ' tbe windwmd hemi.pberc is lbat due to 1.... (9).
and K., i. assumed coo.tant over the leeward hamilphen I I i U Tll_ a1; 90° to
the now. lP.tcgfltioD over the qbt" ~Io. yillldf:
~ '"' 0.)), q,. e
Hence, by substitution ~(2):
... .... -"L.
",,' -In evaluating :a from Ch~" Z fUDelion. it is IUIRumed tbat i and hence ~ •
- .are uoro al u '"' 0.995. Tbc variation of the aerodynamic heatiog JUC with
altitude from lIquUoo(3) is mwn io figure ,.
The total surface ndillted beat output is aiven by:
'ou, •
(2)
(,)