Downloaded from https://www.everyspec.com MIL–STD-81 OB 15 June 1967 . .,’, .. . t This tentative test method hcw been approved bu the D.parl- ment of the Air Force. I t i s optional jor use by all activities. M E T H OD T 517 S P A C E S I M U L A T I O N 1. Purp&e. T h e t e s t s d e s c r i b e d i n t h i s t e s t m e t h o d a r e i n t e n d e d fo r t h e e v a l u a t i o n of s p a c e v e h i c l e co m p o n e n t s , s p a c e v e h i c l e s p o n d i n g t o t h a t of t h e s un i n s p a c e .
T h e t o- t a l s o l a r e n e r gy s h a ll b e e q u a l t o t b e a pp li c a - b e c a p a b l e of p r o v i d i n g r a d i a n t e n e r gy co rr e - s u b s y s t e m s a n d co m p l e t e s p a c e v e h i c l e s i n - c l u d i n g i n s t a ll e d e q u i p m e n t . b l e v a l u e of t a b l e 517–1, co l u m r . 2, a n d v a r i a - t i o n s of t h i s i n t e n s i t y w i t h t i m e s h a ll b e k e p t t o & z .5 p e r c e n t o r l e ss .
At all p o i n t s in t b e t e s t p l a n e , t h e i n t e n s i t y s h a ll n o t d e v i a ~ b y d e t e r m i n e w h e t h e r s p a c e v e h i c l e s s u c h ~ T h e s p a c e s i m u l a t i o n t e s t i s co n d u c t e d t o m o r e t h a n & 2.5 p e r c e n t f r o m t h e a v e r a g e , s a t e lli t e s , e x t e r n a l i n s t r u m e n t a t i o n p a c k a g e s , m e a s u r e d b y a s e n s o r of a r e a 0.1 f t .
~ o r I / 1,000 of t h e i rr a d i a t e d a r e a , w h i c h e v e r i s e q u i p m e n t c a n w i t h s t i n d t h e d e l e t e r i o u s e f- f e c t s of v e r y l o w p r e ss u r e s , l o w t e m p e r a - t u r e s , a n d s o l a r r a d i a t i o n . O r d i n a r il y , t h i s t e s t w ill r e q u i r e e s t a b li s h i n g r e a li s t i c t e m - s p a c e c r a f t , a n d s p a c e s t a t i o n s w i t h a ss oc i a t e d s m a ll e r .
T o i n s u r e un i fo r m i t y in depth, t h e f i e l d a n g l e of t h e s i m u l a t e d s un s h a ll n o t e x - c ee d 4 d e g r ee s , e x c e p t i n s p e c i a l c a s e s , a n d s h o u l d b e l e ss t h a n 2 d e g r ee s , i f p o ss i b l e . A s i t i s li k e l y t h a t t h e s p e c t r u m of t h e s i m u l a t e d r a d i a t i o n w ill d i ff e r i n c e r t a i n w a v e l e n g t h p e r a t u r e d i s t r i b u t i o n s a c r o ss a n d t h r o u g h t h e t e s t i t e m . A e r o d y n a m i c h e a t i n g i s n o t u s u - ,.
a ll y co n s i d e r e d a p a r t of t h i s t e s t b u t m a y b e r e g i o n s f r o m t h e s p e c t r u m of t h e t r u e s o l a r r a d a t i o n , w h i c h i s li s t e d i n t a b l e 517–11, t h e p a r t i a ll y s i m u l a t e d , i f s o s p e c i f i e d , b y t h e a pp li c a t i o n of h e a t . t o t a l e ff e c t i v e a b s o r p t a n c e of t h e s u r f a c e of t h e t e s t i t e m s h a ll n o t d i ff e r b y m o r p t h a n & 2.5 p e r c e n t f r o m t h e t o t a l s o l a r a b s o r p t - e r a l p e r fo r m a n c e r e q u i r e m e n t s of s e v e r a l a p - 2. A pp a r a t u s .
T h i s s e c t i o n d e a l s w i t h g e n - a n c e v a l u e i f s i m r i f i c a n t t e s t i t e m t e m p e r a - t u r e e rr o r s a r e ~ b e a v o i d e d . i n g . P e r fo r m a n c e r e q u i r e m e n t s fo r a s p e c i f i c p a r a t u s i t e m s u s e d i n s p a c e s i m u l a t i o n t e s t - !. t e s t w o u l d b e c a ll e d o u t i n t h e e q u i p m e n t TABLE 517–1. A vt?vage radiation chanxlem”stics of plan. t s s p e c i f i c a t i o n . 2.1 Thermal vacuum chamber. T h e t e s t c h a m b e r s h a ll b e c a p a b l e of p r o v i d i n g a ,Olal radiation i.,..,ity Incident PI*.,I ,17ee,ivity Planet thermal .adiatim mane! m ct ( ~.-f ( alhcd .
) {w,mf S,. ft. ) lam . (*K) v a c uu m of a t l e a s t 10 - 5 T o rr . w i t h t h e t e s t i t e m i n s t a ll e d . P r o v i s i o n s s h a ll b e m a d e fo r ,q. ft. ) b l a c k -co a t e d c r y o g e n i c s h r o u d s c a p a b l e of n e a r li q u i d n i t r o g e n t e m p e r a t u r e s 195 ° C o r 78 ° K ) a n d of s u ff i c i e n t a r e a a n d s h a p e t o E a r t h 130.0 0,36 20.7 250 M a r s 56.2 0.146 12.0 226 I ~ b a m b e r w a ll s . p r e v e n t t h e t e s t i t e m f r o m s ee i n g warm V .. u s 245.0 0.67 20.3 249 E a r t h , s M m . 130,0 0.012 30.1 284 2.2 S o l a r s i m u l a t o r . T h e s i m u l a t o r s h a ll 517-1 hlETHOD 517 ,. . . . .... .
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