Open access

!
!
"#$!%&'%()*!&+*$!+,!-."!/'&(01!2#$!34.4!5'0+!6(77(+08!!
)!95'0+!(0(2()2(:$;!
!
Paper&submitted&to&the&Space&Telescope&Science&Institute&in&response&to&the&call&for&HST&White&
Papers&for&Hubble’s&2020&Vision&
!
<)&%#!=>!?@AB!
!
C&+/$02>!DEA>!FE!F+0,+0/A>!5EGHE!CI&)&/A>!CE!JE!C*)/72+0$?>!5E!DE!3(%#+*7K>!5E!"E!H*)&L$=>!!
ME!F)1$0)*B>!4E!4/&()0(N!
!
!
A!O)P+&)2+(&$!/$!Q#R7(S'$!Atmosphérique.et.Planétaire,.Université%de%Liège,!O(T1$>!F$*1('6!
?!.+'2#U$72!J$7$)&%#!V072(2'2$>!.)0!402+0(+>!"W>!X.4!
K!D$Y)&26$02!+,!Q#R7(%7!)0/!472&+0+6R>!X0(:$&7(2R!+,!O$(%$72$&>!O$(%$72$&>!XZ!
=!H$02$&!,+&!.Y)%$!Q#R7(%7>!F+72+0!X0(:$&7(2R>!F+72+0>!<4>!X.4E!
B!O)P+&)2+&R!,+&!426+7Y#$&(%!)0/!.Y)%$!Q#R7(%7>!X0(:$&7(2R!+,!H+*+&)/+>!F+'*/$&>!H[>!X.4!
N!V34M!V72(2'2+!/(!472&+,(7(%)!$!Q*)0$2+*+1()!.Y)\()*(>!J+6$>!V2)*R!
!
!
!
H+02)%28!D$0(7!C&+/$02>!/E1&+/$02]'*1E)%EP$!
!
!
Abstract(
!
V0! ?@AN>! 2#$! 34.4! 5'0+!7Y)%$%&),2!U(**! (0(2()2$! (27! +0$GR$)&! 6(77(+0! )&+'0/! 5'Y(2$&! )0/!
P$%+6$!2#$!,(&72!Y&+P$!2+!$^Y*+&$!2#$!Y+*)&!&$1(+07!+,!5'Y(2$&E!"#$!-."!X_!(072&'6$027!`."V.!)0/!
4H.a!%)0!1&$)2*R!%+02&(P'2$!2+!2#$!7'%%$77!+,!2#$!5'0+!6(77(+0!PR!Y&+:(/(01!L$R!%+6Y*$6$02)&R!
:($U7!+,!5'Y(2$&b7!X_!)'&+&)!,&+6!c)&2#!+&P(2E!5'0+!%)&&($7!)0!'*2&):(+*$2!.Y$%2&+1&)Y#!`X_.a!)0/!
)0!(0,&)&$/!7Y$%2&)*!6)YY$&!`5VJ4<a!2#)2!U(**!+P2)(0!#(1#G&$7+*'2(+0!7Y$%2&)*!(6)1$7!Y&+:(/(01!
2#$!)'&+&)*!%+'02$&Y)&2!2+!5'0+b7!(0!7(2'!Y)&2(%*$7!)0/!,($*/7!6$)7'&$6$027!U(2#!2#$!Y*)76)!54Dc!
)0/! 5cDV! Y)&2(%*$!/$2$%2+&7E! "#$! 5'0+! 6(77(+0! U(**! P$! 2#$! ,(&72! +YY+&2'0(2R! 2+! 6$)7'&$!
7(6'*2)0$+'7*R!2#$!$0$&1$2(%!Y)&2(%*$7!)2!#(1#!*)2(2'/$!)0/!2#$!)'&+&)*!$6(77(+07!2#$R!Y&+/'%$E!
M+**+U(01!Y&+1&)66)2(%!)0/!2$%#0(%)*!*(6(2)2(+07>!2#$!)6+'02!+,!X_.!/)2)!2&)076(22$/!2+!c)&2#!
U(**! P$! 7$:$&$*R! &$72&(%2$/E! "#$&$,+&$>!(2! (7! +,! $^2&$6$! (6Y+&2)0%$! 2#)2! -."! %)Y2'&$7! )7! 6'%#!
)//(2(+0)*! (0,+&6)2(+0! )7! Y+77(P*$! +0! 5'Y(2$&b7! X_! )'&+&)! /'&(01! 2#$! +0$GR$)&! *(,$! +,! 2#$! 5'0+!
6(77(+0E!"#(7!U#(2$!Y)Y$&!(7!)!Y*$)!,+&!)!95'0+!(0(2()2(:$;!2#)2!U(**!$07'&$!2#)2!)!7',,(%($02!0'6P$&!
+,!+&P(27!(7!)**+%)2$/!2+!2#(7!'0(S'$!7+*)&!7R72$6!6(77(+0E!
!
! !

!
?!
1. Introduction(
!
<)10$2+7Y#$&$7!)&$!0)2'&)*!*)P+&)2+&($7!,+&!72'/R(01!Y*)76)7>!2#$!72)2$!+,!6)22$&!U#(%#!
&$Y&$7$027!2#$!:)72!6)d+&(2R!+,!2#$!:(7(P*$!'0(:$&7$E!5'Y(2$&b7!6)10$2+7Y#$&$!(7!2#$!Y&+2+2RY$!+,!
)! e1()02! Y*)0$2b>! U#(%#! #)7! P$%+6$! )0! (0%&$)7(01*R! (6Y+&2)02! 2RY$! +,! Y*)0$2! )7! 6+&$! )&$!
%+02(0')**R!P$(01!/(7%+:$&$/!(0!2#$!'0(:$&7$E!!<+&$+:$&>!5'Y(2$&b7!6)10$2+7Y#$&$!)%27!)7!)!*+%)*!
)0)*+1'$! ,+&! 6+&$! /(72)02! )72&+Y#R7(%)*! P+/($7>! 7'%#! )7! '*2&)G%++*! /U)&,7>! 6)10$2(%! U#(2$!
/U)&,7!)0/!Y'*7)&7>!)0/!,'**R!$^Y*+(2(01!)0R!&)&$!+YY+&2'0(2R!2+!6)^(6(\$!+'&!'0/$&72)0/(01!+,!
2#(7!+Pd$%2!(7!%&(2(%)*>!)0/!U(**!(6Y)%2!)%&+77!U(/$&!)72&+0+6(%)*!72'/($7E!!
!
M+&! )*6+72! ?B! R$)&7>! 7'%%$77(:$! '*2&):(+*$2! `X_a! (072&'6$027! +,! 2#$! -'PP*$! .Y)%$!
"$*$7%+Y$! `-."a! #):$! P$$0! 2#$! +0*R! (072&'6$027! )P*$! 2+! $^Y*+&$!5'Y(2$&b7! Y+U$&,'*! )'&+&)*!
$6(77(+07! )2! #(1#! 7Y)2()*! )0/! 7Y$%2&)*! &$7+*'2(+0E! V2! (7! &$6)&L)P*$! 2#)2! ),2$&! 7'%#! )! *+01! 2(6$>!
0$U! -."! +P7$&:)2(+07! )&$! 72(**! '0%+:$&(01! %&'%()*!,)%27!)P+'2! 2#(7! 6'*2(,)%$2$/!Y#$0+6$0+0E!
"#$! %+6Y*$^! )0/! #(1#*R! /R0)6(%)*! )'&+&)*! 6+&Y#+*+1R!Y&+:(/$7! )! 1*+P)*! :($U! +,!2#$!
)26+7Y#$&(%! &$7Y+07$! 2+! 0'6$&+'7! *)&1$G7%)*$! )0/! 76)**G7%)*$! Y&+%$77$7! 2)L(01! Y*)%$!
2#&+'1#+'2! 5'Y(2$&b7! $0+&6+'7! 6)10$2+7Y#$&$E!"#$! '0/$&72)0/(01! +,! 5'Y(2$&b7! )'&+&)*!
$6(77(+07! %+6P(0$7! 7$:$&)*! &$7$)&%#! /+6)(07! (0! 6)10$2+7Y#$&(%>! )26+7Y#$&(%!)0/! 7)2$**(2$7!
7%($0%$7E!-$0%$>!(2!,+72$&7!2#$!(02$&$72!+,!)!*)&1$!%+66'0(2R!+,!(02$&0)2(+0)*!7%($02(727>!6)0R!+,!
U#+6!)&$!0+U!(0:+*:$/!(0!2#$!'Y%+6(01!34.4!5'0+!6(77(+0E!!
!
V0! ?@AN>! 5'0+! U(**! (0(2()2$! (27!6(77(+0! )&+'0/! 5'Y(2$&! )0/! P$%+6$!2#$! ,(&72! Y&+P$! 2+!
$^Y*+&$!(27!Y+*)&!&$1(+07E!V2!U(**!)07U$&!0'6$&+'7!&$6)(0(01!S'$72(+07>!$7Y$%()**R!2#+7$!&)(7$/!
PR! 2#$! 72'00(01! -."! :($U7! +,! 5'Y(2$&b7! X_! )'&+&)E!"#$! Y&(6)&R! 1+)*! +,! 2#$! 5'0+! 6(77(+0! (7! 2+!
$^Y*+&$! 2#$! +&(1(0! )0/! $:+*'2(+0! +,! 2#$! Y*)0$2! 5'Y(2$&!fF+*2+0! $2! )*E>! ?@A@gE! .(0%$! 5'0+b7!
Y&$%$77(01! +&P(2! U(**! %)&&R! (2! 2#&+'1#! 6+&$! )0/! 6+&$! +,!5'Y(2$&b7! /$)/*R!&)/()2(+0! P$*27>! 2#$!
0+6(0)*! 6(77(+0! *(,$2(6$! (7! +0*R! +0$!R$)&E! D'&(01! $)%#! +,! 2#$! KK! 7%($0%$! +&P(27! 5'0+! U(**!
)YY&+)%#!)0/!&$%$/$!,&+6!5'Y(2$&!2#&+'1#!#(1#G*)2(2'/$!6)10$2(%!,($*/!*(0$7>!%*+7$!2+!2#$!Y*)0$2>!
U#$&$! 7(10(,(%)02!Y)&2(%*$! )%%$*$&)2(+0! (7! $^Y$%2$/!2+! 2)L$! Y*)%$! )7! )! &$7'*2! +,! (27!72&+01!
6)10$2+7Y#$&$G(+0+7Y#$&$! %+'Y*(01E!"#$! -."!X_! (072&'6$027! `."V.! )0/!4H.a! %)0! 1&$)2*R!
%+02&(P'2$!2+!2#$!7'%%$77!+,!2#$!5'0+!6(77(+0!PR!Y&+:(/(01!L$R!%+6Y*$6$02)&R!:($U7!+,!5'Y(2$&b7!
X_!)'&+&)!,&+6!c)&2#!+&P(2E!"#$!$0+&6+'7!:)*'$!+,!7(6'*2)0$+'7!-."!)'&+&)*!+P7$&:)2(+07!U(2#!
+P7$&:)2(+07!,&+6!Y*)0$2)&R!7Y)%$%&),2!#)7!P$$0!/$6+072&)2$/!+0!6'*2(Y*$!+%%)7(+07!f$E1E!<)'L!
$2!)*E>!?@@?h!3(%#+*7!$2!)*E>!?@@ih!J)/(+2(!$2!)*E>!?@@j>!?@AAgE!"#$!5'0+!7%($0%$!Y)%L)1$!(0%*'/$7!)!
X_! 7Y$%2&+1&)Y#! `X_.a! 2#)2! U(**! +P2)(0! #(1#! S')*(2R! (6)1$7! )0/! 7Y$%2&)! +,! 5'Y(2$&b7! )'&+&)E!
-+U$:$&>!X_.!+P7$&:)2(+07!)&$!#(1#*R!%+0%$02&)2$/!/'&(01!$)%#!+&P(2!(0!)!,$U!#+'&7!0$)&!5'0+b7!
%*+7$72!)YY&+)%#!2+!5'Y(2$&E!.(0%$!+0$!+,!2#$!6)(0!+Pd$%2(:$7!+,!2#$!5'0+!6(77(+0!(7!2+!$72)P*(7#!
2#$! )%2')*!%+00$%2(+0!P$2U$$0! 2#$! )'&+&)*! $6(77(+07! )0/! 2#$! Y)&2(%*$7!2#)2! 1$0$&)2$! 2#$6!
fF)1$0)*! $2! )*E>! ?@A=g>! (2! (7! +,! $^2&$6$! (6Y+&2)0%$! 2#)2! -."! %)Y2'&$7! )7! 6'%#! )//(2(+0)*!
(0,+&6)2(+0!)7!Y+77(P*$!+0!5'Y(2$&b7!X_!)'&+&)!/'&(01!2#$!+0$GR$)&!*(,$!+,!2#$!5'0+!6(77(+0E!!
2. Juno’s(Orbits(and(Relevant(Instruments(
!
5'0+b7!+&P(2!(07$&2(+0!)2!5'Y(2$&!U(**!2)L$!Y*)%$!(0!5'*R!?@ANE!4,2$&!2U+!BKEBG/)R!%)Y2'&$!
+&P(27>! 2#$! 7Y)%$%&),2!U(**! Y$&,+&6! )! 7$&($7! +,! KK! ,+'&2$$0G/)R! 7%($0%$! Y+*)&! +&P(27! +,,$&(01!
'0Y&$%$/$02$/! :($U7! +,! 2#$! )'&+&)*! &$1(+07! +,! 5'Y(2$&E! "#$!0+6(0)*!5'0+! 6(77(+0! U(**! 2#'7!
+:$&*)Y!-."b7!HR%*$7!?=!)0/! ?BE! 5'0+b7!#(1#*R! $%%$02&(%!7%($0%$!+&P(27!#):$! )!Y$&(d+:$! %*+7$!2+!
B@@@! L6! )P+:$! %*+'/! /$%L!)0/!72)&2! +'2! )YY&+^(6)2$*R! (0! 2#$! D)U0GD'7L!Y*)0$E! "#$! 2RY(%)*!
+Y$&)2(+07!%)&&($/!+'2!/'&(01!2#$!7%($0%$!+&P(27!)&$!(**'72&)2$/!(0!M(1'&$!AE!

!
K!
!
!
Figure! 1:![0$!+,!5'0+b7!KK!7%($0%$!+&P(27!`D$%E!?@ANaE!<+72!+,!2#$!X_.!)0/!5VJ4<!/)2)!U(**!P$!
%+**$%2$/!0$)&!Y$&(d+:$!`&$/!%&+77$7aE!"#(7!NG#+'&!7$16$02!+0*R!&$Y&$7$027!*$77!2#)0!?k!+,!2#$!
2+2)*!/'&)2(+0!+,!+0$!5'0+!+&P(2E!
!
5'0+!%)&&($7!)0!X*2&)_(+*$2!.Y$%2&+1&)Y#!`X_.a!fC*)/72+0$!$2!)*E>!?@A=g!)0/!)0!(0,&)&$/!
V6)1(01!.Y$%2&+1&)Y#!`5VJ4<a!f4/&()0(!$2!)*E>!?@A=g!2#)2!U(**!%#)&)%2$&(\$!2#$!)'&+&)*!$6(77(+07!
+,! 5'Y(2$&! +:$&! )**! 7%($0%$! +&P(27E! X_.!U(**! +P2)(0! #(1#G&$7+*'2(+0! 7Y$%2&)*! (6)1$7!2#)2! U(**!
Y&+:(/$!2#$!-?!)0/!-!X_!)'&+&)*!%+'02$&Y)&2!2+!5'0+b7!(0!7(2'!Y)&2(%*$7!)0/!,($*/7!6$)7'&$6$027!
(0! 2#$! *)&1$&! Y+*)&! 6)10$2+7Y#$&$! U(2#! 2#$!Y*)76)! 54Dc!`5+:()0! 4'&+&)*! D(72&(P'2(+07!
c^Y$&(6$02a! )0/! 5cDV! `5'Y(2$&! c0$&1$2(%! Q)&2(%*$! D$2$%2+&! V072&'6$02a! /$2$%2+&7E! 42! 2#$! 7)6$!
2(6$>! 2#$! <4C!6)10$2+6$2$&!)0/! l):$7!(072&'6$02! fF)1$0)*! $2! )*E>! ?@A=g! U(**! )%%'&)2$*R!
%+072&)(0! 6)10$2(%! ,($*/! 6+/$*7! )0/! 6$)7'&$! 7(10)2'&$7! +,! %'&&$027! )0/! U):$7! ,*+U(01! )*+01!
)0/! )%&+77! 2#$! 6)10$2(%! ,($*/! *(0$7E! "#$! X_.! (072&'6$02!(7! 7+6$U#)2! 7(6(*)&! 2+! 2#$! -."! ."V.!
CA=@O! 7Y$%2&)*! 7*(2!)0/!(7! 7$07(2(:$! 2+! cX_GMX_E! X_.! U(**! 2)L$! )/:)02)1$! +,! 5'0+b7! 72)P(*(\(01!
7Y(0!2+!7%)0!2#$!)'&+&)*!&$1(+07!(0!2#$!/(&$%2(+0!Y$&Y$0/(%'*)&!2+!(27!7*(2>!U#(*$!(27!72$$&)P*$!7%)0!
6(&&+&!U(**!)**+U!+,,G7Y(0GY*)0$!2)&1$2(01!+,!7Y$%(,(%!&$1(+07!+,!(02$&$72!(0!5'Y(2$&b7!)'&+&)E!"#$!
V0,&)&$/!4'&+&)*!<)YY$&!`5VJ4<a!(7!$S'(YY$/!U(2#!)!7(01*$!2$*$7%+Y$!)0/!)%%+66+/)2$7!)!0$)&G
VJ!%)6$&)! )0/! 7Y$%2&+6$2$&E! V2! U(**! +P7$&:$! 2#$! -Km!)'&+&)*! $6(77(+07!0$)&! KE=! µ6>! U#(%#!
+:$&*)Y!)!/$$Y!6$2#)0$!)P7+&Y2(+0!P)0/E!"#$!72&'%2'&$!)0/!P&(1#20$77!+,!2#(7!2#$&6)*!$6(77(+0!
/$Y$0/7!+0!P+2#!2#$!/$07(2R!+,!-Km!(+07!)0/!2#$!*+%)*!'YY$&!)26+7Y#$&(%!2$6Y$&)2'&$E!M(1'&$!?!
7#+U7!)!7Y$%2&)*!(6)1$!+P2)(0$/!PR!&$%+072&'%2(01!)0!-."!."V.!2(6$G2)1!7$S'$0%$!fCI&)&/!$2!)*E>!
?@A=g!/'&(01!U#(%#!2#$!CA=@O!7Y$%2&)*!7*(2!U)7!7%)00$/!)%&+77!2#$!0+&2#$&0!)'&+&)*!&$1(+0E!"#(7!
Y7$'/+G(6)1$!(7!)0)*+1+'7!2+!2#$!+0$7!2#)2!U(**!P$!&$%+072&'%2$/!,&+6!2#$!X_.!/)2)E!
!
!
Figure! 2:!.Y$%2&)*! (6)1$! +,!
5'Y(2$&b7!0+&2#$&0!'*2&):(+*$2!&$1(+0!
&$%+072&'%2$/! ,&+6!)0! -."! ."V.!
2(6$G2)1!7$S'$0%$!/'&(01!U#(%#!2#$!
CA=@O! 7Y$%2&)*! 7*(2! U)7! 7%)00$/!
)%&+77! 2#$! )'&+&)!`)/)Y2$/! ,&+6!
CI&)&/!$2!)*E>!?@A=aE!.Y$%2&)*!(6)1$7!
+P2)(0$/! U(2#! X_.! U(**! P$! 7(6(*)&E!
"#$! %+*+&! %+/$! &$,$&7! 2+! 2#$! MX_!
%+*+&! &)2(+! )0/!(7! )! Y&+^R! ,+&! 2#$!
Y$0$2&)2(+0!/$Y2#!+,! 2#$! (6Y(01(01!
Y)&2(%*$7!1(:(01!&(7$!2+!2#$!)'&+&)E!
!
4*2#+'1#!2#$!0+6(0)*!5'0+!6(77(+0!U(**!2)L$!Y*)%$!/'&(01!2#$!KK!7%($0%$!+&P(27>!6'%#!7%($0%$!
%)0!)*&$)/R!P$!)%#($:$/!/'&(01!5'0+b7!+&P(2)*!(07$&2(+0!Y#)7$E!"#(7!$)&*R!Y$&(+/!`-."!%R%*$!?Ka!
U(**!P$! 2#$! +0$! )0/! +0*R! +YY+&2'0(2R! 2+! +P2)(0! )! ,'**! 7$2! +,! &$*$:)02! 'Y72&$)6! /)2)!
40
984
985
986
987
988
989
990
991
Figure 2 992
993
994
995
996
997

!
=!
7(6'*2)0$+'7*R! U(2#! -."! +P7$&:)2(+07>! U#(%#! U(**! /$2$&6(0$! #+U! 5'Y(2$&b7! 6)10$2+7Y#$&$! (7!
/&(:$0!PR!2#$!7+*)&!U(0/E!
3. Anticipated(Science(Objectives(
!
M(1'&$!A! #(1#*(1#27!2#$! +Y$&)2(+07! /'&(01! )! 2RY(%)*!5'0+!+&P(2>!(0%*'/(01! 2#$! (02$07(:$!/)2)!
%+**$%2(+0!0$)&!Y$&(d+:$E!"#$!6)(0!(02$&$72!+,!2#(7!7$16$02!(7!2#)2!(2!%+&&$7Y+0/7!2+!2#$!Y+&2(+0!+,!
2#$! +&P(2! /'&(01! U#(%#! 5'0+! (7!,*R(01! d'72! )P+:$! 2#$! 0+&2#! )0/! 7+'2#! Y+*$7E! "#(7! :($U(01!
1$+6$2&R!(7!0+2!)%#($:)P*$!,&+6!c)&2#!)0/!(2!U(**!Y&+:(/$!2#$!,(&72!:($U7!+,!2#$!0(1#27(/$!7$%2+&!
+,!2#$!)'&+&)!(0!P+2#!#$6(7Y#$&$7E!-+U$:$&>!2#(7!NG#+'&!7$16$02!+0*R!&$Y&$7$027!*$77!2#)0!?k!
+,!2#$!2+2)*!/'&)2(+0!+,!+0$!+&P(2E!-(1#!(072&'6$02)*!0+(7$!*$:$*7!/'$!2+!2#$!#(1#G$0$&1R!$*$%2&+0!
&)/()2(+0!6)R!,'&2#$&!&$/'%$!2#$!)6+'02!+,!'7)P*$!/)2)E!"#(7!(7!U#$&$!-."!(7!%+6(01!(02+!Y*)RE!
V0!)//(2(+0!2+!7(6'*2)0$+'7!)0/!%+0d'1)2$G&$1(+0!+P7$&:)2(+07!0$)&!2#$!5'0+!Y$&(d+:$7>!(2!U(**!P$!
(6Y+&2)02!2+!+P7$&:$!5'Y(2$&b7!)'&+&)!U(2#!-."!)2!+2#$&!2(6$7!`U#$0!5'0+!/)2)!)&$!7Y)&7$a>!2+!
Y&+:(/$!)!P)7$*(0$!,+&!2#$!#(1#*R!:)&()P*$!)'&+&)E!
!
Aa!l#$0!X_.!)0/!5VJ4<!)&$!0+2!+P7$&:(018!
-."!."V.!)0/!4H.!%)0!Y&+:(/$!2#$!6)(0!%#)&)%2$&(72(%7!+,!2#$!)'&+&)*!$6(77(+07!2#)2!U(**!7$&:$!
)7!)! 1*+P)*! %+02$^2! ,+&! 2#$! X_.! )0/! 5VJ4<! 70)Y7#+27! )%S'(&$/! +0%$! $:$&R!A=!/)R7E! Q)72! -."!
+P7$&:)2(+07! #):$! /$6+072&)2$/! 2#)2! Y&+%$77$7! 2)L(01! Y*)%$! (0! 5'Y(2$&b7! )'&+&)!)0/!
6)10$2+7Y#$&$! +Y$&)2$! U(2#! )! U(/$! :)&($2R! +,! 2(6$7%)*$7E! 47! )0! $^)6Y*$>! 2#$! 1*+P)*! (02$&0)*!
6)10$2+7Y#$&(%! /R0)6(%7! +,! 5'Y(2$&! (7! %#)&)%2$&(\$/! PR! )! 2RY(%)*! 2(6$7%)*$! +,! 7$:$&)*! `nNa!
Y*)0$2)&R!&+2)2(+07!`$E1E!Z&+0P$&1!$2!)*E>!?@@Bh!Z(6'&)!$2!)*E>!(0!Y&$77aE!-."!+P7$&:)2(+07!%)&&($/!
+'2!P$,+&$!)0/!),2$&!2#$!5'0+!Y$&(d+:$!7$16$02!)&$!2#'7!0$%$77)&R!2+!Y'2!2#$!5'0+!+P7$&:)2(+07!
(02+! 2#$! Y&+Y$&! 6)10$2+7Y#$&(%! Y$&7Y$%2(:$E!<+&$+:$&>! 2#$! 54Dc>! 5cDV>! l):$7>! )0/! <4C!
(072&'6$027!U(**!P$!6$)7'&(01!$0$&1$2(%!Y)&2(%*$7!)0/!)77+%()2$/!%'&&$027!)*+01!6)10$2(%!,($*/!
*(0$7! $:$0! +'27(/$! 2#$! Y$&(d+:$! 7$16$02E! H+0%'&&$02! -."! +P7$&:)2(+07! U+'*/! P$! $^2&$6$*R!
(0:)*')P*$!2+!(02$&Y&$2!2#$6!(0!2$&67!+,!%+00$%2(+0!U(2#!2#$!)'&+&)!)0/!(27!7Y)2()*!$^2$02E!!
!
?a!l#$0!X_.!)0/!5VJ4<!7)6Y*(01!&)2$7!)&$!0+2!)/$S')2$8!
42! 2#$! +2#$&! 7(/$! +,! 2#$! 2(6$7%)*$! &)01$>! )'&+&)*! )0/! 6)10$2+7Y#$&(%! Y&+%$77$7! )&$! L0+U0! 2+!
:)&R! U(2#(0! A@7! +,! 7$%+0/7E! 5'0+b7! 7Y(0! *(6(27! 2#$! %)/$0%$! +,! X_.! )0/! 5VJ4<! +P7$&:)2(+07! 2+!
$:$&R! &+2)2(+0! `K@7a!)0/! 2$*$6$2&R! &$72&(%2(+07! U(**! Y&$:$02! *+01! '0(02$&&'Y2$/! +P7$&:(01!
7$S'$0%$7E!M+&2'0)2$*R>!-."!#)7!Y&+:$0!2#)2!(7!)P*$!2+!Y&+:(/$!=BG6(0'2$!*+01!)0/!2$6Y+&)**R!
&$7+*:$/!7$S'$0%$7!,+&!%+07(/$&)P*R!(6Y&+:$/!(02$&Y&$2)2(+07!+,!2#$!(0G7(2'!6$)7'&$6$027!U(2#!
54Dc>!5cDV>!<4C!)0/!l):$7E!
!!
Ka!l#$0!X_.!)0/!5VJ4<!)&$!+P7$&:(01!$*7$U#$&$8!
l#$0! 5'0+! (7! :$&R! %*+7$! 2+! 5'Y(2$&>! (2! U(**! P$! (6Y+77(P*$! ,+&! $(2#$&! (072&'6$02! 2+! 6+0(2+&! 2#$!
$02(&$!)'&+&)*!+:)*>!+&!2#$!%+0d'1)2$!)'&+&)*!&$1(+0E!M+&!2#$!,(&72!2(6$>!U$!U(**!P$!)P*$!2+!+P7$&:$!
2#$! U#+*$! Y+*)&! &$1(+0! 7(6'*2)0$+'7*R! (0! P+2#! #$6(7Y#$&$7! `$E1E! -."! *++L7! )2! 2#$! 0+&2#$&0!
)'&+&)!)0/!5'0+!)2!2#$!7+'2#$&0!+0$aE!.'%#!+P7$&:)2(+07!U+'*/!P$!$77$02()*!2+!%#)&)%2$&(\$!*+%)*!
6)10$2(%!,($*/!$,,$%27!)0/!(02$&G#$6(7Y#$&(%!$*$%2&(%!%'&&$027E!c^)%2!7(6'*2)0$(2R!#)7!0$:$&!P$$0!
)%#($:$/! P$,+&$! P$%)'7$! ."V.! )0/! 4H.! M[_7! )&$! 2++! 76)**! 2+! +P7$&:$! P+2#! #$6(7Y#$&$7! )0/!
P$%)'7$!2#$!2(*2!+,!2#$!6)10$2(%!,($*/!Y&$:$027!7(6'*2)0$+'7!1++/!:($U7!+,!P+2#!#$6(7Y#$&$7!)2!
2#$!7)6$!2(6$E!
!!

!
B!
4. Time(Allocation(Issue(
!
4'&+&)7! )&$>! '0*(L$! 6)0R! )72&+0+6(%)*! )0/! (0/$$/! 7+*)&! 7R72$6! 2)&1$27>! 2(6$G/+6)(0!
Y#$0+6$0)E!['&!'0/$&72)0/(01!+,!)'&+&)*!$6(77(+07>!)0/!2#'7!2#$!/R0)6(%7!+,!6)10$2+7Y#$&$7!
(0! 1$0$&)*>! '*2(6)2$*R! /$&(:$7! ,&+6! +P7$&:(01! %#)01$7! (0! 2#$(&! Y&+Y$&2($7! +:$&! )**! 2(6$! 7%)*$7>!
(0%*'/(01! 6$/('6G*+01! (02$&:)*7>! 2#$! *)22$&! +,! U#(%#! )&$! )'2+6)2(%)**R! Y$0)*(\$/! PR! 2#$! Y)0$*!
&$:($U!Y&+%$77>!U#(%#>!)7!$^Y$&($0%$!7#+U7>!,):+&7!76)**$&!Y&+1&)67E!!"#(7!l#(2$!Q)Y$&!&)(7$7!
2#$!(77'$!2#)2!)!Y)0$*!&$:($U!Y&+%$77>!U#(%#!Y*)%$7!)0!$^2&$6$*R!#$):R!$6Y#)7(7!+0!6(0(6(\(01!
+&P(2!0'6P$&7>!/(7,):+&7!(6Y+&2)02!7%($0%$!2#)2!PR!0$%$77(2R!&$S'(&$7!*)&1$&!0'6P$&7!+,!+&P(27E!
!
"#$!$^2&)+&/(0)&R!%)Y)P(*(2($7!+,!-."!#):$!2#$!Y+2$02()*!2+!%+07(/$&)P*R!$0#)0%$!2#$!+'2Y'2!
+,! Y*)0$2)&R! 6(77(+07! )0/! 2#$! 5'0+! 6(77(+0! (0! Y)&2(%'*)&E! .'%#! 6(77(+07>! $7Y$%()**R! 2#+7$!
/$/(%)2$/! 2+! 2#$! +'2$&! 7+*)&! 7R72$6>! )&$! $^2&$6$*R! &)&$! )0/! 2(6$! %&(2(%)*E! l#$0! 7'%#! )0!
+YY+&2'0(2R! )&(7$7>! (2! (7! (6Y+&2)02!2#)2! )0! )YY&+Y&()2$*R! *)&1$!0'6P$&! +,! -."! +&P(27!)&$! Y'2!
)7(/$!2+! 7'YY+&2! 2#$7$! 6(77(+07! U(2#+'2! d$+Y)&/(\(01! +2#$&!7+*)&! 7R72$6! Y&+Y+7)*7!,+&! 2#(7!
Y)&2(%'*)&!%R%*$E!!
!
We!recommend!that! a! category! of! HST! time! be! allocated! specifically! for! "NASA!Juno!
Mission!Support"!similar!to!the!“UV!initiative”,!in!other!words!a!“Juno!initiative”.!!
!!