X-4
3A F
light
Con
trol
s
Etha
n B
aum
ann
NA
SAD
ryde
n Fl
ight
Res
earc
h C
ente
rEd
war
ds, C
alifo
rnia
Mar
ch 6
, 200
6
2
A L
ittle
Abo
ut M
ysel
f
•G
radu
ated
from
Pur
due
Uni
vers
ity D
ecem
ber 1
998
•B
.S. i
n A
eron
autic
al/A
stro
naut
ical
Eng
inee
ring
•P
hysi
cs M
inor
•D
ryde
n Fl
ight
Res
earc
h C
ente
r (D
FRC
)•
2 C
o-op
term
s•
Wor
ked
in C
ontro
ls &
Aer
odyn
amic
s B
ranc
hes
•H
ired
as C
ontro
ls E
ngin
eer J
anua
ry 1
999
•W
orke
d Ja
nuar
y ’9
9 –
June
’05
on H
yper
-X P
rogr
am•
End
ed u
p as
GN
C le
ad fo
r X-4
3A S
hip
3•
Cur
rent
ly D
ryde
n’s
Prin
cipl
e In
vest
igat
or a
nd G
NC
lead
for
putti
ng a
JP
L S
ynth
etic
Ape
rture
Rad
ar a
nd a
pre
cisi
on
auto
pilo
t on
one
of D
ryde
n’s
airc
raft
3
Topi
cs
•N
AS
A D
ryde
n•
Ove
rvie
w•
Cur
rent
& R
ecen
t Flig
ht-T
est P
rogr
ams
•U
AV
SA
R P
rogr
am•
Pro
gram
Ove
rvie
w•
Pla
tform
Pre
cisi
on A
utop
ilot
•H
yper
-X P
rogr
am•
Pro
gram
Ove
rvie
w•
X-4
3A F
light
Con
trols
•Fl
ight
Res
ults
4
NA
SA
Dry
den
Flig
ht R
esea
rch
Cen
ter
Flig
ht R
esea
rch
sepa
rate
s "th
e re
al fr
om th
e im
agin
ed,"
an
d m
akes
kno
wn
the
"ove
rlook
ed a
nd th
e un
expe
cted
."
-Hug
h L.
Dry
den
•N
AC
A E
ngin
eers
firs
t sho
wed
up
Fall
of 1
946
to su
ppor
t X-1
•N
amed
for H
ugh
L. D
ryde
n–
NA
SA D
eput
y A
dmin
istra
tor
•Lo
cate
d on
Edw
ards
AFB
, Cal
iforn
ia–
Exce
llent
Fly
ing
Wea
ther
–D
ry la
ke b
eds s
erve
as n
atur
al ru
nway
s–
Mid
dle
of th
e M
ojav
e D
eser
t–
80 m
iles N
orth
east
of L
os A
ngel
es–
Mid
dle
of N
owhe
re
•N
ASA
’s a
tmos
pher
ic fl
ight
test
faci
lity
•A
ltern
ate
land
ing
site
for S
pace
Shu
ttle
LA
Edw
ards
AFB
5
NA
SA
Dry
den
Flig
ht R
esea
rch
Cen
ter
6
Pas
t Pro
ject
s
•S
pace
Shu
ttle
•X
-1•
X-1
5•
XB
-70
•X
-29
•X
-31
•F-
8 D
FBW
•F-
8 S
uper
-Crit
ical
Win
g•
F-18
HAR
V•
Lifti
ng B
odie
s•
SR
-71
7
Cur
rent
& R
ecen
t Flig
ht R
esea
rch
Pro
ject
s
•Ai
rbor
ne A
eria
l Ref
uelin
g D
emon
stra
tion
(AA
RD
)•
Activ
e A
ero-
elas
tic W
ing
(AA
W)
•E
arth
Sci
ence
•A
ltus
•Ik
hana
(Pre
dato
r-B)
•H
elio
s•
G-II
I •U
AVSA
R P
rogr
am•
F-18
Sys
tem
s R
esea
rch
Airc
raft
•F-
18 c
hase
pla
nes
•A
lso
used
for r
esea
rch
•In
tellig
ent F
light
Con
trols
(IFC
S)
•F-
15B
Res
earc
h Te
st B
ed•
Hyp
er-X
•X
-43A
•S
huttl
e S
uppo
rt
8
NA
SA
Dry
den’
s G
-III A
ircra
ft
•A
ircra
ft G
oal
»P
rovi
de a
rese
arch
test
-bed
for N
AS
A, t
he A
ir Fo
rce,
and
oth
er
gove
rnm
ent a
genc
ies
with
a lo
ng-te
rm c
apab
ility
for e
ffici
ent
test
of s
ubso
nic
fligh
t exp
erim
ents
.•
“Shi
rt sl
eeve
”env
ironm
ent
•R
esea
rch
Infra
stru
ctur
e
•A
ircra
ft P
erfo
rman
ce•
Max
Mac
h -0
.85
•M
ax O
pera
ting
altit
ude
-45K
ft•
Nor
mal
cru
ise
–45
9 kt
s•
Max
pay
load
–45
00 lb
•P
aylo
ad, f
ull f
uel –
2610
lb•
Take
off p
erfo
rman
ce –
5,50
0ft (
SL)
•R
ange
–34
00 n
autic
al m
iles
(full
pass
enge
rs)
•C
limb
–4,
049
fpm
•La
rge
Inte
rnal
Vol
ume
(150
0 cu
. Ft.)
9
Topi
cs
•N
AS
A D
ryde
n•
Ove
rvie
w•
Cur
rent
& R
ecen
t Flig
ht-T
est P
rogr
ams
•U
AV
SA
R P
rogr
am•
Pro
gram
Ove
rvie
w•
Pla
tform
Pre
cisi
on A
utop
ilot
•H
yper
-X P
rogr
am•
Pro
gram
Ove
rvie
w•
X-4
3A F
light
Con
trols
•Fl
ight
Res
ults
10
•Th
e pr
imar
y ob
ject
ive
of th
e U
AVSA
R P
roje
ct a
re to
:»
deve
lop
a m
inia
turiz
ed p
olar
imet
ricL-
band
syn
thet
ic a
pertu
re ra
dar (
SA
R) f
or u
se o
n an
unm
anne
d ae
rial v
ehic
le (U
AV
) or m
inim
ally
pilo
ted
vehi
cle
•R
oles
& R
espo
nsib
ilitie
s»
JPL •
Lead
cen
ter t
hat w
ill de
sign
, fab
ricat
e, in
stal
l and
ope
rate
the
rada
r ins
trum
ent,
deve
lop
proc
essi
ng a
lgor
ithm
s an
d co
nduc
t dat
a an
alys
is»
Dry
den
•M
anag
e th
e de
velo
pmen
t of p
od d
esig
n, fa
bric
atio
n an
d de
liver
y to
JP
L•
Del
iver
RP
I int
erim
pla
tform
and
long
term
ope
ratio
nal p
latfo
rm–N
AS
A’s
G-II
I sel
ecte
d as
the
inte
rim p
latfo
rm•
Lead
the
plat
form
mod
ifica
tion
effo
rt an
d he
ad u
p fli
ght o
pera
tions
of t
he p
latfo
rm•
Dev
elop
Pla
tform
Pre
cisi
on A
utop
ilot (
PP
A) c
apab
ility
»To
tal A
ircra
ft S
ervi
ces,
Inc.
(TA
S)
•U
nder
con
tract
to p
erfo
rm G
-III m
odifi
catio
ns a
nd p
od fa
bric
atio
n•
Firs
t Flig
ht o
f SAR
on
G-II
I in
Fall
‘06
UA
VS
AR
11
Pla
tform
Pre
cisi
on A
utop
ilot
Inte
rfac
e to
G-I
II a
utop
ilot t
hrou
ghIn
stru
men
t Lan
ding
Sys
tem
(ILS
)*
•A
chie
ve re
quire
d tra
ject
ory
perf
orm
ance
•R
epea
t Pas
s Flig
ht w
ithin
10
m tu
be•
Mee
t UA
VSA
R sc
hedu
le re
quire
men
ts•
Faci
litat
e so
ftwar
e de
velo
pmen
t and
de
ploy
men
t•
Min
imiz
e im
pact
to G
-III
Flig
ht
Man
agem
ent S
yste
m (F
MS)
•Pr
ovid
e fo
r saf
e an
d si
mpl
e op
erat
ion
•Fa
cilit
ate
mig
ratio
n to
UA
V p
latfo
rm
•M
akes
use
of i
nher
ent a
ccur
acy
in IL
S•
Sim
ple
mod
ifica
tion
to in
sert
RF
switc
hes
betw
een
ILS
sign
als a
nd P
PA, i
sola
ting
PPA
from
G-I
II F
MS
•PP
A c
ontro
l is e
asily
dis
able
d by
dise
ngag
ing
auto
pilo
t•
PPA
con
trol a
lgor
ithm
s rel
ativ
ely
sim
ple
GOAL
S
IMPL
EMEN
TATION
JUST
IFICAT
ION
*App
roac
h us
ed b
y D
anis
h C
ente
r for
Rem
ote
Sens
ing
(DC
RS)
for a
sim
ilar a
pplic
atio
n
12
Inst
rum
ent L
andi
ng S
yste
m
•IL
S c
onsi
sts
of tw
o ra
dio
trans
mitt
ers
each
with
a s
igna
l at
90
Hz
and
150
Hz
»V
HF
trans
mitt
er fo
r Lo
caliz
er»
UH
F tra
nsm
itter
for
Glid
eslo
pe•
Loca
lizer
and
Glid
eslo
pe
rece
iver
s on
airc
raft
mea
sure
D
iffer
ence
in D
epth
Mod
ulat
ion
(DD
M) o
f the
90H
z an
d 15
0 H
z si
gnal
s.»
DD
M o
f loc
aliz
er s
igna
l in
dica
tes
if ai
rcra
ft is
left
or
right
of c
ente
rline
»D
DM
of g
lides
lope
sig
nal
indi
cate
s if
airc
raft
is a
bove
or
bel
ow g
lides
lope
»D
DM
of z
ero
indi
cate
s ai
rcra
ft is
alo
ng c
ente
rline
or
glid
eslo
peIll
ustra
tion
Sour
ce:
Wik
iped
ia.o
rg
13
Pla
tform
Pre
cisi
on A
utop
ilot H
ardw
are
Inte
rface
s
•A
utop
ilot I
nter
face
Com
pute
r (A
IC)
»P
rovi
de in
terfa
ces
to
exte
rnal
dat
a so
urce
s»
Hos
t the
con
trol
algo
rithm
»D
rive
the
IIS»
Pro
vide
inte
rface
to
oper
ator
sta
tion
of G
-III
for w
aypo
int u
ploa
d, g
ain
cont
rol,
and
data
arc
hive
•IL
S In
terfa
ce S
yste
m (I
IS)
»M
odul
ate
the
ILS
sig
nal
base
d on
inpu
t fro
m A
IC»
Pro
vide
the
ILS
gl
ides
lope
(GS
) and
lo
caliz
er (L
OC
) RF
sign
als
14
Topi
cs
•N
AS
A D
ryde
n•
Ove
rvie
w•
Cur
rent
& R
ecen
t Flig
ht-T
est P
rogr
ams
•U
AV
SA
R P
rogr
am•
Pro
gram
Ove
rvie
w•
Pla
tform
Pre
cisi
on A
utop
ilot
•H
yper
-X P
rogr
am•
Pro
gram
Ove
rvie
w•
X-4
3A F
light
Con
trols
•Fl
ight
Res
ults
15
Pro
ject
Ove
rvie
w
•X-
43A
pro
ject
des
igne
d to
be
the
first
eve
r flig
ht
dem
onst
ratio
n of
an
airf
ram
e-in
tegr
ated
, hyd
roge
n fu
eled
, sc
ram
jet p
ower
ed, h
yper
soni
c ve
hicl
e•
Gat
her i
n-fli
ght d
ata
in o
rder
to v
alid
ate
grou
nd b
ased
an
alyt
ical
tool
s, te
st te
chni
ques
and
met
hodo
logi
es e
xpec
ted
to b
e us
ed to
des
ign
futu
re s
cram
jet p
ower
ed, h
yper
soni
c ve
hicl
es a
nd th
eir s
yste
ms
»Ve
rify
pred
icte
d sc
ram
jet p
erfo
rman
ce»
Col
lect
dyn
amic
s an
d co
ntro
l, pr
opul
sion
, aer
odyn
amic
, th
erm
al, a
nd s
truc
tura
l dat
a
16
Hyp
er-X
Leg
acy
17
Scr
amje
t Fea
ture
s
Impo
rtan
t Scr
amje
t Ter
ms/
Con
cept
sIn
let s
tarti
ngC
ombu
stor
/isol
ator
inte
ract
ion
Igni
tion/
Flam
eout
/Fla
meh
oldi
ngFu
el e
quiv
alen
ce ra
tioIn
let t
rans
ition
Scr
amje
t-Veh
icle
Inte
ract
ion
“Lik
ened
to
keep
ing
a ca
ndle
lit
in a
hur
rican
e”
18
Pro
ject
Ove
rvie
w
•A
thre
e-fli
ght p
roje
ct»
2 fli
ghts
at M
ach
7»
1 fli
ght a
t Mac
h 10
•To
p le
vel g
oal w
as to
acc
eler
ate
the
vehi
cle
•7
year
pro
gram
(199
6 –
2004
)•
~ $2
30m
inve
stm
ent
•~
220+
peo
ple
wor
king
the
proj
ect
19
The
Effo
rt
Pro
puls
ion
•Fu
el s
yste
m•
Scra
mje
t eng
ine
•Pr
opul
sion
con
trol l
aws
•En
viro
nmen
tal s
yste
m
Sys
tem
s•
Flig
ht c
ompu
ters
•Ac
tuat
ors
•Po
wer
•So
ftwar
e•
V &
V te
stin
g
LV, S
ep, &
RV
Sim
s•
GN
C &
PS
C d
esig
n &
test
ing
•M
onte
-Car
lo a
naly
sis
•Ve
hicl
e pe
rform
ance
•S/
W &
H/W
test
ing
•H
IL/A
IL te
stin
g•
Mis
sion
con
trol r
oom
trai
ning
Stag
e Se
para
tion
•N
ever
bee
n do
ne•
Hig
h q,
asy
mm
etric
bo
dies
Aero
dyna
mic
s•
Out
er m
old
line
desi
gn•
Aero
dat
a ba
se –
test
ing
&
CFD
GN
C•
LV, S
ep, &
RV
C
ontro
l law
s
Stru
ctur
es•
Aero
& th
erm
al l
oads
•FE
M m
odel
ing
•St
ruct
ural
ana
lysi
s &
de
sign
Laun
ch V
ehic
le•
The
ride
to M
ach
7•
Mod
ified
Peg
asus
bo
oste
r
Flig
ht O
pera
tions
•Pu
ts it
all
toge
ther
•Ve
hicl
e in
tegr
atio
n, fu
elin
g, fl
ight
, gr
ound
, & c
ontro
l roo
m o
ps
20
The
Team
21
The
Har
dwar
e
Hyp
er-X
Res
earc
h Ve
hicl
eH
XRV,
RV,
X-4
3A
Hyp
er-X
Lau
nch
Vehi
cle
HXL
V, L
V, B
oost
er, P
egas
us
Ada
pter
B-5
2B
Stac
k =
HXL
V +
Ada
pter
+ H
XRV
22
X-4
3A S
yste
ms
Act
uato
r Con
trolle
r
H20
to A
dapt
er
N2
to A
dapt
er
Hor
izon
tal T
ail
Act
uato
r
Hor
izon
tal T
ail
Act
uato
r
Rud
der A
ctua
tor
Rud
der A
ctua
tor
H20
Tan
k
N2
Tank
Sila
ne T
ank
H2
Tank
s
Flig
ht M
anag
emen
tU
nit (
FMU
)
Bat
tery
Tung
sten
Nos
e
Flus
h A
ir D
ata
Sen
sors
(FA
DS
)•F
uel:
Hyd
roge
n
•Igni
ter:
Sila
ne
•The
rmal
Bar
rier:
Shu
ttle
tiles
•Eng
ine
Coo
lant
: G
lyco
l/Wat
er
•Nitr
ogen
Pur
ge
•Ele
ctric
Act
uato
rs
Dat
a S
yste
m
23
Hyp
er-X
Res
earc
h V
ehic
le (H
XR
V)
Mis
sion
Pro
file
•H
yper
-X L
aunc
h V
ehic
le d
eliv
ers
HX
RV
to a
ccep
tabl
e se
para
tion
cond
ition
s•
HX
RV
Gui
danc
e &
Con
trols
Obj
ectiv
es»
Sep
arat
e fro
m th
e H
XLV
»E
ngin
e Te
st (P
rimar
y M
issi
on)
•M
aint
ain
RV
atti
tude
& c
ontro
l•
Mai
ntai
n te
st c
ondi
tions
»D
esce
nt -
Pos
t Cow
l Clo
sed
(S
econ
dary
Mis
sion
)•
Arre
st d
ynam
ic p
ress
ure
build
up
and
heat
ing
•D
esce
nd a
long
a p
rede
term
ined
de
scen
t pro
file
tow
ards
an
impa
ct
loca
tion
•P
erfo
rm p
aram
eter
iden
tific
atio
n m
aneu
vers
and
freq
uenc
y sw
eeps
al
ong
the
desc
ent a
t Mac
h 8,
7, 6
, 5,
4, 3
, and
2.
24
Topi
cs
•N
AS
A D
ryde
n•
Ove
rvie
w•
Cur
rent
& R
ecen
t Flig
ht-T
est P
rogr
ams
•U
AV
SA
R P
rogr
am•
Pro
gram
Ove
rvie
w•
Pla
tform
Pre
cisi
on A
utop
ilot
•H
yper
-X P
rogr
am•
Pro
gram
Ove
rvie
w•
X-4
3A F
light
Con
trols
•Fl
ight
Res
ults
25
Dry
den’
s R
oles
& C
apab
ilitie
s
•R
espo
nsib
le fo
r Gui
danc
e, N
avig
atio
n, a
nd F
light
Con
trol S
oftw
are
on th
e X
-43A
•Fl
ight
Con
trol S
oftw
are
deve
lope
d jo
intly
by
Lang
ley,
Dry
den,
and
Boe
ing
•P
ID c
ontro
ller u
sed
for b
oth
Long
itudi
nal &
Lat
eral
-Dire
ctio
nal a
xes
•G
uida
nce
algo
rithm
com
man
ded
vehi
cle
to h
ead
wes
t tow
ards
an
aim
poin
t•
Sinc
e 19
99, D
ryde
n co
nduc
ted
all u
pdat
es to
Flig
ht C
ontro
l Sof
twar
e•
Incl
udin
g re
-des
ign
of th
e co
ntro
ller f
or th
e M
ach
10 m
issi
on
•R
espo
nsib
le fo
r veh
icle
and
sof
twar
e pe
rform
ance
and
sta
bilit
y an
alys
is•
Tim
e hi
stor
y pe
rform
ance
•S
tabi
lity
mar
gin
anal
ysis
•S
oftw
are
verif
icat
ion
& v
alid
atio
n su
pple
men
ting
Boe
ing’
s V
&V
•D
ryde
n de
velo
ped
a nu
mbe
r of t
ools
and
cap
abilit
ies
to p
erfo
rm th
e G
NC
rela
ted
anal
ysis
•Li
near
ana
lysi
s to
olse
t bui
lt in
the
Mat
lab/
Sim
ulin
k en
viro
nmen
t•
Mon
te C
arlo
Ana
lysi
s C
apab
ility
•H
igh
Fide
lity
non-
linea
r 6 d
egre
e of
free
dom
X-4
3A s
imul
atio
n•
Incl
udin
g de
taile
d ac
tuat
or, s
enso
r, tim
ing
mod
els
•M
onte
Car
lo A
naly
sis
Cap
abilit
y•
Har
dwar
e in
the
Loop
(HIL
) tes
t env
ironm
ent
•Ai
rcra
ft in
the
Loop
(AIL
) tes
t env
ironm
ent
Mon
te C
arlo
/S
imul
atio
n S
tudi
es
HIL
Tes
ting
AIL
Tes
ting
1000
’s
10’s
1’s
•Si
mul
atio
n &
Mon
te C
arlo
resu
lts u
sed
pre-
fligh
t by
Aer
odyn
amic
s &
Scr
amje
t IP
Tsto
ass
ess
vehi
cle
and
engi
ne p
erfo
rman
ce.
26
HX
RV
Fre
e-Fl
ight
Req
uire
men
ts
•D
eliv
er R
V to
acc
epta
ble
sepa
ratio
n co
nditi
ons
•S
ucce
ssfu
lly s
epar
ate
the
RV
from
the
LV•
Eng
ine
Test
»M
aint
ain
RV
atti
tude
& c
ontro
l»
Con
duct
the
pre-
expe
rimen
t tar
e»
Mai
ntai
n te
st c
ondi
tions
»C
ondu
ct th
e po
st-e
xper
imen
t tar
e»
Con
duct
the
cow
l ope
n P
aram
eter
Iden
tific
atio
n M
aneu
ver (
PID
)»
Con
trolle
d fli
ght f
ollo
win
g en
gine
ope
ratio
n•
Des
cent
-P
ost C
owl C
lose
d»
Pos
t eng
ine
test
pul
l-up
to 8
deg
rees
ang
le-o
f-atta
ck (a
rres
t dy
nam
ic p
ress
ure
build
up
and
heat
ing)
»D
esce
nd a
long
a p
rede
term
ined
des
cent
pro
file
and
impa
ct
loca
tion
»P
erfo
rm p
aram
eter
iden
tific
atio
n m
aneu
vers
, fre
quen
cy s
wee
ps
and
push
-ove
r pul
l-up
(PO
PU
) man
euve
rs a
long
the
desc
ent a
t M
ach
5, 4
, 3, a
nd 2
.
27
Con
trolli
ng th
e X
-43A
•X
-43A
con
trol l
aws
use
a P
ID c
ontro
l arc
hite
ctur
e.•
Gai
ns s
ched
uled
as
a fu
nctio
n of
Mac
h &
Ang
le o
f Atta
ck•
Gai
ns s
cale
d by
Dyn
amic
Pre
ssur
e•
Con
trol L
aws
wer
e de
sign
ed to
be
as s
impl
e &
robu
st a
s po
ssib
le.
•O
nly
perfo
rman
ce re
quire
men
t was
to fl
y st
raig
ht a
nd le
vel a
t a s
peci
fied
angl
e of
atta
ck.
•C
arrie
d ≈
6 dB
Gai
n M
argi
n &
≈45
°P
hase
Mar
gin
in a
ll co
ntro
l loo
ps•
Had
to a
ccep
t les
s G
ain
and
Pha
se M
argi
n du
ring
porti
ons
of th
e de
scen
t•
Car
ried
larg
e un
certa
intie
s w
hich
nee
ded
to b
e ac
coun
ted
for.
•S
epar
atio
n st
udie
d by
LaR
C in
Sep
arat
ion
Sim
ulat
ions
.•
Win
gs s
et to
a c
onst
ant d
efle
ctio
n fo
r the
initi
al p
ortio
n of
the
sepa
ratio
n ev
ent.
•C
ontro
l loo
ps a
re d
isen
gage
d at
sep
arat
ion
and
fade
d in
ove
r abo
ut 1
sec
ond.
Gui
danc
eSy
stem
Long
itudi
nal
Con
trol
Law
Late
ral-
Dire
ctio
nal
Con
trol
Law
Hyp
er-X
Res
earc
hVe
hicl
e
Sym
met
ricA
MW
+
Diff
eren
tial A
MW
+
Rud
ders
+
Input Plane
Control Mixer
Flig
ht C
ontr
ol
Win
g
Rud
der
Nav
igat
ion
28
Nom
inal
Sep
arat
ion
Sce
nario
Sta
rt of
Sep
arat
ion
0 m
sec
Mac
h =
7q b
ar=
1066
psf
End
of P
isto
n pu
sh10
0m
sec
9 in
. ext
ensi
on
Beg
inni
ng T
rans
ition
to fr
ee a
ero
250
mse
cx s
ep =
-44
in.
Free
aer
odyn
amic
s35
0m
sec
x sep
= -6
9 in
.
500
mse
cA
ll fe
edba
ck c
ont
rol
loop
s cl
osed
End
of s
epar
atio
n /
Sta
rt of
test
2.5
sec
α =
2.5
°, β
= 0
°
29
3 D
iffer
ent N
on-li
near
Sim
ulat
ions
•A
larg
e po
rtion
of t
he G
NC
an
alys
is w
as c
ondu
cted
with
the
non-
linea
r sim
ulat
ions
.
•E
arly
on,
the
proj
ect d
ecid
ed to
m
aint
ain
3 se
para
te s
imul
atio
ns
to m
odel
the
mis
sion
.•
Laun
ch v
ehic
le s
imul
atio
n m
aint
aine
d by
Orb
ital.
•H
igh
fidel
ity 6
+ 6
DO
F se
para
tion
sim
ulat
ion
mai
ntai
ned
by L
aRC
•H
igh
Fide
lity
RV
pos
t-se
para
tion
sim
ulat
ion
mai
ntai
ned
by D
FRC
.
•E
nd S
tate
s of
one
sim
ulat
ion
used
as
inpu
ts to
the
next
si
mul
atio
n in
the
mis
sion
.Ti
me
HXR
V Si
mul
atio
nD
FRC
Sep
Sim
LAR
CH
XLV
Sim
OSC
Tim
e S
ince
B-5
2 D
rop
Altitude
30
Topi
cs
•N
AS
A D
ryde
n•
Ove
rvie
w•
Cur
rent
& R
ecen
t Flig
ht-T
est P
rogr
ams
•U
AV
SA
R P
rogr
am•
Pro
gram
Ove
rvie
w•
Pla
tform
Pre
cisi
on A
utop
ilot
•H
yper
-X P
rogr
am•
Pro
gram
Ove
rvie
w•
X-4
3A F
light
Con
trols
•Fl
ight
Res
ults
31
Vid
eo S
egm
ent
X-4
3A F
light
102
Jun
e 20
01
32
Ada
pter
Cam
era
Flig
ht 1
33
X-4
3A R
etur
n to
Flig
ht
•X
-43A
Mis
hap
Inve
stig
atio
n B
oard
(MIB
) con
vene
d on
Jun
e 5,
20
01 a
nd s
ubm
itted
dra
ft re
port
Mar
ch 8
, 200
2
•M
IB F
indi
ngs
Mod
elin
g de
ficie
ncie
s ca
used
ove
r-pr
edic
tion
of a
utop
ilot
stab
ility
mar
gins
»Fi
n A
ctua
tion
Sys
tem
»A
erod
ynam
ics
»M
ass
Pro
perti
es
•O
ver-
pred
ictio
n of
fin
actu
ator
torq
ue m
argi
n»
Mis
-pre
dict
ion
of a
erod
ynam
ic h
inge
mom
ents
»Lo
w to
rque
mar
gin
•2
year
Ret
urn
to F
light
effo
rt co
mm
ence
d M
arch
200
2
34
Ret
urn
to F
light
Ris
k R
educ
tion
•H
ighe
r fid
elity
mod
els
»A
erod
ynam
ics
»Ac
tuat
ors
»S
truct
ures
»A
utop
ilot
•Lo
wer
load
s tra
ject
ory:
bo
oste
r pro
pella
nt o
ff-lo
ad•
Act
uato
r upg
rade
for
grea
ter t
orqu
e ca
pabi
lity
•A
utop
ilot
trade
s/op
timiz
atio
n•
Inde
pend
ent
sim
ulat
ion
Laun
ch V
ehic
le•
Hig
her f
idel
ity m
odel
s
•Ad
ditio
nal s
epar
atio
n m
echa
nism
test
ing
•C
ontro
l law
re
finem
ents
for
robu
stne
ss
•In
depe
nden
t si
mul
atio
n
Stag
e Se
para
tion
•H
ighe
r fid
elity
mod
els
•In
crea
sed
AO
A fo
r fla
meo
ut ro
bust
ness
an
d gr
eate
r thr
ust
•U
pgra
ded
engi
ne
cont
rol l
ogic
for
unst
artr
obus
tnes
s•
Ada
pter
flui
d sy
stem
s im
prov
emen
ts•
Red
esig
n of
win
g co
ntro
l hor
ns•
Airc
raft-
in-th
e-lo
op
timin
g te
sts
•In
depe
nden
t si
mul
atio
n
Res
earc
h Ve
hicl
e
35
Flig
ht 2
–M
arch
27,
200
4
•It
was
touc
h &
go
for a
whi
le
»W
eath
er w
as d
icey
up
until
the
mor
ning
of f
light
•H
2 fu
elin
g w
as a
ccom
plis
hed
with
win
d gu
sts
up to
60
knot
s
»Fr
eque
ncy
conf
licts
wer
e re
solv
ed w
ith th
e gr
eat c
oope
ratio
n of
the
F-22
pro
gram
»La
st m
inut
e B
-52
prob
lem
s re
solv
ed
»A
fire
in th
e ra
nge
build
ing
extin
guis
hed
with
out u
se o
f wat
er
36
X-4
3A R
esea
rch
Veh
icle
Res
ults
Fuel
On
Engi
ne c
owl o
pen
Posi
tive
Acc
eler
atio
n
Flig
ht
Acc
eler
atio
n vs
. tim
e
Pre
fligh
t Mon
te C
arlo
P
redi
ctio
ns v
sFl
ight
Dat
a
Axi
al L
engt
h
SURFACEPRESSURE Pressure
Pret
est P
redi
cted
Flig
ht D
ata
Nos
eTa
il
Cen
terli
ne w
all p
ress
ure
37
F3 A
ppro
ach
& P
hilo
soph
y
•Th
e Fl
ight
3 h
ardw
are
was
wor
ked
in p
aral
lel w
ith F
light
2.
•Fi
nal m
odel
s an
d an
alys
is w
ere
not a
vaila
ble
until
afte
r Flig
ht 2
and
initi
al p
ost-
fligh
t ana
lysi
s w
as c
ompl
ete.
•Th
e fo
cus
of th
e te
am s
hifte
d to
Flig
ht 3
in th
e be
ginn
ing
of M
ay 2
004.
•Q
uick
turn
arou
nd, g
oal f
or fl
ight
was
6 m
onth
s af
ter i
nitia
l mod
el re
leas
e in
ear
ly
Apr
il.»
Cap
italiz
ed o
n re
cent
Flig
ht 2
exp
erie
nce
and
Ret
urn-
to-F
light
App
roac
h»
Wor
k ef
ficie
ntly
and
qui
ckly
with
out l
osin
g at
tent
ion
to d
etai
l.»
Team
rem
aine
d m
ostly
inta
ct»
Test
s an
d pr
oced
ures
wen
t fas
ter t
han
they
did
for f
light
2.
•A
ssum
ptio
ns
»D
o ve
ry li
ttle
inde
pend
ent a
naly
sis
(i.e.
no
dupl
icat
ion
of e
ffort)
»Lo
ok a
t Flig
ht 2
dat
a to
det
erm
ine
wha
t Flig
ht 3
mod
ifica
tion
wou
ld b
e ne
cess
ary
for s
ucce
ss.
»M
odel
s w
ould
not
be
upda
ted
base
d on
flig
ht d
ata.
The
flig
ht d
ata
wou
ld b
e us
ed fo
r gui
danc
e fo
r mod
ifica
tions
and
for s
tress
cas
es.
»E
ngin
e te
st re
gion
was
prim
ary
obje
ctiv
e an
d th
eref
ore
was
the
high
est p
riorit
y
•Fl
ight
3 a
ppro
ach
was
suc
cess
orie
nted
and
ass
umed
no
maj
or is
sues
.
38
Upd
ates
Add
ress
ing
Mac
h 7
Mis
sion
Iner
tial A
ngle
of A
ttack
Per
form
ance
•D
urin
g th
e M
ach
7 m
issi
on, t
he H
XR
V w
as s
low
to a
rriv
e at
th
e co
mm
ande
d en
gine
test
ang
le o
f atta
ck a
fter s
epar
atio
n.•
The
angl
e of
atta
ck e
rror
inte
grat
or g
ain
was
incr
ease
d to
impr
ove
perfo
rman
ce.
•A
low
am
plitu
de a
ngle
of a
ttack
os
cilla
tion
occu
rred
dur
ing
the
reco
very
man
euve
r.•
The
caus
e of
the
osci
llatio
ns is
not
fully
un
ders
tood
. •
Prio
r to
the
Mac
h 10
m
issi
on, a
ctua
tor f
rictio
n an
d ae
rody
nam
ic
unce
rtain
ties
wer
e be
lieve
d to
be
poss
ible
ca
uses
.•
The
angl
e of
atta
ck w
as
low
ered
thro
ugho
ut th
e tra
ject
ory
to a
void
flyi
ng a
t th
e sa
me
fligh
t con
ditio
n.
Inertial α(deg) Inertial α(deg)
Tim
e Si
nce
Sepa
ratio
n Se
nsed
(sec
)Ti
me
Sinc
e Se
para
tion
Sens
ed (s
ec)
Inertial α(deg)M
odifi
ed fo
r Mac
h 10
Mis
sion
39
Mac
h 10
Mis
sion
Eng
ine
Test
Per
form
ance
Ove
rvie
w
•S
ucce
ssfu
lly s
epar
ated
from
HX
LV•
Veh
icle
pitc
hed
up p
ast t
he
desi
red
angl
e of
atta
ck a
nd
arriv
ed a
t the
des
ired
cond
ition
sh
ortly
prio
r to
the
cow
l doo
r op
enin
g.•
Mai
ntai
ned
desi
red
angl
e of
atta
ck
with
in 0
.2 d
eg d
urin
g th
e en
gine
test
.•
A s
light
cha
nge
in th
e en
gine
pe
rform
ance
was
see
n as
the
igni
torw
as re
mov
ed fr
om th
e fu
elin
g pr
ofile
. Th
is c
ause
d th
e H
XR
V to
pitc
h up
0.2
deg
and
w
as q
uick
ly re
ject
ed b
y th
e co
ntro
ller.
•M
ach
& d
ynam
ic p
ress
ure
with
in
acce
ptab
le li
mits
.•
Elev
ator
trim
set
tings
dur
ing
the
engi
ne
test
wer
e ne
ar th
e pr
e-fli
ght M
onte
C
arlo
pre
dict
ions
.•
Like
ly d
ue to
mis
-pre
dict
ion
of
Cm
oin
unc
lass
ified
aer
odyn
amic
an
d en
gine
dat
abas
es.
Flig
ht v
s. P
re-fl
ight
Pro
puls
ion
Dat
abas
e
Cow
l Lea
ding
Edg
eC
owl T
raili
ng E
dge
40
HX
RV
Mac
h 10
Mis
sion
Iner
tial A
ngle
of
Atta
ck D
urin
g th
e E
ngin
e Te
stInertial α(deg)
Tim
e Si
nce
Sepa
ratio
n Se
nsed
(sec
)
Elevator Position (deg)
Tim
e Si
nce
Sepa
ratio
n Se
nsed
(sec
)
41
Des
cent
Per
form
ance
Ove
rvie
w
•Th
e H
XR
V in
itial
ly a
chie
ved
the
desi
red
angl
e of
atta
ck d
urin
g th
e re
cove
ry
man
euve
r•
Sho
rtly
into
the
reco
very
man
euve
r, th
e H
XR
V b
egan
to ro
ck in
ban
k an
d dr
op o
ff in
ang
le o
f atta
ck•
Ele
vato
r trim
set
tings
mov
ed o
utsi
de o
f Mon
te C
arlo
pre
dict
ions
.•
It is
bel
ieve
d th
at a
ir w
as fl
owin
g th
roug
h th
e en
gine
dur
ing
this
tim
e pe
riod.
•N
ot k
now
n ho
w th
is h
appe
ned
sinc
e th
e co
wl d
oor i
ndic
ated
full
clos
ure.
•A
ppea
rs a
s if
the
igni
tori
gnite
d w
hen
it w
as v
ente
d•
Veh
icle
per
form
ance
impr
oves
afte
r ven
ting
and
flies
sim
ilar t
o pr
e-fli
ght p
redi
ctio
ns fr
om th
ere
on d
own.
•
The
long
itudi
nal o
scill
atio
ns s
een
in th
e M
ach
7 m
issi
on w
ere
not p
rese
nt d
urin
g th
e M
ach
10 m
issi
on.
•S
ucce
ssfu
lly c
ompl
eted
all
PID
man
euve
rs•
HX
RV
dec
eler
ates
rapi
dly
durin
g th
e M
ach
2 P
ID m
aneu
ver a
nd s
ome
of
the
inpu
ts a
re a
pplie
d in
the
trans
onic
regi
me.
•Lo
ss o
f Sig
nal
Mac
hA
ltitu
deD
ownr
ange
0.72
918
ft~6
00 n
mi
42
Mac
h 10
Mis
sion
Per
form
ance
Pos
t-Eng
ine
Test
Nz(g)
φ(deg)
Left WingPosition (deg)
Tim
e Si
nce
Sepa
ratio
n Se
nsed
(sec
)
Nz(g)
φ(deg)
Left WingPosition (deg)
Tim
e Si
nce
Sepa
ratio
n Se
nsed
(sec
)
43
Mac
h 10
Mis
sion
Ele
vato
r Pos
ition
dur
ing
the
Des
cent
Elevator Position (deg)
Mac
h N
umbe
r
44
Mac
h 10
Mis
sion
Iner
tial A
ltitu
de
Com
pare
d to
Mon
te C
arlo
Pre
dict
ions
Mac
h N
umbe
r
Inertial Altitude (ft)
45
Flus
h A
ir D
ata
Sys
tem
(FA
DS
)
•FA
DS
»A
set
of p
ress
ure
ports
on
the
nose
of t
he H
XRV
wer
e pa
rt of
a F
ADS
sys
tem
.»
FAD
S a
lgor
ithm
s on
boar
d ca
lcul
ate
α FA
DS
and
dyna
mic
pre
ssur
e es
timat
ion.
•FA
DS
alg
orith
ms
not u
sed
to a
id in
ertia
l sys
tem
dur
ing
the
Mac
h 10
mis
sion
»Al
gorit
hms
not v
alid
ated
abo
ve M
ach
8»
Pre
limin
ary
resu
lts fr
om th
e M
ach
7 m
issi
on in
dica
ted
area
s fo
r fur
ther
stu
dy»
Dat
a co
llect
ed fr
om th
e M
ach
10 m
issi
on is
cur
rent
ly b
eing
exa
min
ed.
Sens
ed M
ach
Num
ber
α(deg) Difference(deg)
46
Freq
uenc
y R
espo
nse
Est
imat
ion
•D
urin
g th
e de
scen
t pha
se, a
set
of i
nput
sig
nals
wer
e si
mul
tane
ousl
y ap
plie
d to
the
elev
ator
and
eith
er th
e ai
lero
n or
rudd
er c
omm
and
path
s. T
he in
put
sign
als
wer
e ta
ilore
d to
exc
ite e
ach
of th
e th
ree
path
s at
diff
eren
t fre
quen
cies
m
akin
g it
poss
ible
to e
xtra
ct th
e fre
quen
cy re
spon
ses
for e
ach
axis
.
•Th
is te
chni
que
allo
ws
for s
horte
r ove
rall
exci
tatio
n tim
es re
quire
d to
ac
cura
tely
iden
tify
the
frequ
ency
resp
onse
cha
ract
eris
tics
vers
us tr
aditi
onal
m
etho
ds s
uch
as fr
eque
ncy
swee
ps.
–S
hort
dura
tion
inpu
ts a
re p
artic
ular
ly im
porta
nt fo
r thi
s ve
hicl
e si
nce
it is
co
nsta
ntly
cha
ngin
g fli
ght c
ondi
tion.
•Fr
eque
ncy
resp
onse
s w
ere
extra
cted
from
the
test
inpu
t and
veh
icle
re
spon
se u
sing
FFT
and
Chi
rp-Z
tech
niqu
es.
47
HX
RV
Tai
lore
d E
xcita
tion
Sig
nal T
ime
His
torie
s
•A
uni
que
inpu
t sig
nal w
as u
sed
for t
he e
leva
tor,
aile
ron,
and
rudd
er
cont
rol l
oops
.•
3 si
gnal
s to
tal
•Th
e sa
me
inpu
t sig
nals
wer
e us
ed d
urin
g Fl
ight
s 2
& 3
•C
orre
spon
ding
exc
itatio
n si
gnal
was
app
lied
to a
ppro
pria
te c
ontro
l loo
p fo
r eve
ry P
ID m
aneu
ver.
•D
urin
g th
e M
ach
10 fl
ight
the
rudd
er a
nd a
ilero
n lo
ops
wer
e ex
cite
d at
alte
rnat
ing
Mac
h nu
mbe
rs
48
Blo
ck D
iagr
am D
etai
ling
The
App
licat
ion
of th
e Ta
ilore
d E
xcita
tion
Inpu
t Sig
nals
to th
e H
XR
V•
The
Inpu
t Exc
itatio
n si
gnal
s w
ere
a pa
rt of
the
PID
man
euve
r set
.•
The
PID
man
euve
r set
was
con
tain
ed in
the
fligh
t con
trol s
oftw
are.
•W
hen
trigg
ered
, the
flig
ht c
ontro
l sys
tem
app
lied
the
PID
man
euve
rs to
ea
ch c
ontro
l loo
p co
mm
and.
•
Freq
uenc
y re
spon
se c
alcu
late
d be
twee
n ta
ilore
d ex
cita
tion
sign
alan
d th
e ou
tput
of t
he lo
ngitu
dina
l & la
tera
l-dire
ctio
nal c
ontro
llers
Ele
vato
r Def
lect
ion
–Sy
mm
etric
AM
W D
efle
ctio
nA
ilero
n D
efle
ctio
n –
Diff
eren
tial A
MW
Def
lect
ion
Rud
der D
efle
ctio
n –
Sym
met
ric R
udde
r Def
lect
ion
49
Freq
uenc
y R
espo
nse
Est
imat
ion
•Fr
eque
ncy
resp
onse
s ge
nera
ted
with
bot
h FF
T an
d C
hirp
-Z m
etho
ds fr
om fl
ight
da
ta m
atch
the
linea
r ana
lysi
s pr
edic
tions
at t
he s
ame
fligh
t con
ditio
ns v
ery
wel
l.
Ele
vato
r Fre
quen
cy
Res
pons
e A
t Mac
h 7.
54R
udde
r Fre
quen
cy
Res
pons
e A
t Mac
h 7.
54
Freq
uenc
y (H
z)Fr
eque
ncy
(Hz)
Magnitude (dB) Phase Angle (deg) Coherence
Magnitude (dB) Phase Angle (deg) Coherence
50
Ele
vato
r Loo
p S
tabi
lity
Mar
gin
Est
imat
es fo
r Fl
ight
s 2
& 3
Flig
ht 2
Flig
ht 3
•G
ain
and
Pha
se M
argi
ns w
ere
extra
cted
for F
light
s 2
& 3
from
the
fligh
t dat
a.•
Pos
t-flig
ht li
near
ana
lysi
s to
ol m
argi
n es
timat
es c
ompa
re w
ell w
ith th
ose
deriv
ed
from
the
fligh
t dat
a.•
A s
light
ly g
reat
er d
iffer
ence
is s
een
in th
e ga
in m
argi
n co
mpa
rison
s fo
r Mac
h 5-
8 fro
m F
light
3.
•U
n-m
odel
ed a
nd u
nexp
ecte
d ai
rflow
thro
ugh
the
scra
mje
t en
gine
in th
is re
gion
pos
sibl
y ex
plai
ns th
is g
reat
er d
iffer
ence
.
51
The
Res
ults
Bes
t Pos
sibl
e O
utco
me:
Scr
amje
ts W
ork
& F
light
Tes
t Is
Stil
l Nec
essa
ry
Que
stio
ns ?