Hello and welcome back to this orbiter
2016 video series I'm Tex and this is
episode 2 of journey to Saturn in the
previous episode we launched the dragon
atop a falcon 9 rocket up here to deep
star and by the end of this episode
we'll be on our way to Jupiter for a
slingshot
out to Saturn now before we begin I did
not talk about this in previous episodes
but I'm planning to use the MAV add-on
that is the Mars ascent vehicle for
landing our crew on the surface of Titan
and bringing them back up to deep star
after they finish exploring the surface
now I placed Mavs in orbit around Titan
from the very first scenario assuming
that it was sent in advance of us and
deep star will rendezvous with it when
we get there however as I was filming
episodes I noticed that MAV got ejected
from Titan orbit whenever I used high
time acceleration say between Earth and
Jupiter or Jupiter and Saturn I'm not
sure what causes that to happen and the
only reason I mention it is because if
you happen to download my scenario pack
and you play from the very first
scenario then you too may notice that
when you get to Titan MAV is no longer
orbiting Titan so what you'll have to do
is probably edit your scenario when you
get to Saturn and use the first scenario
that has math in orbit you can copy the
parameters of math and paste them into
your play scenario but with all of that
said let's go ahead and get started with
the episode okay jumping right in here
the first thing I'm gonna do is undock
dragon from deepstar we of course
already transferred the crew over I'll
just open up the remote vessel control
and use that to select dragon and just
translate it back away from deep star so
that we will leave it here in orbit and
wait for our return okay so that should
be good for now we can watch and speed
time up as dragon drifts away from deep
star so adios we will see you when we
get back here in many years from now so
the first order of business let's go
ahead and open up trans X and we need to
input our data from the plan I could
have I guess kept the Delta glider in
the scenario and basically inherited
that plan but it's not a big deal I'll
just manually put in the numbers real
quickly here from our notes so it was
nine thousand six hundred and
ninety-three meters per second for
pro-grade velocity switch over to the
eject date that's five eight one three
four point one four zero eight and then
we're gonna go to the outward velocity
and that was 105 meters per second and
the plane change was negative four
hundred and seventy three point nine
meters per second so you can see we have
our arrival there at Jupiter let's go to
escape and select Saturn there it is and
we'll press view for the sling direct
view looking at the encounter view on
the right side there it is let's go over
to outward angle and swing our angle
around for the sling past Jupiter out to
Saturn and we have an arrival at Saturn
now let's go ahead and tweak this now
we're not actually gonna use the exact
angle numbers from the plan at this
point because we're already in orbit so
we want to go ahead and set up our
arrival at Saturn and this far out I'm
just going to set something up where
we're essentially just hitting Saturn
and I'm not going to concern myself with
setting up a precise altitude for our
arrival at Saturn because we're still
too far out at this point so we'll just
play with the outward angle and the
inclination angle and you'll see that's
bringing us down closer to Saturn and
I'll go forward you know a relatively
low inclination I want to make sure that
we're coming in pro-grade so that
actually was retrograde so bring it on
around now we are pro-grade
just going to change the graph
projection here to focus and let's keep
bringing that around inclinations at 40
degrees we'll bring that down a little
bit more that looks better and I'm not
sure how much more we really need to
mess with this at this point like
said we're still a long ways away from
Saturn so I'm not going to concern
myself too much with setting this up
perfectly I think that will do just fine
now let's go to this view slingshot view
relative inclination and PE ratios I
think that's fine for now we're not
going to mess with that at this point
because we're going to set up a maneuver
later so let's um take a look at stage 1
over there we've got our periapsis and
apoapsis listed on the orbit MFD we want
to set the PE distance let's just go
ahead and set it for our periapsis it's
6 7 6 4 now what I want to do is take
the eject orientation and actually
before I do that let me change graph
projection over here to plan so things
look better there we go let's take the
eject orientation and swing that line of
nodes directly over the ejection point
ok so now we can see that the
inclination there on transics on the
left side is 23.5 8 degrees that's quite
a ways off so we are going to we're
gonna have to align the PIP of the plane
I guess with the with the plan I'm just
gonna do a little translating here and
move our periapsis over to the ejection
point somewhere maybe that's a little
too far let's bring it back somewhere
right in there looks good so yeah so
what we're gonna have to do is we're
gonna have to do a pretty big plane
change here let's open up a line plane
and put in the inclination and the
longitude of the ascending node listed
over there on stage 1 of trans X ok and
you can see that's given us the line of
nodes on the line plane MFD that lines
up with the line of nodes on trans x so
we're looking at 453 seconds of burn
time if we wanted to align the orbital
plane at our current position our
current orbit taking a look at burn time
we actually have 80,000 491 meters per
second and Delta V now that is a lot of
Delta V but I'm guessing
2800 meters per second actually go for
2,900 meters per second gives us 451
seconds of burn time which is pretty
close to what we need for the plane
alignment that's nuts
I mean that's almost the velocity we
need to go to Mars so how are we going
to do that well we'll talk about that in
just a moment but let me open up our
flight log here and put in our total
Delta V and I'm just going to put in the
same number obviously for pre-flight
Mikko and circularization because well
we're already in orbit now we'll come
back and input the data for the align
plane and the after the injection burn
so that we can just track our fuel usage
I'm not going to concern myself with the
fuel weight over there on the right side
that was set up for the xr2 so we're
just going to track our delta v usage so
taking a look at the plan here we'll
have to come back and put in the plane
change but we were looking at 6000 885
meters per second for the injection burn
so if we go to trans X we're looking at
pretty much the same six eight eight six
so that's how much Delta V basically
pro-grade Delta V that we would be
putting in to get out to Jupiter and
slingshot on out to Saturn so I'm going
to open IMF D on the right side just use
the map program there and I'm going to
use an external MFT for the align plane
MFT for now and bring that over to the
right side so we know we have to do this
plane change here we need to bring
relative inclination shown over on trans
x over there on stage one to zero
currently it's twenty two point two five
degrees that's that's pretty massive as
you can see four hundred fifty something
seconds in burn time now how do we
reduce that how do we reduce the Delta V
expenditure that's required for such a
burn well if we do the plane change when
the spacecraft's going slowly than it
would cost less to do the burn well how
do we make the spacecraft go slowly well
if we raise our orbit altitude on one
side of the planet and coasts up to that
high altitude then we would be going
slower than we are down here
so what we want to do is do a pro grade
burn and we want to do that at our
ejection point because we're all we're
already going to be burning pro grade at
the ejection point anyways but we want
to time it in such a way so that when we
come back around to our ejection point
after we align the orbital plane that we
we reach that ejection point at the
ejection time as per our plan so what
I'm doing now is just calculating how
many days we have from now until our
ejection date on the plan and that comes
up as 2.8 days so we have two point
eight days from now until the time we're
supposed to eject the earth to head to
Jupiter so if we go to the time
conversion and put in days two point
eight and let's see actually I want to
convert that to seconds there we go so
that's two hundred forty one thousand
nine hundred and twenty seconds
currently we are one thousand one
hundred ninety three seconds from
periapsis so I guess we should probably
let's go to the calculator subtract the
1990 two seconds now from periapsis so
it's two hundred and thirty nine
thousand nine hundred and twenty-eight
seconds so in other words we would want
to do a burn at the ejection point and
raise our Apple abscess up to an
altitude where it would take us two
hundred and thirty nine thousand 0.9 you
know basically about two hundred thirty
nine thousand nine hundred seconds would
be fine until we reach periapsis and
that would ensure that we can minimize
the plane change burn as much as
possible so I'm just going to put a note
in here we want PE T to equal to hundred
and thirty point nine K seconds and
actually that's uh hold on a second that
was 213 I suppose B to thirty nine to
thirty nine point nine K there we go
okay so just I'm just putting that note
there for reference so that I don't
forget so if we look at imfg you can see
P et listed there so in other words when
we do the burn we want to monitor PE T
and just raise our Apple apps us up
until PE T reaches around that around
that time but I think what we can do is
actually set up a maneuver using trans x
to be a little bit more accurate with
that so just did some basic calculations
calculations just to kind of see where
we stand so if I put in 3000 meters per
second how long is that going to take to
burn that's going to take 467 seconds of
burn time so half of that is to 234
seconds and I'm just just throwing a
number out there because we're looking
at 688 something for the injection burn
so I think with 685 let's just let's
just go ahead and set up a maneuver it's
put in 3000 hold on a second that makes
it really hard to see let's just start
out with a little bit of pro-grade
that's fine for now and then let's swing
the the data round to our rejection
point on this current orbit and just
line that up there we go and then let's
go to pro-grade and let's see I think
there's a number here we can use I think
the bottom one actually HPE mjd so if I
increase pro-grade velocity on a
maneuver here I think it it looks like
it is affecting that hpe mjd so let me
just line up the date a little bit
better and if we go to pro-grade and
let's continue putting pro-grade in here
so yeah that is working okay so I guess
we would want to get to the PE mjd to
our rejection date per the plan
and again that was refer back to my
notes oh it's a one that's five eight
one three four five eight one three four
point one four oh oh eight so let's just
adjust the pro-grade until that pH PE
mjd I'm not sure what the H stands for
actually but that is working so just
about there a little bit too much there
we go okay so the way I'm seeing this
actually if we put in two thousand nine
hundred and fifty six meters per second
at our injection point coming up then
that means we would we would have time
to coast up to apoapsis and then do the
plane change and come back down the
periapsis and when we reached periapsis
we would be there at the exact time as
our ejection time per the plan so what
I've done is I've put in the Delta V
that we just calculated in trans x over
on burn time that's 29:56 meters per
second and we should be able to let me
just check the the eject orientation
here just get that lined up perfectly on
our ejection point the line of nodes
rather and yeah so we should be able to
just use maneuver mode here to conduct
this burn for us so yeah so we're just
gonna coast over here we're watching
begin burn countdown just barely over a
thousand seconds now and counting down
and when that reaches zero of course we
will we'll use burn time MFD to conduct
the burn for us we'll use the external
MF t for burn time and for right now
we'll open up IMF D on the the main MF t
there on the right side so that we can
monitor PE T but I think that we're not
actually going to have to really monitor
PE T since we set up the maneuver on
trans X this is the first time I've
actually
this setting up and maneuver on transact
so hopefully this comes out more
accurately than other times that I've
done this maneuver so we'll turn on Auto
Center and at this point we'll just
begin the burn and what I'll do is I'll
just speed the video up through the burn
because what we're not really going to
be doing anything but just watching as
Delta V counts down and that way we can
sort of try and keep this video a little
bit short we do have a lot to cover and
once the burn is completed we'll come
back and talk about how things look and
getting the plane lined up let's just
get to the burn here it's adjust the
total Delta V here it's currently two
thousand nine hundred and forty seven
meters per second
according to trans x there so I've
adjusted that in burn time we are
oriented the correct direction and the
clock is counting down okay we are now
ten seconds till the burn five four
three two one zero and we're burning
okay so that looks good let me go ahead
and speed the video up and we'll take a
look at things once the burn is complete
okay the burn is almost done delta bees
down to 100 now and dropping we're going
to disable the auto center here in a
moment okay there's a well we burned a
little short let's complete it ourselves
bring Delta V down and we'll use linear
RCS now and there is 0.5 for one that's
good okay so the burn is complete let's
turn off maneuver mode press view of you
and find maneuver mode there it is off
so that looks good so PE T is actually
two hundred twenty eight thousand nine
hundred seconds away that's a little bit
off from what we calculated however I
think since we we set up the maneuver
that's gonna be more accurate so let's
go with that I I believe either way it's
gonna be plenty close enough we're going
to Jupiter so it's not gonna be so super
picky about the timing here but the
closer we can get things the better off
we'll be as far as fuel expenditure so
let's put in what we used here let's see
we actually have seventy seven thousand
four hundred and ninety nine meters per
second left so if we take what we had
what we started with and subtract that
that comes out to two nine nine two
meters per second so I'm just going to
go to our spreadsheet and let me just
expand this row here and I'm just going
to put a note in for right now how much
we've used because we have not completed
the injection burn so we're not going to
put that in the actual line there just
yet so we just put a little note here
we've used two nine nine two meters per
second for that for that burn to get PE
T up to the altitude we got it up to or
apoapsis rather and okay so that looks
fine for now so at this point all we
need to do is Coast up to our apoapsis
or the
the node which is about at our apoapsis
so that looks fine we don't really need
to adjust the line of nodes there so
we'll use a line plane MFT let's go
ahead and put in the correct inclination
and longitude of the ascending node it's
it changed a little bit twenty-three
point eight and one 98.5 as per stage
one on trans x so that looks good so we
can use the align plane MFD to help us
out with this burn but you can see what
we're looking at twenty six point seven
two seconds as of now if we do the burn
at the ascending node which is up really
high at our apple abscess that's a
considerable savings from what we were
looking at we haven't calculated it yet
on burn time but instead of almost three
thousand meters per second i'm guessing
it's gonna be like a couple hundred if
that in meters per second for the Delta
V so let's just put in two sixty so even
that's too much let's put in take a
hundred off of that I guess put in one
sixty that's twenty-four point seven
seconds so a little bit more maybe 175
and even that's too much
so one seventy three and estimated burn
time is twenty-six seconds
one seventy two so okay so that looks
good actually yeah so 172 meters per
second estimated burn time is twenty six
point five seconds and we're looking at
twenty six point eight seconds according
to a line plane MFT we're gonna
purposely undershoot it just a little
bit so that we can finish it off
ourselves manually so yeah what I mean
172 meters per second to align the
orbital plane compared to almost three
thousand that's like I said that's just
nuts so you can see how how valuable a
maneuver like this is and quite frankly
it's it's pretty fun setting this up
getting everything timed perfectly you
know that's that's hard but our Apple
APS's is actually up to
one hundred and forty eight thousand
kilometers there I think it was so what
and that's that's massive so it's sort
of cool we're gonna get two views of the
earth as we drift away from it of course
the second time we drift away it's going
to be for many many years until we get
back from Saturn anyways so we're just
about up to the ascending node here of
course we are time accelerating to get
up there quicker you can see the time to
node counting down on the align plane
MFD this is going to be pretty straight
forward it will be much easier for us to
do this with the align plane MFT taking
a look at our inclination and the land
really no need to do anything there it
still looks the same on trans x so we're
just we're just going to orient the ship
anti normal of course we are approaching
the ascending node so that means we're
going to burn anti normal I'm gonna do
this bird manually just because the the
engines are too powerful for the
autopilot to actually hold the ship in
the correct orientation so it's going to
affect our our Apple apps as periapsis
altitudes really our periapsis altitude
more than anything at this point so
we'll just keep the ship oriented anti
normal here until we get close to the
burn which is coming up and then I will
disable the autopilot and do my best to
keep the ship pointed perfectly anti
normal so the burn is approaching there
it goes we've hit burn on burn time and
let's see if we can stay on top of it
here
relative inclination is coming down it's
a 10 degrees now 9 we can watch a
relative inclination on either the align
plane mft or trans x but I'm actually
more I'm more concerned about it on
transect so at this point I'm just
watching trans x and burn time is
completed the burn we burned short on
purpose so let's point back anti normal
we'll just use translation thrusters
watching relative inclination on trans x
bring that down to zero and there we go
that's good enough we'll do another will
do another adjustment to it as we get
closer to the ejection point but you
know at this point we've we've gotten
ourselves aligned with the plan so
everything looks good so we can in a
moment we can put in some data here
we'll look at our total Delta V
remaining now with 77277 eighty thousand
four hundred ninety one meters per
second subtract the 227 for the plane
change burn so that's 80 264 so that
gives us the DV used correct for the
plane change burn and then let's put in
for after the inject what we have left
now which is 70 72 72 and so we will
actually update that after the injection
burn so we put in two thousand seven
hundred and seventy two I think it was
meters per second into what we need for
the injection burn which was six eight
eight five
so three eight nine three is what we
should have left 3800 93 meters per
second I guess is what we should have
left in burn time to complete the
injection burn so at this point all we
need to do is Coast down closer to the
ejection point we'll go down to maybe
2000 seconds until begin burn and we
also will make one more adjustment to
the
to the plane just to make sure relative
inclination is as low as it can be so
let's go ahead and let's adjust our PE
distance it's currently at okay so our
periapsis is six five eight five so
we've got that set up so that's fine and
I did actually lower periapsis down to
about 200 kilometers so that we're a
little closer to the earth so I think
that that would actually take less
delta-v versus doing the burn up at 400
kilometers where we originally were so I
think that that'll work fine
okay so we're pretty much set up at this
point we just need to Coast down closer
to the ejection point so let's go ahead
and cut forward in time and we'll come
back so that we can set up a maneuver to
complete the ejection burn out to
Jupiter all right we're just under 2000
seconds from the burn it's at 1923 now
22 let's go ahead and orient the ship
pro-grade and let's pull up trans X and
we need to go ahead and set up a
maneuver for our ejection burn here
that's gonna help us keep things more
accurate so let's take a look we know
what do we have left we had three eight
nine three and velocity left for the
injection burn so let's put that in
three eight nine three okay there we go
and let's go to view and let's adjust
the scale on that two to the two target
I guess and actually you know what that
reminds me
let's go back to we didn't adjust the
relative inclination one more time let's
adjust that real quick let's swing the
eject orientation line over our current
position here somewhere right in here
and get it right on top of it there we
go now Rob swimmingly
relative inclination
0.4 let's just use linear RCS and bring
that back down to 2-0 probably should
have done that a little bit earlier but
that's okay and somewhere right in here
there we go that's fine okay so let's go
back over to maneuver mode so we put in
our program aning for the injection burn
let's adjust the date swing that over to
the ejection point just get that
perfectly overlapped right there okay so
that looks fine okay so I think so we've
got our pro great in we've got the date
set up let's go over to just move that
up out of the way a little bit and let
me think about this we need to go to
stage actually I want to leave the sling
plant set up let's go to stage two and
let's kill the variables here so we can
see our maneuver so let's go to
pro-grade and hit X to reset that let's
go to the eject date we'll hit X to
reset that and we'll do we'll do the
same thing for outward velocity and the
plane change velocity here okay so there
we go now we can see the maneuver and
where it's going to take us let's uh
first before we adjust our maneuver
let's adjust the the sling here out it's
Saturn let's bring it back down so that
we're basically hitting Saturn so we're
just going to adjust the the outward
angle and inclination angle
so let's figure out which direction
we're going here so that's bringing
there we go
minimum altitudes coming down let's go
back to inclination angle so we're
getting closer there we go so that that
looks fun
we're hitting Saturn inclination is at
one point three degrees so let's go back
to the manoeuvre and let's go to the
slingshot view here and let's use the
maneuver mode let's adjust our variables
on maneuver mode here to get a relative
inclination on slingshot view on the
right side to zero and PE ratio to one
so we're just going to play around with
the variables I think maybe actually
outward and plane change will probably
be more useful for us here and that
looks like that is working so let's go
back and forth between these two there
we go so relative a clinician is coming
down so is PE ratio and that's getting
pretty darn close but we'll see if we
can't get that better
okay so almost there and so relative
inclination looked good P ratios about
where I want it and let's try one more
with the plane change so P ratio looks
fine relative inclination I think that
looks fine so let's go to let's change
our graph projection to something that
makes sense there we go focus makes more
sense now we don't need the plan view up
anymore and we'll change scale view to
all again and let's go to the target
view there we go and we can see our
Delta V and our begin burn so let's just
time accelerate we'll probably do one
update and we'll have probably have to
tweak it just a bit more let's get a
little closer to the burn and we'll do
an update and see how things have
changed they may have changed quite a
bit so I don't know let's get under 600
seconds here okay we're back at normal
time speed let's um let's do a quick
update and it did in fact change so
let's just do this one time here we'll
just do this quick update and once again
bring relative inclination on zero and
PE ratio to one and that's that's what
I'm gonna go with I'm not going to
concern myself with doing another update
right before the burn I we're using
trans X so I'd really fully anticipate
we're gonna we're gonna have to do some
mid-course Corrections but hopefully by
doing things this way we will minimize
the the velocity that we'll have to put
in for those mid-course Corrections so
relative inclination got on 0 pretty
easy but PE ratio was not on one so
we're gonna have to overshoot one and
come back with the other now we're
getting close P ratios a little bit low
so we'll overshoot that direction and
come back with
some outward well it would help if we go
in the right direction but we'll we'll
get this we still have a little bit of
time left okay that's looking better
we're getting somewhere now Pete your
ratios perfectly at one see if we can't
get relative inclination a little bit
better than that so just small
adjustments now to outward and plain
change here okay I think we're getting
pretty close I don't think there's any
need to split atoms with this that looks
pretty darn good to me so yeah I think
that's what we'll go with
so let's press view to our target view
once again begin burn is counting down
so let's time accelerate we will turn
Auto Center on again and we're going to
use burn time as well for our Delta V
let's get a little bit closer before we
put that in to burn time here
okay so just do a quick save here so you
guys have a scenario to pick up from at
this point just before the burn and okay
so we're just going to continue coasting
forward we're about 200 seconds from the
burn now everything's looking good let's
go ahead and start orienting the ship
toward the burn vector let's go with
that for now we'll turn on auto center
and let it do its thing let's put it in
the Delta V it's currently a three eight
nine eight
let's under six I guess and I understood
it because that way I can finish the
burn myself I don't want to risk
actually overshooting the Delta V and
then having to waste
you know Delta velocity to go backwards
but again I mean we have so much Delta V
and deep start here we don't really need
to worry about being that accurate but
you know I mean why not let's just do
the best we can here okay so we are
about to start the burn one second zero
and burning now you can see Delta
velocity is counting down this is going
to be a relatively large burn but since
we've already put in almost three
thousand meters per second previously we
basically cut the burn in half not quite
but it's not going to take quite as long
as if we've done the burn all in one
time so I think no no maybe that's
actually more efficient but we certainly
were more efficient to do the to do
things that way since we reduced our
Delta V to align the orbital plane so
that looks fine now I've opened up
interplanetary on the right side here
just so we can kind of monitor things
although I'm not going to use that for
adjusting the burn I'm just going to go
with what trans X has for us here and
we'll see where we get with that but we
can zoom out on I am FD and hit will see
page sphere of influence
let's hit display so we can see the
orbits of the other planets maybe change
projection to the ecliptic and if we
zoom out we can see all the planets we
keep zooming out you can see the sphere
of influence for the solar system there
that's pretty cool so let's zoom in to I
guess Jupiter's orbit and I think we can
actually just go ahead and target
Jupiter just so that we can see it we're
not like I said actually going to use
the data from IMF D this time okay we're
just about done with the burn now taking
a look at burn time MFD we have about 10
seconds nine eight seven six five four
three two one and engine cutoff
okay now let's complete the burn we have
Delta V remaining at 72 so we're just
going to manually complete this burn
like I said we purposely undershot on
the Delta V so we'll just continue
burning a little bit here we'll use our
translation linear Arceus bring Delta V
down to zero and that's probably close
enough at this point so let's sum let's
go over to trans X on the right side and
on the left side let's go to view view
maneuver mode we're gonna turn the
maneuver off and let's use some linear
RCS here let me go ahead and point
pro-grade first and we'll use a little
bit of linear RCS to clean the burn up
here according to the slingshot view on
the right MF t we're just just try and
bring the relative inclination back to
zero and PE ratio to 1 so just using
linear RCS whatever direction it takes
you can translate to the right it's
usually going to be inward outward and
then up and down for the plane to adjust
those to get that down to PE ratios
looking pretty good relative inclination
is on zeros
if we can get that a little bit closer
it's going to move around a lot though
once we get this set up so I'm not going
to concern myself too much with it I
think that's fine right there so there's
no sense in continuing to do anything
else so our total delta-v remaining is
seventy three thousand two hundred and
twenty three meters per second so let's
put that in here after the injection
burn and okay so we used seven thousand
forty one meters per second for the
injection burn
according to burn time so that's
actually over what what we originally
calculated but we did make some changes
to the plan so let me see how much is
that since I don't really math that well
let's use our calculator and subtract
the difference so it's 156 meters per
second excess so we used 156 meters per
second more for the injection burn than
we actually calculated for in the plan
so it's not I guess terrible but I don't
know I guess it's not quite as accurate
as I as I estimated but let's go ahead
and put in the plane change here we
actually used was 227 meters per second
so so yeah that looks good
I mean all in the grand scheme of things
I guess we really didn't use too much
more Delta V but you know if we were in
the xr2 and cutting things really close
that that could have been kind of a
problem so anyways guys that's gonna
wrap up this episode we accomplished a
lot but I hope it was interesting it's
these these type of maneuvers are always
really fun to calculate and carry out so
hopefully you you got to see something a
little bit different and but we're on
our way to Jupiter for a slingshot on
out to Saturn so in the next episode I
think we're going to cover things like
the mid-course correction and we'll
probably also complete the slingshot
past Jupiter as we Coast out towards
Saturn listen guys thank you always as
always for watching I hope you guys are
doing really well and
as always take care and we'll see you in
the next episode
