MALE SPEAKER: I'm very excited
to have Dr. Hine here today.
And he's over at Ames.
Our neighbor to
the southeast-ish.
And so Doctor Hine, if you'd
like to take the stage,
that'd be great.
BUTLER HINE: Hi,
I'm Butler Hine.
I'm the LADEE project manager.
I'm going to talk about
the mission today and some
of the technologies
we demonstrated.
I'm not going to talk as much
about the science results.
The mission just ended
a couple of weeks ago,
but the science data analysis
is happening over the next year.
This is kind of a
snapshot of the mission.
We had two objectives.
One is measuring the
lunar dust environment.
The other is measuring the
atmosphere or exosphere.
It's a collisionalist
atmosphere.
So it's a boundary layer
exosphere around the moon.
It's one of the first
questions I always get is well,
the moon has no atmosphere.
Well, it actually does.
And most of the moons around
the solar system do as well.
So it's a very interesting
scientific topic
about characterizing them.
And they're very delicate
so they're easy to disrupt.
We launched September 6.
And then we just had
our impact April 18.
So it was a short mission.
That was by intent.
It takes a lot of fuel
to fly low over the moon.
I'll talk about the orbiter
and the science instruments.
We pioneered a lot of
firsts on this mission.
The launch vehicles.
First flight of
this launch vehicle.
It's the first planetary launch
out of this new launch site.
It's actually not
a new launch site,
but for planetary
missions it is.
But before I start
on LADEE, I wanted
to go back especially
for this audience
and tell you where
LADEE came from.
Because it was an interesting
story about where it came from.
Ames was looking at ways to make
space flight less expensive.
That's one of the
scourges of spaceflight
is it's so expensive that it's
an incredibly high entrance
barrier.
And one of the things that
limits the amount of science
missions that NASA can do
is the cost of each mission.
And it's because of
the traditional way
we do NASA missions.
So one of the things
we were trying
to do in the 2005,
2006 timeframe
was come up with ideas
for how to do missions
at much lower costs than
they were traditionally done.
And so some key ideas
from that effort
were design general
multipurpose architectures,
multimission architectures.
In the past, missions are
kind of custom designed.
So think of a spacecraft
as a custom design.
Every time you start, you
start almost start from scratch
and you custom design it.
Now commercial spacecraft for
communications satellites,
for instance, they do have reuse
of spacecraft architectures.
But science
spacecrafts typically
are designed almost
from scratch every time.
Invert the pyramid was a big
thing we were proponents of.
The normal way
NASA does missions
is you define the
science goals and then
you define the
instruments that are
going to do the measurements.
And then you design
the spacecraft
to accommodate the instruments.
So that's this pyramid.
It's a top down pyramid.
Inverting the pyramid
means designing something,
a bus that's capable
of multiple missions,
and then choosing the science
that can fit into the bus.
So it's inverting
that classic flow.
And what that does is instead
of custom designing spacecraft,
you actually can save cost by
having a multimission design
spacecraft that you then
tailor the science to.
And then the other
thing was NASA
engineers love to design
stuff from scratch.
I'm sure Google engineers
have the same characteristic,
it's classic.
One of things we try
to do to save cost
is not designing anything from
scratch if we can help it.
But take advantage of
this ecosystem of space
qualified commercial
components that are out there.
And so what came out was
this Ames modular common bus
concept.
And these were the
project guidelines.
I'm not going to go
into all of them,
but some noteworthy ones
are develop missions
with multiple destinations.
So if you can design one
spacecraft that can do things
on the surface of the
moon, around the moon,
Lagrange points, even
out to Mars orbit,
you have a lot of
science destinations
you can do with those.
The other thing, number three,
is utilize cost effective
launch vehicles.
If you go with the standard
heavy launch vehicles
that we're used to, especially
back then, the Atlas V
and the Delta IV heavy.
They're very expensive.
In fact, the launch
vehicle's so expensive
that it only makes sense to fly
either lots of small spacecraft
on it or one big expensive
spacecraft to justify the cost.
And so we were going after some
of these new launch vehicles.
Falcon I Space X had just
had successful flights
with Falcon I. We
were going after that.
What we wound up using for
[INAUDIBLE] Minotaur V.
I'll be going over
that in a minute.
Now I'm going to skip
some of this other stuff.
So the common bus
requirements that had were we
had to be compatible with
a range of launch vehicles.
The critical mass and
volume constraints
derived from the
Falcon I back then.
And the Esper is a way to
have multiple missions flying
on a single larger
launch vehicle.
Mission duration turns
out to be a big driver.
If you've designed
for short missions,
then you don't have to make your
components as space hardened
as you do for long
lived missions.
If you're going to go for 10
year mission, 20 year mission,
the component cost goes way up.
If you're going for a
one or two year mission,
the component cost
goes way down.
And then the
targets, lunar orbit,
lunar surface,
anywhere on the moon.
Earth-moon Lagrange points,
near Earth objects, and then
anything within the
Earth Mars orbits.
This is the design evolution.
This is really
interesting because when
you take those goals
or requirements
and you break them
down, you think, well,
I've got to design a
lander because a lander is
a unique thing.
And then I got to
design an orbiter.
And the team
actually started, we
started with those two branches.
We evolved though.
This is the design
evolution over time.
Over a one year period.
And we evolved the evolution
and then kind of at the end,
we were looking at how to
address manufacturing costs.
And one of things you can
do with manufacturing cost
is have your design be modular.
That does a couple of things.
You can sink non-recurring
engineering costs once
and then reuse the modules.
But you can also work on
the modules in parallel
so that you don't have
this serial dependency.
A lot of times the
mission schedule
will have this serial
dependence of work on this
before you work on this,
before you work on this,
and that could stretch
out your timeline.
So we were trying to address
the work on things in parallel.
When the design team was
doing that they realized,
hey, these are
common modules that
can crossover between
landers and orbiters.
So I actually don't
have to design a lander
and then separately
design an orbiter.
I can have one set of modules
that can actually do both.
And so that's what
you see at the right.
On the right, you
see the modules,
the classic modules
within this design.
You have a bus
module which contains
most of the active electronics
power for the system.
You have a payload module
with reaction wheels
for applying attitude control.
And then you have one, or two,
or three extension modules
and then the prop
system is designed
with standard interfaces so that
multiple propulsion systems can
be used and they have common
interface and control points.
And then, obviously, if you're
a lander you have to have legs.
So on the left you can see
four different configurations
of this design.
You can see a three
stack orbiter at the top.
You can see a mini stack and
medium sized stack lander.
And then you can see a near
earth object rendez-vous
which we're trying to
maximize your Delta V, which
means you're
minimizing your mass.
So this is what the common
bus architecture looks like.
So we had a skunkworks team.
There were 12 of us
that were tackling this.
First thing we did was we
prototyped some of this.
Because we had lower performance
launch vehicles in mind,
we wanted it as
light as possible.
So we went with a carbon
composite structure instead
of an aluminum or
titanium structure.
You can see our early
prototypes here.
We did ground testing
of control algorithms.
This is the lander
configuration.
This is using cold gas
thrusters, basically
scuba tanks.
Because we're in an urban area.
We're your neighbors over there.
If we were doing biprop
burning over there,
you would not be happy.
Because there would be toxic
fumes coming over here.
So to do this testing,
we used a variant
of the propulsion
system with coal gas.
Which is basically a
pressurized gas nitrogen.
In this case, pressurized gas
that you blow down and through
the valves in the thrusters and
that gives you your propulsion.
It's not very efficient.
So we couldn't fly
this thing very long,
but it was enough
flight time to allow
us to test the
control algorithms.
And actually a piece of
trivia you may not realize
is your two founders
were actually here.
We were in a
skunkworks mode that
was kind of under the radar.
But somehow they
showed up one day
and saw some of this testing.
And now back to LADEE.
So that was the start
of the common bus design
and the prototype testing in a
terrestrial prototyping mode.
Because of that, it looked
like the concept was viable.
So the first thing
which is always
the hardest thing
with a new bus design
is getting a chance to
actually fly it in space.
Because flying
things terrestrially
is much, much easier than
flying things in space.
You don't have the
problems with thermal
and you don't have the problems
with temperature swings
that you do in space.
Vacuum et cetera.
So at that time,
this was in 2008,
NASA was planning for
significant human activities
around the moon.
And one of the problems
with significant activities
around the lunar
surface is it disrupts
that pristine
exosphere environment.
Dust and exosphere environment.
So there was a goal back then
to measure the environment
before human disruption.
So that's what
actually started LADEE
was to do these measurements
before the human activity
actually got to
be pretty strong.
The LADEE guiding
principles we use,
we designed the spacecraft
to be single string.
So we, instead of
having true redundancy
which a lot of spacecraft
have true redundancy, have
an A set and a B set on
everything, avionics, sensors,
everything, we
had single string.
Which meant everything
was critical.
But we had functional
redundancy.
So if we lost something, we
had a way for something else
to take over its functionality.
I already mentioned
the avoid new design.
Use commercially available
[INAUDIBLE] components.
One of things that
NASA loves to do
is take a vendor's
proven design and say,
we're going to make you
make a change to it.
And that, of course,
makes the cost go up
and eliminates that
reassurance you have
that it's flown before.
So we said we're not
going to do any of that.
Some controversial ones
was minimizing complexity.
We have no deployables on this.
You'll see in a moment that
this has body fix solar rays.
Your classic view
of the satellite
is this folded arrays at launch.
And then once you get on
orbit the arrays deploy.
And you have the
solar collecting area
in a deployed fashion.
Well, deployables or any kind
of articulation on a spacecraft
is a failure point.
So it costs a lot of money.
And it's a place where
something failed.
So we design that out.
We have body fixed solar rays
all around the spacecraft.
What that did as
a side benefit was
have a very simple safe mode.
With spacecraft, you have
your normal operating mode,
but you always have
something called safe mode.
So if the spacecraft
has a problem,
it'll drop back into a control
routine that is very robust.
And that control
routine is designed
to keep the spacecraft
safe while you figure out
what's wrong with it.
And then you come out of safe
mode into the normal mode.
Well, most
spacecrafts since they
have deployed arrays,
that means the arrays have
to point at the sun.
You also tend to have
hot sides and cold sides.
And you have to make sure
your hot side is warm
and your cold side is cold.
And safe mode has to work
guarantee with no question.
So what that means is
that some spacecraft,
90% of your software
development effort,
is around that safe code.
And that 10% is
around the bigger code
that is your nominal run code.
We intentionally made our
safe mode very simple.
So that our safe mode was not
the driver for our software
development effort.
And then the other
thing we did which
is kind of a 50/50 split
within the community
is launching powered off.
Some people love to
launch powered on.
Spacecraft is awake and
alive when it's launched.
And then some people
like us wanted
to launch powered off so that
when the spacecraft separates
from the launch
vehicle, it wakes up.
So this boot-up sequence,
where you do the boot-up
can be controversial.
If you want to
launch powered on,
you have to ensure that
nothing the spacecraft can do
can affect the
rocket in any way.
And since the rocket
is around humans,
you have these two
or three levels
of inhibits you have to
design into your system
so that no matter what happens,
you can't release toxic fuel,
you can't generate a spark, you
can't have an inadvertent radio
transmission.
AUDIENCE: [INAUDIBLE]
reaction wheels.
BUTLER HINE: Can't spin
your reaction wheels.
All of those inhibits
cost a lot of mass.
And we were very
mass constraint.
So we made the decision
to launch powered off
so we wouldn't have
as many inhibits
that we had to deal with.
And then that moves
your risk to on orbit
once you separate from launch
vehicle, that's your power-up.
And so that first boot-up, is
the one that's the most risky.
And then some of
these others are not
as important schedule
and cost guidings.
So this is what the observatory
looks like for LADEE.
And in NASA speak,
an observatory
is a spacecraft with the
science instruments on it.
So without the
science instruments
it's a spacecraft, once you
add the science instruments,
it becomes an observatory.
You can see the modules
that we use to the left.
That bus module,
I mentioned, that
has all of the,
not all of them, it
has most of the active
components of the spacecraft.
So it's like a mini
spacecraft by itself.
Payload module is
where, by design, where
you put most of the
science instruments.
And then we had a two
stack extension module
because our propulsion
system had to not only do
the lunar orbit insertion burn,
which is a big Delta V event,
but it has to maintain
the orbit when
we're flying low over the moon.
The four science instruments
or three sciences instruments
plus one technology demo,
you can see on the right,
we had this bus nominally
carries two main instruments
on the payload
module cantilevered
opposite each other.
In this case, those
locations were taken up
with a neutral mass
spectrometer to the left.
And then the laser com
optical head on the right.
Because of the
science we were after,
we also had two
smaller instruments
that had to go up on
the radiator panel.
So there's an ultraviolet
invisible spectrograph and then
a lunar dust
environment detector.
These are the three science
instruments and the lasercom,
you can see who provided them.
The neutral mass spectrometer
was an instrument
provided by NASA Goddard
over on the east coast.
Paul [? Mahaffey ?] was the PI.
The ultraviolet spectrograph
was Tony [? Culpreet ?] here
at Ames.
This is the same
instrument that was
flown on LCROSS which
is that lunar impactor.
So this instrument
has already flown once
and then we were reflying it.
The dust experiment was a
institute dust impact detector.
So it measured dust by the
impacts onto the aperture.
And then the laser
communications demo,
this was first flight
of optical com system.
It was actually a very
aggressive experiment
to try to close the loop at
lunar distances which pointing
is very difficult at those
distances with the spot
size of the laser.
And I'll tell you
a little bit more
about that part of the mission.
Here are all the
external components.
You can see the main
thrusters that [INAUDIBLE]
you see at the bottom, the
reaction control system
are the pairs of thrusters
on either side off of the CG
so you get full three access
control of the attitude.
You have the laser com and
you have the neutral mass
spectrometer in the prime
instrument locations.
And then up top, you have
the extra instruments,
but you also have the Omni
antenna top and bottom.
And a medium gain antenna.
Those are new technologies
I can talk about.
The star tracker cameras.
We have two heads.
Because when you're
flying low to the moon,
one head is usually
always blocked.
So you need two
heads when you're
doing attitude determination.
And then you'll notice
the body fix solar panels.
So we have solar panels
all around the spacecraft.
And you see the slight
cant at the top.
That's so that there's
really only one orientation
that you don't get
power positive.
And that's if the sun
is pointing right up
the main engine.
That's the only way you cannot
get power to the system.
And that leads you to
this simple safe mode.
Because instead of having
active pointed safe mode,
we can have a random tumble.
We can be safe in
a random tumble.
In fact, we like random tumbles.
Or random spin.
Keeps us nice and toasty
and it keeps power.
If you look inside
the spacecraft,
that top plate, which we
call the radiator panel,
but there's so
much crap on there
that you don't radiate heat
very well off of that thing.
[QUIET LAUGHTER]
Our thermal lead refuses
to call it a radiator panel
because he says it
doesn't radiate well.
But you can see at the
top, to the top left that's
the view you saw before star
tracker cameras, LDACs, UVS,
the omnis, et cetera.
If you flip that plate
over, you see on the right
the star tracker
digital processing unit.
That's the controller
for the star tracker.
You see the transponder, the
s-band RF transponder there.
You see the flight battery
which is charged by solar rays
and then discharged
as you need it.
And then the integrated
avionics unit.
The integrated avionics unit
is a 3U compact PCI chassis.
But it's designed for flight.
So it not only has
the flight processor,
has storage on board,
and a lot of I/O,
but it also has the power
distribution system.
So the switches that
lets you shift power
from the rays to
the battery or power
out to all of the components.
If you look at the bottom left,
you can see the payload module.
The NMS and lasercom
optical head
are in the external position.
But you can see inside there
the four reaction wheels
in a pyramid so that any
three of the reaction wheels
can give you torque
in any direction.
So three of four gives
you full control.
And then there are
two boxes inside that
are part of the lasercom system.
The outside is this
pointed telescope
with a three level pointing
system, coarse, fine and then
the server link system.
Inside is the controller unit
which is, once again, processor
just like the spacecraft has.
And also the modem unit.
The modem unit is actually
the tricky part of this.
How you modulate
this optical signal
is what makes this work well.
And then you see the propulsion
module at the bottom right.
It's a by prop system.
NTO and MMH are the
two fuel and oxidizer.
We have two fuel tanks,
two oxidizer tanks,
and it's a pressurized system.
So we have two high
pressure helium tanks
that pressurize the
fuel and oxidizer tanks.
This is what it looks
like when you're
doing observatory integration.
We have a special
ground equipment
that we designed to
both the spacecraft
to as it's being
assembled and then
you can orient the spacecraft
in either direction you'd like.
You can orient it
vertically or horizontally
and then rotate it
around like a barbecue
to work on any part of
the spacecraft safely.
You can also see the red
covers those are designed
to have a keep out zone
around any critical component.
Those thrusters, those red keep
outs are for the thrusters.
They're very delicate.
You bump into them, you
can bend them a little bit
and then you've had a bad day.
This is what the
observatory looks
like in the flight
configuration.
Interesting thing is you have
a payload adapter fitting that
is usually what a spacecraft
attaches to a launch vehicle
with.
Because we were trying to
save as much mass as possible,
you can see that this path
which is in the bottom there
is this lattice structure.
Normally, these are solid
aluminum or some kind of metal.
This is a lattice
structure who's
kind of an Olympic
style bicycles that
have the carbon composite
rigging in them.
This is a similar design.
It's very strong,
but very lightweight.
It's something the Russians
have been using for years.
This was purchased from
the Russians from RUAG.
But it's not something
the US has used before.
So this is one of the firsts
in this country to use these.
And it made all the
engineers nervous to see
the observatory sitting on
top of this very fragile
looking thing.
But it's actually
stronger than most metal.
Then you see the main
thruster visible through it.
So the mission architecture,
this is the RF architecture
that we used during the mission.
We used an S-band transponder.
So it's roughly 2.4
gigahertz is the frequency.
We actually used all three of
the traditional ground networks
and space networks
that missions use
depending on what phase
of the mission we were in.
The [INAUDIBLE] is the satellite
constellation around the earth
that the spacecraft can talk to.
The International
Space Station uses it.
We used that in
portions of the mission.
The nearest network is a
network of ground stations
that have very good
tracking capabilities.
So when you're flying by on
a close approach to the earth
and you're moving very fast,
the antennas can track you well.
Once we got out
to lunar distance,
we were depending on
deep space network which
is the network that NASA
maintains around the world
to talk to spacecraft
in deep space.
They're big, sensitive antennas.
So we used all three
of these networks.
All of the telemetry
and commanding
through whatever
network we were using
goes back through the mission
op center here at Ames.
We flew the mission
out from here at Ames.
The science operation
center was what
coordinated the instruments
that's back in the Green Belt,
Maryland.
That was at Goddard.
And then each instrument had
an instrument operation center
at their home institution.
So MIT Lincoln labs had
the IOC for the lasercom,
Goddard and Ames had the
IOC for their instruments
and then the dust detector
was University of Colorado
at [INAUDIBLE].
So each PI had an IOC
that they could depend on.
The lasercom architecture
was completely different
because it did not depend on
RF, it was an optical system.
So they had their
main ground terminal
in White Sands, New Mexico
which had the most capability.
It was a custom designed
ground station for them.
But they also used
a telescope that
had been converted into
a ground station for them
in Table Mountain, California.
And then in Tenerife, the
European Space Agency, ESA,
was part of this experiment
where they provided a ground
station in Tenerife.
So this architecture,
once again,
all comes together and flows
through the Lincoln Labs IOC
where the optical ground
station control was done.
I mentioned a bunch of firsts.
One of the firsts was
we were the first one
to use a new launch vehicle.
A Minotaur V launch vehicle.
In the spacecraft
world, you don't
want to be the first
to fly a launch vehicle
because you have a pretty good
chance of something exploding.
This is an interesting
launch vehicle.
The first three stages
are the Peacekeeper ICBM.
The US and Russia have a
treaty, a START treaty,
that allows each
country to re-purpose
their intercontinental
ballistic missiles
for civilian peaceful purposes.
And so this treaty allows
the US to take these ICBMs
and then use them as commercial
or civilian launch vehicles.
So the first three stages are
the peace keeper missile ICBM.
And then orbital sciences
adds a fourth stage
to make it a Minotaur IV.
And that's sufficient power to
put a satellite in earth orbit.
And then we needed a fifth stage
which makes it a Minotaur V.
And that gives us our
kick to lunar orbit.
Or to the moon so that we
can get in lunar orbit.
And so you can see the
fourth and fifth stage here.
And then in the
bottom right, you
can see the spacecraft
stacked onto the fifth stage
within the faring.
So we were first
flight of that which
was a little nerve wracking.
It worked beautifully.
The launch vehicle did
exactly what it needed to do
and actually gave us
a perfect insertion.
Normally, launch vehicles
that are liquid fuel,
they're more precise
than the solid fuel.
These are all solid
rocket motors.
So we expected a poor
insertion and had
to carry extra fuel in case
we got a poor insertion.
But the launch vehicle gave
us a perfect insertion.
We launched out of
Wallops Island, Virginia.
Even people who live
there weren't really aware
that they had a launch
site that close.
It's within sight
of Washington, DC.
In fact, our launch was visible
up and down the east coast.
The reason we flew out or
launched out of Wallops Island
is because the START
treaty specifies
the locations you
can launch from.
So each country since
it is an ICBM launch,
the other country wants to
know where it's coming for.
So Wallops Island
is one location.
Kodiak, Alaska is another.
And then Vandenberg, California.
Those are the three
locations that are allowed.
Vandenberg and Kodiak are
better for polar launches.
So since we're
going to the moon,
we had to launch off
of the East Coast
and Wallops Island was
the launch location
that was allowed
under the treaty.
This is what the
observatory looks like.
Just prior to encapsulation.
Encapsulation is what
happens when you're fully
stacked, checked out,
and you close the faring
on the spacecraft.
So you can see that
the faring in two parts
and then you can
see the final stack
to the right of
the launch vehicle.
We launched September 6,
it was a night launch.
It was beautiful.
As I said, you could see it
up and down the east coast.
There's, if you do web
searches for LADEE launch,
you can see pictures people
took from New York City,
from up and down the east coast.
Just beautiful shots.
This was taken by one of our
integration test engineers.
He's a semi-pro photographer and
he did this multiexposure photo
of the launch that
was just beautiful.
It's my favorite
photo of the launch.
Here's a summary of
the launch events.
You can see the track we used.
We went out over the Atlantic
and flew over parts of Africa
before we finally did our final
staging and left earth orbit.
The solid rocket motors
of this launch vehicle
provide you a really
strong kick at times.
So it's a very
rugged, rough ride.
And that was one
of things that we
had to design for a very
strong spacecraft structure
to handle that rough ride and
that vibration environment.
So here's how we
went to the moon.
I mentioned that solid
rocket motor launch vehicles
are notorious for giving you
unpredictable insertions.
None of you are young enough to
remember the Apollo missions,
but if you saw--
MALE SPEAKER: [INAUDIBLE]
BUTLER HINE: Well, you are.
OK.
You are.
So those of us who can
remember the Apollo missions,
they have a classic figure 8.
You go to the moon.
That figure 8 is an
instantaneous launch window.
So it's something if
you get a bad insertion,
you don't get to
where you want to be.
So we designed this with the
philosophy of phasing loops.
So we launched
into phasing loops
around the earth
where each loop we
get a little higher,
a little higher,
and then finally, we have that
last loop where we hang there
and the moon sweeps past us
and whips us around behind it.
These phasing loops are
how you can compensate
for a poor launch insertion.
Like I say, after it
happened, we didn't need them.
But these loops were
designed so that we
could burn at various times and
compensate the poor insertion
and still get to
where we needed to go.
So you can see the stars where
we actually did engine burns.
The apogee maneuver 1B is
the test of the engine.
So it wasn't a necessary
burn for trajectory,
but we had never tested
the engine in space
before so you have to test it
first before you depend on it.
And then we had
two perigee burns
close to the earth, PM1 and PM2.
And then those were
very precise so we
didn't need any of the
other corrective burns
or the third
perigee burn at all.
And then TCM trajectory
course maneuver
1 was the final maneuver
which set our precise timing
for being whipped around
the backside of the moon.
So once we whipped around,
lunar orbit insertion 1,
LOI happened on October 6.
That was our main
critical event.
Because if we had
missed that burn,
we would've sailed past
the moon and been wandering
around the Earth Moon
system for awhile.
So that was our critical event.
That happened
successfully October 6.
That was during the
government shutdown.
So there was a ghost
town over there.
We were the only
people operating.
You can't not pay
attention to a spacecraft.
So we were able to
work during that time.
But there wasn't a lot of
news coming out about it
until after everything reopened.
But that engine
burn did just fine.
Because NASA has had
a couple of spacecraft
go missing without contact.
And so you don't know
why it went missing.
One of the rules
that we all have now
is that you wait until
you're in view of the earth
to do a critical burn so
that you know whether it
worked or not and have
telemetry from the spacecraft.
So the third phasing
loop since it's up there,
the moon swings around,
whips us around behind it.
As soon as it comes out
from behind the moon,
and here's the
view of it, you can
see earth peeking out around
the horizon down there.
Soon as we're in contact
with the spacecraft,
it's doing everything
preprogrammed.
We just need to be listening
and taking data during the burn
so if something goes wrong,
we know what happened.
It did not.
Everything went great.
So we did two more LO, lunar
orbit, acquisition burns.
LOI1 and then we did 2 and 3.
Those were designed to get us
into this commissioning orbit.
Commissioning orbit is where
you check out the spacecraft
and you check out the
science instruments
before you commit to doing
the science observations.
Some science instruments
need calibration.
Most of them need to blow
their protective covers
before they can operate.
And so it's a time when you
can check out and calibrate
your instruments.
So because the moon has
a lumpy gravity field,
you burn a lot of fuel
when you're close to it.
So we have the commission orbit
set at roughly 250 kilometers.
That's where we sat
for about 30 days.
That is where we checked
out the spacecraft.
Couple of day check
out of the spacecraft.
We did check out of the
science instruments,
but we also did the prime
lasercom experiment.
So that's when we did
the lasercom experiment.
After commissioning, we
did a two stage drop.
We dropped the [INAUDIBLE] down
so we were in elliptical orbit.
Check out the scientist
instrument one more time
and then drop the [? apoapsis ?]
into this circular lunar
orbit where we sat for the
main portion of the mission.
So the lasercom.
The lasercom was
wildly successful.
I was one of these people
who looking at the specs
and looking at how
difficult it was
to close a link at that
distance with the earth,
I thought, oh my
god, they're going
to spend all their time in
a search pattern just trying
to find their ground station
before they could lock up.
And so I thought it would
be very challenging.
It turns out that once
we opened the cover
in one of the phasing loop
maneuvers, opened the cover,
and did the calibration
of the offsets.
I mention that they have
a three stage system.
So spacecraft provides the main
pointing of their instruments.
So we point their optical head.
And then they course point
medium point and then
once they lock up, they have
a piezoelectric server link
system that maintains
very high frequency.
Maintains the lock.
Once they did the
first acquisition
and had all their
calibration offsets,
from thermal
vibrations, anything
that had changed during
launch, once they
got all that calibrated out, the
entire rest of their experiment
they locked up
with in one second.
As soon as they swung
to it, servo, bang,
they there were locked on it.
So it surprised all of us.
It was really well done.
Congratulations to that team.
What they were able
to demonstrate,
and you see some
of it here, they
were able to do 622 megabits per
second downlink from the moon.
20 megabits per second uplink.
It's designed to be asymmetric.
You want more data
down than you want up.
So that was perfect.
The time of flight
measurement less than 100
picoseconds accuracy.
That's very important
for ranging.
One of things you
do to determine
your orbit around the moon is
you do tracking and ranging
of your transponder.
We weren't depending on
lasercom for that, but what
they demonstrated was
orders of magnitude,
better ranging and tracking
than you can do in an RF system.
They also, what's
not on this page,
is they also demonstrated
some things that
are very practical for
use in future missions.
They demonstrated that they
could acquire and lock up
their signal without
the RF back channel.
So they never needed, after
they did it the first time,
they never needed our RF
system to close their link.
They could do it all optical.
That's really important.
They also demonstrated
optical hand off from station
to station.
So they handed off from White
Sands to Table Mountain.
Which with RF we hand
off from ground station
to ground station
all the time with RF.
But that's one of
the things that they
need to demonstrate that they
could do an optical hand off.
They also demonstrated
that they could
operate within three
degrees of the horizon which
is really tough.
So they're going through most
of the murk of the atmosphere.
They also demonstrated that they
could go through light clouds
with a laser.
Unlike RF, moisture and
clouds can block you.
They were able to shoot
through optical opacities
that you couldn't
physically see the moon,
but they were able to shoot the
laser through that cloud cover.
So it was a very, very
impressive experiment.
They did a fantastic job.
Project managers, especially
NASA project managers,
are very reluctant to
depend on new technologies
because it's so easy for
something to go wrong.
But they demonstrated
this enough
where I would fly this as
a primary communications
on a future mission.
It was very, very convincing.
Once we dropped in down from
the commissioning orbit,
the lasercom
experiment was done.
The science instruments
were checked out.
We got into the
primary science orbit.
You can see we refer to
this as the Seadragon,
you can see the backs
of the Seadragon there.
This is because flying low
in this lumpy gravity field,
you never have true
circular orbits.
You're always being moved up
and down by the gravity field.
So to keep ourselves within
the tight band of the science
observations, we did
fairly frequent maneuvers.
So any time you see
a vertical line here,
that's when we did a maneuver.
So we had about 22 maneuvers
during the mission.
To give you a sense
of comparison,
LRO, Lunar
Reconnaissance Orbiter
is also flying around
the moon right now.
They're in a polar orbit
which doesn't have the gravity
gradients that we do.
They do two maneuvers a year.
We typically do a
maneuver every week.
So it's a much higher tempo.
AUDIENCE: [INAUDIBLE]
BUTLER HINE: No, it's the
mass cons within the moon.
The moon doesn't have, we don't
think it has a liquid core.
It's got concentrations of
mass and especially equatorial
orbits fly through
these mass cons
and have a lot of disturbances.
AUDIENCE: [INAUDIBLE]
BUTLER HINE: No, it's not.
And then I mentioned that we
had a perfect launch insertion.
What that allowed was since all
of our maneuvers were perfect,
we had enough fuel to extend
the mission another month.
And during that time, you
can see in the bottom right,
we did extremely low
altitude science.
Our nominal science was
around 30 to 50 kilometers
above the lunar surface.
Once the prime mission
was done and we succeeded
in everything we needed to
do, we could take big risks.
And so one of the big risks was
fly right over the mountains.
And so we have data that
are well below 10 kilometers
there and right at
the end of the mission
we got data down to 300 meters.
Very low.
This is what the mission
op center looks like.
We were split into three rooms.
These views are of the main
[? mocha. ?] What's called
a [? mocha ?] over here at Ames.
These are the folks who
were sending real time
commands to the spacecraft.
We also had an engineering
team that was always
watching all the
subsystems in another room.
But these folks were the
ones that were actually
actively commanding
the spacecraft.
We had to develop some
interesting software tools.
The activity scheduling is
very difficult for LADEE.
This is a tool that was kind
of a child of the tool that
was developed for
the Mars mission.
Where you put your
activity timeline and then
there are resources
attached to each activity
and you can deconflict
the resources
and see what resource usage
against your available
and your margin.
This is what allowed us to
put activities into the plan
that we uplink to the
spacecraft every other day.
So which instruments
were on, which were off,
what the spacecraft was doing,
what attitude it had to be in,
what its power state
was, et cetera.
That was all with this
called [INAUDIBLE]
activity scheduling system tool.
We also did high precision
predicted position.
I mentioned Del LRO is flying
around the moon as well.
They have a nice camera.
And so one of the things that
they did was try to image us
as we flew by.
So this was an
eight kilometer pass
where, you can see in the
bottom left, the two spacecraft
orbits.
So they're flying each one
at 1.6 kilometers per second.
And they're crossing.
And so the camera was able to
actually take a picture of us.
You can see in the top right
the raw picture and then
superimposed in the bottom
right is the spacecraft
attitude against that picture.
So that you can see the
illuminated solar rays,
you can see the
thruster, et cetera.
That's a really challenging
picture to take.
The speeds are so
great that they
had to do image
reconstruction technique.
Which is why you see the
background of that upper right
image has this kind
of a diamond pattern.
It's the image reconstruction
needed to deal with the speeds.
We took star tracker images.
One of things we
were trying to do
is recreate the dust glow image
that the Apollo astronauts
saw around the moon.
So we did a variety
of star tracker.
We didn't have a
camera on board,
but we did have
the star trackers.
And we could put them
into an image mode
and then watch the
sunrise at the moon.
Our impact, I
mentioned that we went
through these really
low altitudes.
This was actually the impact.
It was at the site of a crater.
I'll show you the
crater in a moment.
But our orbit uncertainly
box is that blue box.
It's basically two
kilometers in height.
And you can see the box is
submerged in the ground.
That's what tells you you're
close to impact there.
So we impacted April 18.
Location was on the
far side of the moon,
but it was still just
visible to the earth.
So we actually were in
contact with the spacecraft.
We saw the last telemetry
packet before it impacted.
That helped us localize
exactly where it hit.
And then all the science
data, the real time ops team
were in some kind
of zen state where
they were operating
faster than I've ever
seen an ops team operate.
They closed science data
files, got them to the ground
as soon as the instruments
would take the data.
So they were committed to
not leaving any science data
on the spacecraft at impact.
Which was really
amazing to watch.
This is the impact location
that red plus sign you see.
It's just around the
side of the moon.
This is actually what the
crater, the crater is Sundman V
and you can see
the red cross right
on the edge of that crater.
One of things LRO, they
are a mapping mission.
So they map the entire
surface of the moon.
They passed over this crater
right after our impact.
But their image swap
went through the middle
of the crater.
So they just barely
missed our site.
So they map every
site 28 days later.
So we're waiting to
see when they pass over
again to see if we left a
scar or any kind of debris
on the surface.
But our impact speeds were
so high most predictions are
we vaporized and we didn't
leave physical chunks anywhere.
But you never know.
Science, I mentioned I'm not
going to talk about science,
but the science instrument
results are very interesting.
They detected helium,
neon, argon 40.
Measured a lot of dust.
We, in fact, as
soon as we opened
the covers in the commissioning
orbit, we saw dust.
UVS saw sodium, potassium.
You can see this is a
color-coded histogram
of our orbits.
Our sunrise terminator orbit
was the prime science location
so you can see that
concentration there.
And then these are some of the
species that we discovered.
I'm not going to walk
through this list,
but a couple of notable
ones are we saw water.
After the L-cross mission,
one of the questions
is how does water get into
the polar [? cold ?] traps?
So this gives you
some information
about the transport mechanisms.
Then the dust measurements and
then I'll end on this slide.
The technologies
that we demonstrated,
the new technologies there
are basically four of them
that composite
[INAUDIBLE] structure,
it's so lightweight that two
people, and I was one of them,
so I know this is
true, can lift up
the structure with their hands.
But it's stronger than
most metal structures.
Our s-band transponder
was first flight.
We used and evolved
s-band antenna.
It was not designed by human.
It was designed by
a machine algorithm.
A machine learning algorithm.
Kind of a genetic
algorithm which you guys
know more about that than I do.
But it doesn't look like
what human would design.
The algorithm
designs the antenna
to match the beam pattern
and gains you want.
So it actually looks like these.
These look like
bent paper clips.
That's what a machine designs
to optimize the RF energy.
And those they had flown
once before on a mission
as a technology experiment.
And then just like lasercom
was our technology experiment,
this previous mission
flew these antennas,
then we were able to fly
them for prime mission use.
AUDIENCE: What was [INAUDIBLE]
BUTLER HINE: It's called
ST5, space technology 5.
It was a mission designed
to fly new technologies
and make them eligible.
And that's it.
AUDIENCE: Where
had the [INAUDIBLE]
BUTLER HINE: It
was a new design,
but similar design by the
same principle investigator
had flown on a
couple of missions
like Ulysses and Galileo.
But that particular--
AUDIENCE: [INAUDIBLE]
BUTLER HINE: Yes, yes.
This one's very sensitive.
And these instruments get more
and more sensitive over time.
In fact, the neutral
mass spectrometer
was so sensitive that
one of our worries
was that they would just pick
up the spacecraft outgassing
and not see the actual
measurement that they're
trying to see, but that
wound up not happening.
They actually were able to see.
AUDIENCE: You mentioned that
flying low over the moon
takes a lot of fuel.
I was wondering whether
those were planned burns
to correct for that
or automatic burns?
And do you think that
there is some software that
would give it a map
of the moon's gravity,
be able to give you
a longer mission?
BUTLER HINE: So these
were all planned burns.
All of them occurred,
there was only one burn
that did not occur per our
plan two years ahead of launch.
And that was one
where I mentioned
we passed close to LRO.
We actually had a passage
that was scary close.
It was within three kilometers.
And so we had to do a divert.
We had to move away from them.
And so our planned burn
would have put us very close.
And there's too
much risk of impact.
[INAUDIBLE]
probabilities are low.
So we adjusted that
burn to happen a couple
days later so that we
would not have that.
But aside from that
adjustment, these
were all planned in advance.
The software that allows
us to plan these burns
is very precise now.
Especially Grail
mission which impacted,
a couple years ago, was a
gravity field mapping mission.
And so the gravity field
map that Grail produced
is what you can use for
missions like [INAUDIBLE]
to do very precise predictions.
Just so you predict, you're
going to waiver up and down,
you still have to do
something about it.
So those 22 maneuvers
that you see,
those vertical lines
there, were what
we had to do to keep
ourselves within the band
that we needed to be for
the science observation.
AUDIENCE: It looks like
it's almost always making
your orbit more
elliptical, isn't it?
BUTLER HINE: Yes.
AUDIENCE: [INAUDIBLE]
BUTLER HINE: Yes,
that's why there
are no true circular
orbit around the moon.
The gravity gradients will move
you into an elliptical orbit.
And so you can see if
it got too elliptic,
we would pull it back closer.
Sometimes we would allow the
opposite side of the moon
altitude to grow so that
the side around the sunrise
was where we needed to be.
And also what you
can't see in this plot,
these are just altitudes, but
the orbit also [INAUDIBLE]
the orbit will clock.
So the periapsis will
clock around the moon.
And we needed that periapsis
to stay at the terminator.
AUDIENCE: This is a
question from the members
of the
kerbalspaceprogram.com forum.
I let them ask
questions on my behalf.
BUTLER HINE: OK.
AUDIENCE: So they
want to know do
you think any of the
cost saving features
such as the composite
modular design
will be used elsewhere
in NASA in the future?
BUTLER HINE: Yes.
There's nothing concrete
on the books yet,
but we have two or three
concepts in development
that are going to be
proposed for flights.
As I mentioned,
this bus design can
be used for almost any class
emission between Earth and Mars
orbit.
And so there are some proposals
to use it to go to Mars.
To go into the vicinity of Mars.
It can't land at Mars.
It doesn't have that capability.
But it can go into
the vicinity of Mars.
Near Earth asteroids
is a target.
Lagrange points to
set up an instrument
and keep it at the Lagrange
point, those are good.
A couple of the
Google X-Prize teams
have looked at the
bus or derivatives
of the bus for some
of their designs.
So there's lots of
concepts out there.
I don't know which one
will be chosen next.
I can't tell you.
AUDIENCE: So is that
guy at MIT planning
to send his lasercom to Mars?
BUTLER HINE: Well,
that lasercom was
designed for a class of
missions that were near Earth.
Including the moon
that's near earth.
There's another lasercom
design that hasn't flown yet,
but is done down
at JPL and Caltech.
That is on target to try to
close the loop from Mars.
AUDIENCE: Does the lunar
atmosphere seem to be less
sensitive to human activity
given the almost complete lack
of measurable changes
from the Chang'e 3?
BUTLER HINE: Yeah,
that was interesting.
Although our instruments
were set up to measure any
disturbances from the
Chang'e 3 landing.
They were masked a
little bit because when
we were looking it was also
around a meteor shower which
naturally kicks up
a lot of material.
So we do not see anything that
we could definitively say was
from the Chang'e 3 lander, but
we did see a lot of activity.
It's just ambiguous whether
it was that meteor shower
or whether it was
the actual lander.
AUDIENCE: LADEE had
to endure an eclipse.
Given that it was a
relatively short emission,
why was this not avoided to just
basically save weight and use
a smaller battery?
BUTLER HINE: We
actually did design
it to avoid that eclipse.
What you're talking
about is an eclipse
where the earth is between
the sun in and moon.
So we went through hourly
eclipses through the mission.
So it was designed and scaled
for those hourly eclipses.
What happens in the
bigger eclipse which
happens twice a year,
roughly, is the Earth's shadow
falls on there.
So you stay in eclipse
for a lot longer.
And the eclipse
had just happened
around April 15 was a roughly
four hour total darkness
for us.
We plan the mission
so that we could
accomplish the full mission
and miss that eclipse.
It was only because the
launch vehicle gave us
a perfect insertion.
And then our
maneuvers were perfect
that we had that extra month.
And so that's what allowed
us to try the eclipse.
We actually went, as
an engineering test,
we went through that
eclipse with our systems
in pretty much normal
mode just to see
if it was a big limitation.
And with the exception of being
able to test the propulsion
system coming out, everything
pretty much worked just fine.
We never actually went
dark and had to reboot.
That was one of the
things you worry about.
The system stayed
up and functional.
But we did, since this eclipse
was such a strong driver
in the power system, we did
design the prime mission
so that we avoided that eclipse.
AUDIENCE: [INAUDIBLE]
BUTLER HINE: Yeah.
Thank you.
MALE SPEAKER: Thank you.
[APPLAUSE]
