**NASA**

**May 18, 2004**

**2:00 p.m. CDT**

**Overview**

1.  Trina Ray of the Titan observation science team gives overview of
    Titan science with the orbiter.

2.  Kevin Hussey, manager of visualization technologies of JPL,
    describes simulation of a visualization of Cassini's path near
    Saturn, from 3 hours before to 7 hours after Saturn Orbit Insertion.

Coordinator This conference is being recorded. If anyone has any
objections, you may disconnect at this time. You may begin.

Anita We have two speakers this week. One is Trina Ray, from the Cassini
team, and she's one of the TOST speakers who Kevin Grazier told us about
two weeks ago, and then Kevin Hussey is going to describe the
visualization capability he's been working on that you guys might be
interested in if you are doing any events around the orbit insertion.

Let's go ahead and start with Trina Ray. Trina, do you want to go ahead
and introduce yourself and give us a little background?

Trina Let me just ask a question quickly. Did everybody get the handouts
that I sent out? The first e-mail was really large because it had
embedded pictures, but the second e-mail should have been reasonably
sized. Got them? Okay.

Thank you for inviting me here today. My name is Trina Ray. As you
heard, I work at the Jet Propulsion Laboratory in Pasadena. I've been on
the Cassini project since -- and the years blur -- almost eight or nine
years, I started before launch. I started on the radio science team and
ended up on the Cassini science planning team. The science planning team
is a group here at the Laboratory that works with the scientists from
all over the world trying to integrate all of the various restricted
resources on the spacecraft, and by restricted resources, I mean the
resources that everybody has to share. For example, the pointing or the
data volume, those are things that all the scientists have to share. As
you know, getting scientists to share things is always a challenge.

Specifically, what we did on Cassini is broke up the entire tour into
disciplines. Kevin Grazier probably talked about this a bit last week.
We did the Titan discipline, which is right around the Titan flybys. We
have the icy satellites discipline and I think you'll be having a guest
speaker about that next week, and rings and atmospheres, and so the
different disciplines. Today, I'm going to be talking a bit about the
Titan discipline.

We integrated the 24 hours, plus or minus, all the Titan flybys in the
mission.

Anita Trina, can I ask a question? What was your educational background
and how did you come about to work here at the Lab at this job?

Trina I was actually amazingly lucky. I was a local student here at
California State University Northridge in Physics. They needed somebody
at the last minute to step in and work the Voyager/Neptune encounter. I
heard about that through an avenue you would never imagine, sort of like
at an amateur astronomy group. It was the most amazing thing. I went to
this amateur astronomy group, and I said, "Yes, I'm going to apply for a
job at JPL next summer," and this one guy said, "I know somebody who
needs somebody. Can you send me your resume?" I said, "I'll be out of
town tomorrow. Can I send it to you the next day?" Of course, I had no
resume. I spent the whole next day writing my resume and they hired me.
I kid you not. They hired me to work the Voyager/Neptune encounter. They
paid me money.

When I was here, I got exposed to the experiment rep position. The
experiment representative position at JPL is really neat. You're a
scientist who interfaces between the project and the science team and I
said, "That's a cool job," and I went off and got a Master's Degree in
Astronomy. I have a Bachelor's in Physics and a Master's Degree in
Astronomy and I just celebrated my 15^th^ year here at JPL.

Let's go ahead and start. By the way, how much time do I have?

Anita We have the line for an hour and a half and Kevin \[Hussey\]
probably needs half an hour to 45 minutes of that.

Trina I'll shoot for right around 45 minutes, then. Of course, just ask
questions. It's no problem. The package that I sent out, it was, by the
way, quite a challenge to get everything I wanted to say down into about
four slides. When I first started, the package was over 50. Then I got
it down to 25, and then I got it down to 12 and I said, "I have to send
12. I have to," and then I thought, "No. I can do this. I can get it
down to four." It's a nice summary, I think.

Just to let you know, most of you are probably already familiar -- slide
two -- Titan is the largest moon of Saturn. It's the second largest moon
in the Solar System. It's actually larger than the planet Pluto. It has
a lot of features that are similar to a terrestrial planet. If it had
been in orbit around the Sun instead of Saturn, it absolutely would be a
planet. It has a thick atmosphere, nitrogen rich. There are methane
particles in the atmosphere. The sunshine that falls on the methane
particles produces photochemical smog. For those of you who are local to
Los Angeles, it's very easy to understand why it is that you can't see
the surface of Titan because we live with it every day here. The smog
blocks our view of the mountains, which are only a few miles away. You
could imagine a whole atmosphere just filled with photochemical smog.

The surface of Titan, then, has been hidden from us mostly, although
recently we've had some advances in using filters to see down to the
surface, but we think there might be very exotic features because you've
got this thick atmosphere. You have methane in the atmosphere that gets
hit by the sunshine, and then it makes hydrocarbons. The hydrocarbons
should precipitate out and fall onto the surface, so there might be
hydrocarbon rich lakes or rivers or waterfalls. It's quite exotic,
Titan. It's the largest piece of real estate in our Solar System that is
pretty much completely unknown to us, and I think that it's going to be
very exciting for the public and for all of us, as we start to learn
about Titan as we get there.

The next slide in the presentation, I just threw together, from my
50-page presentation, I tried to capture just a set of interesting Titan
observations through time. We've been observing Titan since the 17^th^
century, and over on the left I found on the Internet -- the beauty of
the Internet -- I just did a search for "Christiaan Huygens' Titan
observations" and some sweet soul somewhere at a library has digitized
all of Huygens' documentation, and you can just click on any page of his
book. I downloaded the two pages that have the Titan observations. You
can see it right there in the center, with Saturn going right down
between the two pages and you can see Titan as a little star that starts
on the left and moves to the right and goes back to the left.

That's the first publication ever of Titan observations and that was
Christiaan Huygens. Christiaan Huygens was a famous Dutch astronomer and
was actually the developer of the pendulum clock. He was the discoverer
of Titan and he was also the one who put together that all the
observations that had been seen over the past several hundred years, at
that point, of Saturn, could be explained by rings around Saturn.

Down at the bottom of this little collage of images are the Voyager
images. Of course, we learned a lot about Titan on the Voyager flybys.
One of them went very close; Voyager 1 went very close to Titan, but as
you can see in that picture, bottom center, what do you see? Nothing but
smog. It's kind of a cruel trick, I think, to send a spacecraft all the
way out to Saturn and for it to particularly fly by Titan as one of its
objectives, and when you do, the filters onboard the spacecraft can't
seen through to the surface. That was a trick, but we did see some
interesting stuff.

You can see, even in that image there at the bottom, you can see that
there's definitely a polar feature, that little dark band up at the top,
and you can also see that there's some sort of differentiation between
the northern hemisphere and the southern hemisphere. Then over on the
right, we've got some close-ups showing the haze, so there's something
going on in the atmosphere of Titan, and then in the upper right, we
have the Hubble images, which are more recent. Now, these are images
where we use a narrow methane filter to peer through the atmosphere and
see to the surface.

Pretty much what you can say about the Hubble images is that there's
clearly a splotch on there and we've been able to get the rotation of
Titan from tracking the splotch, and that's about it. There's a splotch.

M A question, any chance Huygens can make a soft landing? Is it set up
for a possible soft landing on Titan in case it does encounter a solid
surface?

Trina It absolutely is set up for that. In fact, there's a science
surface package onboard the Huygens Probe that is designed to do a
couple of different things. For example, it's got these little prongs
that stick out the bottom of it that will be able to measure how hard
the surface is it's impacting, so if it hits solid rock.

M What's the estimated descent rate, five feet a second or two feet a
second?

Trina Estimated descent rate of the Huygens Probe, I do not know, I will
have to look that up and get back to you, or maybe, since Shannon is on
the line, she can do that.

Shannon Yes, I will look it up while you're talking. I've got it
somewhere.

Anita I have a question, too. Do we know the axis tilt on Titan? I'm
just looking at the north/south hemisphere difference.

Trina Titan is, let me think.

M Synchronous orbit, isn't it?

Trina It's definitely a synchronous orbit. It takes about 16 days for it
to go around and 16 days for it to orbit. It's one to one. I do not know
the tilt. My gosh, two questions and I didn't know either of them.

Anita & Shannon We will look them up.

Trina The tilt of axis of Titan relative to Saturn, I should know that,
shouldn't I? I want to guess, just from looking at that picture in the
center there, I can see the equator in the bottom and I can see the
sunlight coming in, and I know that Saturn is tilted about 20 degrees,
so I'm guessing that it's going to be roughly co-aligned. I predict that
once we learn the answer, it will be roughly co-aligned, just from
looking at that picture. I thought it would be nice to add, in fact, the
picture that I was talking about, the one top center, which is a recent
image from Cassini taken of Titan. You can see where already Titan is
20, 30 pixels across. This was taken 90 degrees difference, so we took a
picture and then we waited for Titan to rotate 90 degrees and then we
took another picture, and that's the little grid that you can see on the
bottom.

I think if you have an imagination, you can say that there is
differentiation in the grayness there, but we're going to get so much
better than this, just wait. We're getting closer every day, and it's
just going to be phenomenal. In fact, we have a really nice Titan movie
suite of observations coming up in late June, just before Saturn orbit
insertion.

Anita When is the closest approach to Titan?

Trina We have actually several closest approaches to Titan and I'll go
through that. In fact, that's a good lead in to the next slide. What an
excellent question.

Shannon I have the impact speed for Huygens when you're ready.

Trina Okay, impact speed for Huygens is?

Shannon Five meters per second.

M That's hard.

Trina It also has, just to round out that question, obviously it has an
accelerometer, so if it hits sand, it will know because it has these
little prongs that stick out of its feet and if it hits water and sinks
slowly, or sinks quickly, or if it hits methane and sinks slowly, we'll
be able to tell both of those things.

Anita And it has landing lights.

Trina It actually has landing lights. That's true. On page four of the
package, what I tried to do here was a summary of our Titan observations
for the whole mission and give you a flavor of what we're going to be
doing with Titan.

We have 46 Titan flybys in the mission. They are scattered throughout
the tour. We probably don't go but two months, I think at the most,
without a Titan flyby. This year, I thought, would be of more interest
to everybody on the line. We have what we call the T0 flyby on July 1,
2004, and in fact, this is a very far, distant flyby, but it's just
hours after Saturn orbit insertion. One of the reasons we're doing these
observations is because the Huygens Probe really needs to have some idea
of the winds on Titan. We're doing a Titan movie in late June and then
we do the Titan observations right after SOI, and hopefully, then, as
we're doing that first big orbit, we'll be able to do the analysis of
that information, that data, and get it to the Huygens people by a
month, or two or three months, so that they can take that into account
when they're getting ready to deploy the Huygens Probe in December and
land it in January.

In between those two times, we have our first two close flybys. The TA
flyby is in October of 2004 and the TB flyby is in December of 2004. The
nice thing about these two flybys is that they trade what's happening at
closest approach. TA is a radar flyby, which we blast the surface of
Titan with radar, which of course can see right through the smog and we
get an echo back. The TB flyby is the ORS, optical remote sensing suite
of instruments that are taking a look at the surface of Titan. This is
where we'll see if the methane filters that we put onboard are going to
perform as excellently as we expect. Of course, we'll get that
information at T0, too. At T0, we will be able to know if the methane
filters are not working. If they're not working, we'll know. If they are
working, then we'll just continually see how good they are. Everyone has
the expectation that, of course, the methane filters will work and that
we'll be able to get surface images both from the camera and from radar
and from the infrared cameras, also.

M How many of the 46 flybys will allow you to see the landing site for
the Huygens Probe from the geometry of the encounters of the 46 flybys?

Trina Only a few of them. The TA flyby has a hint of it. Just in between
the ORS and the radar, they have a tradeoff right on TA, maybe about an
hour or so out from closest approach. They can almost get to the landing
site there and then we won't actually see a really good image of the
landing site until very late in the mission. We have a beautiful flyby,
T44 I think, that goes just right over the landing site. There are only
a few times in the mission where we get really good, high resolution of
the landing site.

Now, of course, I should say that global resolution of the landing site,
we will be able to get that on TA, but that's not going to be the high
resolution. That will be the global resolution.

You guys deal with JPL all the time and I'm sure you're used to our
naming convention now. Of course, the naming convention for the Titan
flybys is as obscure as you could imagine. When we first started the
tour at the tour design and we settled on the final tour that we're
using, we simply numbered them, T1, T2, T3, T4, all the way out to T44,
but then when we had to redesign the early part of the mission for the
Huygens receiver problem, we took the first two orbits and made them
three orbits, so T1 and T2 went away and instead, we have TA, TB, and
TC. That's why you will see a jumping back and forth between A's and B's
and T1 and T2. That's why I always try to put at least a date. I can
give you, in fact, I should have probably put it in there, it's actually
October 27^th^ and December 14^th^ are the two dates on TA and TB.

M Same date as our total eclipse of the moon over the United States,
October 27^th^, I believe. Yes.

Trina Cool. There's a total eclipse of the moon. That's interesting. I
wonder -- no, what would be the chances that there would be an eclipse
of the moon between the Cassini-Moon-Earth line? What would be the
chances? That would be wild. We would lose the downlink. We should check
that. No, I'm sure somebody is checking that. What are the chances of
that happening? Slim and none, and slim just left, but I did make a
note.

Were there any other questions on the scope of the flybys? What I wanted
to do then was give you a sense of how each flyby goes because the
flybys are pretty much plus or minus 24 hours that are just intensely
Titan observations and almost exclusively Titan observations.
Essentially, what's happening is you're flying in towards Titan at about
six meters per second. Titan is growing in the field of view. It's not
really moving sideways too much. It's pretty much just growing, so on
your way in, we're doing all the optical remote sensing observations.
We're doing infrared observations, ultraviolet observations, the big
low-res global mass, all that kind of stuff.

As we get closer, right around two to five hours out from closest
approach, now we have to really turn the spacecraft to continue to track
Titan because in the space of about those two hours at closet approach,
we have to move the spacecraft 180 degrees, as we fly by. It's always
the time around closest approach that is the most valuable. It's always
the time around closest approach that is the most contentiously desired
by the scientists and it's always the time around closest approach that
is the hardest for the spacecraft to accomplish. In fact, the hardest
thing in the Titan group, when we sat down to decide what we were going
to do with the flybys, was to decide what was going to happen at closest
approach. Outside of closest approach, after a while, we got the knack
of it, how to integrate who can use what time most efficiently, who can
get the best science at 9 hours out, and that sort of thing, but the
closest approach time, bitterly fought. It took the scientists working
on the Titan group easily over a year to decide on just the closest
approach times of the 44 flybys, so really, really quite contentious.

Of course, what we have is a nice spread now, now that we're all done
and we have completed that work. Closest approach time varies between
radar flybys. Roughly half of the flybys are radar right at closest
approach. Their main science in the mission, obviously, is at Titan and
they wanted to have at least 20% surface coverage by the time that they
were done. They get these little swathes over the surface of Titan and
they wanted to have at least 20% by the time they're done. We're a
little bit less than 20% right now, but we're right in the ballpark.

We have a few, right at closest approach, that the optical remote
sensing suite of observations were able to argue for and negotiate. We
also do a lot of limb and upper atmosphere observations in that plus or
minus two hours. Not a lot, but we do have a few that go down there.
Obviously, some really good upper atmosphere observations happen in the
nine hours to ten hours away from closest approach.

Another group that comes into play once you get to closest approach is
radio science. Radio science is an instrument where you use the radio
antenna on the spacecraft to shine it through the atmosphere of Titan to
the Earth and since we built the radio on the spacecraft and we built
the receiver on the Earth, the only difference between the signals sent
and received should be how the signal got modified by the atmosphere of
Titan. Radio science comes into play at closest approach for
occultations and also, radio science is able to do an observation
similar to radars, where they blast the surface with the radio and they
bounce it back to the Earth. They can tell you a little bit about the
surface that way, also, very complementary to the radar observations.

Finally, the ion and neutral mass spectrometer instrument takes in situ
measurements of the atmosphere and they desperately want the closest
approach time because it's only the two or three minutes right around
closest approach that they can actually get a good sniff of the
atmosphere. Of course, they want to do that at local daytime of noon, at
6:00 p.m. and 6:00 a.m., and they want to do at different times in the
mission. They want every 950 flyby, but then so does radar, but then so
does ORS. As you can see, it's quite contentious, but it was a lot of
fun to work on.

Another thing that happens with the Titan flybys that is somewhat
atypical of the other talks that you'll hear from the Cassini presenters
is it's quite ambitious, what we ask the spacecraft to do. We are one of
the only groups that asks the spacecraft to routinely go on thrusters.
You can move the spacecraft faster on thrusters and you have more,
what's called, attitude authority. Because we go 950, we're actually in
the upper atmosphere of Titan and Titan's atmosphere is pushing against
the spacecraft and you have to fight against that to hold the spacecraft
steady. We are required, if we get closer than 1300 kilometers, to be on
thrusters because thrusters is the only mechanism onboard the spacecraft
that has the attitude authority to hold the spacecraft steady and not
tumble it in a close Titan flyby.

Anita What do you mean by "go 950?" Could you explain that?

Trina The 950 is the 950 kilometers altitude. Did you want to know how
many times?

Anita I just kind of missed the 950.

Trina Sorry. When we fly by Titan at an altitude of 950 kilometers,
that's when we are in that upper atmosphere and we have to fight the
Titan atmosphere. We are required by flight rules -- I was going to say
by law -- required by flight rules to be on thrusters because it's the
only thing that can hold the spacecraft steady at that altitude.

Anita How often do you do that?

Trina We do that, I don't want to say half the time, but roughly maybe
half the time. We do it a lot more out in the 2007 timeframe because we
have a little set -- I should say 2006 or 2007 -- the set of Titan
flybys that drive the tour design, in fact, I'll come back to this in a
minute, driving the tour design using Titan there's a little set of them
that happen in 2006 and 2007, and those are all 950 flybys, one after
the other, almost in some cases, every 16 days, just boom, boom, boom,
one after the other.

The Titan group is one that asks the spacecraft to do the things that
are the most ambitious. We really push the spacecraft. We're on
thrusters, so obviously, we have to keep track of our usage of our
thruster consumable, which is hydrazine. We always are asking for the
most power, particularly once radio science comes on, to do the radio
science occultations. We always fill up the SSR, so we always enter the
Titan flyby with an empty recorder and we always fill it to the brim and
then we dump the whole thing.

Anita The solid state recorder?

Trina Yes, solid state recorder. It's quite challenging to the
spacecraft. Of all the teams that do the integration work, the Titan
group is one of the teams that routinely has a spacecraft member who
participates in the group and we routinely have to go to the mission
planning people to resolve issues. For example, how much hydrazine are
we using on the Titan flybys and is this where we want to be using the
hydrazine?

Anita How many people are on the TOST team?

Trina Let's see. There's the core TOST team, which is one representative
per instrument, so that's 12 representatives, plus the coordinators, the
Titan discipline scientists, Candy Hansen and Scott Bolton, and then two
or three science planning engineers. Then there's a little bit broader
TOST group that meets every other week and that's more like 20 people.
It's the same 12 as before and then go ahead and add in a sprinkling of
five, six, or seven others.

It's actually a fairly small group. One of the reasons we started with
the one rep per team plan was it was going to be very high powered
negotiations for Titan and you needed to have the people who had the
authority to make that call. When we put the one rep per team rule in
there, that meant they sent their best guy or gal to the meeting, and
then they have the authority to speak.

I wanted to talk a little bit about the broad science themes that we
have of Titan because here we have these 44 Titan flybys. We're spending
48 hours around each one doing nothing but Titan science. The obvious
question is, "What the heck are we doing with all that?" We really have
four major themes and we try to balance the four themes. For example, if
you just went with the radar, the radar team would want to do everything
about surface characterization and forget the other stuff, because they
could get more and more surface coverage. Right now, they are sitting at
20%. They'd love to have 25%. We really had to balance the themes first
and then go in and distribute the flybys so that we met this balance of
science that we really need.

The first one is the interior structure. Obviously, it would be great to
learn something about the interior structure of Titan. We're going to be
doing that mostly with things like the radio science experiment where
you fly by Titan and you use the fact that you can send a radio signal
from the ground to the spacecraft and back to the ground. This makes for
a little like a rubber band link, between the ground and the spacecraft,
which is so accurate that we know exactly how Titan is pulling the
spacecraft in a gravitational sense and we can get it down to
millimeters, how accurately we know where the spacecraft is.

As we do the Titan flyby, as we fly by Titan, we monitor how the gravity
of Titan affects that link. The obvious thing we can learn, first off,
is the mass, but then if we do it really cleverly, we can actually learn
about the interior structure. If you do it when Titan is close to Saturn
and far away from Saturn, because Titan has a slightly eccentric orbit,
you can actually get it sort of like the moment of inertia and a little
bit about how Titan is flexing, and then you can do some modeling and
you can actually get at the interior of Titan. We were successfully able
to do that at Ganymede at Jupiter, so good stuff there. Obviously, the
magnetometer is on all the time, so if we see an internal magnetic
field, that would be interesting just off the top.

The second broad theme is obviously surface characterization. The
surface structure of any body in the outer Solar System is interesting.
It tells us something about the history of the body by looking at things
like cratering statistics. It also tells us something about what sort of
processes are going in. Do we have volcanism? Do we have tectonics?
Titan really is not like any other moon in the Solar System because of
the thick atmosphere, so there are probably interactions between the
surface and the atmosphere that go on, erosion, that sort of thing. We
have very few moons where erosion could be a huge thing, wind and rain.
Just imagine if you get pictures and you've got rain and waterfalls and
tectonics, erosion. That would be so cool.

The third major science theme is the atmosphere. Obviously, the
atmospheric properties of Titan are things that are very interesting to
us. We already know the atmosphere is basically nitrogen, but that it
has a minor constituent, that's significant, of methane. Methane, of
course, when it's hit by sunlight, breaks up into other hydrocarbons;
acetylene, propane, that sort of thing. This is irreversible. When you
have methane and you hit it with sunlight and you break it up, it's
over. You can never get the methane back, so the fact that there's still
methane in Titan's atmosphere is interesting. Where is it coming from?
Is it getting re-supplied and from where? There are all kinds of things
that people talk about. The mythical methanogens, the biological
creatures on the surface of Titan that would make methane, but remember
Titan is very, very cold. It's not like it's cows or anything. That
would be cool, though, wouldn't it? If we discovered cows on Titan, that
would be the front page of the *New York Times* there.

Anita How about termites?

Trina Termites, there you go. That's another methane-producing creature
here on the Earth. First of all, where did the nitrogen come from? What
is the source of the nitrogen because it's a thick nitrogen atmosphere?
It's not just some wimpy nitrogen atmosphere. It's thick. And the
methane, where is the methane coming from? Of course, once the sunlight
hits the methane and you make this acetylene or propane or whatever,
that stuff should just fall to the surface, and just, Titan having been
around for however many billions of years that Titan has been around in
the Solar System, or even millions, how thick is that going to be? Is it
going to be a kilometer thick of ethane, an ocean of ethane? The
questions are just fascinating and so different from any of the other
icy satellites in the whole Solar System, and really, I think, really on
par with Mars in terms of how totally fascinating Titan could be to
people.

We do have some recent observations, where we've blasted the surface of
Titan from the Earth with radar, and we have been able to make some
statements about, "We think that there's no global ocean, but we do
think that there are lakes and seas." They look for things like specular
reflection. I don't know if you've ever seen a picture from space, where
the Sun is behind you and you get this bright, little spot right in the
center of the ocean, where the reflection comes right back. If you had a
large global ocean, we should be able to see stuff like that from the
radar that we blast from the Earth. We see little spots, and that they
come and go, so we don't think it's a global ocean, but we do think
there are definitely some significant lakes and seas.

M We've been doing that with Mars recently, getting reflectivity off of
it directly onto us. Haven't we?

Trina I'm not that familiar with Mars.

M ...the clouds of Mars.

Trina I don't know. What could make that, because Mars is mostly dry?
You really need a liquid. You need a liquid to get a nice, bright
specular point coming back.

Anita Galileo did some very nice things with Earth.
\[http://photojournal.jpl.nasa.gov/catalog/PIA00728\]

\[http://photojournal.jpl.nasa.gov/catalog/PIA00123\]

Trina Yes, that's a good example. Galileo did some very nice things with
Earth that way.

M By the way, I checked that date. The total eclipse is in Aries on
October 27^th^. Mars is in Gemini near the Eskimo Nebula on that date.
It will rise about midnight that night, local time, so you don't have to
worry about the eclipse occulting Saturn.

Trina I was trying to do math in my head, figuring out where Saturn is.

M Near the Eskimo Nebula in Gemini at that time.

Trina We've only got two more topics. We have the atmospheric
properties. We've already talked a little bit about those, the methane.
Where's the nitrogen coming from? Where's the methane coming from? The
atmospheric properties of Titan are obviously a target. We need to
understand the atmosphere. Unlike every other moon that we fly by, the
atmosphere is obviously going to be an important part of the picture.
It's going to contribute to our understanding of the body as a whole
because it is, obviously, so significant.

Of course, like I said, it's very smoggy. There are layers of haze. In
fact, the light that a person standing on the surface of Titan would see
should be somewhat bright, almost 1/1000 of what you would see at the
Earth's surface, so that would be about 350 times brighter than a full
moon night because of the scattering of the atmosphere. If you were
actually standing on the surface of Titan, you probably should be able
to read a book.

The final thing is the magnetospheric interactions. Titan is a moon.
It's about 20 R~S~, Saturn radii, out from Saturn. It moves in and out
of Saturn's magnetosphere relative to the solar wind, so there's a real
interaction between Saturn's magnetosphere, Titan, and the solar wind.
You have magnetic field lines that drape around Titan that create wakes
and bow shocks. We have all of our fields and particles instruments
contribute to investigating Titan's interaction with Saturn's magnetic
field, so that's definitely one of our main goals.

It's convenient that most of the fields and particles instruments can
get their data just as a ride-along with the other observations. If they
have to have their own pointing, and only a few times in the whole Titan
flyby, did the fields and particles instruments have to have their very
own pointing. I think there are only two times that I can think of off
the top of my head. Other than that, they get their observations by just
riding along with everyone else. Thank goodness, because if we had
another team in there, fighting for closest approach time, I would have
been dead. I couldn't take another team. If there was one more team
fighting for everything, it would have killed me.

In summary, with three minutes left on my 45-minute mark, the
exploration of Titan is just so fundamental to this mission, the Huygens
Probe is actually going to Titan. We've got 44 flybys of Titan in the
mission. We've got a handful of icy satellite flybys. We have a dozen or
less targeted flybys of all the other icy satellites, so clearly, Titan
was just an absolute primary mission objective. By working with what we
can learn from Cassini and our time there, what we can learn with
observations we're still doing here on the ground, and obviously, the
Huygens Probe, we really hope to answer all the basic questions
regarding Titan. Where did it come from? What's its evolution? What's
going on with the atmosphere? What's going on, on the surface and
interior, and really, do an entire discovery of a whole new world.

That is the end of my presentation. Are there any questions?

M Can you give us some idea of the data volume that we're going to be
getting back compared to Galileo with its recorder problems and antenna
problems?

Trina Sure. Do you want to know that on a mission sense or on a Titan
sense?

M An overall mission sense.

Trina To give you an idea, I think Galileo sent back over the course of
its mission, I'm going to guess, 12 gigs.

Shannon Yes, that's about right. I don't know exactly what the numbers
were.

Trina Cassini is sending back 45 gigs in the first sequence, which is
only four weeks long. The Titan flybys, of which we have 44, we have a
four-gig solid state recorder and we fill it up every time. We're going
to have over 150 gigs on Titan data alone.

W Galileo, by the way, whole mission, 12 gigs.

Trina Yes, it rocks to be us.

Eric Is that gigabytes or gigabits, just to be specific?

Trina Sorry, gigabits I should say, not bytes. The number for Galileo
was bits, also.

M What do you guys expect for the turnaround time? In other words, when
you get to Titan closest approach, how long after that do we start
seeing images on Web sites?

Trina Of course, what's going to happen is the Titan flyby is roughly 24
hours around the actual closest approach time. We're doing our
observations on the way in and the way out, so we have a full 12, 14,
18, 20 hours of observations, both in and out of Titan. I think the
earliest downlink we do in the whole mission is 15 hours after closest
approach. Then we do a full nine-plus hour downlink and we downlink all
the data after that. It all comes down in that flyby, in that DSS \[Deep
Space Network station pass\]. After that, it's out of my knowledge what
the teams are going to be doing, in terms of the press releases. There
are other teams on Cassini who deal with that, the media teams and
stuff. Just so that you know, plus or minus 24 hours belongs to the
observations and then the downlink is outside of that.

It probably should be noted that that's a challenge for Cassini, in
general. All of our instruments are body-mounted onto the spacecraft, so
it's very hard to do synergistic or cooperative observations. You really
just simply have to share. We have to downlink to the Earth. That means
a high-gain antenna has to be pointed at the Earth. You cannot do
observations when the high-gain antenna is pointed at the Earth because
the chances of your target being confined to the one little strip
around, if you could point the high-gain antenna at the Earth and spin
the spacecraft, the cameras can see a six-milliradian strip circle
around them, cylinder around them. The chances of anything interesting
being in that strip are slim and none. We spend roughly -- roughly -- 15
hours a day doing observations and nine hours a day downlinking and we
do that every day, day in and day out. A Titan flyby is a little bit
different because we spend more like 40 hours doing an observation and
then we do a downlink.

Was there another question?

M I have a question. I'm calling from New Hampshire. I had heard a while
back that on Titan, methane plays a similar role to what water does here
on the Earth, like there might be methane bergs, for example. Is that
still valid?

Trina I believe that it is. The people who do the work on that sort of
thing, what they do is take the rates that we see methane in the
atmosphere now. We assume that that's no different, so we have the same
rates before, and then they say, "Okay. With the sunlight hitting
methane, you would have so many hydrocarbons falling and you would have
an ocean of ethane that was a kilometer thick, all over Titan," and then
they say, "If you had liquid methane, would it be frozen? Would it not
be frozen," and so they do all those modeling games and they've come up
with a lot of ideas that would work, but we really just need to have
some bounding observations. We just really need to know, what is the
surface temperature? We need to know what's the temperature distribution
in the atmosphere? What's really going on in terms of moving heat around
in the system? We just need to have some basic pieces of information and
then we'll be able to focus in on the models that fit that.

Anita Any more Titan questions for Trina?

Trina Okay, sounds like that's it. If you have any follow-up questions,
just feel free to send an e-mail to Shannon or Jane or anybody, and
they'll get the questions to me and I'll go ahead and make sure they get
answered.

Anita Can I just ask one thing? You put in a lot of hours at our Open
House this weekend. Was there any common question amongst our visitors
who got to see our new half-scale model or anything about the mission
that was asked?

Trina I think everybody was excited about the mission. They were like,
"Wow. This is happening? This is neat." I think everybody was impressed
with the fortitude of the Cassini group. I don't think people
appreciated how long we've been at it. We've been cruising for seven
years. Most people have been on the project for over a decade, and when
we had a little party here on lab last week to kick off the S1 sequence,
which was just amazing for those of us who have been on the project for
a decade, we've gone through 44 cruise sequences and we actually got to
the first Saturn sequence. It kicked off on the spacecraft last Friday
at 11:40, and it was like, "Wow." The hours, the years, that project
people have put into this project is staggering compared to the other
missions that are out there.

Shannon Trina. This is Shannon. I can actually add to that. I brought my
seven year old's Tiger Cub group to Open House, and remember, he was a
newborn when we launched.

Trina Oh, my gosh. He was, wasn't he?

Shannon Yes, he was.

Trina That tells you how long we've been in cruise, everybody.

Anita I have to share with you a comment I overheard, where a man was
saying to his son, "And this spacecraft will go into orbit at Saturn
right after we get back from vacation."

Trina Actually, I did have the cutest little girl. I was talking to her
and I was telling her about how the instruments are body-fixed to the
spacecraft and how you have to share. She said, "That means you can't
take pictures all the time?" She's six. I said, "No. We have to share."
She looked at me and she said, "Well, that was stupid." I just looked at
her and I said, "Out of the mouths of babes." If I could go back and
change one thing about this spacecraft, it would be the lack of a scan
platform. That was a huge mistake. Whatever money they saved, they have
spent it many, many times over.

Anita Ellis said that, too.

Trina Yes, but I think they knew that at the time. I don't think they
didn't know it. I think they were thinking, "You know what? Without the
scan platform, it will be hard," but I don't think they realized how
hard it would be because what came to light, only through starting to
work the details, is it's not just sharing the spacecraft. It's
protecting instruments that are not your own, that you know nothing
about, from damage.

For example, the CIRS instrument, which is our composite infrared
spectrograph, the CIRS instrument has a radiator that sticks out the
side to cool it off. It's an infrared telescope. Obviously, it has a
cooler. This cooler cannot have warm bodies shining on it, so it cannot
have the Sun shine on it and it cannot have Saturn. When you're in orbit
around Saturn, guess what? Saturn is big. Saturn is big and it's
everywhere, and if it's not there, then the Sun is there. Whole
hemispheres that are knocked out. "We can't do that because we'll get
heat on the Saturn radiator." The scan platform, the amount of pain that
we've taken because of that is just staggering.

Anything else for me, then? It doesn't sound like it. I'll hang on here
through Kevin's presentation in case anybody thinks of anything.

Anita That would be great. Kevin, are you there?

Kevin I am.

Anita Would you like to introduce yourself and tell us what you're up
to?

Kevin Sure. Kevin Hussey, and I have an interesting title, the Manager
of Visualization Technologies here at JPL. Let me just give you a brief
history. I started here in '79, worked for 16 years, primarily in the
image processing -- I should say, exclusively -- in the Image Processing
Lab and then the Digital Image Animation Lab. I left about eight and a
half years ago to join Disney Feature Animation. I had eight good years
with Disney and came back about seven months ago.

Upon my return, what I wanted to do was work with those people here at
JPL who were involved with the visualization of scientific data and
basically try to help them get additional funding, to work more closely
together, between themselves and with our Office of Communications and
Education, to just promote the field of scientific data visualization.
In my initial return, I spent a good deal of time talking to lots of
people at JPL, who are involved with visualization, with the idea of
finding out what's going on, number one, and seeing if I could put
together people who had capabilities with organizations who had
potential need.

What I'm going to describe today, this visualization broadcast system
that we're trying for Cassini, came out of such a meeting that I had
with a gentleman named Dr. Richard Widener, who is the supervisor of a
modeling group here in the Space Science Data Systems section at JPL.
Over two years ago, he developed this capability to basically allow for
the broadcast of multiple animations, if you will, using a very small
bandwidth of the network. The idea behind it is that of course, to send
an animation, a full screen animation to somebody over the network, it
would be kilobits, if not megabits a second to do an animation, to
broadcast it.

The idea was, and he demonstrated this two years ago -- I wasn't here at
the time -- that you could, instead of sending the entire animation, you
should just send the commands required for the computer receiving these
commands to do the rendering itself. What I'm describing is today's
gaming technology. If you are into network gaming at all and you play
people on different parts of the planet or in the country and you're
able to actually have very elaborate scenes up on your screen and to
have both parties interact, they use this technology of only sending the
graphics ... and having the graphics card in the computer do the
rendering, so that what you see on the screen is of much higher fidelity
than you could afford to send over the network.

I saw what Richard was doing. I'd also been speaking with Alice Wessen,
from the Cassini project, and others who have various challenges in
trying to communicate to the public what is taking place during
something like an orbit insertion. We came up with this idea that
wouldn't it be great, in fact, she had mentioned, "Wouldn't it be great
if there was some way we could actually show people what was happening
at the Cassini spacecraft, while it was happening, so while the
thrusters are firing to put the spacecraft into orbit, could we see that
happen? Could we watch this thing turn to take the images? Could we ride
along, if you will, with the spacecraft?"

Basically, I put two and two together. Basically, I got Richard together
with Alice and Bob \[Mitchell, the Cassini Project Manager\] -- I'm kind
of the intermediator in this -- and we came up with this idea to go
ahead and use this broadcast capability, along with four or five
different simultaneous animations that Richard would create. I shouldn't
call them animations. They are visualizations of simulations. Do you
follow that? We're going to view a simulation. Richard and his group
pride themselves in doing very scientifically accurate simulations for
our flight projects. The idea is that we are going to, in fact, we are
in the process of doing, and I have examples of that, that I know Anita
has seen, Alice has seen, and of course, I'm working very closely with
Bob Mitchell on this, to show what is taking place at the spacecraft
while it's happening.

We've been given the sequences. We know what Cassini is going to do
when, pretty much, and so we're able to speed this up for the purpose of
viewing and planning. We currently are showing about four different
channels of what's going to happen at the spacecraft, while orbit
insertion takes place. What we're setting up, the primary idea is that
when the press and the world is here at JPL during that six-hour period
during orbit insertion, and the burn alone is about 90-some-odd minutes,
the insertion burn.

W Yes, 96 minutes, basically.

Kevin While that's taking place, there really is no data coming back
from the spacecraft. People want to know what's happening, what's going
to happen next, and so these channels will allow you to actually view
what's happening, while it's happening.

For example, we have one channel that we're calling the spectator view,
which is a view that always keeps Cassini in the field of view, as well
as the center of Saturn. You basically are just flying along with
Cassini, watching it go through its motions and you're about a couple
hundred meters above and a couple hundred meters behind, if you will,
Cassini while it goes through its motions, in terms of crossing the ring
plane and whatever it's going to do, you will ride along with it.

At the same time you could observe it from that angle, let's say 200
meters above or 200 meters away, you can also observe it from directly
above at several hundred or several thousand kilometers, so you can see
Saturn. You can see Cassini approaching the rings. You can switch back
and forth between these two views, whichever one you find the most
interesting.

We're also going to have a view, we call it the instrument view, so when
images are being taken of the rings, you'll be able to actually observe
what portions of the rings are being imaged. You'll see little frame
marks come up onto the rings, and that's another view. When we start
sending data back to Earth during this period, you will actually see, in
one case after the descending ring plane crossing when data starts being
broadcast, once again, we turn the high gain toward the Earth, we start
sending them, we're going to do a visualization of sending images back
to Earth. We're going to actually trace sets of images as they leave
Cassini and head toward the Earth. Granted, it's about -- what is it --
one hour and 20 minutes, approximately, one way. Someone can help me
with that.

W Yes, at SOI, it's an hour and 24 minutes.

Kevin There will be one view that will actually show pictures, again,
representations of pictures, traveling from the spacecraft. You'll see a
little Cassini. You'll see Saturn. You'll see a representation of Earth,
and you'll actually be able to trace these images as they come down to
Earth. It's just to give you a feeling for how far away it is. How long
does it take for an image to get from the spacecraft to Earth? Again,
you flip back and forth between these various channels.

We've decided on four of the five channels. The last channel is still
open for discussion in terms of what we're going to show. Right now,
we're showing a rearview mirror look, so you look back over the
shoulder, if you will, of Cassini. We have a channel that actually looks
over the top of Cassini, always focused on the Earth, so that when the
carrier signal from Cassini is occulted by the rings, what you will see
here is the trace of the Doppler. It will be cutting off and turning
back on, based on the density of the A Ring and the B Ring and the
various rings. At the same time that's taking place on Earth, we're
going to be showing, you'll be able to see the Earth, as Cassini would
see it, if it could actually see, of course. The Earth is so far away
that it would be a spec. Again, because it's a visualization we made, we
scaled the Earth much larger, so you're going to actually be able to see
the Earth appear and disappear underneath these rings, as you would if
you could see the Earth from Cassini.

Have I painted a picture of what we're trying to do? Am I making sense
at all to you folks?

W When do we get it? When do we get it?

Kevin There are a couple of catches here and Anita sent a document along
with the invitation to this particular meeting that explains some of the
"gotcha's" here. The biggest single hurdle is you can't use a Macintosh,
unfortunately. I've got a Macintosh sitting on my desk. I'm a Mac
enthusiast.

Anita We make no endorsements.

Kevin Just so you know, it's not an anti-Mac thing. It's just that
Richard is using the latest technology available from Microsoft. It's
called the .NET and it is also using DirectX 9, and he's programming
this stuff in the latest technology, and this is why he's doing it. It's
a technology demonstration for him that we are piggybacking on. We've
convinced him that he should use this insertion period as an example
that not only the project would enjoy, but hopefully many others could
enjoy, so he's bought off on this concept. For him, he looks at this as
a technology demonstration. To the project, they look at it as a very
important outreach and educational tool and one that Bob and other
speakers here at the Lab are going to use to show, to visually
demonstrate, "This is what's going on now."

The deal is you need to have a generic PC. It doesn't have to be a
super-duper one. The configurations are listed in this document here. A
P3 or a P4; it's like a 900 megahertz P3 or any P4 with about a quarter,
256 megabytes of RAM. It has to be running Windows 2000 or Windows XP
Home or XP Pro. You do need a high-speed connection, let's say DSL. It
doesn't have to be super high speed, but a DSL or a cable modem and a
static IP address. You have to be able to send us a specific static IP
address because we're going to only broadcast this to people who are
registered. We can't do it to the world. With the computer we have, we
can accommodate, we're saying up to 300 sites.

We are hoping to take advantage of the fact that the museums, with you
guys, your alliance, already have some good, solid connections. You've
been doing some great stuff and I think continue to do with -- I think
you guys are familiar with Eric De Jong and the work that he's done for
Mars -- we are working with Eric in that he will be responsible for
helping to see that the connection between Richard's computers and those
required to broadcast to you are in order.

Once we're connected, once we have a static IP address, and once you
have these minimal machines -- with a card as described here. You have
to have a graphics card that is DirectX 9, TS2 compliant. You can buy
these. I put one here that we recently purchased. It's an NVIDEA GeForce
FX 5700. I installed one myself. It's not terribly tricky to do. We
spent \$180 for our card. We put it in an existing computer that was
down in one of our conference rooms. It's hooked up to an Epson
projector that met the minimum requirement for broadcast. It has a 1024
by 768 pixel capability. While it's not rendered graphics -- you've got
to understand, this is game quality graphics -- it still looks really
good. It's exciting to be able to observe what's taking place.

Again, we speed the clock up so we can play it over and over again and
observe what's taking place. On the night of the orbit insertion, in
fact, this is what we're planning to do, several days before we're going
to turn this on. We're doing this principally for the museums. We're
going to turn it on and run it at 60 times normal speed so that every
minute of animation that you observe will be equivalent to one hour
during the orbit insertion period. Right now, we're looking at three
hours before insertion to seven hours after, so it will be a 10-hour
period that will equate to 10 minutes, for several days before, so that
every 10 minutes, you'll get to observe from three hours before, to
seven hours after. We will just turn this broadcast on and let it run.

You can switch between channels. You can let it run in one channel for
10 minutes and when it starts over again, you can watch a different
channel, however you want to use it. You'll have enough time to become
familiar with what will be seen on that evening, if you plan to have
events or whatever. Even if you don't have events that evening, it's an
interesting 10 minutes. I'm a channel changer at home, anyway. It's very
hard for me to leave it on one channel because you want to see, from
different views, what's going on. It's a rather compelling display.

When it plays in real time, it's more like watching a clock than an
animation. If you have a watch on right now that has a second hand and
you look at your second had, you can see it moves right along, but
that's the speed at which this animation clips along, at a 60 times
speed up. If you look at your minute hand, that's another story. People
don't sit and watch their minute hands, but it's very instructive to
periodically come back and look at the clock to see what's going on.
That's the way it is in real time. Again, when we get to three days
close, we'll put it into real time mode and you'll be able to see what's
happening in real time.

M It won't work on Windows 98, though.

Kevin No, absolutely not. It's time to upgrade that system, sir. I know
you've heard that before.

M I've heard they have trouble with the other Windows, with XP and 2000.

Kevin My experience has been the opposite. Let's put it this way, again,
being a Mac person, my in-laws have a PC with 98 and I cut my teeth on
Windows 98 and I can't tell you what a blessing it was when they
switched to XP. XP is the closest thing to a Mac operating system in the
Windows world.

M Maybe it's time for me to upgrade.

Kevin It's good.

W ME was the one that was terrible.

Kevin ME was a nightmare. I'm sorry if there are any Microsoft fans out
there, but just personal experience.

Kris Kevin, Kris in Des Moines. This is just a suggestion. For those of
us who may want to display this and not have the audience interaction,
could it be possible to have one channel with four or five views at
once, similar to the Solar System Simulator on some of the missions,
that would show smaller portions of all the views at once?

Kevin I don't believe so. Let's put it this way. We want to do something
like that during our event. We're going to have to have four different
computers. You need a computer per channel. Otherwise, it's like your
home TV set. If you want to show four channels at one time, unless you
have picture-in-picture, you're stuck with having a different tuner for
each channel. That's something that Richard and I would like to do
something about, but we are in such a time scale that we don't know if
that will be possible.

I'll bet you that if you did some work, if you bought a very
high-powered graphics card, there might be something you could do, but
you'd have to be on your own. I'm sorry about that. I love your idea. It
would be so cool because again, you're going to go crazy flipping back
and forth, when you're in the 60 times speed-up mode. When you're in
real time, it won't really be an issue. In the 60 times speed up, when
the spacecraft turns for imaging or turns for configuring itself to go
through the ring plane, it moves pretty quickly from one orientation to
the next. That's because it's moving 60 times faster than it is in
reality.

Kris I wonder if there might be a way to automate the computer to cycle
through each view every 10 or 20 seconds.

Kevin Let me make a note on that, auto channel change.

M I have a question on the simulation of the Earth through the rings and
all. They've got the Sun there, 10 degrees away. I think the Earth
doesn't get any farther than 10 or 15 degrees from the Sun as seen from
Saturn. Are you just eliminating the Sun?

Kevin We're leaving the Sun at the proper scale. It's there, but you
won't see it. We thought about it. One of the biggest nightmares for us
in this whole visualization process has been the scale issue. It's a
nightmare and if you want to see things done at the proper scale, you
look at the beautiful work that David Seal has done, his simulations
that are on the Cassini Web site.

M The Sun will be there, but just not blindingly bright.

Kevin It will look like a star. It's just going to look like another
star.

M That was a good idea.

Kevin Richard did use a star field, so things are fairly accurate. They
should be very accurate. Again, his bag is simulation. It's hard for him
to take some of the artistic lease that you must take, but again, this
is a visualization of a simulation. He's very, very particular; I say
that because he doesn't want people thinking that his simulations are so
far from reality.

M You'd be looking back at the constellation Sagittarius, roughly.

Kevin Yes, it would be nothing. You couldn't see it. I was able to show
Bob the Earth being occulted by the rings yesterday. It was the first
time I had seen it because he did it last week while I was out of town,
and it looks good. Again, it isn't a Hollywood production. This is a
graphics, game quality simulation, but it's not bad.

M Sell ABC on the idea, or NBC.

Kevin I tell you what. After having seen this, Alice ... believed that
this is the standard that we should be using for these types of events
because there are great periods of time, where you just don't know
what's going on. We, as humans, we want to know, "What's happening now?
What's going on?" You're going to be able to see. During the event,
you're going to be able to see when the burn starts. You're going to see
an image of the spacecraft, up close, with the thruster A on. You'll see
a representation of the burn. You can go out and get something to eat,
come back, and it's still burning, right?

That's the idea. My main concern about this is that we got into this so
late that we have not been able to package this and put it in a form
that would make it as simple as possible for Museum Alliance members. I
feel bad about that, but we are really concentrating on getting these
views done. Let me give you a couple of dates that are important for
you. One is June 4^th^. By June 4^th^, in fact, between now and the
4^th^, you'll be hearing from Anita, or from me, or from Eric De Jong,
or from all three of us, more than likely, on what we need from you.

One of the things, we're going to need your static IP address for the
machines that will be receiving the broadcast. We're also going to be
sending you what we're calling a beta agreement. We'll be mailing you
this notice, letting you know that this is an experiment, that we can't
promise this is going to work flawlessly. We've never done this before.
This is a new thing. You're participating in a beta test of some new
technology for us. We don't know how it's going to interact at the
farthest reaches of the network.

One of the tricky things about this and the part of the iceberg that's
under the surface, the part that we don't see, but is the most
challenging, is in order for this to work across a network, knowing that
the network is so unreliable in terms of being able to have stable,
long-term, continuous broadcast, Richard came up with a method to buffer
a lot of information, sends it to your computer. It sits on your
computer and it's fed to your computer at the right rate, and then he
sends another pack of data that needs to arrive before the first packet
is exhausted. That is a trick. That's networking technology. That's one
of his specialties, but it's not simple because you don't want to send
it too frequently. You don't want to send it too late and we don't know
how it's going to work in Europe or on the east coast, depending on the
speed of your network connection, or people who are local, who have
several jumps from here to their machine.

You guys are going to help with this. We're hoping that on June 4^th^,
we'll have your addresses. We'll have a little agreement that says that
you understand you're participating in an experiment and that if you
need help with this, you'll be given a person to call here at JPL, who
will try to help you, but you are primarily on your own, given the
instructions and an installation CD that we will send you. If you do run
into problems, there will be someone on the MIPL \[multimission image
processing laboratory\] team, one of the folks who helps with the Mars
Alliance portion, who can help with specific questions, but it will be a
limited support. Richard and I will not be available for that.

I'm just trying to let you know up front that this a prototype. If it
works and we're able to get some of you guys up and running and things
work well here, for our next mission, we'll know from the blood, sweat,
and tears that you all are going to sweat, and we have, what absolutely
needs to be done to make this happen smoothly. Do you understand what
we're after, what we're trying to accomplish here?

Kris That sounds like a great idea. I think it's got great implications
for all the other missions to follow.

Anita Kevin, I have a question. Is there any chance of a little test,
sooner rather than later, because if folks want to do events on orbit
insertion night, they want to know whether this is going to be working
for them or not, before they plan their programs.

Kevin Let me think about this. We were basically picking a week, from
June 14^th^ through the 25^th^, and that's when the testing would occur.
Let me make a note to see if there's something we can do. The problem is
that right now, this basically is a one-person effort. Richard is
working his tail off on making these animations the best they can be and
getting the channels down to Bob Mitchell's satisfaction. I've got to
tell you, we're very impressed with the level of commitment that Bob
Mitchell is putting in this project. I have unprecedented access to Bob.
He's approving these sequences and these animations himself.

So, auto channel change and the other thing is any pre-June 14^th^
testing. Here's what I'd like to try. I don't know if Richard will buy
off on this, but if some of you are able to use the minimum spec that
you've got, that I've given you, and can set your machines up and send
me your static IPs, again, I can't promise anything, but it would sure
make me feel better if I could get a couple of you online and maybe I
can work with you myself to try to see if we could get a couple up ahead
of time just to see feasibility.

Pat One thing we would love to do, if possible -- this is Pat \[Reiff\]
from Rice University -- we now have a portable inflatable planetarium
that uses a 1024 by 768 fisheye projector, so it goes to the inside of a
dome. We've got the top-rated video cards and everything. It would be a
hoot to see if we can actually get this to come up on the inside of our
dome, as well. We'll be taking it to the International Planetarium
Society in Valencia, Spain and will be there for the orbit insertion.
Gosh, if we could have a demo there of this system, that would blow them
away.

W The static IP is going to kill us.

Pat Yes, the static IP might be a problem in Spain. We may have to
figure out how to do that.

Kevin That could be a problem. I've got to be careful here.

Pat If we could download it before we leave. Can we play it back once
it's on our machine?

Kevin That's a different thing. We're going to take one of the channels
and produce a Quick Time version. That's so the Web folks will have
something that they can Web broadcast, if they choose to do so, but that
comes later on. That is secondary to making sure that the live broadcast
works and we've got that scheduled, let me see, it's due, the actual Web
stuff, June 7^th^ through 11^th^ is generation of image sequence for Web
display or Quick Time movies. We're planning to do it, but not until
then.

What popped into my head was if there are any local museums to JPL, you
should contact me directly because I might be able to actually come out,
bring my little install disk, and you can be a guinea pig locally. For
folks who are farther away, who are more adventuresome, there are some
portable computers that have fairly decent graphics cards that would
actually meet this requirement, that are here. If I could get my hands
on your computer, I could load the stuff up, test it, and ship it back.

W We could do that.

Kevin I'm not promising I'm going to do that, but I'm just throwing out
an idea here. That would mortify Richard, I believe.

Eric Kevin, this is Eric \[de Jong\]. What we did during MER was we used
a couple of museums to be like alpha testers, even before the beta
testing. That worked quite well because we got feedback directly with a
handful of people. They realized it was alpha testing and we were just
actually trying to debug it. In some senses, we're kind of in that mode
with the XP server that we've set up. It might be good to get a couple
of alpha testers so that we could actually test the server that we're
planning on using and that way, we'd get feedback and you still could
keep your schedule that you have for your beta test agreement with
Richard, if that would work for you.

Kevin Eric, I think that's brilliant. I love the idea because I need to
go and install something on that server that you've mentioned. What you
just described, for me, would be ideal. It would give us that level of
confidence that I'd feel good about and would provide those alpha
testers with what they're looking for. It gives your team the ability to
see what issues are going to come up. It's brilliant. Let's do it.

Eric Okay. Sounds good.

Kevin Let's do it. Excellent, so there you go.

Pat How do we volunteer to be an alpha tester?

M Yes, maybe Rice will volunteer there.

Kevin Eric, how do you want them to volunteer for that?

Eric I would suggest, one thing about alpha testers are someone that
already has the configuration that Kevin has outlined there, including
the operating system, etc., that you have such a machine in place. I
think that's the minimum to be an effective alpha tester.

Anita Everybody who wants to be an alpha tester, send an e-mail to
Anita, which I will forward to Kevin as a group.

Kevin You can forward those to Eric and carbon copy Kevin.

Anita No, forward it to me, Anita.

Kevin I'm sorry. I'm talking to you, Anita.

Ken Anita, this is Ken at the Science Center. I just want to make sure I
understood what was said, clearly. Were you saying that local
institutions were invited either to have Kevin come down or to bring a
machine up? I just want to make sure I got that right.

Kevin Let me clarify. Eric's idea is the primary mode for alpha testing.
His idea supersedes the one that I said. Now, if there is a problem, if
you're a local institution and you can qualify for alpha testing and
there's a problem, let's put it this way. Let's go through Eric and I
might be willing to actually come locally and help you out if there's a
problem, but let's stick with one mode. I really appreciated Eric's
idea. Let's go with it. Send your request to Anita and we'll work with
you. If you're local and have a problem, it may initiate a trip by
myself down to help you. That's all I can say. Eric, does that sound
reasonable?

Eric Yes, that sounds like a really good way to go, Kevin. Again, if we
can do it by helping you online and using the actual server we plan to
use, that's actually better than having Kevin come out because
hopefully, we'll learn exactly what it takes to do this, to set you up
remotely. We'd really like to do that if we can.

Kevin Right. Good. Are there any other questions that I can answer?

Anita Eric, we are going to require a license agreement for this, too,
aren't we? Software?

Kevin You know what? I don't believe so. We're hoping to try to stay
away from that. The way we're looking at this is this is a visualization
and while there is some software, all the software is here and we're
broadcasting a visualization to these museums. Richard gets very nervous
when we talk about software because this is not software being developed
for Cassini. It's not software. It's a visualization.

Eric A clarification. I think what Kevin is looking at is we're
broadcasting information to the client who displays these things. The
simulation, most of the aspects of it, of course, lives here on the
server side. I'm not totally sure whether the client software needs
something or not, but again, like we did in alpha testing, I think we're
working out those details probably in the agreement that Kevin will have
for the real beta test, I would assume. Is that correct, Kevin?

Kevin Correct. My understanding is that the software that you need to do
this is available from Microsoft. Part of what I do to set computers up
here -- I've only done a couple -- is I download DirectX 9 and .NET,
directly from the Microsoft update Web site, and so this is not software
that we're providing. It's software that Microsoft is providing. We're
just, again, sending just the portion that's necessary for the Microsoft
software to display the simulation. Okay?

Eric Yes, and so really, it's data files or image files or information
files that are coming across to the client, besides the downloads from
Microsoft. Is that correct?

Kevin Yes. You'll have to excuse me. I have to wrap things up here. I
have a 2:00 meeting, in another part of Lab, I've got to dash to. Anita
can handle any correspondence. If you have any questions, send them
through her and she'll know to send it to either Eric or myself or both.

Eric Likewise on this end, Kevin, and thank you very much. We'll talk to
you all soon and I'll see you later, Anita and Kevin. Thank you.

Kevin Good-bye. I've got to sign off.

Anita Thank you, guys. Before we sign off, anybody have any other topics
they want to bring up?

Ken Yes, this is Ken in North Carolina. In the beginning of the telecon
as we were chatting, several people talked about modifying Ring World
and I'd be really fascinated to know how you did it. If you could e-mail
me off-line or after the thing or e-mail Anita and she can forward it to
me, I'd really appreciate it. Thank you.

W How much modifying are you interested in?

Ken I'm curious to see how you adapted it for your audiences.

Anita You guys can communicate with each through the list serve, museum
\@rushmore, or you can just e-mail me privately and I'll collect them
and have them available for whoever wants them.

W There's going to be a chat on the transit of Venus that's available if
anybody is interested. I could forward some information about that
through the list serve if anybody wants it.

M That sounds good.

Anita That would be good.

W It's going to be on www.earthsky.org.

Anita Tomorrow, the Solar System Ambassadors have a training on Phoebe,
which I have invited the museum folks to listen in if you'd like and at
least one of those speakers will also be part of our next Cassini
telecon on June 1^st^. Right, Jane?

Jane \[Jones} Yes. June 1^st^, it will be on the icy satellite flybys.
It will be talking about all the other moons of Saturn that we're going
to be flying by. It's a really wonderful talk and Amanda Hendricks will
be giving that and you can see a little flash feature on the Cassini Web
site, featuring Bob Mitchell and Amanda right now. If you go to the
Cassini Web site, you can get a little flavor for her style and
everything.

Anita I have a question that I'm going to e-mail out to everybody, but
maybe I'll just take the opportunity now since we seem to have a quota
online. Genesis brings its solar wind samples back to Earth in early
September and we are thinking of doing a pre-return Web cast. I'm saying
that folks would have a bigger audience through your museums and
planetariums than they would through schools, in the summer. Is that a
good assumption?

W Yes.

M Say that again now, Anita? What's your assumption?

Anita That if we were to do a Web cast in the summer, it would be better
to do it through you guys, the museums, than through schools.

W Probably.

W Unless you are very, very close. School starts in Texas in mid-August.

Anita Right. Now the second question is if we were going to do a Web
cast, I've had at least one planetarium director say that they only do
their special events on weekends. Would you guys be interested in a Web
cast, more or less, if it were during the week or during a weekend?

W It depends on when it is. If it's early August, say, then weekday or
weekend would work for us here in Chicago because we're busy no matter
what. If it starts to get into the end of August, then we start to die
down a little bit, although Chicago public school doesn't go back until
after Labor Day, so weekend would probably be better at that point.

Pat I have a teacher workshop the week of August 2^nd^. I would have an
audience.

W That would be good.

Anita The week of August 2^nd^, they're going to be doing a Genesis
educator workshop in Salt Lake and I don't think they're Web casting
that. Okay, we're trying to get an idea when to schedule this and we
will be inviting you to participate in some trainings about Genesis in
the next month or so and we'll see how tall your interest is before we
totally fill all your time with telecons with us.

Ken, can I pass along the note you e-mailed to us about the
pronunciation of Huygens?

Ken Yes, sure. Absolutely.

Anita Would you like to tell us what it is? Would you like to say it for
us?

Ken Yes. It was interesting. I had spent a little time on some projects
in Holland when I was back at Raytheon. This was 100 years ago at the
Raytheon Corporation. There were some funny things about the language
and I was wondering what the proper pronunciation of Christian Huygens'
name was and it turns out I found a Web site that confirms what I
suspected. It's a real guttural pronunciation. It's actually pronounced
(sounds like) Christ-i-an Hull-ken. It's a totally counter intuitive way
to pronounce it. It's almost like the "k" in Hull-kins is like Kalda,
the word for cheese. It's a very guttural language.

Anita I'm going to forward Ken's e-mail about that because he also
included a Web site.

Ken I had a general question I was actually going to ask. Isn't today
the day that the spacecraft crosses formally into the gravitational
dominance of the Saturnian system? Doesn't that happen on the 18^th^? Is
that not today? I thought I read that on the Ciclops page back in
February when you first started your weekly announcements.

\[http://ciclops.lpl.arizona.edu/index.shtml\]

Anita Shannon or Jane, do you know?

Shannon No, I don't know. I could run over and ask Trina.

Trina I'm still on the line. I guess I wouldn't have said it like that
because what it is the influence of Saturn is slowing growing. What I
can say is that Friday at 11:40, we formally switched the spacecraft
over from being a Sun-centered spacecraft to a Saturn-centered
spacecraft, so inside the Cassini spacecraft, the attitude control has a
little set -- they do everything with vectors to vectors -- if they want
to point at the Earth, they know the vector between the Earth and the
Sun, and Sun and Saturn, and Saturn and Cassini. That's how it is now.
For the last seven years, it's been Earth and Sun and Sun and Saturn.
It's always been the Sun/Saturn connection is the base. The Sun was the
route of the entire directory, but now as of Friday at 11:40, Saturn is
the base. We formally switched over to Saturn base, in terms of the AACS
\[attitude and articulation control\] computer onboard the spacecraft.

Anita Last Friday or this coming Friday?

Trina Yes, last Friday, May14th at 11:40 a.m. PDT. That's 18:40 UTC
time.

Anita Unless we have any other burning questions, I will let it go for
today. Next week, by the way, for Mars, we are hoping to have one of the
Moessbauer Spectrometer team members online. That was a question, how do
we know what we know from the Moessbauer, about the past water on Mars.
We've set that up for you guys.

I will talk to you all later, e-mail for sure. Thank you again, Trina.

Trina You're welcome. Thank you for inviting me.

Anita Thank you, everybody.

M It was a very nice presentation.

Trina Thank you.

Anita Thank you.