Cassini Orbiter End of Mission Ideas

I understand that as the mission evolves controllers will use Titan to
slowly change the orbit of Cassini to a more or less Saturn polar one.

I was wondering if at the end of the mission there is any chance to use
Saturn, Titan or any of Saturns other moons to change Casini's orbit such
that Titan could capture it.

If enough propellant was available could this be done??

"Bernard Isker" wrote in news:yCZvf.4297$%
:

I understand that as the mission evolves controllers will use Titan to
slowly change the orbit of Cassini to a more or less Saturn polar one.

I was wondering if at the end of the mission there is any chance to use
Saturn, Titan or any of Saturns other moons to change Casini's orbit such
that Titan could capture it.

If enough propellant was available could this be done??

It probably could. But like the Galileo probe to Jupiter, Cassini
will probably be making a one way trip to Saturn to preclude the
possibility of contamination to any biospheres.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
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In message , Skywise
writes
"Bernard Isker" wrote in news:yCZvf.4297$%
:

I understand that as the mission evolves controllers will use Titan to
slowly change the orbit of Cassini to a more or less Saturn polar one.

I was wondering if at the end of the mission there is any chance to use
Saturn, Titan or any of Saturns other moons to change Casini's orbit such
that Titan could capture it.

If enough propellant was available could this be done??

It probably could. But like the Galileo probe to Jupiter, Cassini
will probably be making a one way trip to Saturn to preclude the
possibility of contamination to any biospheres.


And the moon they absolutely, positively don't want to contaminate is
Titan!

But I very much doubt if it's possible. The difference in velocity
between a Saturn orbit and Titan orbit is probably considerable, and I
doubt if Cassini has the fuel, even with aerobraking, which it isn't
designed for AFAIK (although a discussion I found here proposes just
that
http://www.unmannedspaceflight.com/lofiversion/index.php/t659.html )
There's also the point that the end of the mission will occur only when
the spacecraft is terminally ill or the money is running low, or both.

Seems to me that the probe that landed on Titan has already contaminated
it?? Of course they took precautions to sterilize it but even the best
sterilization efforts leave some biological remains.

Cassini will have been exposed to the vacuum of space and to the radiation
envionment for ~15 years by the time the mission ends. And in any event
Titan has a large atmosphere that would do a good job of burning up any
Cassini orbiter entering it's atmosphere.


"Jonathan Silverlight" wrote
in message ...
In message , Skywise
writes
"Bernard Isker" wrote in
news:yCZvf.4297$%
:

I understand that as the mission evolves controllers will use Titan to
slowly change the orbit of Cassini to a more or less Saturn polar one.

I was wondering if at the end of the mission there is any chance to use
Saturn, Titan or any of Saturns other moons to change Casini's orbit
such
that Titan could capture it.

If enough propellant was available could this be done??

It probably could. But like the Galileo probe to Jupiter, Cassini
will probably be making a one way trip to Saturn to preclude the
possibility of contamination to any biospheres.


And the moon they absolutely, positively don't want to contaminate is
Titan!

But I very much doubt if it's possible. The difference in velocity between
a Saturn orbit and Titan orbit is probably considerable, and I doubt if
Cassini has the fuel, even with aerobraking, which it isn't designed for
AFAIK (although a discussion I found here proposes just that
http://www.unmannedspaceflight.com/lofiversion/index.php/t659.html )
There's also the point that the end of the mission will occur only when
the spacecraft is terminally ill or the money is running low, or both.

Jonathan Silverlight wrote:
In message , Skywise
writes

"Bernard Isker" wrote in
news:yCZvf.4297$%
:

I understand that as the mission evolves controllers will use Titan to
slowly change the orbit of Cassini to a more or less Saturn polar one.

I was wondering if at the end of the mission there is any chance to use
Saturn, Titan or any of Saturns other moons to change Casini's orbit
such
that Titan could capture it.

If enough propellant was available could this be done??


It probably could. But like the Galileo probe to Jupiter, Cassini
will probably be making a one way trip to Saturn to preclude the
possibility of contamination to any biospheres.


And the moon they absolutely, positively don't want to contaminate is
Titan!

But I very much doubt if it's possible. The difference in velocity
between a Saturn orbit and Titan orbit is probably considerable, and I
doubt if Cassini has the fuel, even with aerobraking, which it isn't
designed for AFAIK (although a discussion I found here proposes just
that http://www.unmannedspaceflight.com/lofiversion/index.php/t659.html )
There's also the point that the end of the mission will occur only when
the spacecraft is terminally ill or the money is running low, or both.

Jonathan, you're right. The speed of Cassini relative to Titan is about
6.8 km/sec at each flyby. No way could it be captured into Titan orbit.
Aerobraking would probably lead to excessive torque on the spacecraft
and produce tumbling long before it gave you any significant decrease in
velocity. We can't fly any closer than about 1000 km to the surface,
for attitude stability considerations.

Incidentally, during the nominal tour we get something like 31 km/sec
worth of delta-V out of Titan encounters.

-- Bill Owen