Re: Cassini Orbiter End of Mission Ideas
- From: Bill Owen <wmo@xxxxxxxxxxxx>
- Date: Mon, 09 Jan 2006 13:48:40 -0800
Jonathan Silverlight wrote:
In message <11s1617p4vebk00@xxxxxxxxxxxxxxxxxx>, Skywise <into@xxxxxxxxxxxxxxxxxxxx> writes
"Bernard Isker" <bernard_isker111@xxxxxxxxxxxxx> wrote in news:yCZvf.4297$%
W1.2162@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:
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
.
- References:
- Cassini Orbiter End of Mission Ideas
- From: Bernard Isker
- Re: Cassini Orbiter End of Mission Ideas
- From: Skywise
- Re: Cassini Orbiter End of Mission Ideas
- From: Jonathan Silverlight
- Cassini Orbiter End of Mission Ideas
- Prev by Date: Scientists Probe Black Hole's Inner Sanctum (Forwarded)
- Next by Date: Milky Way Galaxy is warped and vibrating like a drum (Forwarded)
- Previous by thread: Re: Cassini Orbiter End of Mission Ideas
- Next by thread: Definition of Resurfacing Rates
- Index(es):
Relevant Pages
|
