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John Kierein
2003-Feb-27, 03:53 AM
Guy Webster (818) 354-6278
Jet Propulsion Laboratory, Pasadena, Calif. February 26, 2003

News Release: 2003-026

Galileo Team Disbanding as Long Jupiter Tour Winds Down

The flight team for NASA's Jupiter-orbiting Galileo spacecraft will cease operations on Friday, Feb. 28 after a final playback of scientific data from the robotic explorer's tape recorder.

The team has written commands for the onboard computer to manage the spacecraft for its short remaining lifetime. Galileo will coast for the next seven months before transmitting a few hours of science measurements in real time, leading up to a Sept. 21 plunge into Jupiter's atmosphere.

"This mission has exemplified successful team efforts to overcome obstacles to make outstanding discoveries," said Dr. Eilene Theilig, Galileo project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "While the team is sad to see it come to an end, there is great pride in Galileo's remarkable accomplishments."

In the years since astronauts deployed Galileo from the cargo bay of Space Shuttle Atlantis in 1989, the mission has produced a string of discoveries about asteroids, a fragmented comet, Jupiter's atmosphere, Jupiter's magnetic environment, and especially about the geologic diversity of Jupiter's four largest moons. The prime mission ended six years ago, after two years of orbiting Jupiter. NASA extended the mission three times to continue taking advantage of Galileo's unique capabilities for accomplishing valuable science.

Now, the onboard supply of propellant is nearly depleted. Without propellant, the spacecraft would not be able to point its antenna toward Earth nor adjust its trajectory, so controlling the spacecraft would no longer be possible. Before that could happen, the flight team last year put Galileo on course for disposal by a dive into the crushing pressure of Jupiter's atmosphere. This strategy eliminates any possibility of an unwanted impact between the spacecraft and the moon Europa. Galileo's own discovery of a likely subsurface ocean on Europa has raised interest in the possibility of life there and concern about protecting it.

On Nov. 5, 2002, the orbiter passed closer to Jupiter than it had ever ventured before, flying near an inner moon named Amalthea and through part of Jupiter's gossamer ring to begin its 35th and last orbit around the giant planet. This elongated farewell loop will take Galileo farther from Jupiter than it has been since before it entered orbit in 1995, to a point more than 26 million kilometers (16 million miles) away on April 14 before heading back in for impact.

Scientific data recorded on the tape recorder during last November's flyby have been gradually played back for transmission to Earth since the flight team repaired radiation damage to the tape recorder in December. Transmissions during a communication session with a NASA Deep Space Network antenna at Goldstone, Calif. Thursday night and early Friday will finish the playback.

"After this month, we have no further activities planned until the day of impact," Theilig said.

The Galileo flight team numbered about 300 people at its peak during the prime mission, but has run much leaner in recent years, with about 30 since the Amalthea flyby. That smaller team is now disbanding, mostly to work on other JPL-managed NASA missions that are in development or already flying.

JPL, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about the mission and its discoveries is available online at http://galileo.jpl.nasa.gov .

-end-

Peter B
2003-Feb-27, 06:55 AM
That's a rather loaded statement to use on the title line, isn't it John?

Are you implying anything by it?

Lexx_Luthor
2003-Feb-27, 07:20 AM
The title is in code words. What he tried to say is that when Jupiter eats the lil bugger, if it tastes good, they are gonna want more where that came from. Lots more.

Yum, tasty, greasy little blue snack

kucharek
2003-Feb-27, 08:59 AM
We just saw how few is left from even a massive spacecraft with plenty of heat protection when it comes in at a relative low speed having a damaged heat protection and gets into a bad attitude.

Galileo is a fragile spacecraft with not re-entry system and it will plunge into Jupiter at an incredible speed. Everything, even the RTGs will get atomized. Surely Shoemaker-Levy gave the Jovians much more of a headache than any man-made object that will drop into Jupiter for many, many years to come.

Harald

John Kierein
2003-Feb-27, 12:13 PM
What I've always said is that they should leave it to orbit for a future civilization achaeologist to marvel at.

kucharek
2003-Feb-27, 12:23 PM
On 2003-02-27 07:13, John Kierein wrote:
What I've always said is that they should leave it to orbit for a future civilization achaeologist to marvel at.

That would be nice, but NASA wants to avoid the risk of polluting Europa.
I don't know how stable the orbit of Galileo would be if left alone for some time. NASA wants to have a controlled flight into terrain.

Harald

Kaptain K
2003-Feb-27, 07:10 PM
John,
1) I'm not sure you realize just how BIG Jupiter is. It is over 1300 times the volume of Earth and the gaseous volume is billions of times that of Earth's atmosphere. I'm sure that the radon concentration in my house is greater than the concentration of radioactive particulates that Galileo will leave in the jovian atmosphere.
2) There is no safe orbit (in the long term) for Galileo. We do not have the precision data to calculate all the possible perturbations caused by the interacting gravity fields of all the moons, and even if we could, who can predict another SL-9 and its effects? No matter what orbit it is in, eventually Galileo would crash into one of the moons.

Nanoda
2003-Feb-28, 12:56 AM
What the Kaptain said.
-Galileo got smacked down by radiation from Jupiter, not the other way around.
-Its current orbit is highly elliptical, and it might get a slingshot boost from a moon years later to end it up anywhere.

I'll add that we're positive that Jupiter does not have life (http://www.spacedaily.com/news/galileo-00k2.html) - it's a nasty nasty place to be, with no surface and a super-dense core. Frankly I think the only better place to ditch something is the Sun. /phpBB/images/smiles/icon_smile.gif

David Hall
2003-Feb-28, 03:51 AM
If dropping something into Jupiter's atmosphere is all it takes to contaminate the whole planet, then it's already too late. Galileo dropped a probe into it when it first arrived there. So I'd expect the inhabitants to be long extinct by now. /phpBB/images/smiles/icon_smile.gif

tracer
2003-Feb-28, 08:36 PM
On 2003-02-27 14:10, Kaptain K wrote:
I'm sure that the radon concentration in my house is greater than the concentration of radioactive particulates that Galileo will leave in the jovian atmosphere.
Ah! But radon is a natural radioactive substance. The plutonium in the Galileo spacecraft's RTG(s) is an artificial radioactive substance.

And, as we all know from reading labels in health food stores, natural = good and artificial = bad. /phpBB/images/smiles/icon_rolleyes.gif

<font size=-1>[ This Message was edited by: tracer on 2003-02-28 15:37 ]</font>

Jigsaw
2003-Feb-28, 09:54 PM
But I see John's point--say in 100 years or so we eventually get around to closer inspections of Jupiter, and say we find something, maybe an element or something, that *some* scientists may think shouldn't be there ("according to current gas giant theory..."), then the first thing that everybody will think will be that it was something to do with Galileo, and there will be finger-pointing at the decision back in 2004 to "pollute" Jupiter instead of sending the trash out.

Tuckerfan
2003-Feb-28, 10:50 PM
On 2003-02-27 07:23, kucharek wrote:


On 2003-02-27 07:13, John Kierein wrote:
What I've always said is that they should leave it to orbit for a future civilization achaeologist to marvel at.

That would be nice, but NASA wants to avoid the risk of polluting Europa.
I don't know how stable the orbit of Galileo would be if left alone for some time. NASA wants to have a controlled flight into terrain.

Harald
Why? To make it harder for them to attack Chinese astronauts in 2010?

<font size=-1>[ This Message was edited by: Tuckerfan on 2003-02-28 17:51 ]</font>

SiriMurthy
2003-Feb-28, 11:19 PM
On 2003-02-27 02:20, Lexx_Luthor wrote:
The title is in code words. What he tried to say is that when Jupiter eats the lil bugger, if it tastes good, they are gonna want more where that came from. Lots more.


I don't eat meat myself, but does'nt everything taste like chicken?

sts60
2003-Feb-28, 11:25 PM
Yes. Even chicken.

DaveC
2003-Feb-28, 11:40 PM
On 2003-02-28 15:36, tracer wrote:
Ah! But radon is a natural radioactive substance. The plutonium in the Galileo spacecraft's RTG(s) is an artificial radioactive substance.


Not quite correct. Plutonium has resulted from natural fission of uranium:

http://www.physics.isu.edu/radinf/oklo.htm

It is just a very rare element on earth because it has a relatively short half life (24,000 years) and unlike radon which is continually produced by uranium decay, any plutonium that may have been around when the Earth was born has long since decayed to undetectable levels - except at Gabon as far as we know.

Nanoda
2003-Mar-01, 03:18 AM
Jigsaw - if you have something that can detect the leftovers of any communications satellite that ever burnt up in Earth's atmosphere, there are people who want to know about it. And recall again that Jupiter is extra-amazingly-humongously- extensivly-"ohmagawdisthateverhuge"-tasticly big!!!!

And you've talked about the uranium, but what about... the gold?! That was man-made gold, totally different from naturally-occuring cometary gold. /phpBB/images/smiles/icon_razz.gif

Rift
2003-Mar-01, 05:37 AM
And recall again that Jupiter is extra-amazingly-humongously- extensivly-"ohmagawdisthateverhuge"-tasticly big!!!!



LOL

Reminds me of the start of Hitchicker's Guide...

/phpBB/images/smiles/icon_smile.gif