Author Topic: Europa Jupiter System Mission  (Read 5469 times)

Online dsmillman

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Europa Jupiter System Mission
« on: 01/01/2011 04:15 PM »
There is an extensive document on this dual mission at:

http://www.lpi.usra.edu/opag/JJSDTNASAReport.pdf

The launches are targeted for 2020.

Offline alexw

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Re: Europa Jupiter System Mission
« Reply #1 on: 01/01/2011 08:49 PM »
There is an extensive document on this dual mission at:

http://www.lpi.usra.edu/opag/JJSDTNASAReport.pdf

The launches are targeted for 2020.

It appears that one of the limitations once in Europa orbit will be memory: the main 16GB ram is assumed to fail, and a 1 GB rad-hardened phase-changing CRAM (Chalcogenide) will be provided. The report notes laconically "For the Europa Science phase, JEO would need to perform similarly to MRO but with memory constraints more like those for Magellan."

-Alex

Offline Robotbeat

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Re: Europa Jupiter System Mission
« Reply #2 on: 01/03/2011 03:31 AM »
There is an extensive document on this dual mission at:

http://www.lpi.usra.edu/opag/JJSDTNASAReport.pdf

The launches are targeted for 2020.

It appears that one of the limitations once in Europa orbit will be memory: the main 16GB ram is assumed to fail, and a 1 GB rad-hardened phase-changing CRAM (Chalcogenide) will be provided. The report notes laconically "For the Europa Science phase, JEO would need to perform similarly to MRO but with memory constraints more like those for Magellan."

-Alex
Isn't 10 years long enough to get some better better rad-hardened RAM, and/or qualify the main RAM more extensively? Maybe some sort of super-"chip-kill" RAM that can survive the loss of multiple memory cells while retaining almost full functionality (I believe this sort of technology already exists)?

I mean, if that's a major constraint on the mission, isn't there something they can do about it?
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline kevin-rf

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Re: Europa Jupiter System Mission
« Reply #3 on: 01/03/2011 01:25 PM »
Just costs money, as in the kind needed for a Fab run. Kinda make these long tubes with flames coming out one end look cheap ...
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Offline simonbp

Re: Europa Jupiter System Mission
« Reply #4 on: 01/07/2011 08:14 PM »
Isn't 10 years long enough to get some better better rad-hardened RAM, and/or qualify the main RAM more extensively? Maybe some sort of super-"chip-kill" RAM that can survive the loss of multiple memory cells while retaining almost full functionality (I believe this sort of technology already exists)?

Most of the funding for rad-hard microcircuitry comes from a few Three-Letter Agencies, and so NASA essentially gets the leftovers from those production runs. This means that the designs are focused at what the TLAs need (long-term low radiation, and pulses of high), rather than the environment that EJSM will be flying in (long-term high rad).

Plus, the budget/resources that EJSM is commanding is already so high (it has gobbled up the vast majority of the remaining Plutonium) that adding a chip development effort on top is just asking for overruns...

Online Comga

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Re: Europa Jupiter System Mission
« Reply #5 on: 01/07/2011 09:53 PM »
Plus, the budget/resources that EJSM is commanding is already so high (it has gobbled up the vast majority of the remaining Plutonium) that adding a chip development effort on top is just asking for overruns...

Are you saying that EJSM has "called dibs" on enough of the remaining Plutonium for its RTG's?  (I just saw an image in a proposal with five RTGs.  The current number could be different.  Is our current stockpile enough for five?)

The New Horizons mission to Pluto learned that even having Plutonium assigned to your mission is no garauntee that you can keep it.    It can be reassigned by organizations whose authority superceeds NASA's.
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline EE Scott

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Re: Europa Jupiter System Mission
« Reply #6 on: 01/09/2011 06:34 PM »
This is going to be a great mission, if they follow through with it.  2020 seems like a long time to wait for the journey to begin.
Scott

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