Author Topic: Europa Clipper  (Read 4937 times)

Offline vjkane

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Re: Europa Clipper
« Reply #20 on: 03/13/2019 04:37 pm »
Yet to me not to expect discussion of the launchers on a forum mostly dedicated to such technology seems a odd stance to take.
Too often discussions of launchers in the science forums has gone the way of thinking about what ifs, "if we do multiple launches and stack elements in orbit..."  These are fine discussions and there are boards to vet and debate these kinds of issues.  However, they are outside the realm of options being considered by the project teams.  I believe that the discussions on the science board should be among the options being considered by the project teams.

So I support discussions of the implications of different commercial launches here, whether ice giant missions should have SEP stages, etc., in the science boards.

I write this knowing that the head of NASA has just suggested in orbit stacking of elements for the first Orion moon launch.  That now makes this legitimate to discuss on the Orion, SLS, and Falcon Heavy boards.


Offline Star One

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Re: Europa Clipper
« Reply #21 on: 03/14/2019 06:41 am »
Yet to me not to expect discussion of the launchers on a forum mostly dedicated to such technology seems a odd stance to take.
Too often discussions of launchers in the science forums has gone the way of thinking about what ifs, "if we do multiple launches and stack elements in orbit..."  These are fine discussions and there are boards to vet and debate these kinds of issues.  However, they are outside the realm of options being considered by the project teams.  I believe that the discussions on the science board should be among the options being considered by the project teams.

So I support discussions of the implications of different commercial launches here, whether ice giant missions should have SEP stages, etc., in the science boards.

I write this knowing that the head of NASA has just suggested in orbit stacking of elements for the first Orion moon launch.  That now makes this legitimate to discuss on the Orion, SLS, and Falcon Heavy boards.

My fear is it could drive the thread being split between science and launcher and discussion and I am not sure that’s particularly desirable.

Offline Kesarion

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Re: Europa Clipper
« Reply #22 on: 03/19/2019 12:02 pm »
https://www.lpi.usra.edu/opag/meetings/mar2019/Findings.pdf

Here’s a recent report from OPAG which also addresses the recent termination of ICEMAG. I’m surprised to find out that the cancellation of certain risky instruments seems to be new process and I am pleased to see others call for transparency regarding this new approach towards keeping science missions within their cost caps.

However, I’m not sure that alluding to possible sex-based discrimination is the most professional or wise thing to do when calling for said transperancy, especially when you consider that the current acting director of the planetary division is a woman. ???
« Last Edit: 03/19/2019 12:52 pm by Kesarion »

Offline su27k

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Re: Europa Clipper
« Reply #23 on: 03/20/2019 03:07 am »
More interesting to me is the fact that we have often been told in this section of the forum that a launch cost saving of $10M to $20M doesn't matter to science missions, since it's a tiny fraction of the total mission cost. Yet here we have an important instrument on a multi-billion dollar mission getting canned because it's $8M to $16M over budget. So the question is, does $10M to $20M matter to a science mission or not?

Offline Kesarion

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Re: Europa Clipper
« Reply #24 on: 03/20/2019 06:12 am »
More interesting to me is the fact that we have often been told in this section of the forum that a launch cost saving of $10M to $20M doesn't matter to science missions, since it's a tiny fraction of the total mission cost. Yet here we have an important instrument on a multi-billion dollar mission getting canned because it's $8M to $16M over budget. So the question is, does $10M to $20M matter to a science mission or not?


When it comes to flagships the answers seems to be no, because as far as I understand it, the problem was not just regarding the cost growth of the instrument.

https://spacenews.com/nasa-dealing-with-cost-growth-on-planetary-science-flagship-missions/

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Glaze said that cost alone was not the reason for removing ICEMAG. “The emphasis is not so much on the overall cost growth but on the other risks that were inherent in the design and the approach that was going forward,” she said. “Most of the concern had to do with the future risks and the fact that instrument was not stabilizing.”

I have in no way shape or form any expertise regarding the construction of space probes, but this seems to be a case of flawed engineering which could potentially force a redisgn in other parts of the spacecraft and ultimately endanger the entire mission. Either that or they weren’t even sure that ICEMAG was capable of performing its baseline goals.

One of the purposes of flagships is to develop new instruments, but if the risks outweight the benefits, cancelling one in a phase were you could still replace it with a proven design is the responsible thing to do. After all, good science is still better than no science. The prospect of price ballooning when Europa Clipper lost its strongest congressional advocate (John Culberson) should be mitigated as much as possible.
« Last Edit: 03/20/2019 06:18 am by Kesarion »

Offline ccdengr

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Re: Europa Clipper
« Reply #25 on: 03/20/2019 12:31 pm »
So the question is, does $10M to $20M matter to a science mission or not?
If I were going to be cynical, I'd say that it depends on who's getting the money.

Instruments are developed under separate subcontracts that are small fractions of the overall mission cost and typically cost-plus-fixed-fee with a budget cap.  Projects maintain some reserves in case of unexpected cost growth, typically not allocated by instrument, so if one instrument overruns, that comes out of reserves and means there's less to cover other instruments' problems.  If one instrument gets into a lot of trouble, it could use up all the reserve or potentially cause the whole mission to go over budget.

You could run these missions in a "cost is no object" mode (*cough*JWST*cough*) and just keep ratcheting the cost up and up, but if you don't want to do that, you have to compartmentalize spending and descope or delete elements that are going over budget.

Maybe it's paradoxical considering that these missions are flown for the instruments ultimately, but the instruments are usually on the bottom of the heap in terms of control.

Offline Kesarion

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Re: Europa Clipper
« Reply #26 on: 03/29/2019 03:55 pm »
Mission to Europa Gets New Instrument to Look for Signs of Habitability

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Margaret Kivelson, a professor emerita at the University of California, Los Angeles, will lead the effort to develop a simplified magnetometer to replace ICEMAG. The instrument will measure Europa’s magnetic field and gather data on the ocean’s depth and salinity. Kivelson previously led the magnetometer team on the spacecraft Galileo, which orbited Jupiter in the 1990s. She is credited with discovering the ocean beneath Europa’s ice shell.
ICEMAG’s estimated cost had grown to $45 million—nearly three times its proposed price—according to NASA headquarters. Sophisticated internal sensors had vexed the ICEMAG science team and led to much of the extra expense. The new magnetometer will do away with those sensors, using simplified components instead. The downside is that the new sensors will likely lose calibration over time and drift in response to temperature variations. The team is now devising strategies to compensate for these effects.

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“We are gearing up for one last review needed for confirmation of the mission by NASA,” Pappalardo says. “That is where NASA says that you are ready and cleared to go build the instruments and spacecraft.” In April, the project will go through its “delta preliminary design review” (PDR)—a reevaluation of certain elements of the spacecraft that had given NASA pause.

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Once completed successfully, the project will go through another review at NASA headquarters called “key decision point C.” The agency will commit to the calendar and cost determined during the PDR, and the process of finalizing design and fabricating the hardware can begin.[...]After the April design review, Clipper will likely enter the final design and fabrication phase in August. If all goes well, it will lift its first inch from the launchpad in 2023.

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When Culberson was defeated for reelection last year, things looked grim. He still had a few tricks up his sleeve, however. “Before I left,” he says, “I won the support of a number of my House colleagues to be sure that they would protect those missions.” And tying Clipper to SLS should help.

*Fingers crossed* that Culberson reached a hand to democrat members of the House of Represantatives so that the Europa Lander could at least continue as a technology development program.

Offline redliox

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Re: Europa Clipper
« Reply #27 on: 04/01/2019 08:27 pm »
While the magnetometer is getting tweaked, apparently the prototype to the main antenna is already receiving testing:  http://spaceref.com/europa-1/europa-clipper-high-gain-antenna-undergoes-testing.html

It also reminds me of a bronze Voyager antenna.
"Let the trails lead where they may, I will follow."
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