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Kepler Mission
Habitable Zoner
post Nov 16 2010, 12:48 PM
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The paper "Discovery and Rossiter-McLauglin Effect of Exoplanet Kepler-8b" (Jon M. Jenkins et al 2010 ApJ 724 1108) has now been published online.
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Syrinx
post Nov 16 2010, 02:34 PM
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That's behind a paywall.

Here's a free one: http://arxiv.org/abs/1001.0416
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Habitable Zoner
post Nov 21 2010, 03:06 AM
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It's interesting to go to the AAS Seattle Meeting website, type "Kepler" into the advanced search "abstract body" field, and hit return. There are three pages of results, most of them dealing with the mission (rather than the astronomer, for instance, although there are a couple of talks devoted to him, too). Of course the abstracts don't provide any big "reveals," but they do whet your appetite for what will be an exciting meeting--and in just 7 weeks from now.
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NGC3314
post Nov 21 2010, 03:14 AM
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Some of the rest of us, planning (say) Hubble image releases, are desperately hoping that the Kepler people will not make the Big Announcement on the same day! Another reason to prowl the AAS abstract search, though lately I expect more from the February 1 announcement which would coincide with the big public data release.
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Holder of the Tw...
post Dec 7 2010, 03:27 PM
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Latest status

Interesting details of the upcoming February anouncement, and future data release.

Recent ground based follow up season is over.
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NGC3314
post Dec 16 2010, 12:42 PM
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Kepler meets citizen science! From the people who brought you Galaxy Zoo, Solar Storm Watch, Moon Zoo... now there's Planet Hunters. This interface lets people interact with light curves from the growing Kepler public archive, especially to look for transits that the pipeline software might have missed, for example due to stellar variability. (I had the chance to talk with Debra Fischer about this before it went into testing, and it should be a powerful approach). If previous Zooniverse projects are any guide, there will be additional interesting byproducts that we didn't know to look for in advance.
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remcook
post Dec 16 2010, 12:56 PM
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That looks really cool smile.gif

edit - aaaargh...sucked in!!!
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Greg Hullender
post Dec 31 2010, 03:23 AM
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New manager's update: Safe Mode Update

http://www.kepler.arc.nasa.gov/news/mmu/in...s&NewsID=91

They're stopping science operations until next week to decide whether to switch to backup hardware.
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nprev
post Dec 31 2010, 06:38 PM
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Rats. sad.gif

The press release didn't provide any specifics about what function(s) were impaired/otherwise affected. Is this mission hardware, bus, power generation...?


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A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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FatSplenda
post Jan 3 2011, 09:05 PM
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QUOTE (nprev @ Dec 31 2010, 10:38 AM) *
Rats. sad.gif

The press release didn't provide any specifics about what function(s) were impaired/otherwise affected. Is this mission hardware, bus, power generation...?

(new here!)

I used to do engineering and ops for Kepler, so I can shine some light on the situation...

I haven't rummaged through this whole topic/thread, so I don't know how much it has been discussed here. But the most common problem that Kepler has is with the Star Trackers. They have caused more safe mode entries than anything else, by far! The issue for this most recent safe mode regression is the same. This season, especially during the roll to this new attitude in December, caused a lot of problems the first time we did it last year. Each season is unique in many ways.

There are several contributing factors to this. One, the flight software has a complex way of maintaining pointing... not a trivial thing when you have two different kinds of hardware (star trackers and the fine guidance sensors) maintaining pointing. Two, the star trackers are flaky. They buzz out all the time, dropping guide stars, thinking that radiation events are new stars, etc.... it gets messy real quick. The hardware is not top-of-line, either.


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Syrinx
post Jan 4 2011, 06:28 AM
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Thanks for the info! Please stick around!
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FatSplenda
post Jan 4 2011, 05:43 PM
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QUOTE (Greg Hullender @ Dec 30 2010, 07:23 PM) *
New manager's update: Safe Mode Update

http://www.kepler.arc.nasa.gov/news/mmu/in...s&NewsID=91

They're stopping science operations until next week to decide whether to switch to backup hardware.

This is kind of a vague statement in regards to Kepler, but it makes sense for a few of the redundant components on board. For instance, everything like the computers, interface boards, etc. are dual-string (and cross-strapped!) as we might expect; they actually use the B-side as the primary side. However, the culprit is often the Star Trackers, and Kepler uses both of them all the time.

But it's still interesting to see that the A-side wouldn't have responded in the same way, according to that report. I wouldn't have guesses it based on my experience with that spacecraft.

Either way, she's still a marvel! Undoubtedly my favorite spacecraft of all time, maybe with the exception of the Mars Rovers (a project with which I am now employed!).


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FatSplenda
post Jan 7 2011, 09:49 PM
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I spoke to my former colleagues at LASP and BATC, and here's what actually happened...

I was mistaken. This most recent regression out of science data collect mode to Safe mode was NOT due to the Star Trackers, but rather due to the Coarse Sun Sensors. It occurred during the roll maneuver from the Fall attitude to the Winter attitude. (Actually, it was't QUITE that maneuver, since they don't do pure season-to-season roll maneuvers; during the quarterly contacts with the DSN, they roll out of the current attitude to their science data downlink attitude first, and then from THERE they go to the new season's attitude. It's almost a pure roll anyways, but the SDDL attitude is an intermediary.)

At the beginning of the winter season, the spacecraft is peering "over" the sun to point at the star field for science collection. Therefore, the sun avoidance volume is as close to the photometer boresight as it's ever going to get over the year. It's only a few degrees -- less than 10, from what I remember last year. So the margin for error is small. This caused a problem at the end of January last year when the Star Trackers fuzzed out for a bit, which is a common occurrence, so the spacecraft went to an internal attitude propagator. This propagator told the computer that the boresight was in the sun avoidance zone, and BAM, Safe Mode! The story there is a bit more complex, but that's the gist.

This time around, the *sun sensors* had a glitch that spat out a measurement that put the apparent position of the sun in the sun avoidance zone. It was only a few degrees, but again, Kepler is in the season where its science attitude is close to the sun avoidance zone. This sun sensor behavior was strange to the Kepler engineers because the A-side and B-side computers, which are both always powered but the B-side is prime (I know, silly!), calculated different positions of the sun. The B-side computed the faulty one, and since it's prime, it safed the spacecraft.

They have since run tests where they slewed back to the winter science attitude and saw lots of sun sensor noise on the B-side but none (or very little) on the A-side. Same sensors, different measurements. Odd, indeed!

I am privy to more information (I do work with a guy who works on Deep Impact, another BATC spacecraft), but that's about all I'm able to tell without getting in trouble.

-fs


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"There's no Launch Checklist Step 4a: 'Pause and reflect on the enormity of what happens next'."
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DEChengst
post Jan 10 2011, 04:39 PM
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New discovery to be announced today:

QUOTE
A new planet discovery will be announced Monday Jan. 10 during the 'Exoplanets & Their Host Stars' presentation at the American Astronomical Society (AAS) conference in Seattle, Washington


This announcement will be followed by online chat with Dr. Natalie Batalha:

http://www.nasa.gov/connect/chat/kepler_chat.html


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DEChengst
post Jan 10 2011, 07:01 PM
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NASA'S Kepler Mission Discovers Its First Rocky Planet:

http://www.nasa.gov/topics/universe/featur...cky_planet.html


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PDP, VAX and Alpha fanatic ; HP-Compaq is the Satan! ; Let us pray daily while facing Maynard! ; Life starts at 150 km/h ;
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