Stardust-NExT, Revisiting Tempel 1 Options

[Paolo]

I thought it was time to start a new thread on Stardust's flyby of Tempel 1, the first time a comet receives a second visit from a spacecraft one perihelion later.
There was an interesting story about this on Spaceflight now recently http://www.spaceflightnow.com/news/n1012/23stardustnext/
note that the flyby will be around 23.30 eastern time on 14 February, so thinking in GMT it will not happen on Valentine's day.
Stardust should have started imaging Tempel 1 twice weekly in mid-December, but there is nothing yet on the mission site http://stardustnext.jpl.nasa.gov/index.html
see also http://stardustnext.jpl.nasa.gov/mission/m...tatus10_q4.html for updates on the mission status

[ElkGroveDan]

Stardust, which is about the size of an office desk, has a modest propulsion system.

Ladies and gentleman we have a new never-seen-before unit of measure of volume, the "office desk."

[Stu]

Hmmm. Now, is that an office desk in its naked, uncluttered state, or one that's covered in post-Christmas stuff? 'Cos if they're going to base their measurements on mine then that's going to seriously mess up any calculations, you know..?

[djellison]

It's not that small really - http://stardustnext.jpl.nasa.gov/multimedia/sc.html - if my desk was that big, I wouldn't fit in my cube anymore

I'm changing the thread title to be more appropriate.

[centsworth_II]

Ladies and gentleman we have a new never-seen-before unit of measure of volume, the "office desk."

We've come a long way since the early days when only a breadbox was available as a unit of measure!

[ZLD]

Right, it's more the size of an outhouse. That doesn't seem an appropriate unit of size either though...

I'm really glad they are able to start doing more intricate extended missions like this and Deep Impact. 2011 appears to possibly be the most productuctive year for astronomy in some time. Should be quite exciting.

[elakdawalla]

I think that the Web outreach for this encounter is going to be less than the mission would like it to be because of unavoidable timing problems. It's a small team and everybody who's involved in Stardust was also involved in Deep Impact/Hartley 2 -- same science team, same outreach folks. They were spread too thin to do much advance work on Stardust -- and then there were the holidays. I know they are scrambling now to get their website prepared for the flyby but I don't think we can expect a whole lot of advance information.

[JohnVV]

Now, is that an office desk in its naked, uncluttered state

that is because the clutter was " EXTERMINATE , EXTERRRRAAAMINATEEE... "

the "desk" ????
well is it bigger than " fill in ...the blank "

some of the young folk here might have never seen a bread box
nor have had the "bread person" deliver house to house
orieies bakery ( i think it's name was ) delivered when i was a young kid

[ups]

I hope this thing is bigger than my office desk or we aren't going to get much science back.

[djellison]

The spacecraft bus is basically 6ft x 2ft x 2ft - and the high gain antena is just short of 2ft across. This is a small, light (<400kg all up), cheap spacecraft.... but it's still not a desk

[nprev]

Surely some imagemage will shortly produce a faux movie poster for "Attack Of The Spacedesks"...but not post it on this thread!

[elakdawalla]

In the hopes of dragging this thread back to some actual discussion of the Stardust mission, I thought I'd post this somewhat worrying mission status update from December 15:

The spacecraft experience another safe mode entry on Thursday, December 9. The next communications pass was scheduled for Friday morning, and the team was able to establish communications quickly with the help of the DSN personnel, and a health check revealed all the subsystems were healthy and operating normally. The playback of all available data – command history logs, error logs, lower DRAM dump, etc. – was started. Safe mode entry was completed on Saturday, December 11, getting the spacecraft back under the control of the background sequence, easing communications during the planned DSN tracks. The data showed that this safe mode entry was caused by a MEEB (Memory Error External Bus) event. This a phenomenon observed on other spacecraft using this processor and memory architecture. It is caused by a latch-up of a redundant memory address register that causes the memory checking software to check a region of memory never used before and encountering many uncorrectable errors due to this. In response, the system is rebooted, and the reboot process then checks and corrects these new memory addresses and the system continues operating. The analyses performed on other missions have concluded that the standard response to a MEEB is a cold boot that resets the memory address registers to the original values. A tiger team was convened to help the project address this latest event in light of the two other recent safe mode entries. The tiger team has concluded its work and concurs with the project plan to perform a cold boot on side B to prepare the spacecraft for the upcoming comet flyby. This reboot is currently planned for January 4, 2011. Until then, the spacecraft will be acquiring optical navigation image sets twice a week.

According to an earlier update, Stardust should have acquired its first optical navigation images of Tempel 1 on December 16.

[tedstryk]

Ugh.

[nprev]

On the plus side this sounds like a well-understood fault state (esp. because it appears that there is some heritage with this system), and they are taking preventative actions well before the flyby.

Just gotta keep her together for another 3 months or so...go Stardust-NExT!

[volcanopele]

Quick question: is the rotation of Temple 1 understood well enough that the mission planner's can ensure that the DI impact site will be on the comet's sunlit side when Stardust-NExT flies by?

[Decepticon]

Quick question: is the rotation of Temple 1 understood well enough that the mission planners can ensure that the DI impact site will be on the comet's sunlit side when Stardust-NExT flies by?

According to this yes. http://www.sdnext.org/mission/pdfs/SD_NEXT_Fctsht.pdf

[stevesliva]

On the plus side this sounds like a well-understood fault state (esp. because it appears that there is some heritage with this system), and they are taking preventative actions well before the flyby.

Yeah, just a bit flip. Somewhat amusing that it was an error with the error-checking, if I read that right.

[djellison]

Actually - I would urge caution on the crater observation. It's a goal, but it's not a certainty. The mag-curve of the nucleus is double bumped, and using the shape model you can match it very well in both bumps - so basically, we may get the crater, or we may not.

If we get it - awesome. If we don't - we get to map the other side of the Nucleus which is also awesome.

[JohnVV]

somewhat worrying mission status update

?? i would not use "somewhat worrying" it looks like a normal everyday address allocation bug

At least it is not a BSOD

It is caused by a latch-up of a redundant memory address register

sounds like a raid 1 set up

[stevesliva]

sounds like a raid 1 set up

Yeah, pretty much. Sounds like they're comparing addresses with completely redundant memory words. Sucks when one of the address registers goes haywire.

[Phil Stooke]

"It's a small team and everybody who's involved in Stardust was also involved in Deep Impact/Hartley 2 -- same science team, same outreach folks."

That's where UMSF comes in...

Phil

[Astro0]

That's where UMSF comes in...
Hey, anything we can do to help They know we're watching, ready and willing to lend a hand.

Just thought about the fact that it was 7 years ago today that Stardust encountered comet Wild2 and now here we are, 42 days from the encounter with Tempel1. I remember it as a hectic time at the Canberra DSN, we were prime for the comet encounter and 24 hours later, prime for MER Spirit's landing.

[Paolo]

a new status update. stardustnext.jpl.nasa.gov/mission/mission_status11_q1.html
it turns out the comet is still too faint to be visible in OpNav images

[CJSF]

a new status update. stardustnext.jpl.nasa.gov/mission/mission_status11_q1.html
it turns out the comet is still too faint to be visible in OpNav images

And it says they have lower fuel reserves than expected. I'm really excited about this encounter. It also mentioned the cold boot due to the "MEEB" restored the memory to its factory default. Does this mean they lost any patches or updates to the memory or memory management that were uploaded to the craft since launch?

CJSF

[stevesliva]

No updates for awhile, but this RSS feed may point to updates in that status page:
http://feedity.com/rss.aspx/nasa-gov/UVRWW1ZV

[Paolo]

a new status update http://stardustnext.jpl.nasa.gov/mission/m...tatus11_q1.html
comet still not in sight

January 19, 2011
The spacecraft continues to operate as expected and all subsystems are healthy on approach to comet Tempel 1. This week the spacecraft started to tip back and forth to the imaging attitude in order to fix the Navcam mirror in a position that results in less scattered light reaching the CCD. This strategy has resulted in much lower background noise. The comet has not yet been detected in the images, and may not be detected for another week yet. The team continues to prepare for the Tempel 1 flyby by completing the tests of the encounter sequences.

[elakdawalla]

Thanks for keeping an eye on that site, Paolo!

[Hungry4info]

Stardust has located Tempel 1.
http://www.jpl.nasa.gov/news/news.cfm?rele...elease_2011-029

[ZLD]

Heres a slightly cleaned up version:


You can just barely make out a slight crescent and the shape of Tempel 1.

[djellison]

That's just the coma - not the nucleus itself. Stardust's Navcam is 3.5 deg FOV, so we wont resolve the nucleus until very near close approach.

[ngunn]

Hey Doug - good to see factual contributions on many threads all in a bit of a rush. Did they give you a day off?

Seriously, glad you're still on the case.

[djellison]

Probably my busiest day on lab yet I find myself tweeting, facebooking and foruming the most, when I'm busiest - it's counterintuitive, but that's how it goes

[stevesliva]

http://stardustnext.jpl.nasa.gov/mission/m...tatus11_q1.html

Updated with TCM information.

[Explorer1]

They said they were running low even before the maneuver, and another 300 grams spent, any estimates on how much is left?

[djellison]

The estimates of how much they had / needed included TCM's such as this.

[Explorer1]

I realize that. I should've made that more clear in my post but I was just curious about how much will be left after the flyby; purely academic of course.

[stevesliva]

February 3, 2011
The spacecraft is healthy and continues to operate as expected. A trajectory correction maneuver, TCM 31, was executed at 21:00 UTC on Monday, January 31. This 2.6 m/s maneuver adjusted the spacecraft trajectory for the desired flyby point of comet Tempel 1 on February 14. This was the first maneuver based on ground and optical navigation data. The spacecraft continues to acquire daily optical navigation image sets. The next planned maneuver will be executed on Monday, February 7, at 23:00 UTC. This maneuver will be based on a data cut-off on February 2. The spacecraft will turn to the final comet approach orientation, with the +x side of the spacecraft facing the comet direction. Right after the TCM on February 7, the spacecraft will begin imaging the comet every 2 hours as it continues its approach for the flyby. These images will provide optical navigation data as well as frequent comet monitoring, and will be used to design the final approach maneuver that will be executed on February 12, two days before the flyby.

[Gsnorgathon]

NASA Hosting Events for Valentine's Night Comet Encounter - details of media stuff for everyone's favorite Valentine's Day activity (or post-, depending on your time zone). Interestingly, there's no mention of spotting the Deep Impact crater; I'd guess it's considered unlikely enough that they don't want to get everyone's hopes up. Probably of most interest is that the first 5 images are expected to show up between midnight and 1:30 A.M. Pacific Time.

[Hungry4info]

The comet's rotation isn't known well enough to know if said crater will be visible to the spacecraft during flyby.

[djellison]

They have made a simulated light curve based on DI data, and have an actual light curve based on Hubble imagery. From that - there is a correlation, but also there's another correlation at 180 deg from that, just not quite as strong.

Thus - they targetted to get the nucleus on approach ( http://www.news.cornell.edu/stories/May07/stardust-NExT.jpg ) but it's not certain that they'll see it. It's not quite 50/50 - probably slightly better odds than that.

Of course, the comet may have changed so much over the past 5 years that we can't even tell if we're looking at the same side or not

A Stardust NExT 'Live' module will be on Eyes on the Solar System before Monday night ( http://solarsystem.nasa.gov/eyes ) including a nucleus shape file with a map showing the expected crater, and the un-seen terrain. Yours truly will be demoing it during the first of the NASA TV broadcasts from JPL on the night of the flyby

[Phil Stooke]

Something to think about - this is a panel from my LPSC poster. Maps of Tempel 1 and Wild 2.

Phil

[MahFL]

Stardust NExT 'Live' module is up and running on Eyes on the Solar System.

[dilo]

Great maps, Phil... for sure you will soon update left one!

[ElkGroveDan]

closer.......

[Astro0]

Don't forget to login to the Eyes on the Solar System for Stardust-NExT LIVE!
It's a great browser based simulation using realtime, real data for the encounter.
Watch Stardust as it glides past Tempel-1. COOL!



http://solarsystem.nasa.gov/eyes/

Psst! I think someone very close to the Forum had something to do with it. Shhhh.

[djellison]

I've heard that someone might be demoing it live, twice, on the first NASA TV broadcast tomorrow evening, and that there might be a frickin great big camera on top of his console staring him in the face.

(and if I do say so myself, the C/A looks really awesome in EotSS - took some work by a very very clever programmer called Jon to get the camera to flip from periscope to off periscope. He's actually programmed the spacecraft to do faux-auto-nav based on the provided trajecgories for Stardust and Tempel 1. Plus - our 3D guy, haivng produced a BEAUTIFUL Stardust spacecraft, went and created a brailliant Tempel 1 complete with stuff seen by Deep Impact ( grey ) stuff not seen ( blue ) and the hoped-for crater ( red target )

If I do say so myself, it's fairly cool.

Oh and don't - whatever you do - look at the tutorials page.

[ElkGroveDan]

Don't have any chocolate the night before. Never fails the day you are going to be on television ...

[MahFL]

What time does the NASA tv coverage start ?

[Astro0]

Of course "what time?" depends on where you live on our worldwide forum.

The schedule is always available on the NASA website...or just a Google query away.

[MahFL]

I know, just being lazy, also I don't actually frequent the nasa site much, and would have had to guess where the tv schedule was......

Bottom line is it's on too late for me....I need to be zzzzzzzzz at 11:30 EST. Oh well.

[stevesliva]

I don't know if these updates all came in at once, or if changes in the page format fooled feedity:
http://stardustnext.jpl.nasa.gov/mission/m...tatus11_q1.html

Some excerpts.

Frday, Feb 11. E- 3days
The opnavs received today are all at 0.25 pixel quality, and have moved the solution since yesterday’s opnav solution. The science team believes that we are seeing the nucleus signal starting to come through, and these latest opnavs are the best indication of the nucleus location. The maneuver design is being finalized, and will be around a 170 km maneuver.

Sunday Feb 13, E-1 day
The overnight activities taken by the flight team went very well, and the final OpNavs taken at E-42 hours were successfully acquired and downlinked.
The navigation solutions were finished this morning, and they show that the predicted delivery is within the ‘green zone’ of the delivery chart. The nominal flyby point is at 191 km from the surface of the comet with a 11km uncertainty radius. The current Time of Closest Approach estimate is still around 04:40 UTC on February 15 (20:40 February 14 in Pasadena). Based on these discussions and updates, the following decisions were made, with full concurrence between the PM and PI:
- No TCM 34 will be executed

Monday Feb 14, E-21 Hours
The spacecraft team has just completed the final commanding prior to encounter.
This included the encounter sequence and the supporting files that were built this afternoon with the final trajectory and time of arrival estimates.
Most fault protection has now been disabled, and the Mission Phase Bit has been set to ‘Encounter’. From now on, a safe mode entry will trigger the autorecovery sequence that will attempt to recover the spacecraft autonomously and restart the encounter sequence

Crazy! But after the worry, optical navigation got them where they wanted, with a TCM to spare.

[CosmicRocker]

Don't forget to login to the Eyes on the Solar System for Stardust-NExT LIVE! http://solarsystem.nasa.gov/eyes/

It's awesome. I'm going along for the ride!

[stevesliva]

So there was just a large solar flare. Did that send high-energy particles towards Stardust, and if it did, when do they get there?

[brellis]

I have EoSS on and Norton telemetry says it's safe!

[djellison]

You'll want to re-start EotSS later ( about 8.30pm Pacific - just when the broadcast starts ) - as we'll have adjusted for the updated C/A time.

And that flare was on the Earth side of the sun ...and using EotSS (sorry to plug it so much ) you can see Stardust is on the other side of the Solar System.

[ElkGroveDan]

I used EotSS this weekend to wash my car and it did a marvelous job. It also repaired my grandfather's broken watch. I only wish I had discovered this incredible tool sooner. It really has changed my life.

[JohnVV]

my only gripe it
the site is MS only

i could boot up an illegal copy of MS win7
For i have NO intention to buy it

[Ron Hobbs]

When I try to go to the site, all I get is hash (bars of colors). ???

[djellison]

That sometimes happens before your GFX card has finished initializing - give it time. If it doesn't clear after a few seconds, then...er.....it's still a beta.

NTV will be cutting to Eyes... live during the flyby

[nprev]

EoTSS running sweet here on Win7...nice view!

Steady as she goes, Mr. Ellison!

[ElkGroveDan]

While we are waiting for our Glorious Leader to take the stage, may I take this opportunity to remark how unbearably boring NASA TV is 99% of the time - especially immediately preceding live events.

EDIT - it's on now 8:20 pm PST

[MahFL]

Watching.

[Explorer1]

Broadcast started now on NASAtv.

[ZLD]

Its not PBS or the BBC, but it also receives a really small budget in comparison, and still is able to put on informative shows, albeit with a certain cheese factor.

[Explorer1]

Dust Flux instrument is on!

[CosmicRocker]

EotSS demo coming up soon!

[Explorer1]

There's Doug!

[nprev]

Well done, Doug!

[Explorer1]

Closest approach done! (my heart jumped when that guy said 'impact').

[ZLD]

This is really a fantastic tool. Curious, is the positioning of the comet accurate? The last I was aware, the comet movement wasn't known well enough to predict it at that time.

[ElkGroveDan]

The orbit of the comet is actually very well understood. The big unknown is its rotation, though they have a pretty good idea based on light curves.

[Explorer1]

More dust after CA than before; interesting.

[Hungry4info]

Not at all surprising, imho. Outbound, the spacecraft is heading into the "tail" IIRC.

Edit: 181 km was closest approach.

[Astro0]

Doug was pretty awesome.
This was his view http://twitpic.com/3zywnw

[volcanopele]

This is really a fantastic tool. Curious, is the positioning of the comet accurate? The last I was aware, the comet movement wasn't known well enough to predict it at that time.

Well, clearly they are trying to center the comet in the frame so they will point to where they think the comet will be to the best of their knowledge of the predicted trajectory of both the comet and the spacecraft. Though obviously, when the real images, that doesn't mean the comet will actually be in the center of the image.

[belleraphon1]

Nicely done Doug!

Fun to watch simulation on 'Eyes on the Solar System'.

Comet encounters so exciting... dust impacts galore.... can't wait for images.

Have to nap for a few hours.... get up at 3:00am Eastern to see the fave five images and then out the door for work at 5:30am...

NASA TV boring!? At least we have coverage! I applaud them.

Craig

[Explorer1]

3 Ice Tea bottles of fuel, haha! I was wondering how much they'd have left.
Another layman's unit of measure!

EDIT: Prop on someone's desk too!

[Astro0]

Hey, it's the boss!

[CosmicRocker]

Yeah, demo II was terrific. Now, I know how to drive this thing. I might even have to watch some of those demos on the home page.

[Astro0]

Canberra DSN did a great job today. Two antennas on point for the encounter and a very tired but happy team
Here's a pic of DSS43 in action from just a few minutes ago. http://twitpic.com/400llt

[dilo]

Stardust seems very low on the horizon, indeed!

[Astro0]

Yep, we've been tracking all day, so a full horizon to horizon arc.
We'll be handing over to the Madrid DSN shortly.

[elakdawalla]

Astro0, we don't say it enough: many many thanks to everyone at the DSN for making sure of the safe arrival of our precious data on Earth!

[ZLD]

In relation to my question, I wasn't curious if the comet would be centered or if we knew the orbit, I was curious how well the orientation of the comet would appear in actuality versus what was seen in the simulation (was it set up to look the same/similar as what will be seen in the images).

[brellis]

Mr. Ellison, that was a great presentation!

[djellison]

We have a predicted trajectory for both spacecraft and comet - and then just like the spacecraft itself, Jon (lead dev for EotSS) programmed autonav - the spacecraft rotated and the mirror tracked to keep the comet in the middle of the field of view.

And as for geometry/lighting etc - we did our best to match this : http://2.bp.blogspot.com/-GgFZHEkOXh4/TVk-...0/planned_1.jpg : and I think we did quite well. There's an adjustment we've made here to the timing (15 seconds early) - so the 5 images will be more like -21sec to +51sec rather than centered on C/A

And thanks for the kudos guys - a lot of fun tonight, and it seems like the technology for EotSS, and our faithful old spacecraft...has held up.

We're in for a slightly longer wait for the images, but hopefully it'll be worth it.

[djellison]

my only gripe it
the site is MS only

It's not. It's Mac or PC. I'm sorry it doesn't work for Linux, but that's just a symptom of the Unity plugin not being available for Linux. For 0.3% of the audience, I can understand their reluctance to develop one.

[Guest_Sunspot_*]

Whats going on? lots of people around monitors.....my sound has gone off on the NASA feed

[Gsnorgathon]

First images! Tiny ones, so far. ~2,500km away.

[Explorer1]

First taken, rather then 'planned five'.
Unknown why this happened.

[Hungry4info]

Apparently, they intended to download the closest approach images first, but for some unknown reason, the images are coming in in the order they were taken.

edit: Will have press conference tomorrow to show closest approach images.
edit2: Tomorrow being... in the morning

[Astro0]

First image. 20 x zoom


Better:

[Gsnorgathon]

They're saying ~6hr wait to get the closest approach images. Looks like it's time for bed. (And great consolation for all the folks who couldn't stay up!)

[Explorer1]

2 up at : http://www.jpl.nasa.gov/news/stardust/

Flicking between them shows some vagueness...

Still to early to say for sure.

EDIT: several more: oh this is excruciating! Looks like some vague circle. Dare I say it's the crater? Going to be no matter what now. Press conference delayed so at least I'll get some sleep.

http://www.nasa.gov/images/content/516881main_n30008te01.jpg

[ugordan]

http://www.nasa.gov/images/content/516881main_n30008te01.jpg

This one is sharper - no motion blur: http://www.jpl.nasa.gov/news/stardust/index.php?fileID=6073

[Astro0]

EDIT: Revised animation sequence - first 6 images @200% (no sharpening)

[ugordan]

6th image is down. Also blurry.

Tick... tock...

[jasedm]

Hmmm tantalising, but still too early to say whether the same hemisphere's in view..

[Toma B]

In image "n30007te01" 2 circular formations (craters) can be seen.



Could they be theese 2 craters?

[ugordan]

I don't know, the sharpened images Astro0 posted really suggest to me we're seeing that crater and crescent feature near the impact site, it's just that the comet is rotated slightly. If only my Photoshop at work didn't crap out on me...

If that is the case, it's also pretty obvious any resulting crater isn't huge.