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?