New Horizons: Pre-launch, launch and main cruise, Pluto and the Kuiper belt Options

[Alan Stern]

Active Checkout (ACO) 2 is now in its final phases. We're taking in situ dust and particles and fields data with SWAP, PEPSSI, and VB-SDC every day this month and the first half of December. Hibernation commences on Dec 16th. Dust data collection will continue continuously in hibernation right through early July. Onward, ever deeper into the abyss.

-Alan

[MahFL]

Thank you Dr. Stern. My name heads deeper into the abyss.

[Alan Stern]

After a wildly successful run in ACO-2, including three s/c-level software upgrades involving almost 100 changes, full s/c and payload checkouts, instrument calibrations and new capability tests, star tracker imaging, trajectory tracking refinement, extensive cruise science, and more, New Horizons is back in hibernation.

...Now for a few hundred million miles of quiet cruise...

New Horizons will be in Hibernation until just after 4 July, with only cruise moniroing TM and beacon passes, while the crew here on Terra plan THE encounter.

-Alan

[djellison]

Thanks for the update Alan ( and kudos to your Twitter feed - hopefully everyone here is tuned in )

Out of curiosity - what bit rate are you operating at out at 10+Au, and what's that telling you about post Pluto data rates?

[just-nick]

New Horizons will be in Hibernation until just after 4 July, with only cruise moniroing TM and beacon passes, while the crew here on Terra plan THE encounter.

How long does this hibernation period compare to the original plans? On no evidence at all it seems like the sleepy times have been shorter than I expected. Or is that just a natural side effect of getting comfortable with the process?

Congrats on a good software update. You seem to have much better luck than I do.

--Nick

[Alan Stern]

Thanks for the update Alan ( and kudos to your Twitter feed - hopefully everyone here is tuned in )

Out of curiosity - what bit rate are you operating at out at 10+Au, and what's that telling you about post Pluto data rates?

Doug--

We run at various bit rates depending on the DSN antenna used, how close to Earth we are pointed, and our geocentric distance. Also, when we use both xmitters we can double the data rate. In hibernation, TM passes are 10 bps because we are usually pointed well of Earth and therefore DSN isn't directly in the beam. In active modes in the middle solar system where we are now, we run up to ~10 Kbps (near Earth we were up at 104 Kbps).

At Pluto we'll max out at about 5 Kbps, but that will be rare-- 3.5 kbps with both xmitters will be the downlink standard.

-Alan

[Alan Stern]

How long does this hibernation period compare to the original plans? On no evidence at all it seems like the sleepy times have been shorter than I expected. Or is that just a natural side effect of getting comfortable with the process?

Congrats on a good software update. You seem to have much better luck than I do.

--Nick

Hi Nick--

We plan to hibernate 200-300 days per year. We first hibernated in '07, and we planned to walk before running, so we went 14 days, then 30, then 90. In '08 we planned two 100 day-class stretches with a s/c antenna precession maneuver between them, but the latter 100 days run in hib was interrupted by a s/c safing event this summer. Our current 200 day sleep that we just entered will be a record if all goes well, but later in the flight we'll go well over that.

Alan

ps. As to the FSW updates being bug free, well, APL of course extensively tested before we uploaded, and then there is Murphy, who *always* lurks-- even now. My fingers and toes have been crossed for three years straight now....

[just-nick]

ps. As to the FSW updates being bug free, well, APL of course extensively tested before we uploaded, and then there is Murphy,

Do you have an "iron bird" or some sort of duplicate hardware set to test the new loads on? And I assume you stagger them, one side first so the other is on the old version in case you need to failover?

[Alan Stern]

Do you have an "iron bird" or some sort of duplicate hardware set to test the new loads on? And I assume you stagger them, one side first so the other is on the old version in case you need to failover?

We have several software testbeds that use the onboard computer hardware. Additionally, there are two spacecraft simulators called NHOPS ("N-hops", or New Horizons Ops Simulator); these contain engineering model replicas of *all* of the flight subsystem and instruments avionics.

When we put up new software, we do as you suggest-- we leave ourselves an out, but the way we do it is more finessed than just leaving the B-side with the old flight software. Instead, we can actually leave a copy of the previous flight software inside each computer itself until we get enough run time on the new code to feel confident in it.

-Alan

[Guest_PhilCo126_*]

Thanks for the update Alan!
Amazing, this means that the spacecraft will only get a wake up call once a year (every 200 days) to go from passive spin hibernation into normal spin. Is this planned for the next 6 years to get a final wake up call to keep the spacecraft alive for the complete Pluto-Charon flyby?
The New Horizons spacecraft LORRI imager got its first glimpse of Pluto in September 2006. When, earliest, will LORRI plan to image the dwarf planet again?

[Alan Stern]

Thanks for the update Alan!
Amazing, this means that the spacecraft will only get a wake up call once a year (every 200 days) to go from passive spin hibernation into normal spin. Is this planned for the next 6 years to get a final wake up call to keep the spacecraft alive for the complete Pluto-Charon flyby?
The New Horizons spacecraft LORRI imager got its first glimpse of Pluto in September 2006. When, earliest, will LORRI plan to image the dwarf planet again?

Phil-- We wake her up every year for 4-14 weeks, depending on our to do list.

By the way, http://pluto.jhuapl.edu/news_center/news/121908.php

ps. LORRI will next see Pluto in 2010.

[hendric]

Hmmm...Somehow I never heard about the SDC data being available for viewing. They have a nice website at

http://lasp.colorado.edu/sdc/

with a viewing tool at

http://lasp.colorado.edu/sdc/interface/index.html

An interesting picture is the Full Mission View of the dust profile

http://lasp.colorado.edu/sdc/interface/images/longview.gif

Interesting that the dust density has remained fairly constant so far, with four density spikes between Mars and Jupiter. Alan, is the SDC team planning on any presentations or papers soon?

Edit: BTW, this is how E/PO should be done.

[Alan Stern]

Hendric--

Glad you like it! And I agree it's a nice outreach tool. The SDC team will present at the next NH science team meeting (Jan 22-23); I don't offhand know of any specific public presentations. You can ask Horanyi directly if you like. He is probably thinking of LPSC or IAU. By the way, Pioneers 10 and 11 had dust detectors that worked out to almost 18 AU, and they also found constant dust density out to there-- the implication, realized only much later, is that there must be an external source making up for the volume dilution effect-- the Kuiper Belt. Imagine-- the Pioneers produced a strong hint in the early 80s but no one caught on!


-Alan

[Guest_Oersted_*]

Dear Alan Stern,

I am mostly a lurker in this forum, but I just want to say that I am so excited by the fact that we´ll hopefully get good imagery of Pluto from NH in the not too far-off future. Truly a dream come true for me and for untold others I'm sure, a "silent majority" of space exploration enthusiasts from all over the world.

A few questions: What kind of resolution can we expect from the LORRI imager? And will the geometry of the encounter make a Pluto-Charon moon-rise-like image possible?

Happy New Year 2009 to the New Horizons team!

[Hungry4info]

Truly a dream come true for me and for untold others I'm sure, a "silent majority" of space exploration enthusiasts from all over the world.

Yes indeed. I, too, look forward to these images. An uncharted globe far away, shrouded in a veil of mystery and at times, controversy, and beckoning to us for sixty years.

And will the geometry of the encounter make a Pluto-Charon moon-rise-like image possible?

That would be 100% awesome. I would really love to see such an image.

How long is the SDC supposed to function? I think it would be great to have SDC data all the way out to the heliopause.