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Unmanned Spaceflight.com _ New Horizons _ New Horizons Hibernation and Cruise to Pluto

Posted by: AlexBlackwell Jun 28 2007, 10:05 PM

I thought I'd kick off a new thread with this announcement:

http://pluto.jhuapl.edu/news_center/news/062807.htm
June 28, 2007

Posted by: Stu Jun 28 2007, 10:21 PM

Nite nite NH, and thanks for a great trip so far. Enjoy your rest, you've earned it. smile.gif

Posted by: hendric Jun 29 2007, 03:31 AM

Not to die, but to sleep,
To sleep: perchance to dream...

We'll see you in August NH. Sleep tight.

Posted by: John Flushing Jul 12 2007, 05:51 PM

http://pluto.jhuapl.edu/news_center/news/071207.htm

Posted by: ustrax Jul 18 2007, 01:05 PM

http://www.space.com/scienceastronomy/070717_charon_geysers.html blink.gif
One more possible harbour for life...
Man...We're surrounded... rolleyes.gif

Posted by: Alan Stern Jul 30 2007, 06:56 PM

..this will be coming out later in the week sports fans; I thought USMFers would like to see it first.

“Outbound at 7 AU”

Alan Stern
01 August 2007


IMAGE: New Horizons launched just over 18 months ago on a journey that will take 114 months to reach the Pluto system. (NASA photo.)


Since I last wrote here, in mid-June, New Horizons has been continuing its speedy journey across the space from Jupiter’s orbit at 5.2 AU to Saturn’s at 9.5 AU. On average, we travel about a third of an astronomical unit each month, or roughly a million miles per day. So as July turns into August, we’re nearing the half-way point in the Jupiter-Saturn leg of our journey, reaching 7 AU on 6 August. We’ll pass Saturn’s orbit (but not Saturn, which will be far away from our path) next April.

During the six weeks since I last wrote, the spacecraft has primarily been in hibernation. In fact, since June 27th we’ve been in hibernation except for a brief, 9-day wake up that began on July 12th.

The highlight of the mid-July wake up period was the opening of the solar occultation port (SOCC) on the Alice UV spectrometer (UVS). This was the last of the seven instrument aperture doors to be opened on New Horizons. Like all the other openings, this one also went smoothly. Now, Alice can use its pinhole-sized SOCC aperture to stop down the intensity of sunlight by a factor of about 6000, making it possible to trace the density and composition of Pluto’s atmosphere versus altitude without blinding the detector. After opening the Alice SOCC door, the spectrometer gathered its first-light SOCC spectrum by observing the B star Bellatrix. The Alice UVS also performed a series of self tests and also received a software update during the wakeup.


IMAGE: The New Horizons Alice UV spectrometer showing the Solar Occultation port as the black protuberance near center bottom; the main Alice aperture is the much larger black aperture protruding from the instrument’s right side. (Credit: SwRI)


Other activities during the July wake up included onboard data compression testing, some LORRI and SWAP instrument tests, and a data dump of the Venetia Burney Student Dust Counter’s data memory. New Horizons was returned to its hibernation state on July 21st and will remain in hibernation until August 16th when we wake up for about three months of intensive onboard activities that will include numerous instrument calibrations and tests and a small course correction maneuver (see my previous PI Log). Until then, we will listen to its telemetry or beacon tone broadcasts four times per week, but we won’t be actively controlling the spacecraft; all commands it executes were stored in onboard memory before entering this second hibernation period.

But while our spacecraft slumbers, our ground team is busy planning those activities for the wake up period, which will stretch into mid-November. And, simultaneously, our science team continues to analyze Jupiter data and work to select a final targeting distance for our Pluto closest approach. I’ll have more to say about that next time I write. For now, however, I want to tell you that in early July the team completed a series of 8 scientific papers about some of the most important Jupiter system results we achieved, and then submitted those papers to the journal Science for publication in a special section issue this fall. And while the spacecraft and science teams kept busy as I just described, engineers working on New Horizons are busy building a second New Horizons Operations Simulator (“NHOPS II”) which will serve as both an insurance policy against the failure of NHOPS I during the long flight to Pluto and the Kuiper Belt, and also as a “surge” simulator for times when NHOPS I is booked up. NHOPS II, replete with high-fidelity engineering models of the instrument payload and the spacecraft subsystems, will be completed and then extensively checked out early next year.

In other project news, it is my pleasure to tell you that our project manager, Glen Fountain, has been selected to receive the American Institute of Aeronautics and Astronautics (AIAA) 2007 von Braun Award for Excellence in Space Program Management. This award gives national recognition to an individual for outstanding contributions in the management of a significant space or space-related program or project. I think Glen was an obvious choice, but I am biased, of course. Nonetheless, we’re all proud of him and look forward to Wednesday, 19 September when he’ll be presented with the award in conjunction with the AIAA Space Conference and Exhibit, Long Beach Convention Center, Long Beach, California.


IMAGE: New Horizons Project manager Glen Fountain; Sunday 15 January 2006. (Credit: Alan Stern)


Well, that’s what I wanted to tell you about this time. I’ll be back with more news in another update in September. In the meantime, keep on exploring, just like we do.

-Alan Stern

Posted by: Rakhir Jul 30 2007, 08:23 PM

Thanks Alan for this update.

Posted by: Alan Stern Aug 6 2007, 10:19 PM

7 AU from Sol! The Sun is 49x reduced now from launch. At encounter it declines to about 1000x, by this (slanted) measure we're most of the way there.

Posted by: nprev Aug 7 2007, 06:01 AM

She appears to be running sweet and true indeed, Alan...nothin' but love for NH & the team! smile.gif

Posted by: Paolo Aug 7 2007, 08:21 AM

Any idea of when the results of the Jupiter flyby will be published in Science?

Posted by: Alan Stern Aug 7 2007, 08:41 AM

Paolo- The editor at Science is shooting for early October for the Jupiter issue.

Nprev- Overnight we had a routine DSN pass to check NH's beacon status; this is the tone-generation system that reports red or green based on a rack up of s/c health. For the first time, we got a red beacon. It is Red 2, which is severe but not ultra-severe. We commanded the s/c to transit telementry and are now collecting TM and diagnosing the issue. More later.

-Alan

Posted by: djellison Aug 7 2007, 09:00 AM

Well - at least you get a a true-to-life test of the beacon system before the calibs later in the month.

Doug

Posted by: Alan Stern Aug 7 2007, 09:27 AM

Agreed, but I'd have gladly settled for the ground testing we did. Early indications are that our bus controller (C&DH 1) computer reset itself, generating the Red 2 beacon tone owing to a watchdog timer reset. This is not certain (data rates are glacial still, ramping up shortly after the long round trip light time); we'll have more visibility then.

-Alan

Posted by: nprev Aug 7 2007, 03:25 PM

Thanks for the info, Alan (me and my mouth...I could kick myself sad.gif ).

Just out of curiosity, are each of the CD&H computers internally redundant in terms of power supplies & operating channels?

Posted by: ugordan Aug 7 2007, 03:29 PM

I do hope this turns out to be a weird software issue rather than a hardware problem even though extensive ground testing probably makes software bugs less likely.

Posted by: nprev Aug 7 2007, 03:34 PM

Actually, Gordon, the odds are that you're probably right about it being software. It really is impossible to test every possible case (or even foresee them all), so hopefully this is just an easy to find & fix bug.

Posted by: stevesliva Aug 7 2007, 04:14 PM

QUOTE (ugordan @ Aug 7 2007, 11:29 AM) *
I do hope this turns out to be a weird software issue rather than a hardware problem even though extensive ground testing probably makes software bugs less likely.

I hope it's neither. I hope it was an uncorrectable, transient, radiation-induced error. What will be most interesting is how deep the safe mode is, and how graceful the failure is.

Posted by: ugordan Aug 7 2007, 04:26 PM

QUOTE (stevesliva @ Aug 7 2007, 05:14 PM) *
I hope it was an uncorrectable, transient, radiation-induced error.

That wouldn't be too good, either. It would mean the spacecraft is too sensitive to random, unpredictable cosmic-ray events even while in the state of hibernation when most of the electronics are powered off. Imagine a trip like that during Pluto closest approach. I'd actually put those kinds of faults in the hardware "fault" category.

Posted by: stevesliva Aug 7 2007, 05:31 PM

QUOTE (ugordan @ Aug 7 2007, 12:26 PM) *
That wouldn't be too good, either. It would mean the spacecraft is too sensitive to random, unpredictable cosmic-ray events even while in the state of hibernation when most of the electronics are powered off. Imagine a trip like that during Pluto closest approach. I'd actually put those kinds of faults in the hardware "fault" category.

I think it was reading the GP-B updates with all the talk of multi-bit errors that makes me think they're something you have to live with... GP-B dealt with them far more often than 1 in 2 years.

i.e. http://einstein.stanford.edu/highlights/hl_040105.html
"Investigations into the root causes of the recent spate of MBEs suggests the possibility that the scrub routine which is checking the memory cells of the on-board Command & Control Computer Assembly (CCCA) could trigger a safemode response on a single MBE if that error occurs in certain locations. As a result, the team has re-programmed the safemode response for the MBE test to automatically stop the mission timeline, rather than rebooting the computer."

Posted by: ugordan Aug 7 2007, 05:42 PM

Oh, they're something you have to live with, alright. Statistics are hell, but it just doesn't seem right for the spacecraft to run into a red alert mode only some 2 months (?) into hibernation. Statistically, that can mean anything from an unlucky fluke to a spacecraft that has to be babysitted every month. It could be a combination of the two for all we know, a cosmic ray trip triggers a software corrective action that's buggy and you wind up in a reset.

Take Cassini for comparison - it has a couple of trips of a certain power-related circuit (I forget) per year due to cosmic rays and that's with a spacecraft doing stuff basically 24/7. The fact NH had a mostly trouble-free flight up until hibernation does seem to suggest it's in some way related to that mode, but all this is wild speculation. Hopefully, Alan and co. will find out the real sequence of events soon enough.

Posted by: Alan Stern Aug 8 2007, 07:52 AM

Status: Recovering. DSN Allocating Additional Shifts to Assist in Recovery.

Root Cause of C&DH Reset: Remains TBD.

Team: Working Long Hours; Need to Pace.

Prospect: Back in Hibernation in <1 Week.

Posted by: nprev Aug 8 2007, 10:10 AM

Thanks for the update, Alan. Best of luck to the team, and sympathy for the long, long hours...please tell them we REALLY appreciate their efforts!!!

Posted by: ChrisP Aug 8 2007, 10:16 AM

Thanks for the update Alan. I've lived through all the first visits to the Moon and other planets and I do so want New Horizons to make it to Pluto. Best of luck to you all!

Fingers Crossed,
Chris.

Posted by: ElkGroveDan Aug 8 2007, 02:54 PM

QUOTE (Alan Stern @ Aug 7 2007, 11:52 PM) *
Prospect: Back in Hibernation in <1 Week.

You or the spacecraft?

Posted by: Alan Stern Aug 10 2007, 09:00 AM

Recovery complete! New Horizons is back to nominal hibernation.

Posted by: djellison Aug 10 2007, 09:02 AM

Wake up, scratch, roll over, go back to sleep.

We've all been there.

Thanks for the updates Alan.

Doug

Posted by: nprev Aug 10 2007, 04:39 PM

Excellent. Alan, if you get a chance, could you please tell us what seemed to be the most probable cause of this event? Interesting.

Posted by: Alan Stern Aug 11 2007, 06:29 AM

Nprev-- Forensics continue down at the 1's and 0's level to learn why the reboot occurred. Attention is focusing on a possible (and subtle) C&DH software interaction with autonomy rules.

-Alan

Posted by: nprev Aug 11 2007, 08:11 PM

Yep; that's exactly what I meant earlier about it not being possible to test every case when it comes to software. Thanks, Alan! smile.gif

Posted by: ed_lomeli Sep 18 2007, 04:30 PM

Hello Alan,

I read somewhere in a response to the media that the code for the Pluto encounter will be designed and written this year and in '08. Then, in '09, there would be a first rehearsal. Does this mean a major wakeup in '09? Any details of what that will entail? Thanks.

Posted by: edstrick Sep 19 2007, 08:18 AM

I would expect so.

Posted by: Alan Stern Nov 20 2007, 09:27 AM

UMSFers-- To Be Posted at the NH mission website today, with illustrations:



The PI’s Perspective
November 19, 2007

Autumn, 2007: Onward To the Kuiper Belt

New Horizons rolls out to launch on January 16, 2006. The trees in the foreground reveal the vehicle’s true size.

New Horizons has now covered 85% of the distance from the Sun to Saturn’s orbit, which it will pass in mid-2008. Of course, Saturn will be nowhere near New Horizons when we pass that milestone, as it is by chance located far around the Sun from the path New Horizons is following to Pluto, but as you can tell, we are really getting to be well into the outer solar system now

Since I last wrote you, at the start of October, the New Horizons team has been busy on two major fronts. One of these has been planning and executing our 2007 “Annual Checkout” (ACO) of the spacecraft and its payload. As our first ACO, this three-month operation has been a pathfinder for the team, teaching us how to make improvements for subsequent ACOs in 2008, 2009 and beyond.

The other front we’ve been working on is Pluto encounter planning. As I’ve written here before, we are planning for Pluto now, to take advantage of the experienced team that took us through our virtually flawless Jupiter encounter earlier this year. Budget constraints will force us to slim down the team in mid-2009, so we need to finish the Pluto planning before many of the Jupiter encounter team members move on to other projects.

Our first Annual Checkout was a great success. In fact, ACO-1 just wrapped up, after more than 500 separate spacecraft and instrument activities. We also took the data to recalibrate our instruments — something we’ll do several times as we fly out to the Pluto system. As you know from my last posting here, we also planned and successfully accomplished an engine burn during ACO-1. This maneuver refined our course and dramatically narrowed our expected trajectory errors at Pluto.

We did have a couple of unexpected events in ACO-1. One came in early October when the spacecraft partially lost track of its timeline owing to a very subtle kind of error generated by a command script we’d sent it. The operations team caught this and recovered from it very quickly. It’s was really a blessing that this subtle behavioral flaw manifested itself now, rather than at Pluto, so we can protect against it. It’s just these kinds of idiosyncrasies that our testing and flight operations hope to expose, so despite the fact it cost us some lost sleep and some cruise science observations, we’re very glad to have learned this lesson.

The second unexpected event came just last week, on November 12th, when a cosmic ray or some other kind of charged particle caused our main computer to reboot. This is the fourth such computer reboot we have had in flight owing to space radiation bursts. Preflight predictions were for these events to be far rarer than this, and our engineering team is looking into why this is occurring more often than predicted. Fortunately, on all four occasions this occurred, the onboard spacecraft autonomy software performed as planned and recovered New Horizons safely.

The third and final such event took place on November 16th when the spacecraft main computer executed a power on reset (POR) due to a glitch on its power line. Because this was so unexpected, we are currently analyzing what happened and have decided not to enter hibernation until late December while we analyze the root cause of this anomaly and put in place some software protection against future events. For the next couple of weeks, we’ll monitor the spacecraft three to four times per week using NASA’s Deep Space Network to collect more data.

Then, between December 11 and 17, the spacecraft will pass near the Sun as seen from Earth. (Don’t worry, New Horizons really is out in the frigid cold near Saturn, it just appears to be near the Sun when seen from Earth’s vantage point.) This event is called “solar conjunction” and it occurs every year as the Earth itself reaches a point nearly opposite the Sun from New Horizons. As during last year’s solar conjunction, we will lose contact with New Horizons due to radio interference from the Sun, which will be just one to three degrees away from New Horizons and in our tracking antennas’ field of view.

December 17, the day we exit this year’s solar conjunction, is an anniversary for us, as on that day in 2005, New Horizons was lifted onto its Atlas launch vehicle down in Florida. It’s a nice coincidence to note that precisely 102 years before that day, in 1903, the Wright brothers made their first flight at Kitty Hawk.

And as we exit solar conjunction on December 17th, we’ll have a fairly intense week of activity. During that week we will re-point our dish antenna to better position it for communications with Earth, play back recorded engineering and Student Dust Counter detector telemetry; and prepare the spacecraft for a long period of hibernation that will begin on December 23 and continue uninterrupted (we hope!) until next May when we next break hibernation for about a week to reposition our antenna again for better communications with Earth. We’ll also use that operations opportunity in May to send home some of the lower priority “cruise science” data taken this month that couldn’t be squeezed down during ACO-1. And then we’ll go back to silent running until ACO-2 begins late next September.

During the almost 40 weeks we’ll be in hibernation in 2008, we won’t be sending commands to the spacecraft, but we will check its health via weekly beacon tones and (beginning in early 2008) monthly telemetry sessions. Many of you may notice that this is a less frequent set of checks than we performed in 2007– because as we gain experience with the spacecraft in hibernation mode, we can reduce the oversight we perform on it. This “lengthening of the leash” as I like to call it, is something we have planned for years. And unless something untoward occurs, this pace of weekly beacon tone and monthly telemetry checks is how we will run hibernation activities in future years on the way to Pluto.

That’s my update on mission activities for now, but before I close I’d like to show you two things related to the Pluto encounter we are now beginning to plan.

First is the “block schedule” that defines our Pluto system encounter phases. By studying this figure–which I’ve placed below--you will see that we plan to begin the encounter operations about 6 months before reaching Pluto, and we do not finish—including all of the data transmissions and plasma and dust environment measurements until 6 months after the July 14 encounter itself. Of course, most of the action occurs in the roughly two-month period centered on encounter day, when our resolution and sensitivity are dramatically better than anything Earth-based and Earth-orbiting telescopes can match.

New Horizons’ encounter with the Pluto system will span a year, in which there will be three successively closer approach phases (APs 1, 2 and 3), a near encounter phase (NEP) lasting two days, which will be followed by three successively more distant departure phases (DPs 1, 2 and 3).

The second encounter-related diagram I want to show you is a view of the Pluto system at our moment of closest approach. It shows where the spacecraft will be at its moment of closest approach to Pluto, relative to Pluto and all three of Pluto’s satellites, i.e., at the green “+” symbol. As you can see, we will be 13,700 kilometers from Pluto’s center and therefore 12,500 kilometers from its surface. You can also see that Nix and Charon are arrayed on different sides of the spacecraft at roughly similar distances, but Hydra is considerably farther away, off in the rough direction that Charon will appear to be.

The geometry of Pluto and its three satellites – Charon, Nix and Hydra – are shown here relative to our spacecraft aim point (the green “+”) at the moment of closest approach (C/A) to Pluto.

In the coming year while our beauty sleeps, we will plan this encounter in great detail, leading to a full suite of rehearsals on our mission simulator in 2009, which will in turn lead to rehearsals on New Horizons itself in 2010. As 2008 unfolds, I’ll keep you apprised of many of the interesting things we plan to do during the Pluto encounter and how we plan to do them.

Well, that catches you up with where New Horizons is and what the spacecraft and project team have been doing. I’ll be back with more news around the start of the new year. In the meantime, keep on exploring, just like we do!

-Alan Stern

Posted by: djellison Nov 20 2007, 09:44 AM

When do you sleep!! Thanks, as ever, for the update - much appreciated.

Posted by: Alan Stern Nov 20 2007, 09:53 AM

QUOTE (djellison @ Nov 20 2007, 09:44 AM) *
When do you sleep!! Thanks, as ever, for the update - much appreciated.


And you Doug?

Posted by: ugordan Nov 20 2007, 10:43 AM

Thanks for the heads up, Alan. As always, one notices the bad news first:

QUOTE (Alan Stern @ Nov 20 2007, 10:27 AM) *
The second unexpected event came just last week, on November 12th, when a cosmic ray or some other kind of charged particle caused our main computer to reboot. This is the fourth such computer reboot we have had in flight owing to space radiation bursts. Preflight predictions were for these events to be far rarer than this, and our engineering team is looking into why this is occurring more often than predicted. Fortunately, on all four occasions this occurred, the onboard spacecraft autonomy software performed as planned and recovered New Horizons safely.

Is this a concern for Pluto approach observations, e.g. are you expecting to be able to deliver a software udate which would recognize these kinds of events and would not result in a safing event which terminates the observation sequence? I'm thinking of something similar to what was recently incorporated into Cassini flight s/w. Recalling the recent Iapetus flyby and the safing event, it would be tragic to have something similar occur during Pluto C/A.

Posted by: djellison Nov 20 2007, 10:49 AM

I'm a Brit, so I'm 5hrs ahead. Infact, I feel a cup of tea coming on.

I'm reminded of something from 'The Last Lecture of Randy Pausch' - he said people ask him what his secret is to being so succesfull - his reply 'Call me in my office any Friday night at 10 O'clock and I'll tell you'


Doug

Posted by: nprev Nov 20 2007, 11:51 AM

Well, I'm selfishly thankful for the fact that BOTH of you guys are insomniacs (me too, but much, much less productive); awesome update, Alan, thank you! smile.gif

Kind of curious about the energetic particle situation. IIRC, the terrestrial observatories looking for 'shower' events is just coming online, so there isn't a very good baseline yet to evaluate the overall environment in this regard. Do you suppose that it's been heavier than average of late, given that Cassini also experienced an event not too long ago? Don't know if other missions have had any problems.

Posted by: ElkGroveDan Nov 20 2007, 03:56 PM

QUOTE (Alan Stern @ Nov 20 2007, 01:27 AM) *
New Horizons has now covered 85% of the distance from the Sun to Saturn’s orbit, which it will pass in mid-2008.


Holy smokes! These kinds of velocities are just mind blowing.

Thanks again for dropping by here for us Alan.

Posted by: jasedm Nov 20 2007, 09:52 PM

Thank you very much for the information - great to have some idea of the situation around C/A - I can only begin to imagine the flurry of activity and sleepless nights/overtime when, a couple of weeks prior, 3 or 4 more moons turn up on the approach imagery and some rings/ring arcs hove into view.......

Posted by: mchan Nov 21 2007, 05:45 AM

QUOTE (nprev @ Nov 20 2007, 03:51 AM) *
IIRC, the terrestrial observatories looking for 'shower' events is just coming online, so there isn't a very good baseline yet to evaluate the overall environment in this regard. Do you suppose that it's been heavier than average of late, given that Cassini also experienced an event not too long ago?


Neutron monitors have been around since around the time Sputnik-1 launched. These detect secondary particles created by collisions with atmosphere molecules. The intensity is that on Earth's surface and it varies with the 11 year solar cycle. The data does not reflect (at least not directly) what is experienced by spacecraft in deep space.

http://ulysses.sr.unh.edu/NeutronMonitor/neutron_mon.html has many links to historical data in many formats. One of the links is to a monitor in Moscow with real time data. Have fun.

Posted by: nprev Nov 21 2007, 10:15 AM

What a terrific resource; thanks very much, mchan! smile.gif Gotta go play with it now...

EDIT: It sort of looks like CR activity was pretty busy on 11-12 Nov, but it actually looks busier 19-20 Nov. It's all a roll of the dice, anyhow; since these things are thought to be the result of random high-energy astrophysical events (and, apparently, Centaurus A's central black hole & those of other active galaxies burping every so often as they eat), there's no way to predict them.

Posted by: Alan Stern Nov 21 2007, 11:36 AM

QUOTE (ugordan @ Nov 20 2007, 10:43 AM) *
Thanks for the heads up, Alan. As always, one notices the bad news first:
Is this a concern for Pluto approach observations, e.g. are you expecting to be able to deliver a software udate which would recognize these kinds of events and would not result in a safing event which terminates the observation sequence? I'm thinking of something similar to what was recently incorporated into Cassini flight s/w. Recalling the recent Iapetus flyby and the safing event, it would be tragic to have something similar occur during Pluto C/A.


Ugordan- Actually, during encounter we plan to lock out most of the autonomy that would safe the s/c. The logic here is that we have only one shot at encounter and you want to ride out events like reboots rather than calling home for help which can only come after the main festivities would be over. By contrast, in cruise, one always has time to ring home and play it safe...

-Alan

Posted by: PhilCo126 Nov 21 2007, 06:11 PM

After a 35 years long experience of venturing out past the outer planets (since Pioneer 10: Jupiter Dec 1973 - Neptune June 1983) I guess we can sleep on both ears concerning the radiation-hardened computer unsure.gif

Posted by: Liss Feb 26 2008, 08:18 AM

I'm somewhat at loss regarding the current status of New Horizons.
Was it put to hibernation on February 21 as scheduled?
Was it put to hibernation earlier on December 23 as advertised? If not, why? Else, what was the reason to wake up her between December and February and when was it done?

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