IPB

Welcome Guest ( Log In | Register )

New Horizons Hibernation and Cruise to Pluto
Guest_AlexBlackwell_*
post Jun 28 2007, 10:05 PM
Post #1





Guests






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

New Horizons Slips into Electronic Slumber
June 28, 2007
Go to the top of the page
 
+Quote Post
 
Start new topic
Replies
edstrick
post Sep 19 2007, 08:18 AM
Post #2


Senior Member
****

Group: Members
Posts: 1870
Joined: 20-February 05
Member No.: 174



I would expect so.
Go to the top of the page
 
+Quote Post
Alan Stern
post Nov 20 2007, 09:27 AM
Post #3


Member
***

Group: Members
Posts: 529
Joined: 19-February 05
Member No.: 173



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
Go to the top of the page
 
+Quote Post

Posts in this topic
- AlexBlackwell   New Horizons Hibernation and Cruise to Pluto   Jun 28 2007, 10:05 PM
- - Stu   Nite nite NH, and thanks for a great trip so far. ...   Jun 28 2007, 10:21 PM
- - hendric   Not to die, but to sleep, To sleep: perchance to d...   Jun 29 2007, 03:31 AM
- - John Flushing   Good morning, New Horizons.   Jul 12 2007, 05:51 PM
|- - ustrax   Are we there yet?! One more possible harbour...   Jul 18 2007, 01:05 PM
- - Alan Stern   ..this will be coming out later in the week sports...   Jul 30 2007, 06:56 PM
- - Rakhir   Thanks Alan for this update.   Jul 30 2007, 08:23 PM
- - Alan Stern   7 AU from Sol! The Sun is 49x reduced now from...   Aug 6 2007, 10:19 PM
- - nprev   She appears to be running sweet and true indeed, A...   Aug 7 2007, 06:01 AM
- - Paolo   Any idea of when the results of the Jupiter flyby ...   Aug 7 2007, 08:21 AM
- - Alan Stern   Paolo- The editor at Science is shooting for early...   Aug 7 2007, 08:41 AM
- - djellison   Well - at least you get a a true-to-life test of t...   Aug 7 2007, 09:00 AM
- - Alan Stern   Agreed, but I'd have gladly settled for the gr...   Aug 7 2007, 09:27 AM
- - nprev   Thanks for the info, Alan (me and my mouth...I cou...   Aug 7 2007, 03:25 PM
- - ugordan   I do hope this turns out to be a weird software is...   Aug 7 2007, 03:29 PM
|- - stevesliva   QUOTE (ugordan @ Aug 7 2007, 11:29 AM) I ...   Aug 7 2007, 04:14 PM
|- - ugordan   QUOTE (stevesliva @ Aug 7 2007, 05:14 PM)...   Aug 7 2007, 04:26 PM
|- - stevesliva   QUOTE (ugordan @ Aug 7 2007, 12:26 PM) Th...   Aug 7 2007, 05:31 PM
- - nprev   Actually, Gordon, the odds are that you're pro...   Aug 7 2007, 03:34 PM
- - ugordan   Oh, they're something you have to live with, a...   Aug 7 2007, 05:42 PM
- - Alan Stern   Status: Recovering. DSN Allocating Additional Shif...   Aug 8 2007, 07:52 AM
|- - ElkGroveDan   QUOTE (Alan Stern @ Aug 7 2007, 11:52 PM)...   Aug 8 2007, 02:54 PM
- - nprev   Thanks for the update, Alan. Best of luck to the t...   Aug 8 2007, 10:10 AM
- - ChrisP   Thanks for the update Alan. I've lived through...   Aug 8 2007, 10:16 AM
- - Alan Stern   Recovery complete! New Horizons is back to nom...   Aug 10 2007, 09:00 AM
- - djellison   Wake up, scratch, roll over, go back to sleep. We...   Aug 10 2007, 09:02 AM
- - nprev   Excellent. Alan, if you get a chance, could you pl...   Aug 10 2007, 04:39 PM
- - Alan Stern   Nprev-- Forensics continue down at the 1's and...   Aug 11 2007, 06:29 AM
- - nprev   Yep; that's exactly what I meant earlier about...   Aug 11 2007, 08:11 PM
- - ed_lomeli   Hello Alan, I read somewhere in a response to the...   Sep 18 2007, 04:30 PM
- - edstrick   I would expect so.   Sep 19 2007, 08:18 AM
|- - Alan Stern   UMSFers-- To Be Posted at the NH mission website t...   Nov 20 2007, 09:27 AM
|- - ugordan   Thanks for the heads up, Alan. As always, one noti...   Nov 20 2007, 10:43 AM
||- - Alan Stern   QUOTE (ugordan @ Nov 20 2007, 10:43 AM) T...   Nov 21 2007, 11:36 AM
|- - ElkGroveDan   QUOTE (Alan Stern @ Nov 20 2007, 01:27 AM...   Nov 20 2007, 03:56 PM
- - djellison   When do you sleep!! Thanks, as ever, for ...   Nov 20 2007, 09:44 AM
|- - Alan Stern   QUOTE (djellison @ Nov 20 2007, 09:44 AM)...   Nov 20 2007, 09:53 AM
- - djellison   I'm a Brit, so I'm 5hrs ahead. Infact, I f...   Nov 20 2007, 10:49 AM
- - nprev   Well, I'm selfishly thankful for the fact that...   Nov 20 2007, 11:51 AM
|- - mchan   QUOTE (nprev @ Nov 20 2007, 03:51 AM) IIR...   Nov 21 2007, 05:45 AM
- - jasedm   Thank you very much for the information - great to...   Nov 20 2007, 09:52 PM
- - nprev   What a terrific resource; thanks very much, mchan...   Nov 21 2007, 10:15 AM
- - PhilCo126   After a 35 years long experience of venturing out ...   Nov 21 2007, 06:11 PM
- - Liss   I'm somewhat at loss regarding the current sta...   Feb 26 2008, 08:18 AM


Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 29th March 2024 - 05:35 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.