Where is New Horizons now Options

[cawest]

i found this web site

http://www.heavens-above.com/solar-escape.asp

it show where NH is compared to voy1, 2/pioneer

any one else have a fav web page that shows NH loc? I think this one is updated onece a day

[ugordan]

You won't believe this, but the New Horizons' official site also has diagrams showing the current position.

[Toma B]

You won't believe this, but the New Horizons' official site also has diagrams showing the current position.

...and it is updated 24 times more often then Heavens Above is...WOW!
This one is updated every second...

[cawest]

You won't believe this, but the New Horizons' official site also has diagrams showing the current position.

yes but the last one is blocked by most company's web blocking software.. at my company blocks it.

[odave]

Here's a screen capture from the NH site. I think someone in a past thread called it the "bat out of hell trajectory"

[Rob Pinnegar]

Right on. NH is already one-eighth of the way to Jupiter. Speedy little guy.

[gpurcell]

Looking at the trajectory side view. I never realized that NH will encounter Pluto right near the point it passes the plane of the solar system.

[Redstone]

New Horizons passes orbit of Mars.

NH website article

[Rem31]

How is it possible that New Horizons has passed the orbit of Mars in only a few months? I always thought that a trip to Mars takes a year or so. And how much kilometers per second is New Horizons traveling at this moment?

[Jeff7]

That's assuming that you want to stay at Mars. In that case, full-speed isn't your best bet - otherwise you need a LOT of fuel to slow the spacecraft down. When we send a probe to Mars to stay there, it's done gradually, so that the probe can use a smaller amount of fuel for orbit-insertion.
New Horizons isn't concerned with any of that - it's just zipping right by.

So a flight to Mars need not take very long. Just depends on 1) if you want to land there, and 2) how much fuel you can carry.

And NH is moving at 21 kilometers/sec.

[cawest]

well NH is almost two AU from the sun and 1 AU from home.... movein out

[tfisher]

So a flight to Mars need not take very long. Just depends on 1) if you want to land there, and 2) how much fuel you can carry.

3) How you feel about lithobraking.

[cawest]

so now that we are 2 AU from the sun wha is the Skin temp of the NH? anybody know?

[ugordan]

Errr... Skin time???

[Alan Stern]

We don't measure skin temp, but our bulk structure is running 27 C.

-Alan

[climber]

Oh oh ! Be care of what we say All...God's watching us

[Planet X]

The next major milestone for New Horizons: Passing Ceres, the largest main belt asteroid

The spacecraft will cross the orbital path of Ceres on July 6, 2006. The actual passing of Ceres in heliocentric distance will take place on July 25, 2006 at 18:30 UTC due to Ceres being close to it's outermost possible distance from the sun. Indeed, the 3 AU crossing takes place just two days later on July 27, 2006! Later!

J P

[Hari]

Are spice kernels available for the New Horizons spacecraft? I'd like to make some pretty pictures myself!

[Guest_PhilCo126_*]

Well, it looks like we know where Dr Stern will be on 12th April
New Horizons Mission to Begin Pluto Encounter April 12th, 2015 in Salute to Early Space Explorers
The year 2015 will be the 54th anniversary of the spaceflight of Yuri Gagarin, the first person to orbit the Earth and the 34th anniversary of the first Shuttle launch. Each April 12, Yuri's Night holds parties around the planet to commemorate these occasions. New Horizons mission PI Dr. Alan Stern will be present at theYuri's Night Washington, D.C. party to talk more about the mission...

[cawest]

Errr... Skin temp???

We don't measure skin temp, but our bulk structure is running 27 C.

-Alan

can we have an update please

it was 80.6F it would be nice if we could get a monthly update on this.. i would like to see how cold NH will get. thanks

[MahFL]

NH is designed to stay warm inside, its built like a vaccum flask.

[Planet X]

UPDATE! On 05/03/2007, at 00:01:54 UTC, the NH spacecraft reached 900 million km from the sun. The spacecraft's distance from Earth, by comparison, is 772 million km. NH is now less than 3.837 billion km from Pluto and traveling at a rate of 21.31 km/s. Later!

J P

[cawest]

UPDATE. She is now 1AU from Jupiter and still seems to be doing good.

[Planet X]

Important milestone! On 07/06/2007, at 21:30:30 UTC, the NH spacecraft reached it's first 1 billion km from the sun. The spacecraft's distance from Earth, by comparison, is 870.4 million km. NH is now less than 3.72 billion km from Pluto and traveling at a rate of 20.6 km/s. Later!

J P

[Greg Hullender]

Looking at the New Horizons Current Position chart: http://pluto.jhuapl.edu/mission/whereis_nh.php

I notice that we'll be moving off the edge of the top chart in a few months. Rather than dropping the chart entirely or rescaling it to make it closer to the "Full Trajectory" chart, I wonder if it would be possible to simply shift the center of the chart, keeping the scale the same. That is, instead of putting the sun at the center, would it be possible to center the chart on the point where New Horizons crossed the orbit of Jupiter? I'm pretty sure that'd keep the start point on the chart, and if we're lucky, it'd include the point where New Horizons will cross the orbit of Uranus. That's just past the half-way point, if I figure it correctly.

Failing that, switching to a chart that kept the same scale but was centered on New Horizons itself would be almost as good.

--Greg

[Planet X]

UPDATE! On 09/10/2007, at 08:36:45 UTC, the NH spacecraft reached 1100 million km from the sun. The spacecraft's distance from Earth, by comparison, is nearly 1.108 billion km. Halfway between the mean orbits of Jupiter and Saturn, NH is now less than 3.616 billion km from Pluto and traveling at a rate of 19.97 km/s. Later!

J P

[cawest]

UPDATE! On 09/10/2007, at 08:36:45 UTC, the NH spacecraft reached 1100 million km from the sun. The spacecraft's distance from Earth, by comparison, is nearly 1.108 billion km. Halfway between the mean orbits of Jupiter and Saturn, NH is now less than 3.616 billion km from Pluto and traveling at a rate of 19.97 km/s. Later!

J P

just an FYI NH is down to 70,000 KPH but still going good

[Alan Stern]

...And crossing 8 AU early next week.

[Greg Hullender]

Going to be hard to find interesting milestones over the next seven years. I note, though, that on April 1, 2008, it should reach the "Browserpause," which is that thin white space on the "Current Position" map right where the path exits the picture. :-)

--Greg

[YesRushGen]

Regarding milestones with which to follow NH's progress, I found myself wondering if there are any minor objects that orbit between Jupiter and Saturn's orbits. I came across the following abstract:

http://www.springerlink.com/content/t74010qg40q4745l/

The abstract seems to indicate that there are 5 known objects between Jupiter and Saturn's orbit. I'm trying to search for more info. We could use these object's orbits as a sort of milestone.

edit: This plot suggests that there are many more: http://cfa-www.harvard.edu/iau/lists/OuterPlot.html

[alan]

Not counting comets and Jupiter Trojans there are currently 40 minor objects between 5 and 10 AU from the sun (by my calculations at least)

Next object New Horizons will pass (in current distance from the sun) is 2000 GM137, a centaur at 8.06 AU

This post has been edited by alan: Nov 10 2007, 08:19 AM

[infocat13]

I would like to know the current location of the star motor upper stage please

[djellison]

It will not have been tracked since launch - it would only be a best guess - you may find some info regarding it in the annals of the NH website, it was mentioned in the past.

Doug

[Planet X]

UPDATE! On 11/15/2007, at 11:04:35 UTC, the NH spacecraft reached 1200 million km from the sun. The spacecraft's distance from Earth, by comparison, is nearly 1.332 billion km. NH is now only 3.514 billion km from Pluto and traveling at a rate of 19.463 km/s. Later!

J P

[ugordan]

...only 3.514 billion km from Pluto

I expect an update at only 3.14159 billion km from Pluto, as that figure will obviously be of cosmic importance as well!

[cawest]

I expect an update at only 3.14159 billion km from Pluto, as that figure will obviously be of cosmic importance as well!

Well, NH has travelled 1.5 Billion KM (well 1.499 as this post). and she is almost 2 now

[Greg Hullender]

And in the "are we there yet" spirit, I note that the current-position chart has be rescaled again, so the outer boundary is now Saturn's orbit, not Jupiter's.

http://pluto.jhuapl.edu/mission/whereis_nh.php

Amazing how fast we're reaching the orbit of Saturn -- after just 2.5 years. Amazing how that'll only be half-way to the orbit of Uranus. And 1/3 of the way to Neptune's.

--Greg

[Planet X]

UPDATE! On 01/21/2008, at 05:10:15 UTC, the NH spacecraft reached 1300 million km from the sun. The spacecraft's distance from Earth, by comparison, is nearly 1.419 billion km. NH is now only 3.414 billion km from Pluto and traveling at a rate of 19.026 km/s. Later!

J P

[SpaceListener]

As I see that New Horizons is decreasing its speed toward Pluto. How fast will NH be traveling past Pluto?

[Greg Hullender]

As I see that New Horizons is decreasing its speed toward Pluto.

I blame the Sun.

--Greg :-)

[MahFL]

As I see that New Horizons is decreasing its speed toward Pluto. How fast will NH be traveling past Pluto?

I think its about 12,000 mph when the Pluto flyby occurs.

[Alan Stern]

I think its about 12,000 mph when the Pluto flyby occurs.

14 km/sec at Pluto.

[ugordan]

14 km/sec at Pluto.

Relative to Pluto or the Sun?

[MahFL]

Relative to Pluto or the Sun?

I meant to say 12 km/s, so I was fairly close. 14 it is then. NH will fly by Pluto at 14 km/s.

[Planet X]

UPDATE! On 03/28/2008, at 16:30:15 UTC, the NH spacecraft reached 1400 million km from the sun. The spacecraft's distance from Earth, by comparison, is 1.372 billion km. NH is now only 3.314 billion km from Pluto and traveling at a rate of 18.628 km/s. Later!

J P

[SpaceListener]

NH will arrive very soon Saturn's orbit and its distance travel would be similar from Earth to Saturn and from Saturn to Uranus. Wait for another around 2 1/2 years to reach Uranus.

P.S.The times and distances shown were just done only by mentally estimating. Would be interested to hear the real numbers?

[Greg Hullender]

According to the NH website, "New Horizons' next checkpoint comes on June 8, 2008, when it passes the orbit of Saturn" so it's still a couple of months away.

http://pluto.jhuapl.edu/mission/passingpla...ets_current.php

Here are the other interesting dates from the same page

Uranus: March 18, 2011
Neptune: August 24, 2014
Pluto: July 14, 2015

So Uranus' orbit is almost exactly 3 years away.

--Greg

[Alan Stern]

These planet orbit crossings are based on whatever day we pass the distance of the planet, so although we are currently beyond Saturn's semi-major axis, Saturn is near its aphelion and we don't count the orbit crossing until we are further out than Saturn itself is. Some interesting coincidences are going to occur:

Uranus passage occurs just as MESSENGER (another APL mission) settles into Mercury orbit--same day.

Neptune passage is the 25th anniversary of Voyager 2's Neptune flyby-- essentially to the day.

Pluto encounter is the 50th anniversary of Mariner 4--the first mission to Mars--to the day.

-Alan

According to the NH website, "New Horizons' next checkpoint comes on June 8, 2008, when it passes the orbit of Saturn" so it's still a couple of months away.

http://pluto.jhuapl.edu/mission/passingpla...ets_current.php

Here are the other interesting dates from the same page

Uranus: March 18, 2011
Neptune: August 24, 2014
Pluto: July 14, 2015

So Uranus' orbit is almost exactly 3 years away.

--Greg

[nprev]

Rather remarkable coincidences indeed, Alan! Come clean; you planned this all along!

The Mariner 4 connection is an excellent educational tie-in on that day, which itself will be a profound milestone for UMSF: 50 years of optical reconnaissance of the Solar System, and the initial completion of same for all the planets as we understood them at the dawn of the Space Age.

[SpaceListener]

Alan, good comments! These will help us to feel closer to the NH mission! Every anything anniversary or milestone, will revive the presence of NH.

[edstrick]

"...These planet orbit crossings are based on whatever day we pass the distance of the planet, so although we are currently beyond Saturn's semi-major axis, Saturn is near its aphelion and we don't count the orbit crossing until we are further out than Saturn itself is..."

I've thought that there's a pedantically-over-precise :-) way of saying when something's outside whatever's orbit, especially for something leaving the solar system outside the vicinity of the ecliptic (like the Voyagers).

Each planet's orbit is an ellipse, with the semi-major axis going through the sun. Imagine rotating the planet's orbit on the semimajor axis, to form an elliptcal sphereoid "membrane" with the sun at one focal point. A spacecraft or whatever is beyond the planet's orbit when it punches through that membrane. (let's hope it doesn't deflate it!)

[Alan Stern]

All-- Today we are 810 days from launch and 405 days from Jupiter C/A. That is, we have spent precisely as many days post-Jupiter as it took to get there.

And at the very end of May we will be 25% of the way to the Pluto system in days—so we are about to enter the long middle of the journey that will last until early 2013.

There are still 2652 days to go. Vigilance is our watchword.

-Alan

[MahFL]

25 % sounds good, until you realize you have 3 more 25's to go.....In the mean time I look forward to Phoenix.

[ElkGroveDan]

25 % sounds good, until you realize you have 3 more 25's to go.....

But it seems like yesterday that NH was launched. Just three more 'seems like yesterday's to go.

[Spirit]

Are my calculations correct that within 42-43 days NH will be 10 AU from the Sun or just app. 10 days before crossing the orbit of Saturn?

[Alan Stern]

Are my calculations correct that within 42-43 days NH will be 10 AU from the Sun or just app. 10 days before crossing the orbit of Saturn?

Correct-- The NH 10 AU crossing is 2 June 2008 and the NH Saturn heliocentric distance position crossing is 8 June 2008.

-Alan

[DFinfrock]

I believe that Hew Horizons is supposed to be the fasted spacecraft ever launched. So at what point in the distant future does it pass the Pioneer and Voyager spacecraft to become the farthest from earth? (I know they have a big head start, but NH should eventually take first place).

David

[elakdawalla]

Hi David, the idea that New Horizons will outstrip the Voyagers is a very common misconception due to this sentence in the post-launch press release: "The 1,054-pound, piano-sized spacecraft is the fastest ever launched..." New Horizons did leave Earth after launching faster than any other spacecraft to date, having launched about four percent faster than the previous record holder, Ulysses. And New Horizons will receive one further burst of speed during its flyby of Jupiter in 2007. However, both Voyagers also received gravity assists from Jupiter, and because they both flew closer to Jupiter than New Horizons will, their gravity assists were larger. In addition, both Voyagers also received boosts from Saturn flybys, and Voyager 2 went on to further flybys of Uranus and Neptune. The Uranus flyby sped it up, but the Neptune one actually slowed it down. New Horizons, on the other hand, gets only one more close flyby, of Pluto. And Pluto's mass is so tiny that it will be unlikely to add enough speed to New Horizons to allow it ever to overtake either of the Voyagers.

(If this sounds pat, it's because I wrote it for a Planetary Radio Q and A. Hope it's right. )

--Emily

[Greg Hullender]

It's also worth pointing out that, in terms of mere velocity, Messenger is now (I think) the fastest space probe ever. I'm thinking NH had the greatest delta-V imparted by a rocket. And Voyager 2 has the greatest hyperbolic excess so far. All different ways of interpreting "fastest."

--Greg

[mchan]

The two Helios approached closer to the Sun than Messenger, and may have a higher orbital velocity at perihelion.

[Spirit]

I think it's better to ask:

"What was the velocity of Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2 at some point (lets pick up 25 AU for it is past the Voyager 2 gravity assists) and what will be the velocity of NH at the same point?"

This will be a better question and we will see how many % is the difference of the velocities of these spacecraft. Actually I was looking for Emily's thread for Q&A yesterday in order to submit this question for the Planetary Radio, but I couldn't dig it out.

[TritonAntares]

The two Helios approached closer to the Sun than Messenger, and may have a higher orbital velocity at perihelion.

Yes, Helios II should still hold the recordspeed of 252.792 km/h (70,2 km/s) at a minimum distance of 43,4 Millionen km from sun.
This is about 0,0234% of the speed of light. So we are a bit far away from useful interstellar travel speeds...

Bye.

[dmuller]

Atanas, the following web-page and graph would give you an impression on how the 5 solar system leaving crafts are faring, distance over time, but doesnt give speed. Anyway, what you'd want to know is speed at infinity (from the Sun), i.e. the speed the probes will have when the Sun has no more gravitational influence on them.

[dmuller]

I would like to know the current location of the star motor upper stage please

I found the following source about the upper stage motor. It's actually ahead of NH since the first NH TCM slowed it down a little, at least up to Jupiter, but there received less "kick" than the spacecraft did, so that NH will catch-up and overtake its engine (in a way)

Jupiter Flyby:
NH on 28-FEB-2007 05:41:23 UTC at 2,305,447 km
Upper stage on 28-FEB-2007 01:44:19 UTC at 2,819,811 km
thus 4 hours earlier and 500,000 km farther out

Pluto Flyby:
NH on 14-JUL-2015 11:58:00 UTC at 11,095 km (old schedule)
Upper stage on 09-OCT-2015 22:42:27 UTC at 187,044,046 km
V-infinity: NH 13.77 km/s, upper stage 13.33 km/s

[Spirit]

what you'd want to know is speed at infinity (from the Sun), i.e. the speed the probes will have when the Sun has no more gravitational influence on them.

That's exactly my question and I thinks it's the only relevant question when comparing the speeds of these spacecraft.

[Greg Hullender]

The hyperbloic excess is the "speed at infinity (from the Sun)," and you can calculate it from the other orbital parameters.

http://en.wikipedia.org/wiki/Hyperbolic_trajectory

--Greg

[dmuller]

Without doing calculations, just checking the internet, I found the following speeds at infinity:

16.62 km/s Voyager 1 (Source)
13.** km/s New Horizons (Same source)
The New Horizons figures of course still depend on future trajectory correction maneuvers etc

Gut feeling (how scientific) tells me that Voyager 2 is somewhat slower than Voyager 1, and the Pioneers behind New Horizons

[dmuller]

And now with calculations, using
(1) a = semi-major axis from the SSD Horizons system (date set for today, reference set to solar barycenter)
and using
(2) v_infinity = square root of ( G * M_sun / |a|) [as per Greg's reference]

I get:

16.6 km/s - Voyager 1
14.9 km/s - Voyager 2
12.5 km/s - New Horizons
11.3 km/s - Pioneer 10
10.4 km/s - Pioneer 11
I wonder what Ulysses might have after that rumored Jupiter flyby in 2099 ...

Sort of tallies with the values I quoted in my earlier post. Warning though ... I dont do these sorts of calculations for a living, so I may have missed something along the way

[mrabcx]

As NH is about to pass the orbit of Saturn: if Saturn was to be found in it's orbit in the path between the current NH position and the outer course, would NH then have then crashed into Saturn or it would have flown 'north' or 'south' of Saturn (ignoring any gravitional pulls) ?

[Alan Stern]

I would like to know the current location of the star motor upper stage please

Infocat-- Since you asked, I had a propper analysis done. See attached.

Alan

Attached File(s)

 STAR48_Third_Stage_Trajectory.ppt ( 593.5K ) Number of downloads: 869

 

[JRehling]

As NH is about to pass the orbit of Saturn: if Saturn was to be found in it's orbit in the path between the current NH position and the outer course, would NH then have then crashed into Saturn or it would have flown 'north' or 'south' of Saturn (ignoring any gravitional pulls) ?

General hand-waving answer: Since Pluto is inclined significantly from the ecliptic, NH has to gradually make that journey from Jupiter (near the plane) to Pluto (not near the plane). Saturn's diameter is microscopic compared to the distance above/below the plane that Pluto occupies at almost all times of its orbit. There's no way it would happen to strike Saturn, although I'm sure that it would gravitationally warp the trajectory significantly if it happened to be within a fraction of an AU.

[nprev]

Infocat-- Since you asked, I had a proper analysis done. See attached.

Alan

Interesting! And, frankly, very cool of you; I should've asked you if you had somebody available to do my thesis for me last year!

[dmuller]

Infocat-- Since you asked, I had a propper analysis done. See attached.

Beautiful! I'll add information gathered from those slides to my (planned) New Horizons' script, once I'm done working on the Phoenix real-time simulation script ... if I may do so, of course. Good luck Alan with NH!

Daniel

[dmuller]

2600 days and 3.5 billion km to go to the Pluto encounter ... feels like it will be tomorrow!

[Alan Stern]

http://pluto.jhuapl.edu/news_center/news/052908.htm

Milestones Ahead: New Horizons Set to Cross Saturn’s Orbit
Spacecraft Will Be First to Journey beyond Ringed Planet Since 1981

Last week, New Horizons woke up from its longest electronic hibernation period to date — 89 days. And over the next 10 days, the New Horizons team will celebrate a trio of milestones on the spacecraft’s long journey to explore Pluto in 2015.

The team roused New Horizons from hibernation mainly to re-point the spacecraft’s antenna, adjusting to the changing position of Earth around the Sun. The operations team is also carrying out navigation-ranging tests that mimic operations at Pluto, as well as conducting additional tracking, downlinking data from the student dust counter instrument, installing and testing bug-fix software for the SWAP solar wind plasma instrument, and uploading the spacecraft flight plan for the next several months. These activities will be complete by June 2; the next day, New Horizons will re-enter electronic hibernation for another 91 days. It will awaken for its annual checkout on Sept. 2.


Scientific diagram of New Horizons quickly approaching Saturn's Orbit.
New Horizons is quickly approaching
Saturn’s orbit. Click on image to enlarge.

New Horizons reaches the first milestone just before going back into hibernation. On June 2, the spacecraft will be 10 Astronomical Units (AU) from the Sun. One AU is the distance from the Earth to the Sun, about 93 million miles (or 149 million kilometers). New Horizons will be 930 million miles, or just about 1.5 billion kilometers from the Sun.

On June 3, the mission team will celebrate the spacecraft’s 866th day in flight – or one-quarter of its 3,463-day (9.5-year) journey to Pluto. New Horizons will pass its halfway mark to Pluto in another 866 days, on Oct. 17, 2010.

Most notably, however, on Sunday, June 8, the spacecraft will cross the orbit of Saturn, though Saturn itself is nowhere near the course New Horizons is following to Pluto. “This milestone is significant because the last time any spacecraft journeyed beyond Saturn was 27 years ago, in August 1981, when Voyager 2 passed Saturn on its way to encounters with Uranus and Neptune later in the 1980s,” says New Horizons Principal Investigator Alan Stern.

After New Horizons passes the distance where NASA’s Cassini orbiter is operating at Saturn, only two spacecraft will be operating farther out than the Pluto-bound probe. These are NASA’s Voyagers 1 and 2, which are at the edge of the Sun’s heliosphere approximately 100 AU away.

[Planet X]

UPDATE! On 06/04/2008, at 18:05:25 UTC, the NH spacecraft reached 1.5 billion km from the sun. The spacecraft's distance from Earth, by comparison, is 1.352 billion km. NH is now only 3.219 billion km from Pluto and traveling at a rate of 16.921 km/s. Saturn orbit crossing is now just 4 days away. Later!

J P

[dmuller]

I have rushed a beta-release of the New Horizons real-time simulation at http://www.dmuller.net/newhorizons/ Not all data is in yet, but the important events such as crossing the Saturn orbit and distance from Sun (250,000 km to go to the 1.5 bn distance from the Sun ... the solar system simulator rounds to full million kms) are in.

[MizarKey]

I really like your countdown timers, very nice work. Perhaps you could develope something smaller to be used as a google gadget?

[dmuller]

Saturn Orbit Crossing: I have analyzed the JPL's Horizons system data and I now estimate that New Horizons will cross the Saturn orbit on 08 June 2008 at 08:16am SCET UTC. Saturn will reach the same point (in the xy plane) on 02 Sep 2017 15:49 Saturn time. The xy-plane error of this analysis is around 380 km.

MizarKey: Good idea ... I can look into that down the road. First I want to populate the scripts with data.

[dmuller]

I have received a question about the definition of the Saturn orbit crossing:

(edited for formatting) Concerning the upcoming Saturn orbit crossing, how exactly are you defining this?
According to the thread on UMSF, Alan Stern says this is when the heliocentric distance of NH first exceeds that of Saturn and will occur on 2008 June 08, as your simulator also indicates.
However, according to my own calculation this has already occured, on 2008 March 21 (to be precise at 10:55:52 UTC/SCET). At this time the distance of both objects is 9.287447 AU.
On June 08 NH's distance already exceeds Saturn's by about 0.75 AU, but this is still within the distance variation of Saturn's orbit, so you may be using a different criterion for determining when NH crosses it.

The " thread on UMSF, Alan Stern" refers to this:

These planet orbit crossings are based on whatever day we pass the distance of the planet, so although we are currently beyond Saturn's semi-major axis, Saturn is near its aphelion and we don't count the orbit crossing until we are further out than Saturn itself is.

I used the following:

The Saturn orbit crossing is the point in space where the trajectory line of New Horizons intersects with the orbit line of Saturn as seen from above. So the intersection is in the xy plane. Of course, this works only in 2 dimensions as NH and Saturn have different elevations above the ecliptic at that point. On 08 June 2008 at 08:16am SCET UTC, New Horizons will be at the same x,y coordinates as Saturn will be on 02 September 2017 15:49 Saturn UTC (well ... within a 2 dimensional error distance of 378km since the analysis was done in minute intervals and not seconds)

This is also what is shown on the New Horizons website as it shows "crossing the line" rather than being as far from the Sun as Saturn. Whilst this does not tally with the definition Alan Stern gave, his definition is possibly more meaningful, since by being further away from the Sun than Saturn (i.e. Cassini) now makes New Horizons the 5th farthest man-made object from the Sun (not counting rocket stages etc)

EDIT: corrected mission name ... thanks mps

[mps]

The Saturn orbit crossing is the point in space where the trajectory line of New Messenger intersects with the orbit line of Saturn as seen from above.

"New Messenger"? Also a cool name, though

[dmuller]

"New Messenger"? Also a cool name, though

Aaarrrggghh it just had to happen sometime. I dont know why I keep mixing up NH and Messenger ... especially since NH - the one to Pluto - is my favorite current mission. Lack of holidays? Old age? Geez I hope I make it to 2015 ...

[Alan Stern]

UMSFers-- As of last week, New Horizons is Twittering: NewHorizons2015 is the Twitter username for those interested.

-Alan

[jamescanvin]

Thanks Alan, I'm following.

Here's a direct link for lazy people.

http://twitter.com/NewHorizons2015

[Alan Stern]

Thanks Alan, I'm following.

Here's a direct link for lazy people.

http://twitter.com/NewHorizons2015

James-- Excellent!

Alan

[ElkGroveDan]

I'm in now too!

[ugordan]

In, too! Can't help but wonder though - what will become of Twitter 7 years from now seeing how fast "it" things change on the net...

[climber]

Argh! I was able to sign for Phoenix & LRO and can't get in here. Can remember what to do to sign in. Some help needed please

[nprev]

Caveman question, here...what the hell does Twitter do? I don't subscribe to jack on my cel, only hit the Net from PCs (at work it's quite limited).

Please, somebody, tell me what the flint & bearskins are good for here!

[Del Palmer]

Nick, I have the same question. At first I thought it was a broadcast model where one user updates many others. But reading a recent Cassini report suggested it was more like an instant-messaging service ("For Cassini, the user submits a question or message and members of the flight team respond from the perspective of the spacecraft.") Even more confused now...

[TheChemist]

Del, it is exactly as you say.
A Twitter user can update all his followers via the web, SMS from a cellphone, or any instant messaging program.
Followers can also submit questions or comments to a Twitter account using any of the above ways.

[Alan Stern]

Del, it is exactly as you say.
A Twitter user can update all his followers via the web, SMS from a cellphone, or any instant messaging program.
Followers can also submit questions or comments to a Twitter account using any of the above ways.

http://en.wikipedia.org/wiki/Twitter

[nprev]

Thanks, TC & Alan; me & Del thank you!

One sign of advancing age in the Third Millenium, unless you work at it: you eventually become a technotard. So, gonna learn the ins & outs of Twitter; might hold back the senile dementia a year or two, anyhow!

[Planet X]

UPDATE! On 08/12/2008, at 12:10:40 UTC, the NH spacecraft reached 1600 million km from the sun. The spacecraft's distance from Earth, by comparison, is 1.511 billion km. NH is now only 3.123 billion km from Pluto and traveling at a rate of 16.767 km/s. Later!

J P

[Alan Stern]

Latest NH Twitter Teet, posted today at http://twitter.com/NewHorizons2015

Solar distance now 10.77 AU. Tomorrow the Student Dust Counter begins a calibration of noise thresholds & detector gains in quiet cruise.

...Hibernation wakeup and Active Checkout for 2008 begin in just under two weeks, on Sep 2.

-Alan

[Ken90000]

Thanks for the update, Alan. It is always nice to know that you are interested in the forum.

It will be 2015 before we know it.

[cawest]

well 1 billion km from Jupiter and going

[Vultur]

Wow, already? Awesome!

[cawest]

1.939 billion km travelled

[ElkGroveDan]

1.939 billion km travelled

That's 7.63385827 × 10¹³ inches