Will New Horizons overtake Voyager?

[mikeell]

Hi All,<br /><br />I asked this just a point of curiousity. This data is from what I've been able to find online:<br /><br />As of Nov-11-2005<br />Voyager 1 at 97.3 AU from the sun moving at 3.6 AU per year (rel. to the sun)<br />Voyager 2 at 78.0 AU from the sun moving at 3.3 AU per year (rel. to the sun)<br /><br />New Horizons is currently on track to travel to Pluto (~40AU) in 9.5 years (averaging 4.2AU per year!). However, the probe will pass Pluto at 2.52 AU per year (rel. to Pluto).<br /><br />I had assumed that NH would eventually overtake V1 as the most distant man-made object but can't definitely confirm this. Does anyone have trajectory data as to whether NH will do this? If so, when?<br /><br />Cheers,<br />MikeELL

 

[najab]

I know that it now has the record for the fastest human-man object - something like 31,000mph - but I'm not sure what it's trajectory will be after the Jupiter encounter: it could be in a highly eliptical helocentric orbit, or it could be on an escape trajectory.

 

[bpcooper]

OHH! Totally forgot to post about this.<br /><br />The answer is no, straight from Ralph McNutt on the NH team. New Horizons is not going as fast as Voyager (it is only the fastest probe to actually leave Earth). Voyager picked up moer speed during its flybys than NH will, and thus NH will never pass.<br /><br />It took asking a few people but they have indeed figured it out. <div class="Discussion_UserSignature"> <p>-Ben</p> </div>

 

[henryhallam]

Interesting! Thanks. I still think they should have put a plaque on though.

 

[nacnud]

Well it's got a CD with my name (and a lot of others) on it, that do?

 

[bobw]

I tried working it out, for what it's worth. I started with:<br /><br />Voyager 1: 17 km/sec = 3.5836 au/yr = 5 pixels x, 5 pixels y, slope = 1, 45 degrees <font color="red">red line</font><br />New Horizons: 21 km/sec = 4.4269 au/yr = 5 pixels x, 6.1766 pixels y, slope = 1.2352, 51 degrees <font color="green">green line</font><br />Voyager 1 launch date: Sept. 1977 = 28.3 yr. ago = 141 pixels<br /><br />I found some drawings of the New Horizons and Voyager 1 trajectories. I guess they both seem pretty radial. The point of equal distance (y coordinate) is 592 pixels (x coordinate) later than the New Horizons launch; at 5 pixels per year that works out to be 118 years from now. <div class="Discussion_UserSignature"> </div>

 

[henryhallam]

Haven't seen the graphic yet, but do your calculations take into account the deceleration as the probes climb out of the Sun's gravity well? IIRC, 21km/s is the velocity after the Jupiter flyby, it won't be going quite as quickly as that by the time it's got all the way out to Pluto. Voyager had the advantages of multiple high-energy slingshots.

 

[bobw]

No, doesn't include deceleration. I've seen a lot of places that say it will eventually be the farthest object but only two estimates of how long that will take. One here, by shuttle guy, and another in a post by a "science advisor" in the math help section at physics forums . com. He guessed 25 years. I just plotted a graph which would give the minimum catch-up time. You are right, though, if it decelerates more than 4 km/sec it won't catch up at all. <div class="Discussion_UserSignature"> </div>

 

[lampblack]

<font color="yellow">Haven't seen the graphic yet, but do your calculations take into account the deceleration as the probes climb out of the Sun's gravity well? IIRC, 21km/s is the velocity after the Jupiter flyby, it won't be going quite as quickly as that by the time it's got all the way out to Pluto. Voyager had the advantages of multiple high-energy slingshots.</font><br /><br />Given that the two Voyagers took somewhat different paths with different planetary encounters (one of them flew by Uranus, right?), I wonder if it's possible New Horizons will someday overtake one of them -- but not the other?<br /><br />I also recall reading that the two Voyagers are flying in essentially opposite directions from each other relative to the sun's orbit around the middle of the galaxy. One of them is flying in roughly the same direction as the sun's orbital path, with the result that it hasn't traveled as far relative to the sun.<br /> <div class="Discussion_UserSignature"> <font color="#0000ff"><strong>Just tell the truth and let the chips fall...</strong></font> </div>

 

[ehs40]

i read a month or two ago on SDC that a probe could be built to overtake the voyager probes in an amazingly short period of time i think it was like 16 years and its goal was to study space at 200 AU from the sun

 

[thalion]

The NH site mentions that the relative speed of NH to Pluto will be only 14 km/s at encounter. Admittedly, that's a relative rather than absolute speed, but it's considerably slower than the Voyagers.

 

[yurkin]

On a separate note the fastest space probe and in fact the fastest manmade object is Helios 2. But Voyager 1 is still the fastest interplanetary probe. I wonder though why isn’t it Voyager 2, after all it had two more gravity assists then Voyager 1 did. <br /><br />Voyager 1 = 38,600 mph<br />Helios 2 = 150,000 at perihelion<br />

 

[mikejz]

Voyager 2' flyby of Triton slowed it down AFAIK

 

[henryhallam]

JPL's HORIZONS system has ephemeris and state vector data for New Horizons and the Voyagers if anyone would like to run the numbers through a simulator.

 

[bpcooper]

According to McNutt, NH will not reach 21 kps; it's maximum is that 14-15 or so, less than the 17 of Voyager. <div class="Discussion_UserSignature"> <p>-Ben</p> </div>

 

[najab]

><i>On a separate note the fastest space probe and in fact the fastest manmade object is Helios 2.</i><p>But it's still in heliocentric orbit, how can it be the fastest?</p>

 

[henryhallam]

Very high speed during relatively close approach to the sun at 0.3 AU perihelion (but less total energy than Voyager way out at the edge)

 

[spacester]

Those doggone frames of reference again! <img src="/images/icons/laugh.gif" /><br /><br />I suppose that 'fastest' is meant as 'magnitude of heliocentric velocity vector' and that works fine until you go so fast that your vehicle's kinetic energy becomes unbound by exceeding the local potential energy. This is also called going from an elliptical heliocentric orbit to a hyperbolic orbit.<br /><br />IOW if you're leaving the solar system at any velocity at all, you've actually got more orbital energy relative the the Sun's gravity well than the sum of potential and kinetic energy of anything still in elliptical heliocentric orbit.<br /><br />So the voyagers are 'faster' because they have more energy, yet they are 'slower' in actual velocity magnitude ("speed") relative to the Sun. Orbital mechanics can be weird. <div class="Discussion_UserSignature"> </div>

 

[SpaceKiwi]

I'll bet Mike thought this was a relatively simple question when he asked it! <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>