Pluto Update March 2015: "New Horizons" Tweaks Course

With all of the excitement surrounding the Dawn mission to the dwarf planet Ceres, we can sometimes forget about the other mission happening this year to arguably the most famous dwarf planet -- Pluto, and the New Horizons spacecraft.

The New Horizons spacecraft, scheduled to do a fly-by of Pluto on July 14 of this year, has performed a course correction burn in order to put it in the best possible location as it zooms passed the dwarf planet. This trajectory correction is based on more precise data we now have of the orbits of Pluto and its main moon Charon.

The burn was the first maneuver of New Horizons' Pluto approach phase, which began in January. The trajectory correction should delay the spacecraft's arrival in the Pluto system by 14 minutes and 30 seconds.

"It will also shift the course 'sideways' (if looking from Earth) by 3,442 kilometers (2,139 miles) by July 14, sending the spacecraft toward a desired flyby close-approach target point," mission officials wrote in an update. "The shift was based on the latest orbit predictions of Pluto and its largest moon Charon, estimated from various sources, including optical-navigation images of the Pluto system taken by New Horizons in January and February...

...The spacecraft will come within about 8,500 miles (13,600 km) of Pluto's surface at its closest approach on July 14. But New Horizons won't linger; it will zoom right past Pluto, speeding out farther into the Kuiper Belt, the ring of icy bodies beyond Neptune's orbit."

With this engine burn, New Horizons became the farthest spacecraft from Earth to have conducted an engine burn maneuver as commanded from Earth:

The New Horizons probe, which will zoom through the Pluto system on July 14, fired its engines for 93 seconds on Tuesday (March 10), when it was about 3 billion miles (4.83 billion kilometers) from Earth. No spacecraft had ever conducted an engine burn at so great a distance from its handlers, New Horizons principal investigator Alan Stern said.

"Today's engine burn by New Horizons set an ALL TIME record for the most distant by ANY spacecraft in history!" Stern, who's based at the Southwest Research Institute in Boulder, Colorado, tweeted Tuesday via the account @NewHorizons2015.

NASA Probe Makes Record-Setting Engine Burn on Path to Pluto


Here is the planned trajectory of New Horizons as it speeds through the Pluto system on July 14 -- however I don't think these times have been updated relative to this latest course correction, but this information is still relatively accurate. The plan is for the spacecraft to fly-by Pluto at a distance inside the orbit of Charon:

Source: The Path to Pluto - Mission Timeline


New Horizons has also passed a milestone point along its path to Pluto -- it is now less that 1AU from the dwarf planet. An AU (Astronomical Unit) is the average distance the earth is from the Sun, which is 92,955,807.3 miles -- or let's just say 93 million miles. So New Horizons is now closer to Pluto as Earth is to the Sun.

As mentioned above, New Horizons cannot stay in the Pluto system very long (it was not designed to have the massive amounts of fuel needed to slow down enough to achieve orbital insertion), and will zoom by at 33,000 mph (about 52,000 kmh). It is hoped, however, that a mission extension will be funded that would allow New Horizons to visit other Kuiper Belt objects (KBOs) as early as 2019. There are a few potential targets for this possible next phase of the New Horizons mission.

Peering out to the dim, outer reaches of our solar system, NASA’s Hubble Space Telescope has uncovered three Kuiper Belt objects (KBOs) the agency’s New Horizons spacecraft could potentially visit after it flies by Pluto in July 2015....

...The New Horizons team expects to submit such a proposal to NASA in late 2016 for an extended mission to fly by one of the newly identified KBOs. Hurtling across the solar system, the New Horizons spacecraft would reach the distance of 4 billion miles from the sun at its farthest point roughly three to four years after its July 2015 Pluto encounter. Accomplishing such a KBO flyby would substantially increase the science return from the New Horizons mission as laid out by the 2003 Planetary Science Decadal Survey.

NAS A’s Hubble Telescope Finds Potential Kuiper Belt Targets for New Horizons Pluto Mission


Additional New Horizons information and sources:

With Trajectory Correction, NASA’s New Horizons Homes in on Pluto

A Record Day for New Horizons

New Horizons Main NASA/JPL Website

a reply to: Soylent Green Is People

Nice OP, thanks. That this is the most distant course correction ever undertaken the fact that it even worked adds more data to the science. This will be a fun and nice look at Pluto, looking forward to seeing it pose for us.

a reply to: Soylent Green Is People


Is Pluto back to being a planet again? They keep changing it up on me, so I'm not sure anymore. I'm only interested if my Pluto is a planet once again. LOL

originally posted by: Anyafaj
a reply to: Soylent Green Is People

Is Pluto back to being a planet again? They keep changing it up on me, so I'm not sure anymore. I'm only interested if my Pluto is a planet once again. LOL

Nope -- still a dwarf planet. Sorry

It's been that way since 2006, a change prompted by the discovery of Eris -- which is another Kuiper Belt object that is even larger than Pluto. If Pluto was still the 9th planet, then Eris would be the 10th planet. There would be some who'd even Sedna could be called a planet.

a reply to: Soylent Green Is People

Nope -- still a dwarf planet. Sorry

Too far, too small, too cold doth not a planet make? Or because its only one of many other bodies we discovered-- 'late'?

Thanks for the update. I heard it said that hitting these planets with our probes was like sinking a hole in one with a golf ball hit from Los Angeles to New York.

Yah, a golf ball with retro rockets.

ETA: Still a hella shot, considering…

originally posted by: Soylent Green Is People

originally posted by: Anyafaj
a reply to: Soylent Green Is People

Is Pluto back to being a planet again? They keep changing it up on me, so I'm not sure anymore. I'm only interested if my Pluto is a planet once again. LOL

Nope -- still a dwarf planet. Sorry

It's been that way since 2006, a change prompted by the discovery of Eris -- which is another Kuiper Belt object that is even larger than Pluto. If Pluto was still the 9th planet, then Eris would be the 10th planet. There would be some who'd even Sedna could be called a planet.

Not cool dude! LOL

originally posted by: intrptr
a reply to: Soylent Green Is People

Nope -- still a dwarf planet. Sorry

Too far, too small, too cold doth not a planet make? Or because its only one of many other bodies we discovered-- 'late'?

Thanks for the update. I heard it said that hitting these planets with our probes was like sinking a hole in one with a golf ball hit from Los Angeles to New York.

Yah, a golf ball with retro rockets.

ETA: Still a hella shot, considering…

Because if Pluto was planet, then Eris should be planet too. Even Pluto's moon Charon should be planet, as it doesn't orbit Pluto, as they are nearly same size. They kinda orbit each other, the common gravity center.


static.ddmcdn.com...

And this picture shows one reason too.

frigg.physastro.mnsu.edu...

originally posted by: intrptr

That "helical orbits" video is misleading, and is only from the point of view of someone who is not moving along with the solar system.

I mean, the same "helical path" could be said for that path of a ball you are spinning around your head on a string. If some outside observer who does not move along with the Earth's rotation is watching the path of that ball around your head, he would see the ball following a complex helical path as it (and your head) moves along with the rotating Earth.

However, you wouldn't claim that the ball was on a helical path. You would (rightfully) claim that fro your relative perspective and from the relative perspective of the people on earth watch you spin the ball around your head, the ball is on a circular path around your head.

So the information in that video really isn't much of a revelation, and is logical if you think about it. However, from the point of view of our solar system, the planets actually do orbit our central Sun along elliptical paths.

originally posted by: Soylent Green Is People
That "helical orbits" video is misleading, and is only from the point of view of someone who is not moving along with the solar system.

It's not only misleading, it's outright wrong; Djsadhu's video shows the planets "trailing behind" the sun. He makes this point explicitly in his second video of that series:

That is not how the solar system moves. If it were we'd never see Venus or Mercury transit the sun, none of the outer planets would ever pass directly behind the sun from earth's perspective, and in general our models of solar system motion would just plain not work at predicting the location of planets in the sky. DJSadhu is a woo woo whose claims fly in the face of empirical data.

a reply to: Thebel

Should we go back to galaxies are nebula, too? I mean it was an early misunderstood 'object' as well. Wait, Galaxies aren't 'objects'…

The idea of Planets (bodies orbiting around the sun) were only fixed with the technology of the day,-- Mark 1 eyeballs, what we could see with the naked eye. Maybe we should go back to that era of labeling 'objects'. Pluto is a planet because it was named back then.

Planet means "wanderer", right?

All the bodies 'wander' , right?

Terminology is always fun when it comes to "heavenly… bodies".

originally posted by: ngchunter

originally posted by: Soylent Green Is People
That "helical orbits" video is misleading, and is only from the point of view of someone who is not moving along with the solar system.

It's not only misleading, it's outright wrong; Djsadhu's video shows the planets "trailing behind" the sun. He makes this point explicitly in his second video of that series:

Point taken about the planets trailing behind the Sun in his video. That is certainly incorrect.

However, I was making more of a general comment about how the idea of the "helical orbits" being misleading. Even if he showed the planets orbiting at roughly the same plane as the Sun (not trailing behind), and indicated how the orbits could appear helical as viewed from a reference point that is not moving along with the sun through the galaxy, it would still be misleading, due to example I mentioned regarding twirling a ball on a string around your head...

...Sure -- from some reference points, the ball could be said to be taking a helical path as the ball and your head both moved through space -- and thus the same could be said about the orbits of the planets as they and the Sun move through the galaxy.

However, there are people who hear this and are convinced that they have been taught the wrong thing in school. They weren't really taught the wrong thing (they learned the correct orbits when viewed from our reference point), but rather they never took the time to use their critical thinking skills to consider how other points of reference would view those motions that they learned in school.

a reply to: Soylent Green Is People

That "helical orbits" video is misleading, and is only from the point of view of someone who is not moving along with the solar system.

Okay, lets play semantics. Why bother drawing 'little circles' showing the orbits? They aren't there, either.

"orbital paths"

I agree naming all the orbiting objects in the solar system in children's books is too much. Better stick to a few.

Last response here. I'm up against a wall of Convention.

a reply to: Soylent Green Is People

Oh absolutely. It's just that Sadhu tries to argue against the whole concept of reference frames and tries to suggest that his is the "one true" frame of reference and that a solar system barycentric reference frame is false, a lie, or wrong. People swallow it up and it leads to massive confusion. But even beyond that he's showing a model which is physically incorrect on several key points, and even if most people are unfamiliar with the concept of the ecliptic or great circles, many seem to be able to understand the visualization enough to realize that it contradicts standard models of solar system motion... and yet they default to thinking it's the standard models which are wrong rather than the other way around. It's quite frustrating to someone like me who actively engages in using and presenting those models for the purposes of debunking other claims.

Total failure of the spacecraft should be the only reason why an extended mission to several additional KBOs should not be undertaken. The science return of such an endeavour would be enormous.

originally posted by: Mogget
Total failure of the spacecraft should be the only reason why an extended mission to several additional KBOs should not be undertaken. The science return of such an endeavour would be enormous.

Absolutely. I'm not a NASA bean-counter, but I have to think that by the closeout of the primary mission, the high-ticket items for this mission (design, development, and construction of the probe, plus the cost of the launch vehicle) have already been bought and paid-for, and extending the mission probably would not cost that much (relatively speaking).

I'm sure there will be some costs associated with extending the mission -- e.g., the labor costs for the mission controllers, rent paid to use mission control facilities, radio antenna time for communicating with the probe, labor costs for the mission scientists, costs for the dissemination of data to outside researchers, cost for dissemination of info to the public and media, administration costs, etc., etc. -- but all of that could only be a few million dollars per year, which is cheap, relatively speaking.

a reply to: Soylent Green Is People

An additional benefit of extending the mission for about 6 years would be the ability to set very tight constraints on the mass/distance of any would-be "planet X."

Conversely, range residuals statistically compatible with zero having an amplitude of 10 m would imply that PX, if it exists, could not be located at less than about 4,500 au (mX=0.7m⊕) or 60,000 au (mX=5mJ)

arxiv.org...

originally posted by: ngchunter
a reply to: Soylent Green Is People

An additional benefit of extending the mission for about 6 years would be the ability to set very tight constraints on the mass/distance of any would-be "planet X."

Conversely, range residuals statistically compatible with zero having an amplitude of 10 m would imply that PX, if it exists, could not be located at less than about 4,500 au (mX=0.7m⊕) or 60,000 au (mX=5mJ)

arxiv.org...

What if Planet X were on the other side of the solar system (on the opposite side of the Sun) relative to the trajectory of New Horizons? I assume any planet out that far would take a few hundred years to orbit the Sun, so would it ever get close enough to new Horizons to have any noticeable effect?

Or am I misunderstanding the methods by which they envisage being able to detect signs of its existence/parameters of its orbit?

originally posted by: Box of Rain

originally posted by: ngchunter
a reply to: Soylent Green Is People

An additional benefit of extending the mission for about 6 years would be the ability to set very tight constraints on the mass/distance of any would-be "planet X."

Conversely, range residuals statistically compatible with zero having an amplitude of 10 m would imply that PX, if it exists, could not be located at less than about 4,500 au (mX=0.7m⊕) or 60,000 au (mX=5mJ)

arxiv.org...

What if Planet X were on the other side of the solar system (on the opposite side of the Sun) relative to the trajectory of New Horizons? I assume any planet out that far would take a few hundred years to orbit the Sun, so would it ever get close enough to new Horizons to have any noticeable effect?

Or am I misunderstanding the methods by which they envisage being able to detect signs of its existence/parameters of its orbit?

According to my own solar system integration I get results that a 5MJ planet would be easily detected in the New Horizons ranging data even if it were more or less directly opposite the sun from New Horizons and 10,000 AU from the sun out to nearly 20,000 AU. That's still a significant improvement over current constraints:
arxiv.org...
I know the previous constraint listed there was 4 MJ, not 5, but even at 4 MJ I still get the same result.
For the 0.7 Earth mass example, I get a signal in the ranging data on the same order of magnitude to Iorio's results even if it's on the opposite side of the sun at about 2000 AUs distance, and the signal becomes very noticeable in the ranging data (>10 meters) by 1000 AU, also a significant improvement over current constraints, and would directly refute most current planet X hypotheses. The thing is that the ranging difference is cause by a differential in Planet X's gravity on the probe vs the earth. Even if it's the earth feeling the greater pull than the probe because Planet X is on the opposite side of the sun from the probe, the signal would still be there in the ranging data even at ridiculous distances of Planet X.

Here is the output from my own solar system integration using ORSA. Here is the result for a 4MJ planet X at 10,000 AU:
dropcanvas.com...
And here is the result for a 0.7 earth mass planet X at 1000 AU:
dropcanvas.com...
The time code is time in years from 3/19/15. Both integrations start at that time and proceed for about 6 years. For the sake of rigor I also tested this with a "null mass Planet X" which only had 1kg of mass and the results showed the integrator was consistent to within about .1 meters. At that level you're just dealing with small rounding errors in the distance, but the signals here are a hundred times that large.

As I mentioned in my OP, NASA was considering extending New Horizon's mission once it zips past Pluto. The extended mission would send New Horizons to investigate another Kuiper Belt object. I mentioned that the Hubble telescope were looking for potential targets that New Horizons could reach.

Coincidentally enough, news coming out of the Lunar and Planetary Science Conference in Houston, Texas last week mentions Hubble's search, and that search is now down to two candidates -- although there is only enough fuel to steer the spacecraft toward one of them:

The newly named objects are 2014 MT69, a 37-mile (60-km) wide body circling some 44.3 times farther away from the sun than Earth. An encounter with MT69 would occur around New Year's Day 2019.

"It's not a terribly bright target and it's not very big … and it's quite possibly smaller, if it's a binary or if other things are going on," said astronomer and New Horizons team member Simon Porter, with the Southwest Research Institute in Boulder, Colo.

The advantage of MT69 is that New Horizons can reach it using less fuel. The encounter also would occur three months sooner than a flyby of the other candidate, known as 2014 MT70.

MT70 is brighter than MT60, and possibly larger, with a diameter of about 47 miles (76 km), so more desirable from a scientific perspective, Porter said.

Source:
After Pluto, Where Will NASA's New Horizons Go?

I clicked on the Source link above, and I had to laugh when I saw the comment from someone about using the remaining fuel to put New Horizons into orbit around Pluto. Oh, if only it were that simple!