New Horizons flyby of Pluto [updated for Ultima Thule]

[Janus]

Too bad the probe didn't have the necessary delta-v to enter an orbit...

If I remember right, it was moving with a relative speed of ~13 km/s relative to Pluto during the fly by. So it would have had to be carrying something like 17 times the probe's own mass in fuel for that much delta-v. But that would mean that the booster launching it to Pluto would have had that many times more fuel also.

 

[Lord Crc]

But that would mean that the booster launching it to Pluto would have had that many times more fuel also.

No problem! Just attach several dozen SRB's on the thing!

 

[mfb]

If I remember right, it was moving with a relative speed of ~13 km/s relative to Pluto during the fly by. So it would have had to be carrying something like 17 times the probe's own mass in fuel for that much delta-v. But that would mean that the booster launching it to Pluto would have had that many times more fuel also.

Well, the mission would have been planned differently.
Dawn achieved over 10 km/s delta-v with 425 kg of xenon for 625 kg of dry mass. Solar cells are impractical for a probe to Pluto, but a large RTG or a small nuclear reactor (or something subcritical in between) could work. Leave Earth with chemical rockets, accelerate with fly-bys, drift for a while, then use the ion drive to slow down. More expensive, needs more R&D, takes longer to reach Pluto, but certainly not impossible.

 

[Janus]

Well, the mission would have been planned differently.
Dawn achieved over 10 km/s delta-v with 425 kg of xenon for 625 kg of dry mass. Solar cells are impractical for a probe to Pluto, but a large RTG or a small nuclear reactor (or something subcritical in between) could work. Leave Earth with chemical rockets, accelerate with fly-bys, drift for a while, then use the ion drive to slow down. More expensive, needs more R&D, takes longer to reach Pluto, but certainly not impossible.

Not impossible, no. You could likely get to Pluto and park in orbit with the delta-v budget of the present mission and chemical rockets alone, but at the cost of increasing the length of the mission immensely. A 13 km/s delta-v with a Dawn type engine would require a reaction mass of roughly equal to that of the dry mass. So you would be doubling the mass of the probe (not counting the additional mass of the power source). So for the same Earth relative launch velocity you need to double the fuel.

If you are going to use the same launch vehicle, then you are going to halve your Earth-relative velocity with the subsequent increase in Earth to Pluto travel time. (though to be fair, if you decrease the Initial delta-v, you are also going to reduce the "fly-by" velocity upon reaching Pluto, which in turn reduces the delta-v needed to match Pluto's orbital velocity and decreases the mass of the probe, which effects the available delta-v upon leaving Earth.. The final result would have to take in the balancing out of all this.)

So, let's assume we have worked all this out. Now the next question is, will the benefits outweigh the extra costs? How much more data do we get by leaving the probe in orbit? Because of the distance, New Horizons can only transmit its collected data back to Earth at a slow bit rate and as a result, the data collected during the several hr flyby will take 16 months to transmit back to Earth. So you would end up with a situation of the probe collecting several hours of data, spending 16 months sending that data back, collecting another several hrs of data... Since the power source on the probe is presently expected to last until 2030, you might expect to get 11 cycles of this over the life time of the craft.( likely less, since we are assuming a longer trip time, some of the lifetime of the power source will be used up during the trip)

So, in the end you might end up with a couple of hundred hrs of data collected in all. Factoring in all the extra expense for the mission, is it worth it? Now for many of us, the answer would be yes, however, generally speaking, we are not the ones holding the purse strings, and the difference between what type of mission we might ultimately want and the one we get is what Congress will provide the funds for.

 

[nsaspook]

More WOW in color.
http://www.nasa.gov/mission_pages/newhorizons/main/index.html

 

[diogenesNY]

That is just about so freaking cool...

Um... I want to go... ya, there...

diogenesNY

 

[DennisN]

And more WOW in color :
Source: Perplexing Pluto: New ‘Snakeskin’ Image and More from New Horizons (Sept. 24, 2015)

 

[DennisN]

Pluto, Charon and moons update:

1) A nice article with pictures and a video clip:
Pluto’s Big Moon Charon Reveals a Colorful and Violent History (NASA, Oct 1, 2015)

Image: Charon in enhanced color.

2. And another article with pictures, some analysis information and a video clip:
Four Months after Pluto Flyby, NASA’s New Horizons Yields Wealth of Discovery (NASA, Nov 9, 2015)

Video clip, "Pluto's Spinning Moons":

 

[nsaspook]

http://www.nasa.gov/feature/new-horizons-returns-first-of-the-best-images-of-pluto

 

[Imager]

This enhanced color mosaic combines some of the sharpest views of Pluto that NASA’s New Horizons spacecraft obtained during its July 14 flyby. The pictures are part of a sequence taken near New Horizons’ closest approach to Pluto, with resolutions of about 250-280 feet (77-85 meters) per pixel – revealing features smaller than half a city block on Pluto’s surface. Lower resolution color data (at about 2,066 feet, or 630 meters, per pixel) were added to create this new image.

Link:http://www.nasa.gov/feature/pluto-s-close-up-now-in-color

 

[DaveC426913]

What would my 10-year-old self make of this?

This is what Pluto was to us for decades:

 

[Drakkith]

What would my 10-year-old self make of this?

Did your ten-year-old self exist when that picture was taken?

 

[DaveC426913]

Did your ten-year-old self exist when that picture was taken?

I was unable to find any 40 year old pictures of Pluto, which would have been no more than an artist's impression of a featureless ball.

Danged internet. Why can't it show me stuff from the 70s? There should be a 'time' filter.

 

[OmCheeto]

I was unable to find any 40 year old pictures of Pluto, which would have been no more than an artist's impression of a featureless ball.

Danged internet. Why can't it show me stuff from the 70s? There should be a 'time' filter.

This is why I keep old books around.

From my 1990 edition of the Encyclopædia Brittanica, which is coincidentally the same year Hubble was launched;

Solar System
THE SURFACES OF THE PLANET AND ITS SATELLITE [Volume 27, page 575]
Because the telescopic image of Pluto is generally indistinguishable from that of a faint star, all efforts made by the early 1980s to detect surface features by conventional methods were unsuccessful. That the surface is not uniform has been known since 1955, when M.F Walker and R.H. Hardie at the Lowell Observatory found that the brightness of the planet varied regularly by about 12 percent within a period of 6.39 days.

There were only two pages devoted to Pluto, at that point.

Ha! The following is EVERYTHING written about the Hubble Space Telescope in that edition;

Exploration
SPACE PROGRAMS [Volume 29, page 49]
The most powerful orbiting observatory currently under construction is the Hubble Space Telescope. Its 2.4-meter-wide reflector telescope is designed to observe objects one-fiftieth as bright as those that can be seen with present Earth-based telescopes and its resolution will be at least 10 times higher.

hmmm... <google google google>

Thank god JPL keeps their old images up:

IMAGES | MARCH 28, 1998
Hubble Portrait of the "Double Planet" Pluto & Charon

 

[DaveC426913]

Thank god JPL keeps their old images up:

Yah, I found that one too. Still decades after my formative years.

 

[Janus]

It wasn't until 1978 that Charon was was even noticed, and that was as an elongation of the image of Pluto. Up until then the pair was seen as a single image and was thought to be a single object. (The discovery of Charon caused us to realize that we were over estimating the size of Pluto, since the light we thought was just due to Pluto was actually due to a pair of objects. For instance, I have a 1955 astronomy text that gives an estimated diameter of 4000 mi for Pluto which put it between Mercury and Mars in terms of size.)

 

[DaveC426913]

...I have a 1955 astronomy text ...

Woah woah woah. Let's not go as far back as before the invention of science here.
I mean, you guys thought the Sun was a Chariot!

 

[mfb]

They are never more than 1 arcsecond apart, that is close to the resolution limit of ground-based telescopes without adaptive optics or techniques like lucky imaging.

 

[Janus]

Woah woah woah. Let's not go as far back as before the invention of science here.
I mean, you guys thought the Sun was a Chariot!

The book itself is older than I am, I have it because several years ago I had the chance to go through some books that had been removed from the Oregon State Library. At the same time I picked up a physics text from 1916.

 

[OmCheeto]

...a physics text from 1916.

That wouldn't be "A First Course in Physics", by Millikan and Gale would it? It seems I picked up a copy, for 50 cents, some time in the past.

[edit] Doh! Never mind. It says 1913.

 

[Janus]

That wouldn't be "A First Course in Physics", by Millikan and Gale would it? It seems I picked up a copy, for 50 cents, some time in the past.

[edit] Doh! Never mind. It says 1913.

Mine is "College Physics" by Reed and Guthe. The first copyright date is 1910, but I got the 1916 reprint.
I also have a copy of "Introductory College Physics" by Blackwood, Copyright 1939 and " An Outline of Atomic Physics" by the Physics staff of the University of Pittsburgh, copyright 1933. One of the 7 authors of which is the Blackwood from the previous text

 

[|Glitch|]

I was unable to find any 40 year old pictures of Pluto, which would have been no more than an artist's impression of a featureless ball.

Danged internet. Why can't it show me stuff from the 70s? There should be a 'time' filter.

I found and image of Pluto from 1970!

 

[Astronuc]

In memory of marcus, who would enjoy things fascinating and surprising, and even astonishing.

Scientists studying the treasure trove of data yielded by NASA's New Horizons mission have found that Pluto's interaction with the solar wind is unique in our solar system.

http://www.csmonitor.com/Science/20...t-a-planet-A-comet-Or-something-else-entirely

“The results are astonishing. We were fascinated and surprised,” said lead author David J. McComas, who manages the Solar Wind Around Pluto (SWAP) instrument aboard New Horizons. “We've now visited all nine of the classical planets and examined all their solar wind interactions, and we've never seen anything like this.”

“This is an intermediate interaction, a completely new type. It's not comet-like, and it's not planet-like. It's in-between,” said Dr. McComas, who is also a professor in Princeton University's Department of Astrophysical Sciences and vice president for the Princeton Plasma Physics Laboratory.

To their surprise, they found that Pluto’s gravity was sufficiently sturdy to retain heavy ions in its extended atmosphere. Indeed, as noted by Michael Liemohn, a University of Michigan astrophysicist not involved in the research but who helped edit the paper, the researchers found that “only a wisp of atmosphere leaves the planet as ions.”

 

[DennisN]

Scientists studying the treasure trove of data yielded by NASA's New Horizons mission have found that Pluto's interaction with the solar wind is unique in our solar system.

Very interesting!

 

[Astronuc]

New Horizons' Best Close-Up of Pluto's Surface
http://www.nasa.gov/feature/new-horizons-best-close-up-of-plutos-surface

 

[Borg]

Today's APOD shows Pluto from its dark side.

 

[DaveC426913]

New Horizons' Best Close-Up of Pluto's Surface
http://www.nasa.gov/feature/new-horizons-best-close-up-of-plutos-surface

I made an image out of this, so it can be browsed at-will.

http://www.davesbrain.ca/miscpix/hi-rez-pluto.jpg

Also, is there a badge for longest post?

 

[Drakkith]

Also, is there a badge for longest post?

You've got my vote!

 

[DaveC426913]

You've got my vote!

Heh. For a second there, I thought you were going to quote my whole post - and steal the badge right out from under me.

 

[Borg]

More Pluto goodness on APOD today.

Explanation: Pluto's pitted plains meet rugged highlands in this stunning view. On the left lies a southeastern extent of the bright region still informally known as Sputnik Planum. At right the edge of a dark region, informally Krun Macula, rises some 2.5 kilometers above the icy plains. Along the boundary, connected clusters of large pits form deep valleys, some over 40 kilometers long with shadowy floors. Nitrogen ice is likely responsible for the more reflective plains. The dark red color of the highlands is thought to be from complex compounds called tholins, a product of ultraviolet light induced chemical reactions with methane in Pluto's atmosphere. The enhanced color image includes portions of the highest and second highest resolution image data from the New Horizons July 2015 flyby of the distant world.

 

[1oldman2]

Here is something new.
http://Earth'sky.org/space/liquid-water-ocean-under-pluto-ice

 

[1oldman2]

The mission continues to evolve.
http://www.nasa.gov/feature/new-hor...ension-to-kuiper-belt-dawn-to-remain-at-ceres
https://blogs.nasa.gov/pluto/
https://blogs.nasa.gov/pluto/2016/06/24/new-horizons-getting-to-know-a-kbo/

 

[Astronuc]

We really need to get some probes and cameras down on that surface.
I'd like to have craft flying through the atmosphere of Jupiter, Saturn, Uranus and Neptune.

 

[mfb]

You want a reliable source of power without too many moving parts - a nuclear powered ramjet? Would be amazing.

The outer planets always have the data transmission issue - you can quickly shoot thousands of photos and do other measurements, but they need years to get back, and the probes have to survive long enough.

 

[1oldman2]

I'm thinking "New Horizons" has got to be one of the most important missions ever launched, I can't wait to see what becomes of the next target encounter. http://www.planetary.org/blogs/guest-blogs/2016/0711-new-horizons-science-team-meeting.html