• Hi Guest! Forum rules have been updated. All users please read here.

Pluto flyby: New Horizons

FighterJock

ACCESS: Top Secret
Joined
Oct 29, 2007
Messages
1,649
Reaction score
384
It will be interesting to see if there will be any more KBO flyby's by New Horizons. It obviously depends on where New Horizons is in regards to what KBO it targets.
 

Archibald

ACCESS: Top Secret
Senior Member
Joined
Jun 6, 2006
Messages
4,431
Reaction score
1,934
Not sure, Ultima Thule ate most of the prop left after the 2015 encounter. We shall know soon...
 

Archibald

ACCESS: Top Secret
Senior Member
Joined
Jun 6, 2006
Messages
4,431
Reaction score
1,934
Not sure, Ultima Thule ate most of the prop left after the 2015 encounter. We shall know soon...

It will be a shame if New Horizons does not get to do another flyby of a KBO because of the issue of the onboard fuel.

Alas, Robert Heinlein taught us "there ain't such thing as a free launch / lunch"
Well it also applies in deep space. Unless they find a KBO pretty close from New Horizon present trajectory, no way to bend the trajectory without prop.
See Voyager 1 past Saturn and Voyager 2 past Neptune - no prop left and no meaningful gravity field to bounce off = no possible trajectory change.
 

Rhinocrates

ACCESS: Secret
Joined
Sep 26, 2006
Messages
309
Reaction score
206
I really recommend this book. It chronicles the tortured history of the probe from Alan Stern's perspective, explaining the crises and trade-offs along the way. It's a miracle that it was ever launched. A lot of people in charge of funding thought that Pluto would be boring and not worth the expense...
 

Attachments

  • 1250098963-chasingnewhorizonsbyalanstern-181029161358-thumbnail-4.jpg
    1250098963-chasingnewhorizonsbyalanstern-181029161358-thumbnail-4.jpg
    182.1 KB · Views: 501

chimeric oncogene

ACCESS: Confidential
Joined
May 23, 2019
Messages
130
Reaction score
63
They have to find a target first, they're still working on that.

I'd guess they blew their recon on Arrokoth. They'd have surveyed the entire flight cone for targets. And NH is now >50Au out, IIRC. You're not spotting anything smaller than 50-100km that far out, and there's not that many bodies that big out there.
 

Hobbes

ACCESS: Top Secret
Senior Member
Joined
May 9, 2008
Messages
900
Reaction score
265
I'd guess they blew their recon on Arrokoth. They'd have surveyed the entire flight cone for targets. And NH is now >50Au out, IIRC. You're not spotting anything smaller than 50-100km that far out, and there's not that many bodies that big out there.

Between Akkoroth's discovery and the Akkoroth encounter, the survey continued. They haven't found anything yet, so I agree another flyby is unlikely.

Akkoroth is 36 km long, and it showed up as a splodge (not a single pixel) in Hubble images:



Perhaps this means objects smaller than 50 km can still be seen at that distance.
 

Michel Van

ACCESS: Top Secret
Senior Member
Joined
Aug 13, 2007
Messages
4,747
Reaction score
828
During current state it main mission, if's finance until April 30, 2021.

if prolong, New Horizon could made one or two KBO fly-by

the probe RTG run out power in late 2030s
in 2038 New Horizon will be 100 AU fron Sun.
 

FighterJock

ACCESS: Top Secret
Joined
Oct 29, 2007
Messages
1,649
Reaction score
384
During current state it main mission, if's finance until April 30, 2021.

if prolong, New Horizon could made one or two KBO fly-by

the probe RTG run out power in late 2030s
in 2038 New Horizon will be 100 AU fron Sun.

I did not know that New Horizons had enough fuel in the RTG to last until the 2030s.
 

chimeric oncogene

ACCESS: Confidential
Joined
May 23, 2019
Messages
130
Reaction score
63
probe RTG run out power in late 2030s

Voyager's RTG seems to still be working at reduced power after forty years in space. NH could last substantially longer than spec.


Hmm... this is interesting. They're talking about redoing the software on NH to enable it to work as a Kuiper Belt telescope station, with LORRI being the main instrument, presumably for distant (~AU) flybys of SDOs. Because Hubble time is expensive, and sky surveys at that distance are hard, they're also talking about using LORRI as the survey instrument instead of Earth based telescopes to find targets for those flybys.

That must have been the conference the tweet waa talking about.

I wonder if they could make LORRI do parallax observations, like TAU was supposed to.
 
Last edited:

Archibald

ACCESS: Top Secret
Senior Member
Joined
Jun 6, 2006
Messages
4,431
Reaction score
1,934
I really recommend this book. It chronicles the tortured history of the probe from Alan Stern's perspective, explaining the crises and trade-offs along the way. It's a miracle that it was ever launched. A lot of people in charge of funding thought that Pluto would be boring and not worth the expense...

27 years ago one of the first space themed magazine I bought, aged 11, had the headline "NASA target Pluto". By 1993 this was "Pluto fast flyby" and NH only launched a decade later or more... yet Alan Stern was already part of the team.

Capture.PNG
 

FighterJock

ACCESS: Top Secret
Joined
Oct 29, 2007
Messages
1,649
Reaction score
384
probe RTG run out power in late 2030s

Voyager's RTG seems to still be working at reduced power after forty years in space. NH could last substantially longer than spec.


Hmm... this is interesting. They're talking about redoing the software on NH to enable it to work as a Kuiper Belt telescope station, with LORRI being the main instrument, presumably for distant (~AU) flybys of SDOs. Because Hubble time is expensive, and sky surveys at that distance are hard, they're also talking about using LORRI as the survey instrument instead of Earth based telescopes to find targets for those flybys.

That must have been the conference the tweet waa talking about.

I wonder if they could make LORRI do parallax observations, like TAU was supposed to.

That is highly interesting news about New Horizons. Using it as a Kuiper Belt telescope would be a good idea, though it depends on how much thruster fuel remains as to what potential KBO targets New Horizons observes.
 

Hobbes

ACCESS: Top Secret
Senior Member
Joined
May 9, 2008
Messages
900
Reaction score
265
probe RTG run out power in late 2030s

Voyager's RTG seems to still be working at reduced power after forty years in space. NH could last substantially longer than spec.

No. The factors that influence RTG power are well-known: Plutonium decay (which is entirely predictable) and thermocouple degradation (which can be measured accurately). The point at which the RTG can no longer power the minimum combination of equipment can be calculated with good accuracy.

Voyager still works because it had a large power margin at launch. NH's power margin was much smaller.

Voyager also has several power-hungry instruments that could be switched off after the planetary encounters (the camera platform and cameras, for example). Much of Voyager's longevity is caused by clever power management (beyond what was envisioned at launch), including careful experimentation (turning off various heaters) to run instruments out of spec.
This can be done with New Horizons too, to a degree, but NH has far fewer unknowns to take advantage of.
 

Archibald

ACCESS: Top Secret
Senior Member
Joined
Jun 6, 2006
Messages
4,431
Reaction score
1,934
probe RTG run out power in late 2030s

Voyager's RTG seems to still be working at reduced power after forty years in space. NH could last substantially longer than spec.

No. The factors that influence RTG power are well-known: Plutonium decay (which is entirely predictable) and thermocouple degradation (which can be measured accurately). The point at which the RTG can no longer power the minimum combination of equipment can be calculated with good accuracy.

Voyager still works because it had a large power margin at launch. NH's power margin was much smaller.

Voyager also has several power-hungry instruments that could be switched off after the planetary encounters (the camera platform and cameras, for example). Much of Voyager's longevity is caused by clever power management (beyond what was envisioned at launch), including careful experimentation (turning off various heaters) to run instruments out of spec.
This can be done with New Horizons too, to a degree, but NH has far fewer unknowns to take advantage of.

Also those geeks at JPL deliberately (and discretely) build the two Voyagers with colossal margins, for a simple reason.
The original Grand Tour not only had the TOPS advanced and extremely durable computer.
It also had four probes, not two (and a half).
Thus unlike the lone Voyager 2 that flew by all four big planets, Grand Tour was to split, Uranus, and Neptune, and Pluto (as a bonus) between separated probes. This meant that these probes could flew shorter / faster trips - avoiding one or another gas giants to get to Neptune or Pluto faster.
Voyager not only lost the TOPS computer, it also lost 50% of the fleet, and finally, it used a beefed-up Mariner, except the farther a Mariner had ever gone back then was Mars or perhaps the asteroid belt. There were real anguish a Mariner couldn't make it to Jupiter or to Saturn, and even less to the outer gas giants.
But Congress and the Shuttle, and also an agonizing NERVA, had screwed Grand Tour late 1971. Administrator Fletcher was lucky so salvage Mariner Jupiter Saturn early 1972.

JPL then decided to make lemons into lemonade. They quietly started building two MJS, plus a backup, with colossal redundancy and margins. They stuffed the RTGs with a boatload of plutonium, to the point that, well, those things are still working nowadays.
In the end the Voyagers that reached the launch pad in August 1977 discretely threw a giant middle finger to Congress and all the others that had tried to cancell the program.
 

Michel Van

ACCESS: Top Secret
Senior Member
Joined
Aug 13, 2007
Messages
4,747
Reaction score
828
The same thing they done with Cassini
filled it up with RTG up to max
To provide the Instruments maximum power need for mission.

and used a Titan IV as giant middle finger toward the crazy environmentalist...
 

Hobbes

ACCESS: Top Secret
Senior Member
Joined
May 9, 2008
Messages
900
Reaction score
265
In both cases the RTGs were filled with the amount of plutonium they were designed for, not "a boatload of plutonium".
 

chimeric oncogene

ACCESS: Confidential
Joined
May 23, 2019
Messages
130
Reaction score
63
I wonder if they could make LORRI do parallax observations, like TAU was supposed to.


Yep. NH is doing parallax measurements.
 

FighterJock

ACCESS: Top Secret
Joined
Oct 29, 2007
Messages
1,649
Reaction score
384
I wonder if they could make LORRI do parallax observations, like TAU was supposed to.


Yep. NH is doing parallax measurements.

Interesting that they are asking the general public to get involved.
 

Flyaway

ACCESS: Top Secret
Senior Member
Joined
Jan 21, 2015
Messages
4,623
Reaction score
2,287
Two related articles on a current New Horizons science project:


 
Last edited:

robunos

You're Mad, You Are.....
Senior Member
Joined
May 1, 2007
Messages
1,919
Reaction score
262
A weblink about the parallax measurements :-


cheers,
Robin.
 

FighterJock

ACCESS: Top Secret
Joined
Oct 29, 2007
Messages
1,649
Reaction score
384

chimeric oncogene

ACCESS: Confidential
Joined
May 23, 2019
Messages
130
Reaction score
63
That is excellent news Flyaway, I think that there should be another mission to Pluto to explore this underground ocean, also it would be good if there were some form of life living in the sub surface ocean.

Eh. I vote for a Uranus or Neptune system mission first (Triton's going to be interesting to compare with Pluto), a centaur, or a mission to Eris or another trans-Neptunian population (Yes, Arrakoth counts, but a bigger one might be nice too). With mission opportunities this limited, coverage rather than depth seems to be the watchword.
 

FighterJock

ACCESS: Top Secret
Joined
Oct 29, 2007
Messages
1,649
Reaction score
384
That is excellent news Flyaway, I think that there should be another mission to Pluto to explore this underground ocean, also it would be good if there were some form of life living in the sub surface ocean.

Eh. I vote for a Uranus or Neptune system mission first (Triton's going to be interesting to compare with Pluto), a centaur, or a mission to Eris or another trans-Neptunian population (Yes, Arrakoth counts, but a bigger one might be nice too). With mission opportunities this limited, coverage rather than depth seems to be the watchword.

I would like all three planets to get missions, but it depends on where NASA wants to go and what mission gets the big money.
 

Flyaway

ACCESS: Top Secret
Senior Member
Joined
Jan 21, 2015
Messages
4,623
Reaction score
2,287
 

FighterJock

ACCESS: Top Secret
Joined
Oct 29, 2007
Messages
1,649
Reaction score
384

Five years since the Pluto flyby? It does not see that long. But we have learned a lot since the flyby such as Pluto possibly having a sub-surface ocean beneath the frozen surface, the possibility of life in that ocean may be the same as that of Europa.
 

Flyaway

ACCESS: Top Secret
Senior Member
Joined
Jan 21, 2015
Messages
4,623
Reaction score
2,287

Flyaway

ACCESS: Top Secret
Senior Member
Joined
Jan 21, 2015
Messages
4,623
Reaction score
2,287

Similar threads

Top