New Horizons

[notsosmart]

Thanks for the effort you're putting in this thread, dude. If it wasn't for the whole Pluto aerobraking debate halfway in this thread, it would be one the best I've ever seen in the Labs. Keep it up!

[basic.syntax]

A possible 1 m/s burn... on some KSP craft, I can't mash keys fast enough, to cut a maneuver that fine

[MockKnizzle]

Turn your thrust limiter down to 1% and you'll better approximate the TWR of most real-life probes

[Leszek]

The thrust limiter doesn't go down to 1%, it cuts off at 5 and drops to 0. Unless that is a mod that does that. Anyway that is what I do sometimes, also I might use the RCS to make a maneuver like that.

Back to the topic, I can't wait for BTH pictures. I wanna know what pluto looks like!

[Camacha]

The thrust limiter doesn't go down to 1%, it cuts off at 5 and drops to 0. Unless that is a mod that does that.

Depending on the speed of your system, you can get some pretty fine grained control through kOS You should be able to fire at 1% for something like 0,02 seconds, but accuracy and performance really depend on the speed of your real world computer.

[lajoswinkler]

Thanks for the effort you're putting in this thread, dude. If it wasn't for the whole Pluto aerobraking debate halfway in this thread, it would be one the best I've ever seen in the Labs. Keep it up!

Those debates are what makes up The Science Labs, dude.

The thrust limiter doesn't go down to 1%, it cuts off at 5 and drops to 0. Unless that is a mod that does that. Anyway that is what I do sometimes, also I might use the RCS to make a maneuver like that.

Back to the topic, I can't wait for BTH pictures. I wanna know what pluto looks like!

Actually, it's 5.5. Lower thrusting can be done with attenuated RCS system at precision mode.

[Meithan]

A possible 1 m/s burn... on some KSP craft, I can't mash keys fast enough, to cut a maneuver that fine

That's what happens when your 478 kg spacecraft has a total thrust of 17.6 N. No, I'm not missing a 'kilo' there. That's a TWR of 0.0038, or an acceleration of 0.037 m/s^2. A 1 m/s maneuver takes around 27 s under that acceleration.

[Camacha]

That's what happens when your 478 kg spacecraft has a total thrust of 17.6 N. No, I'm not missing a 'kilo' there. That's a TWR of 0.0038, or an acceleration of 0.037 m/s^2. A 1 m/s maneuver takes around 27 s under that acceleration.

That too. Moderation goes a long way.

[Frida Space]

Thanks for the effort you're putting in this thread, dude.

Thanks!!

By the way, a quick encounter timeline from Emily Lakdawalla of Planetary Society:

• We expect a really great photo of Pluto to hit the ground very late in the evening Monday, July 13.
  
• On Tuesday, July 14, we will get no images. We will hear a beep from the spacecraft if it survived close approach at about 6pm PDT / 9pm EDT / 1am UT.
  
• Wednesday, July 15 should see two downlinks, one in the morning and one in the afternoon, with some really great photos -- Pluto and Charon both filling the frame, the best picture of Nix, and a couple of high-res photos of sections of Pluto.
  
• In general, the New Horizons team has planned carefully to receive the very most photogenic images first, with images trickling in over the next couple of days so that Sunday (July 19) papers and news shows will have great material for big features including global views of all the objects and a few selected high-res detail photos of Pluto and Charon.
  

[magnemoe]

A possible 1 m/s burn... on some KSP craft, I can't mash keys fast enough, to cut a maneuver that fine

In that case use RCS or reduce trust on engine, mechjeb is able to do 0.1 m/s burns even on high TWR crafts like small probes with 48-7S

[Frida Space]

A full day on Pluto-Charon....

[Frida Space]

Happy birthday, Pluto! Clyde Tombaugh was only 24 and had a high school diploma when he discovered Pluto on Feb 19th, 1930. Today, 85 years later, an ounce of his ashes is on Pluto's doorstep.

[Aethon]

A Pluto primer.

http://www.universetoday.com/13872/interesting-facts-about-pluto/

[Frida Space]

Nix & Hydra seen from New Horizons!!

[Robotengineer]

I really doubt Pluto will look that interesting, all though I would be glad to be wrong. Really, really looking forward to this encounter.

[Frida Space]

I really doubt Pluto will look that interesting, all though I would be glad to be wrong. Really, really looking forward to this encounter.

Well, we've never seen a Kuiper belt object up close. I'm loving the Dawn mission but I gotta say Ceres looks kinda "plain". However, I think Pluto will be much more interesting: cryovulcanoes, vallies etc. Plus we already know that it has an atmosphere which interacts in a very complex way with Charon and that there is an exchange/transfer of various materials between the two bodies, so the data should be very very interesting.

"I guess most surprising would be to find there are no surprises" -- Alan Stern

[Newt]

I really doubt Pluto will look that interesting, all though I would be glad to be wrong. Really, really looking forward to this encounter.

Pluto is also widely suggested to be related to Triton (as Triton was captured from the same region. Earlier there had been suggestions about Triton and Pluto being a sort of double planet or moon which, after encountering Neptune or another object ended up being a moon and a planet separately, but with more Kuiper belt objects discovered, that seems a bit of an unjustified stretch)which is anything if not really weird. Some of Triton's features (like geysers) are probably related to the Sun interacting with the surface ice, not like Enceladus's tidally driven heat, so we may anticipate the possible existence of those, and other things of course, too.

[KerikBalm]

While some are due to the sun... a lot of triton's features are likely due to tidal heating, and a lot are to the the heating that would have resulted after capture and circularization.

Pluto could look very different.

Triton at some point was subjected to a lot more melting than pluto was (most likely... it seems unlikely that pluto was the partner of Triton that ws flung off when triton was captured... given that pluto also has charon), so it will be interesting to see what difference results from that.

[Tommygun]

Would Charon's interaction alone with Pluto be enough to cause cryo-geysers?

[Frida Space]

Would Charon's interaction alone with Pluto be enough to cause cryo-geysers?

It depends on many other factors too (for example, a hydrated core would make cryo-geysers more plikely, whilst an undifferientiated crust would not). It also depends on Pluto's composition: CO is an excellent driver for explosive venting, whereas species such as CO2 and sulfur gases are not. Primordial N accreted as N2 could also drive cryo-geyser events if its abundance, currently unconstrained, is above a few percent with respect to water. So I don't think Charon's influence would be enough.

[lajoswinkler]

Well, we've never seen a Kuiper belt object up close. I'm loving the Dawn mission but I gotta say Ceres looks kinda "plain". However, I think Pluto will be much more interesting: cryovulcanoes, vallies etc. Plus we already know that it has an atmosphere which interacts in a very complex way with Charon and that there is an exchange/transfer of various materials between the two bodies, so the data should be very very interesting.

"I guess most surprising would be to find there are no surprises" -- Alan Stern

Ceres looks plain because we get infrared images, yet it really has significant color which gives him more character than it would seem judging by gray images only.

[Frida Space]

Ceres looks plain because we get infrared images, yet it really has significant color which gives him more character than it would seem judging by gray images only.

True, I overlooked that. However, I still think Pluto will be somwehat "cooler": it has moons, maybe some undiscovered ones too and it could even have rings. The simple fact that it has a moon as big as Charon has so many consequences (gas transfer, dust exchange, transient atmosphere etc.) which will be fascinating to study. That said, Ceres is really cool too, can't wait for Dawn to begin its orbital mission.

[lajoswinkler]

True, I overlooked that. However, I still think Pluto will be somwehat "cooler": it has moons, maybe some undiscovered ones too and it could even have rings. The simple fact that it has a moon as big as Charon has so many consequences (gas transfer, dust exchange, transient atmosphere etc.) which will be fascinating to study. That said, Ceres is really cool too, can't wait for Dawn to begin its orbital mission.

Yes, I expect Pluto to be similar to Triton. Probably not active as it, though.

[Newt]

Would Charon's interaction alone with Pluto be enough to cause cryo-geysers?

On Triton, the cryovolvanism has, as we currently understand it, absolutely nothing to do with Neptune, and everything to do with the sun. The geysers witnessed on the surface during the Voyager II flyby were all very close to the subsolar point of the moon, and thus probably were caused by that, not by tidal heating. It is entirely conceivable that Pluto could have similar sun driven eruptions. That does not mean that there are not on Triton, and are not on Pluto, tidally driven activities, just that geysers are not so driven.

What is more, the Pluto/Charon system is tidally locked into a nearly circular orbit, tides on Pluto are small, and from Charon very very small. This does not mean that the effect was not once large, simply that by now there is not too much going on in the Pluto Charon system with regard to internal tidal heating.

[Tommygun]

It depends on many other factors too (for example, a hydrated core would make cryo-geysers more plikely, whilst an undifferientiated crust would not). It also depends on Pluto's composition: CO is an excellent driver for explosive venting, whereas species such as CO2 and sulfur gases are not. Primordial N accreted as N2 could also drive cryo-geyser events if its abundance, currently unconstrained, is above a few percent with respect to water. So I don't think Charon's influence would be enough.

On Triton, the cryovolvanism has, as we currently understand it, absolutely nothing to do with Neptune, and everything to do with the sun. The geysers witnessed on the surface during the Voyager II flyby were all very close to the subsolar point of the moon, and thus probably were caused by that, not by tidal heating. It is entirely conceivable that Pluto could have similar sun driven eruptions. That does not mean that there are not on Triton, and are not on Pluto, tidally driven activities, just that geysers are not so driven.

What is more, the Pluto/Charon system is tidally locked into a nearly circular orbit, tides on Pluto are small, and from Charon very very small. This does not mean that the effect was not once large, simply that by now there is not too much going on in the Pluto Charon system with regard to internal tidal heating.

OK, I was thinking with Charon's size being relatively large to Puto's to the point it forms a binary system, that it might cause same cryo-volcanism along with the solar based ones.

I was wondering or hoping that when the atmosphere finally freezes out that tidal forces would continue to make eruptions. I'm assuming we don't know how far out the Sun can cause solar based geysers yet.