New Horizons: Approach Phase, OpsNav - 25 January 15 to 28 June 15 |
New Horizons: Approach Phase, OpsNav - 25 January 15 to 28 June 15 |
Jun 7 2015, 09:18 PM
Post
#226
|
|
Newbie Group: Members Posts: 18 Joined: 4-January 07 Member No.: 1558 |
OK, so you are planning the encounter trajectory. You must maximise the chances of passing through intact so rings are an issue. And you want the Earth and Sun occultations for Pluto and Charon for radio/atmospheric science. And there is no point getting too close because everything will be a blur. And blowing through at 50, 000km/h you can't afford to spend too much time rotating.
All in all you want the moons all on one side of Pluto, and take NH by on the other side at a sensible distance. Is Pluto's gravity strong enough to make the occultations work whichever side you go, or is it built in to the heliocentric trajectory? |
|
|
Jun 7 2015, 09:33 PM
Post
#227
|
||
Member Group: Members Posts: 555 Joined: 27-September 10 Member No.: 5458 |
So this bit confused me. I've never come across this particular graphic with an error zone. Does it infer the remote possibility that we may capture nearly nothing should Pluto be in the upper right most portion? I'm not the least bit worried but that zone seems rather large. -------------------- |
|
|
||
Jun 7 2015, 09:41 PM
Post
#228
|
|
Newbie Group: Members Posts: 18 Joined: 4-January 07 Member No.: 1558 |
Giving it more thought, aided by a beer, it is obvious that NH must pass to the East, "in front of" Pluto, and have Pluto's orbital motion (3-4 km/s) bring it into line behind NH. And the spacecraft will have to move in the Pluto-Charon-Earth/Sun plane to get the occultations.
|
|
|
Jun 8 2015, 01:17 AM
Post
#229
|
|
Junior Member Group: Members Posts: 59 Joined: 4-July 08 Member No.: 4251 |
Was anybody able to gets the NASA newsaudio stream to work? All I ever got was the page with a blank/black embedded window, no playback. Now I have to hope that someone captured it ... I did end up finding a recording of the June 3rd press conference, so I thought I'd contribute by sharing. First, here is a Youtube recording of the telecon. It has the telecon audio, and the slides as video, but the motion video is not playing. In other words, when they offered an animation, all you see here is the first frame: https://www.youtube.com/watch?v=AKPMYkgi-tY (side note: if anyone here has a Youtube account, please thank that user, Matthew Travis, for recording and posting it!) Second, here's the briefing materials, with working animations: http://www.nasa.gov/content/goddard/briefi...f-pluto-s-moons So, listen to the Youtube video's audio, while looking at the briefing materials. Finally, for completeness ... Yes. See the actual paper. http://hubblesite.org/pubinfo/pdf/2015/24/pdf.pdf
|
|
|
Jun 8 2015, 05:56 PM
Post
#230
|
||
Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
So this bit confused me. I've never come across this particular graphic with an error zone. Does it infer the remote possibility that we may capture nearly nothing should Pluto be in the upper right most portion? I'm not the least bit worried but that zone seems rather large. The error ellipse has to do with uncertainty in Pluto's orbital position -- because we haven't tracked it over a full orbit, the uncertainty in its path is more than we're used to for planets, moons, and asteroids. Optical navigation images being taken now will help to reduce the uncertainty, and they'll be able to update parameters close to encounter to accommodate better positional predictions, but they've had to plan the whole encounter with the best orbital predictions we have, and yes, that error zone captures the level of uncertainty. Like any error ellipse, though, Pluto is more likely to be in the middle of the zone than at the edge. -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
|
|
|
||
Jun 8 2015, 06:14 PM
Post
#231
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
The best images so far keep reminding me of what Titan looked like in pre-Cassini imagery, although there's not much chance that the dark areas on Pluto have the same origin as on Titan (e.g., sand dunes).
This is starting to get good. Some of us have lived through the first spacecraft reconnaissance of Venus, the Galileans, etc. All of us for Titan, some of us for Mars. But this is it. This is almost certainly the last time that a world of this size will be visited for the first time by spacecraft in our lifetimes, barring the unlikely event of a blazing-fast trajectory to Eris. Savor the moment. It won't come again. |
|
|
Jun 8 2015, 08:52 PM
Post
#232
|
|
Solar System Cartographer Group: Members Posts: 10145 Joined: 5-April 05 From: Canada Member No.: 227 |
It is getting good!
But I expect some of us can remember when the far side of the Moon was the frontier of exploration. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
Jun 9 2015, 12:39 AM
Post
#233
|
|
Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
An update of the 2015-06-05 "footprint" images, with 6x9, 8x9, and 8x9 images, total exposure times a little less than 9, 12, and 12 minutes respectively:
Animation of three stacked images: Preliminary differences 4-fold stretched, animated: There are probably ways to improve the latter numerically, since I've been storing the stacked files with 8-bit channels. |
|
|
Jun 9 2015, 11:39 AM
Post
#234
|
||
Forum Contributor Group: Members Posts: 1372 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
So this bit confused me. I've never come across this particular graphic with an error zone. Does it infer the remote possibility that we may capture nearly nothing should Pluto be in the upper right most portion? I'm not the least bit worried but that zone seems rather large. No, it means the right edge of Pluto could be on the right of the ellipse, so you'd still get the data, the downside is the extra images take up space on the data recorder, but it's a trade off to make sure you get the data needed. Also it accommodates any slight errors in pointing by the spacecraft, but the spacecraft pointing has as far as I know been excellent, as you'd expect with such a good team. |
|
|
||
Jun 9 2015, 11:43 AM
Post
#235
|
|
Forum Contributor Group: Members Posts: 1372 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
.... and they'll be able to update parameters close to encounter to accommodate better positional predictions... My impression was the flyby sequence was loaded way back in 2009, and won't be changed, except to fill in gaps that were deliberately left to accommodate imaging new moons. |
|
|
Jun 9 2015, 11:54 AM
Post
#236
|
|
Member Group: Members Posts: 529 Joined: 19-February 05 Member No.: 173 |
My impression was the flyby sequence was loaded way back in 2009, and won't be changed, except to fill in gaps that were deliberately left to accommodate imaging new moons. The flyby sequence was finalized after the 2012 spacecraft rehearsal. No additions are allowed. The only changes are to fill in blanks like DSN schedules we did not know in 2012. Better is the Enemy of Good Enough, we prefer 80% of something to 100% of nothing-- we're not taking risks just to do a little better. |
|
|
Jun 9 2015, 02:14 PM
Post
#237
|
|
Junior Member Group: Members Posts: 95 Joined: 5-September 07 Member No.: 3662 |
The flyby sequence was finalized after the 2012 spacecraft rehearsal. No additions are allowed. The only changes are to fill in blanks like DSN schedules we did not know in 2012. Better is the Enemy of Good Enough, we prefer 80% of something to 100% of nothing-- we're not taking risks just to do a little better. Alan, is there a doc you can point to, or much you can say (without spending too much of your very valuable time!) about how fault protection is going to be handled during the period around close approach? I'd assume there is some sort of inhibition against entering safe mode for most possible faults, but maybe I'm wrong on that. Thanks! |
|
|
Jun 9 2015, 02:18 PM
Post
#238
|
|
Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
Pluto and Charon in raw images from 5-8 June:
Here's an enlarged version for Charon for 5-7 June: I guess we might be seeing hints of surface variation on Charon in the raw images (edit: after posting this, I realised comparing frames taken seconds/similar between them would be a good way to check the noise levels..). -------------------- |
|
|
Jun 9 2015, 03:48 PM
Post
#239
|
||
Solar System Cartographer Group: Members Posts: 10145 Joined: 5-April 05 From: Canada Member No.: 227 |
Very good! I split the Pluto gif into its four frames and processed them to bring out more detail. Not a real deconvolution, but playing with histograms in multiple layers.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
||
Jun 9 2015, 06:06 PM
Post
#240
|
||
Member Group: Members Posts: 555 Joined: 27-September 10 Member No.: 5458 |
So I applied some light LR-deconvolution to your processed frames Phil.
NH is approaching Pluto with one of the poles somewhat facing us correct? Maybe I'm too excited and hopeful here, but those look and behave like atmospheric structures, like clouds. Edit: Also before this blows up, grain of salt here. Deconvolution can sometimes add strange artifacts. We are still too far away for it to provide entirely reliable information. Edit 2: Went back and made a few modification to settings to lighten up the impact of the process. The right animation used maximum entropy followed by a Lucy Richardson process. Click to animate -------------------- |
|
|
||
Lo-Fi Version | Time is now: 17th April 2024 - 07:55 PM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |