Uranus and/or Neptune Exploration |
Uranus and/or Neptune Exploration |
Jun 13 2017, 07:41 PM
Post
#16
|
|
Junior Member Group: Members Posts: 27 Joined: 2-December 14 Member No.: 7359 |
ICE GIANTS PRE-DECADAL STUDY FINAL REPORT (NASA) https://twitter.com/jjfplanet/status/874366189622796288 |
|
|
Jun 13 2017, 10:43 PM
Post
#17
|
|
Member Group: Members Posts: 318 Joined: 1-October 06 Member No.: 1206 |
Golly, now lets see what comes of it.
I'll be in my rocking chair if and when these things deliver but my god they are needed. P |
|
|
Jun 16 2017, 08:53 PM
Post
#18
|
|
Senior Member Group: Members Posts: 1598 Joined: 14-October 05 From: Vermont Member No.: 530 |
To ensure that the most productive mission is flown, we recommend the following:
An orbiter with probe be flown to one of the ice giants The orbiter carry a payload between 90 and 150 kg The probe carry at minimum a mass spectrometer and atmospheric pressure, temperature, and density sensors The development of eMMRTGs and HEEET be completed as planned Two-planet, two-spacecraft mission options be explored further Launch would be 2030, arrival 2043 for Neptune Launch would be 2031, arrival 2043 for Uranus All of the above: Orbiter and Probe for both projected to cost $3.671B ... $125M per year for the next 30 years. |
|
|
Jun 16 2017, 09:37 PM
Post
#19
|
|
Senior Member Group: Members Posts: 1278 Joined: 25-November 04 Member No.: 114 |
I get sad seeing those dates. I don't know if I'll be on earth anymore to observe those missions.
Uranus moons have so much to show us still. |
|
|
Jun 16 2017, 11:59 PM
Post
#20
|
|
Senior Member Group: Members Posts: 2113 Joined: 13-February 10 From: Ontario Member No.: 5221 |
A launch on the SLS to avoid a bunch of inner solar system gravity assists would speed the trip up.
Trouble is, getting to the ice giants faster means using more delta-v to slow down, as the paper notes. There must be some good balance of the two pressures. We can always hope for a propulsion breakthrough... |
|
|
Jun 17 2017, 12:43 PM
Post
#21
|
|
Member Group: Members Posts: 154 Joined: 21-April 05 From: Rochester, New York, USA Member No.: 336 |
This week's Planetary Radio also mentioned briefly that there was an option to fly Cassini to Uranus, although she characterized it as a "1%" option.
http://www.planetary.org/multimedia/planet...er-cassini.html |
|
|
Jun 17 2017, 02:29 PM
Post
#22
|
|
Senior Member Group: Members Posts: 2113 Joined: 13-February 10 From: Ontario Member No.: 5221 |
There were a number of such concepts for Cassini EOM. More details here (http://www.lpi.usra.edu/opag/march_08_meeting/presentations/spilker.pdf)
20 (!) years to get to Uranus after Saturn escape! Easier to just go from Earth with a whole new mission. |
|
|
Jun 21 2017, 09:41 PM
Post
#23
|
|
Interplanetary Dumpster Diver Group: Admin Posts: 4405 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
Launch would be 2030, arrival 2043 for Neptune Launch would be 2031, arrival 2043 for Uranus Brings new meaning to, "When I'm 64" (or 63 if it's early in the year). -------------------- |
|
|
Jun 22 2017, 10:02 PM
Post
#24
|
|
Senior Member Group: Members Posts: 2113 Joined: 13-February 10 From: Ontario Member No.: 5221 |
On the bright side, if a orbiter is at Neptune in April 2046 with a good imager, it will have quite the show: http://xplanet.sourceforge.net/Gallery/20460429_jupiter/
|
|
|
Jun 22 2017, 10:15 PM
Post
#25
|
|
Newbie Group: Members Posts: 15 Joined: 26-March 12 From: San Antonio, Texas Member No.: 6368 |
On the bright side, if a orbiter is at Neptune in April 2046 with a good imager, it will have quite the show: http://xplanet.sourceforge.net/Gallery/20460429_jupiter/ That would be awesome. I'll be 79 if I'm still alive. -------------------- Axes Grind and Maces Clash!
|
|
|
Sep 29 2017, 04:53 PM
Post
#26
|
|
Senior Member Group: Members Posts: 2113 Joined: 13-February 10 From: Ontario Member No.: 5221 |
Looking at the maps of the solid bodies in the outer solar system, I figured this to be the best place to ask (as we all want better maps!):
Given the high axial tilts of the Uranian moons (and Triton), when combined with their lengthy seasons, how would an orbiter conduct mapping the geography/geology of the unlit hemispheres? As we saw at Pluto, one ends up with a giant fraction of the map remaining completely unknown; even a future Pluto orbiter would have to wait many decades for sunlight to reach the southern hemisphere. What sort of instrumentation could deal with this? There is only so much reflected light from the planet one can use like Cassini did (and even then only for the planet-facing hemisphere). Is RADAR like Cassini's practical at all? Something like MOLA on Mars Global Surveyor? Star occultations behind the limb during a flyby could get outlines of particular dramatic topography, like Miranda's canyons? Maybe a really big flashlight? Just brainstorming, and I'm curious if anyone else has thought about it. |
|
|
Sep 29 2017, 10:57 PM
Post
#27
|
|
Member Group: Members Posts: 903 Joined: 30-January 05 Member No.: 162 |
Here's a combined view of Enceladus in light and radar (radar scan is in the arc shaped area). Radar appears to have worked quite well. (Haven't posted a picture here in years, hope I do it right)
|
|
|
Sep 29 2017, 11:23 PM
Post
#28
|
|
Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
That's a really interesting enquiry. I would first like to add a complicating factor which is that the superficial appearance of these bodies may change significantly on a seasonal timescale. For example the parts of Pluto and Triton that we saw by day might look quite different during a long polar night as a result of 'repainting' by mobile volatile materials. Even a perfect night-time flashlight might show a different map. That said, the topography would not change and that could be reliably mapped by radar. How much do we learn from visible light images compared with a really good topographic survey? I don't know but would be interested in expert opinions.
|
|
|
Sep 30 2017, 05:21 AM
Post
#29
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
A few thoughts here
A mission that arrived just before equinox would soon see the entire surfaces of the whole system, so that would be one approach (two flyby craft would be another), but doesn't address the question of seasons. These worlds have a lot less gravity than Triton or Pluto and they're much closer to the Sun, so I'd be skeptical about seasonal dynamics on a grand scale. It's always possible that a seasonal change would consist of a very thin layer that has profound implications for albedo but would be invisible on the scale of geomorphology. Earth and Mars both show such things. Radar may see right through a thin layer, but depending upon its dielectric properties, may see it as a major change in radar albedo. I don't think radar is likely to make the cut for a Uranus orbiter simply because the use case is speculative and radar is both heavy and places constraints on the trajectory (very close encounters are required). In terms of seeing dark sides in uranus-shine, the geometry produces a quirky result. Near uranian solstice, half of each moon would be seen in daylight. Half of the other half could be lit favorably for uranus-shine observations. So, we might end up with 3/4 of each moon mapped. Keep in mind that terrestrial telescopes are going to be able to observe uranian moons with increasing resolution as the massive South American telescopes come online in the next decade, so we might get some imaging of value to supplement whatever a mission would fail to see. My suspicion for all of the above, though, is that we're whistling past the graveyard. I don't think Uranus or Neptune are going to get an orbiter until Europa, Titan, and Enceladus each have a turn or two in the queue, and we're talking about a good chunk of a century before that would run its course. If the Breakthrough Starshot technology to visit another star goes anywhere, Uranus and Neptune might make some nice test cases, though. |
|
|
Jul 25 2018, 06:42 AM
Post
#30
|
|
Member Group: Members Posts: 318 Joined: 1-October 06 Member No.: 1206 |
Outer Solar System Exploration:
A Compelling and Unified Dual Mission Decadal Strategy for Exploring Uranus, Neptune, Triton, Dwarf Planets, and Small KBOs and Centaurs A.A. Simon (NASA GSFC), S.A. Stern (SwRI), M. Hofstadter (Caltech/JPL) https://arxiv.org/ftp/arxiv/papers/1807/1807.08769.pdf Yep, not perfect (I'd prefer the Uranus orbiter and the Nepture / KBO flyby) but I understand the rationale. Something has got to happen soon, or just about everyone on this board will be pushing up daisies before we return to the outer solar system. P |
|
|
Lo-Fi Version | Time is now: 31st October 2024 - 11:11 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. |