Just to let everyone know about the blog I recently posted at Beyond the Cradle, a site i recently joined.
It relates to the upcoming 20 yr anniversary of Voyager at Neptune. I include a flyover movie of this amazing satellites.
Lets start a discussion on how we might Return to Neptune!
cheers!
paul
http://beyondthecradle.wordpress.com/
(scroll down to near bottom)
AN ADDED NOTE: New Horizons team members will be remapping Triton starting later this year, using the best available
data from a variety of sources, including the topography used to make my movie!
Full Version: 20 years after Voyager: Triton Lives!
QUOTE (DrShank @ Apr 9 2009, 02:11 PM) 
Just to let everyone know about the blog I recently posted at Beyond the Cradle, a site i recently joined.
My opinion is that you did the right thing joining that site...I heard the editor is just...wow...incredible...
Here's the direct link to your flyover piece.
Hi All
Well the best way to return might be to do a fast flyby (New Horizons II) on the way to visit a few KBOs - there's so many known now we should be able to line up for at least a couple of little ones, especially with a boost from Neptune and Triton's gravity.
Of course the next step is an Orbiter, but what's the best approach? Understandably NASA hates to lose a probe to untested technology, so what I'm proposing probably will be ignored. But it has style! Assuming a microwave power satellite in orbit - which might be online by 2016 according to the news - perhaps we can purchase a burst of microwave energy aimed at a solar-sail - one impregnated with something volatile to degas. This is a new idea from Greg & James Benford and can give a solar-sail a huge kick - in this case inbound for a 0.1 AU perihelion, then the solar-sailer shoots out at highspeed bound for Neptune. Or, for a bit more juice, it fires off straight to Neptune. We want a decent trip time - and we need to brake from that transfer orbit - so I'd suggest aerocapture (another untried trick.) For a 5 year trip the relative velocity when it hits the upper atmosphere is 31.84 km/s and the delta-v we want shaved off as shockwave heat is ~11.5 km/s. A 6 year trip means entry at 28.75 km/s and 8.3 km/s delta-v. Since the "Galileo" drop-probe survived a 48.5 km/s entry and dissipated all its energy I'd say the aerocapture requirements aren't too onerous. They only have to dissipate 25% & 17% of the "Galileo" entry energy respectively.
That aerocapture puts the probe into a highly elliptical orbit, which will need a peri-apsis raising burn. Timed right we might then do a first fly-past Triton and be able to drop a lander. Another untried trick is a ballute deccelerator to brake the lander, which will be needed in the ultra-tenuous Tritonian stratosphere. Something longer lasting than "Cassini" is preferred, perhaps RTG powered. With improvements in thermoelectrics expected in a couple of years we might be able to get by with a cooler thermal source, thus reducing the localised heating around the lander. Perhaps it can use balloon tyres and do some roving? A balloon probe might even be possible (!)
As for the orbiter more efficient RTGs might allow electric thrusters thus extending its operational life. We could even power up decent SAR systems to scan Triton's sub-surface, do some active probing of Neptune itself.
Well the best way to return might be to do a fast flyby (New Horizons II) on the way to visit a few KBOs - there's so many known now we should be able to line up for at least a couple of little ones, especially with a boost from Neptune and Triton's gravity.
Of course the next step is an Orbiter, but what's the best approach? Understandably NASA hates to lose a probe to untested technology, so what I'm proposing probably will be ignored. But it has style! Assuming a microwave power satellite in orbit - which might be online by 2016 according to the news - perhaps we can purchase a burst of microwave energy aimed at a solar-sail - one impregnated with something volatile to degas. This is a new idea from Greg & James Benford and can give a solar-sail a huge kick - in this case inbound for a 0.1 AU perihelion, then the solar-sailer shoots out at highspeed bound for Neptune. Or, for a bit more juice, it fires off straight to Neptune. We want a decent trip time - and we need to brake from that transfer orbit - so I'd suggest aerocapture (another untried trick.) For a 5 year trip the relative velocity when it hits the upper atmosphere is 31.84 km/s and the delta-v we want shaved off as shockwave heat is ~11.5 km/s. A 6 year trip means entry at 28.75 km/s and 8.3 km/s delta-v. Since the "Galileo" drop-probe survived a 48.5 km/s entry and dissipated all its energy I'd say the aerocapture requirements aren't too onerous. They only have to dissipate 25% & 17% of the "Galileo" entry energy respectively.
That aerocapture puts the probe into a highly elliptical orbit, which will need a peri-apsis raising burn. Timed right we might then do a first fly-past Triton and be able to drop a lander. Another untried trick is a ballute deccelerator to brake the lander, which will be needed in the ultra-tenuous Tritonian stratosphere. Something longer lasting than "Cassini" is preferred, perhaps RTG powered. With improvements in thermoelectrics expected in a couple of years we might be able to get by with a cooler thermal source, thus reducing the localised heating around the lander. Perhaps it can use balloon tyres and do some roving? A balloon probe might even be possible (!)
As for the orbiter more efficient RTGs might allow electric thrusters thus extending its operational life. We could even power up decent SAR systems to scan Triton's sub-surface, do some active probing of Neptune itself.
Interesting short piece (definitely written for a non-specialist audience) on work on simulation tools for lifting ballutes for aerobraking at, e.g., Neptune: http://www.theregister.co.uk/2009/04/17/do...tes_go_to_mars/ ... presumably based on this press release. Oh, and here's the SBIR study proposal: Hypersonic Control Modeling and Simulation Tool for Lifting Towed Ballutes.
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