"Dragonfly" Titan explorer drone, NASA funds Johns Hopkins University Applied Physics Laboratory (APL) |
"Dragonfly" Titan explorer drone, NASA funds Johns Hopkins University Applied Physics Laboratory (APL) |
Dec 20 2017, 09:04 PM
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Junior Member Group: Members Posts: 66 Joined: 3-August 12 Member No.: 6454 |
Is there a specific website for this Johns Hopkins University Applied Physics Laboratory (APL) concept for a Titan explorer drone?
Looks to be an RTG powered machine, somewhat reminiscent of MSL Curiosity (RTG sticking out the tail end). But no camera mast, ChemCam, or sampling arm visible in the concept illustration. QUOTE Dec. 20, 2017 RELEASE 17-101 NASA Invests in Concept Development for Missions to Comet, Saturn Moon Titan Dragonfly Dragonfly is a drone-like rotorcraft that would explore the prebiotic chemistry and habitability of dozens of sites on Saturn’s moon Titan, an ocean world in our solar system. Elizabeth Turtle from the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, is the lead investigator, with APL providing project management. https://www.nasa.gov/press-release/nasa-inv...turn-moon-titan |
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Dec 31 2017, 09:31 AM
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
I wonder how effectively it could navigate over long distances. We don't have nearly good enough surface maps for AI terrain recognition, there's no significant magnetic field, so all that's left is inertial. Maintaining a good heading alignment over long periods may be problematic since IMUs do have inherent drift, and though periodic realignment is the usual method to correct that Titan's outer shell rotation seems to vary significantly in comparison to the rest of the moon's mass (not sure if that's a fixed offset or variable), and measuring rate & direction of rotation after vertical alignment is the usual method of finding true north (and latitude).
This could possibly be augmented by RDFing the vehicle's downlink to Earth, but not sure how much position precision could be achieved...tens/hundreds of km? Then again, maybe the position of the Sun could be used as well, foggy though it's gonna be. Dunno if Saturn would be detectable, but the Sun's definitely gonna be the only possible reference star. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Dec 31 2017, 04:46 PM
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Member Group: Members Posts: 715 Joined: 22-April 05 Member No.: 351 |
I wonder how effectively it could navigate over long distances. We don't have nearly good enough surface maps for AI terrain recognition, there's no significant magnetic field, so all that's left is inertial. Maintaining a good heading alignment over long periods may be problematic since IMUs do have inherent drift, and though periodic realignment is the usual method to correct that Titan's outer shell rotation seems to vary significantly in comparison to the rest of the moon's mass (not sure if that's a fixed offset or variable), and measuring rate & direction of rotation after vertical alignment is the usual method of finding true north (and latitude). This could possibly be augmented by RDFing the vehicle's downlink to Earth, but not sure how much position precision could be achieved...tens/hundreds of km? Then again, maybe the position of the Sun could be used as well, foggy though it's gonna be. Dunno if Saturn would be detectable, but the Sun's definitely gonna be the only possible reference star. From Ralph et al.'s paper, Dragonfly would do 40 km hops with 16 days between. I presume the quadcopter would have its position updated during the between days. The paper hints that longer flights are likely possible and 40 km is the safe planning distance. One factor that would shorten traverses is the plan to use each flight to locate a more distant future landing site and then fly back to a previously scouted nearer landing site. With experience, the mission team might gain the confidence to not do the fly back and allow the quadcopter to chose its own safe landing site. With lidar or structure from motion (building 3D maps from stereo images), Dragonfly could continuously search for safe landing sites below its flight path and know of safe landing sites. -------------------- |
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Dec 31 2017, 10:17 PM
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
With experience, the mission team might gain the confidence to not do the fly back and allow the quadcopter to chose its own safe landing site. With lidar or structure from motion (building 3D maps from stereo images), Dragonfly could continuously search for safe landing sites below its flight path and know of safe landing sites. Interesting, and thanks for the responses, all. Didn't know that terrestrial-based radiometry was accurate at sub-km resolution, Mike, so that solves the main problem: navigating to targets like lakes and cryovolcano candidates that may be extremely distant from the original landing site. Periodic position fixes combined with the local-scale 'hop & look' nav methods described should solve that with a high degree of precision and operational safety. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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