How infeasible is a Kuiper Belt equivalent of Dawn |
How infeasible is a Kuiper Belt equivalent of Dawn |
Nov 25 2008, 01:41 PM
Post
#1
|
|
Junior Member Group: Members Posts: 22 Joined: 3-January 07 Member No.: 1551 |
I presume that it is completely infeasible without a very powerful nuclear reactor and many years' production of ion engines to do anything remotely like Dawn in the Kuiper belt - the distances are just too long.
Is it in fact feasible with current technology even to get a probe into orbit around Haumea or Makemake? I'd suspect not, that the speed you need to get it out to the Kuiper belt in a lifetime is much too great to cancel down to orbital velocity. |
|
|
Nov 25 2008, 02:29 PM
Post
#2
|
|
Member Group: Members Posts: 293 Joined: 22-September 08 From: Spain Member No.: 4350 |
(warning: ignorant speculation) A "Huygens like" orbiter maybe? Send a robotic micro-orbiter on batteries without Direct-to-Earth communications hardware, orbit the KBO during several days, hibernate until the flyby probe passes by and upload the data to it so it's slowly retrieved through the DSN pipe.
|
|
|
Nov 26 2008, 01:29 AM
Post
#3
|
|
Member Group: Members Posts: 509 Joined: 2-July 05 From: Calgary, Alberta Member No.: 426 |
It's possible that it could be done with current technology. But it would be unbelievably expensive -- and yes, we'd be talking about decades before any science results came in.
I'm guessing that a Neptune flyby would pretty much be a prerequisite -- just to help get the thing into something resembling a desirable orbit. Unfortunately, it would also cut down the number of possible targets. |
|
|
Jan 14 2009, 04:43 PM
Post
#4
|
|
Newbie Group: Members Posts: 6 Joined: 1-August 08 Member No.: 4280 |
What seems far more realistic to me is a fly-by mission (similar to NH) which should greatly cut down costs, risks, technology challenges and travel time to such distant objects. Another reason is that I don’t see how it will be possible, from the scarce data collected by near-earth based observations of these objects, to define scientific goals which would be achievable by an orbiting mission but not by a fly-by mission and critical enough to justify the (big) drawbacks listed above. The exception being Pluto (a very interesting KBO indeed) if for some reason NH discoveries scheduled for 2015 raise some kind of interest for further investigation. I guess that any orbital mission to objects at typical KB distances would require at least 30 years to complete the trip, whatever the propulsion technology / gravitational assists strategy used.
About technology, Dawn’s solution (ion thrusters + solar panels) seems not feasible at KB where the distance to the sun is too great. I don’t believe in a solution of powering ITs by RTGs (too much power required ?). Given the fact that KBOs orbital velocity is rather low, it might be possible to design a rendez-vous trajectory (maybe with Neptune gravitational assist) where the delta-V required to enter orbit is small enough to be handled with standard chemical thrusters. |
|
|
Feb 22 2010, 11:32 AM
Post
#5
|
|
Newbie Group: Members Posts: 8 Joined: 21-February 10 Member No.: 5226 |
it should be quite unfeasible to power the probe and the electric propulsion with RTG, since the power output decreases with time (power from a 238Pu source decays by about 10% per 10 years). Considering the cruise time needed to reach a KBO (with or without gravity assists), the spacecraft would reach its target with a small amount of power aveable to operate the instruments (and propulsion). IMHO, the best power source is a fission reactor.
|
|
|
Feb 22 2010, 11:36 AM
Post
#6
|
|
Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
New Horizons is expected to reach, and be fully functional at, one or more KBO's after it's Pluto flyby.
|
|
|
Feb 22 2010, 11:49 AM
Post
#7
|
|
Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
At least Pluto orbiter is possible.
Some informations here: http://www.esa.int/gsp/ACT/doc/MAD/pub/ACT...neerAnomaly.pdf -------------------- |
|
|
Feb 22 2010, 01:03 PM
Post
#8
|
|
Newbie Group: Members Posts: 8 Joined: 21-February 10 Member No.: 5226 |
New Horizons is expected to reach, and be fully functional at, one or more KBO's after it's Pluto flyby. yes, i know, but the topic is about some Dawn-style mission, which involve ion propulsion, not just chemical. RTG of course is able to power a scientific platform, but is fat too unpowered to sustain some electric propulsion (a RTG unit can provide 300-400W, while a ion thruster needs several kW. Using multiple RTG units would result in a too heavy probe). The real problem with nuclear reactors is that today they need a great R&D work. Just some prototipes have actually flown in space (i.e. USSR' topaz). |
|
|
Feb 22 2010, 01:10 PM
Post
#9
|
|
Newbie Group: Members Posts: 8 Joined: 21-February 10 Member No.: 5226 |
Here's a publication I just found on a proposed fly-by mission to Neptune-Triton and KBOs
http://futureplanets.blogspot.com/2009/08/white-paper-argo-mission-to-neptune.html |
|
|
Feb 23 2010, 04:59 AM
Post
#10
|
|
Senior Member Group: Members Posts: 1018 Joined: 29-November 05 From: Seattle, WA, USA Member No.: 590 |
Yup. Here's the thread where we're talking about it.
http://www.unmannedspaceflight.com/index.php?showtopic=5413 It is a very appealing idea, isn't it? --Greg |
|
|
Feb 23 2010, 05:04 AM
Post
#11
|
|
Senior Member Group: Members Posts: 1018 Joined: 29-November 05 From: Seattle, WA, USA Member No.: 590 |
At least Pluto orbiter is possible. Some informations here: http://www.esa.int/gsp/ACT/doc/MAD/pub/ACT...neerAnomaly.pdf This is a paper about the so-called Pioneer Anomaly. Did you post the wrong link? --Greg |
|
|
Feb 23 2010, 09:00 AM
Post
#12
|
|
Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
No. Some informations about this mission are in this paper and this is only paper which I found on net with some informations.
But I searched my personal archive and I have original paper about this mission (it's one of ESA ACT studies). It was freely available on net, but now It's somewhere in ESA archives. I don't know if I can send copy here, It's ESA copyrighted material. But at least some informations about this study: Pluto Orbiter Probe (POP): Wet mass: 830 kg. Dry mass: 510 kg. Power: 4×GPHS-like RTG (MMRTG) (1.05 kW at Pluto). Propulsion: 4×QinetiQ T5 ion engines with 270 kg of Xe. Communication: X/Ka band. 380 bps to 35 meter ESA antenna (Ka band). Instruments: Camera, near infrared spectrometer, X-ray spectrometer, radiation experiment, SAR, bolometer (20 kg). Launch: XII.2016 (enhanced Ariane 5). JGA: 2018. Pluto orbit: VI.2034 (after 1 year spiral down phase). Final orbit: Circular with a inclination 99°, altitude 1000 km, Charon visited on spiral-down phase. -------------------- |
|
|
Lo-Fi Version | Time is now: 24th April 2024 - 11:47 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. |