Timeline for What would it cost to bring a 1 gram payload to the CMBR rest frame (i.e. Δv 368 km/s ?)
Current License: CC BY-SA 4.0
18 events
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| S Aug 26, 2018 at 8:10 | history | suggested | user10840 | CC BY-SA 4.0 |
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| Aug 26, 2018 at 7:36 | review | Suggested edits | |||
| S Aug 26, 2018 at 8:10 | |||||
| Aug 25, 2018 at 18:22 | vote | accept | chriswa | ||
| Aug 25, 2018 at 16:49 | comment | added | uhoh | @SteveLinton tell me more! :-) Could a laser ablation-based propulsion system really accelerate an object to 0.001 c? | |
| Aug 25, 2018 at 16:36 | comment | added | Steve Linton | @uhoh Laser ablation is pretty effective. You blast the surface layer of something into plasma and the electric fields of the laser accelerate the ions close to lightspeed. Half of them hit the payload and the other half are reaction mass. | |
| Aug 25, 2018 at 15:13 | comment | added | uhoh | @SteveLinton propulsion is about momentum, not just energy. You need a reaction mass or at least something to carry the opposite momentum. It's hard to imagine how those could really accelerate something to 0.001c | |
| Aug 25, 2018 at 15:00 | history | tweeted | twitter.com/StackSpaceExp/status/1033368620620017666 | ||
| Aug 25, 2018 at 14:44 | answer | added | asdfex | timeline score: 15 | |
| Aug 25, 2018 at 11:41 | answer | added | Jack | timeline score: 19 | |
| Aug 25, 2018 at 10:28 | comment | added | Steve Linton | It depends, among other things, on your payload. I think it might be possible to accelerate a payload on that scale to that velocity very quickly using either a nuclear explosion or a laser ablation from a very high power pulsed laser. The KE you need is about 100 MJ, which is contained in < 100 pulses of the National Ignition Facility. These would be fairly cheap (especially if you wanted to do multiple launches) but the payload would need to be rather tough. Laser lightsail or possibly a coilgun could provide a more gentle (say < 10000g) acceleration. | |
| Aug 25, 2018 at 8:50 | comment | added | uhoh | @Jack no, but I don't feel compelled to leave a comment saying the question can't be answered or the answer would be "fairly meaningless" either. You could include that in your answer instead. | |
| Aug 25, 2018 at 8:44 | comment | added | Jack | @uhoh Agreed, but these technologies are still in development so extrapolating beyond the very small data set of tested prototypes and giving a monetary value would be speculative, I believe. I'm writing an answer for conventional engines, you could write one covering the techs you mentioned? | |
| Aug 25, 2018 at 8:29 | comment | added | uhoh | @Jack This speed is way way lower than the speeds considered by the Breakthrough Starshot project, so if done with a laser instead of sunlight, it wouldn't need anything near as big as Breakthrough Starshot's 100 Gigawatt laser array - what's the current thinking how this might work? | |
| Aug 25, 2018 at 8:27 | comment | added | uhoh | @Jack I think you are overstating the hopelessness/meaninglessness situation. While it's not something you can order out of a catalog yet, there should be enough work on practical realizations of solar sails to make a guesstimate. See How will The Planetary Society's LightSail 2 Spacecraft's retroreflectors be used? It is also possible to estimate how thin the sail would be to reach this speed (about 0.1% c) based on this answer. | |
| Aug 25, 2018 at 7:52 | comment | added | Heopps | It can't be done by rocket engines currently. You can exercize yourself using Rocket equation en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation. Note that main problem is we can't reach high enouth exhaus velocity, even with ion engines. I guess maybe some magnetic levitatgion loop in vacuum theoretically could... | |
| Aug 25, 2018 at 7:30 | comment | added | Jack | 368km/s is far beyond our current capabilities, even using ion engines or other in-development high efficiency engines. So assigning a monetary value to it will be fairly meaningless, but maybe still a fun exercise! | |
| Aug 25, 2018 at 6:55 | review | First posts | |||
| Aug 25, 2018 at 7:04 | |||||
| Aug 25, 2018 at 6:54 | history | asked | chriswa | CC BY-SA 4.0 |