191–197 of 197 posts
Dragonfly is a super exciting mission. Between it and the other New Frontiers finalist, CAESAR, it makes sense that Dragonfly would win because the ESA just announced their own comet exploration mission (the Comet Interceptor, which is 3 spacecraft that will loiter together at L2 until an interesting comet or Oumuamua-like interstellar object wanders into the inner solar system). Anyway, Dragonfly: RTG-powered quadco…
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I think a flying mission is actually superior to a rover as it can cover far more ground and reach some sites that wouldn't be feasible for a rover. And Titan is uniquely suited to using flight to explore as its gravity is a factor 7.25 lower and its atmosphere a factor of 4.4x denser. That means it's about 30 times easier to hover and covering the same distance is at least 7 times as efficient as on Earth, besides h…
> over its ~10 year lifespan (assuming it can last as long as Cassini did...) Cassini wasnt exposed to solvents, rocks and didn't have moving parts (at least not to keep it aloft). Have they made a public statement about lifespan?
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In a sense tho, at-the-speed-of-light is real time, as it's the maximum speed of anything.
If, as clock A nears the speed of light it appears that stationary clock B is slowing down, doesn't that mean that at the speed of light is no time? Does a photon in a vacuum arrive instantly at its destination? If a photon looks at another photon, does the other photon appear not to be moving at all, or... Ouch my brain.
If clock A could reach the speed of light (which it can't), then, yes, clock B would appear to be 'frozen in time'.
> Does a photon in a vacuum arrive instantly at its destination?
From the perspective of any possible observer, no, it always appears to be traveling at the speed of light. If an observer could travel at the speed of light (which it can't), then, yes, it would appear as if it arrived instantly in the sense that clocks at both its source and destination would appear to be not running at all.
> If a photon looks at another photon, does the other photon appear not to be moving at all, or... Ouch my brain.
Yeah, this is tricky. Photons can't look or see – what could that mean as looking/seeing involves detecting photons (or, in the sense that something like echolocation is 'seeing', detecting a pattern of matter, e.g. sound)? In a sense, not moving at all or both moving at the same maximum speed don't seem to be much different, from the 'perspective' of a photon.
Somewhat related, this video describes how, if one could travel on a vehicle that could accelerate at a constant rate continuously for decades, one would eventually see the cosmic microwave background radiation as a rainbow ring because traveling closer and closer to the speed of light would shift the apparent frequency of the radiation first into the visible spectrum (and then beyond it).
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If, as clock A nears the speed of light it appears that stationary clock B is slowing down, doesn't that mean that at the speed of light is no time? Does a photon in a vacuum arrive instantly at its destination? If a photon looks at another photon, does the other photon appear not to be moving at all, or... Ouch my brain.
> If, as clock A nears the speed of light it appears that stationary clock B is slowing down, doesn't that mean that at the speed of light is no time? If clock A could reach the speed of light (which it can't), then, yes, clock B would appear to be 'frozen in time'. > Does a photon in a vacuum arrive instantly at its destination? From the perspective of any possible observer, no, it always appears to be traveling at…
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Super fast compute, but awful ping…
To put it into perspective: https://solarsystem.nasa.gov/moons/saturn-moons/titan/overvi... According to this (at the time of reading) a one way trip at the speed of light is ~75 minutes, so you will have approximately two and a half hours of ping. Ouch. Still, it raises an interesting question: how would a hypothetical Earth-Titan network protocol work?
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Perfect for mining bitcoin
Not really; if you find a block it will mostly likely have been beaten by someone else's block by the time yours reaches most nodes...unless there is a Saturn based side chain or similar.
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Naively, a round trip requires twice the delta-v, which means you need to launch with a lot more than twice the fuel. Maybe they could produce more fuel and oxidizer in situ, and maybe Earth is a more attractive target for aerocapture, and maybe gravity assists line up better one way or the other, but it's not a bad starting point to assume a round trip is far more expensive than a one-way trip. I'm not sure on what…
Sorry for the late reply. Titan has lakes of liquid methane rather than water. Raptor is a methalox engine. I think refueling on the planet would be quite possible.
Can you fit that equipment in a single Starship, by mass and volume? Is that what we're talking about here? No idea.