NSEP Posted January 27, 2018 Share Posted January 27, 2018 Say we had a Hydrolox (Liquid Hydrogen and Liquid Oxygen) sea-launch rocket. Would it be more cost-effective to develop an ISRU system for the launch ship to gather its fuel from the nearby waters or would it be better to just carry some pre-made Hydrogen and Oxygen? Quote Link to comment Share on other sites More sharing options...
adsii1970 Posted January 27, 2018 Share Posted January 27, 2018 1 minute ago, NSEP said: Would it be more cost-effective to develop an ISRU system for the launch ship to gather its fuel from the nearby waters or would it be better to just carry some pre-made Hydrogen and Oxygen? Theoretically, this is plausible, but there may be one serious complication - the cost effectiveness. Here's an article discussing ocean water as a clean fuel possibility: http://www.newsweek.com/ocean-water-and-sunlight-are-turned-clean-energy-brilliant-new-floating-solar-751192 And here's a basic discussion on the power requirements to do such a conversion of creating oxygen and hydrogen from ocean water: https://physics.stackexchange.com/questions/131168/how-many-joules-of-energy-are-required-to-convert-1-liter-of-water-into-hydrogen To sum it all up, you'd essentially need an on-site nuclear power source to generate the needed joules to produce the oxygen and hydrogen to fuel a rocket. At the current stage of technology, it is not feasible financially or with the level of technology we have at our disposal. Quote Link to comment Share on other sites More sharing options...
SaturnianBlue Posted January 28, 2018 Share Posted January 28, 2018 Instead of the classic approach to space-based solar power, which uses a solar array to generate electricity and transmit it down to Earth for collection, would it be better to have a solar mirror that reflects the light down to Earth for collection? Quote Link to comment Share on other sites More sharing options...
0111narwhalz Posted January 28, 2018 Share Posted January 28, 2018 14 hours ago, adsii1970 said: on-site nuclear power source Such as an aircraft carrier? Quote Link to comment Share on other sites More sharing options...
Steel Posted January 28, 2018 Share Posted January 28, 2018 6 hours ago, SaturnianBlue said: Instead of the classic approach to space-based solar power, which uses a solar array to generate electricity and transmit it down to Earth for collection, would it be better to have a solar mirror that reflects the light down to Earth for collection? From a practical point of view, maybe. From the point of view of not needlessly killing anything that strays into the path of the beam, definitely not. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted January 28, 2018 Share Posted January 28, 2018 (edited) (And that's why KSPI-E mod contains a plenty of parts for the microwave network, to transmit the energy from the orbital collector to a random (including planes, ships or rovers) receiver. Keep in mind that different purposes require (as in real world) different wave lengths. So you put a primary collector near the Sun, transmit energy to the distributing receiver/transmitter at one wave length. Then send this energy to the clients with different emitters depending on distance, atmosphere, etc, at other wave lengths) Edited January 28, 2018 by kerbiloid Quote Link to comment Share on other sites More sharing options...
Racescort666 Posted January 28, 2018 Share Posted January 28, 2018 On 1/27/2018 at 6:15 PM, NSEP said: Say we had a Hydrolox (Liquid Hydrogen and Liquid Oxygen) sea-launch rocket. Would it be more cost-effective to develop an ISRU system for the launch ship to gather its fuel from the nearby waters or would it be better to just carry some pre-made Hydrogen and Oxygen? Is this a Sea Dragon type of rocket? Because the other thing you’d have to worry about is seawater freezing to your rocket. Quote Link to comment Share on other sites More sharing options...
NSEP Posted January 30, 2018 Share Posted January 30, 2018 On 29/01/2018 at 12:44 AM, Racescort666 said: Is this a Sea Dragon type of rocket? Because the other thing you’d have to worry about is seawater freezing to your rocket. Yeah, hopefully that would just shake of when it launches and if not, it might need to have some kind of shroud, that catches all the ice during fueling and when it the launches detaches from the rocket so there is no ice to worry about during launch. Is there a way to stop Liquid Hydrogen/Oxygen from boiling off and out of the tanks? Are the holes in Graphene small enough to stop it from happending? Quote Link to comment Share on other sites More sharing options...
p1t1o Posted January 30, 2018 Share Posted January 30, 2018 (edited) 1 hour ago, NSEP said: Is there a way to stop Liquid Hydrogen/Oxygen from boiling off and out of the tanks? Yes, but it requires storing it under pressure, or actively refrigerated down to its liquefaction temp, both of which cost way too much mass. **edit** For the record, the Sea Dragon design used kerosene and LOx in its 1st stage (ie: the stage most in contact with seawater) so there is going to be far less ice than you'd think. You dont need as much volume of LOx as fuel (especially when its LH2), and LOx is much less cold than LH2. This is a good thing, because I dont think a massive tank of LH2 is going to take kindly to being immersed in water that is 250K hotter than it. **edit2** Actually scratch that, from the material on project rho, the whole thing is fuelled horizontally in the water, so the whole thing about LOx and kerosene and water is moot. Dang thing is crazy. Maybe its just supposed to have really good insulation I dunno... Edited January 30, 2018 by p1t1o avoid double-post Quote Link to comment Share on other sites More sharing options...
Aghanim Posted February 1, 2018 Share Posted February 1, 2018 What happens if a hardware divider attempts to divide a number with zero? In calculators they usually errors with divide by zero error, but what happens if we remove that divide by zero check? Quote Link to comment Share on other sites More sharing options...
Green Baron Posted February 1, 2018 Share Posted February 1, 2018 (edited) That depends on what is divided, the representation of the number, and the algorithm. For integers: if it does multiple subtractions then nothing happens. If it does shift operations (division by 2) then nothing happens. For floating point one could multiply by the reciprocal of the denominator, which would result to 0. There are other approaches for fast algorithms, but in the end it boils down to if the compiler or assembler or interpreter or runtime environment or whoever is responsible doesn't spit out an error weird things will happen. But i am not a specialist :-) Edited February 1, 2018 by Green Baron Quote Link to comment Share on other sites More sharing options...
Human Person Posted February 2, 2018 Share Posted February 2, 2018 What‘s the name of our sun? Quote Link to comment Share on other sites More sharing options...
Green Baron Posted February 2, 2018 Share Posted February 2, 2018 Depends on the language. Sol (Latin), sol, sole, sun, Sonne, soleil, ... It doesn't belong to a constellation so no alpha/beta/gamma constellationis. Is it listed in one of the numerous star catalogues ? Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted February 2, 2018 Share Posted February 2, 2018 3 hours ago, Physics Student said: What‘s the name of our sun? Depends on who are "you". Sirius? Fomalhaut? HD 135344B? Quote Link to comment Share on other sites More sharing options...
p1t1o Posted February 2, 2018 Share Posted February 2, 2018 Nobody walks around in London asking "What is the name of our city?" Sure mate, "our". VERY suspicious.... Oh and "Physics Student" what an ingenious cover...was "Human Person" taken? Quote Link to comment Share on other sites More sharing options...
MaxwellsDemon Posted February 2, 2018 Share Posted February 2, 2018 On 1/27/2018 at 9:58 PM, SaturnianBlue said: Instead of the classic approach to space-based solar power, which uses a solar array to generate electricity and transmit it down to Earth for collection, would it be better to have a solar mirror that reflects the light down to Earth for collection? I wouldn't think so... my guess is that you'd be reflecting down unwanted wavelengths like ultraviolet which are a good thing for power but not so good on the skin. Quote Link to comment Share on other sites More sharing options...
Human Person Posted February 3, 2018 Share Posted February 3, 2018 9 hours ago, p1t1o said: Oh and "Physics Student" what an ingenious cover...was "Human Person" taken? Guess what Quote Link to comment Share on other sites More sharing options...
Mrcarrot Posted February 3, 2018 Share Posted February 3, 2018 1 hour ago, „Human Person“ said: Guess what Hmmm... you have German-style quotation marks in your username... Quote Link to comment Share on other sites More sharing options...
p1t1o Posted February 3, 2018 Share Posted February 3, 2018 19 hours ago, Human Person said: Guess what Im on to you, I saTHIS HUMAN CONSIDERS YOUR NEW USERNAME TO BE A VERY NORMAL CHOICE Quote Link to comment Share on other sites More sharing options...
0111narwhalz Posted February 3, 2018 Share Posted February 3, 2018 Are there solutions (in a simple system of one planet and two minutely small satellites) in which two orbits with the same semimajor axis intersect at exactly one point with a significant relative velocity? Quote Link to comment Share on other sites More sharing options...
Green Baron Posted February 4, 2018 Share Posted February 4, 2018 Different inclinations ? Quote Link to comment Share on other sites More sharing options...
Aghanim Posted February 5, 2018 Share Posted February 5, 2018 I found this when I was browsing Alibaba: https://www.alibaba.com/product-detail/DragonPower-induction-tankless-water-heater_60700064987.html?spm=a2700.7724838.2017115.136.3d264856I15qnw For some reason the seller description fonts render as some sort of wingdings on my Linux Firefox, but the question is that in what use case does induction heated tankless water heater makes sense? I cannot think about any advantage of this compared to resistive heating Quote Link to comment Share on other sites More sharing options...
magnemoe Posted February 5, 2018 Share Posted February 5, 2018 5 hours ago, Aghanim said: I found this when I was browsing Alibaba: https://www.alibaba.com/product-detail/DragonPower-induction-tankless-water-heater_60700064987.html?spm=a2700.7724838.2017115.136.3d264856I15qnw For some reason the seller description fonts render as some sort of wingdings on my Linux Firefox, but the question is that in what use case does induction heated tankless water heater makes sense? I cannot think about any advantage of this compared to resistive heating induction heat the metal pipe directly so you don't need to open it. Yes an heating coil would work better as I see it as you heat the water rather than the pipe. Seeing how short the coil is I have issue seeing much uses, one is to keep water from freezing in pipes, this would only help with running water however. Quote Link to comment Share on other sites More sharing options...
Spaceception Posted February 5, 2018 Share Posted February 5, 2018 Hey guys, I think I need help double checking my numbers. I'm designing a ringworld (New writing project, in development ), and I'm trying to find the surface area compared to Earth. It orbits Lalande 21185 (not important, just context), at 0.15 AU, it has a 1.41 x 10^11 circumference, a 4,023,360 m width (2500 miles wide, about ~300 miles wider than the moon), and from my numbers, it has an internal surface area of 3,693,284,000,000,000,000 meters. When I tried seeing the land area in relation to the Earth, the numbers were huge, way more than what's probably realistic, so I dropped the '^2' on both sides, and got 95.2623x the land area of Earth, but that doesn't sound right, which is why I'm asking for the actual number, and where I messed up. Or if it is correct, and it's just a lot lower than I expected. Thanks Quote Link to comment Share on other sites More sharing options...
Green Baron Posted February 5, 2018 Share Posted February 5, 2018 (edited) Let's see (rounding): 150,000,000 km * 0.15 * 2 * PI * 4,000km width = 567,000,000,000 km² / 149,000,000 km² = 3,805.37. Your tape with radius 0,15 AU and width 4,000km has ~3,800 (threethousandeighthundred) times the surface of earth's landmass. Edit: miscalculation on first try (4pi instead of 2) :-) Edited February 5, 2018 by Green Baron Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.