Duski Posted July 19, 2016 Share Posted July 19, 2016 Got a question guys. I'm sure most of you know the Dragon 1 that is used to deliver cargo to the ISS right? Well, what stage does it use to rendezvous with the ISS? I can only see the tiny Draco engines use to control attitude and the pod with the trunk. So does it use the Draco engines or another stage? Quote Link to comment Share on other sites More sharing options...
PB666 Posted July 19, 2016 Share Posted July 19, 2016 (edited) 5 hours ago, Duski said: Got a question guys. I'm sure most of you know the Dragon 1 that is used to deliver cargo to the ISS right? Well, what stage does it use to rendezvous with the ISS? I can only see the tiny Draco engines use to control attitude and the pod with the trunk. So does it use the Draco engines or another stage? Its grappled by the iss and attached. All it has to do is position the grapple point a certaian distance from the ISS and off the grapple and ISS crew do the rest. 1. F9 1st stage 2. F9 2nd stage 3. Dragon stage 4. Payload Note if the payload is an earth return it need to stay attached until,released so that it can de orbit the reentry vehicle. If the payload is to remain attached the dragon releases and deorbits itself. Edited July 19, 2016 by PB666 Quote Link to comment Share on other sites More sharing options...
Duski Posted July 19, 2016 Share Posted July 19, 2016 14 minutes ago, PB666 said: Its grappled by the iss and attached. All it has to do is position the grapple point a certaian distance from the ISS and off the grapple and ISS crew do the rest. 1. F9 1st stage 2. F9 2nd stage 3. Dragon stage 4. Payload Note if the payload is an earth return it need to stay attached until,released so that it can de orbit the reentry vehicle. If the payload is to remain attached the dragon releases and deorbits itself. So does the F9 2nd stage do all the rendezvous burns? If so, doesn't dragon get deployed and waits to get approach with the ISS and get grappled aboard? Oh yea last thing, do they take the dragon trunk with all the supplies or do they just unload them? Quote Link to comment Share on other sites More sharing options...
Kryten Posted July 19, 2016 Share Posted July 19, 2016 Dragon separates from the second stage immediately after orbit insertion, and the stage then deorbits itself; rendezvous is with the dracos; you don't need big engines for orbital maneuvering. I'm not sure what you mean with your second question, could you rephrase it? Quote Link to comment Share on other sites More sharing options...
Duski Posted July 19, 2016 Share Posted July 19, 2016 54 minutes ago, Kryten said: Dragon separates from the second stage immediately after orbit insertion, and the stage then deorbits itself; rendezvous is with the dracos; you don't need big engines for orbital maneuvering. I'm not sure what you mean with your second question, could you rephrase it? Oh, I thought the F9 second stage did all the rendezvous burns and Dragon is deployed then grappled on board basically. But gee, using those tiny draco engines? Well looks like i'm going to have a lot of patience for the Dragon i'm using Quote Link to comment Share on other sites More sharing options...
shynung Posted July 20, 2016 Share Posted July 20, 2016 8 hours ago, Duski said: Oh, I thought the F9 second stage did all the rendezvous burns and Dragon is deployed then grappled on board basically. But gee, using those tiny draco engines? Well looks like i'm going to have a lot of patience for the Dragon i'm using To be fair, TWR isn't much of an issue once orbit is achieved. As long as there's enough propellant, even using RCS thrusters to do the maneuver burns are feasible. Quote Link to comment Share on other sites More sharing options...
Duski Posted July 20, 2016 Share Posted July 20, 2016 37 minutes ago, shynung said: To be fair, TWR isn't much of an issue once orbit is achieved. As long as there's enough propellant, even using RCS thrusters to do the maneuver burns are feasible. Yea had a go with de-orbiting with them and took a bit. Quote Link to comment Share on other sites More sharing options...
shynung Posted July 24, 2016 Share Posted July 24, 2016 (edited) Is building a fusion-powered rocket possible using late 1970s-early 1980s technology? I'm thinking of an alternate timeline where the US/USSR space race didn't end at the moon, but goes all the way to Saturn. Edited July 25, 2016 by shynung double space Quote Link to comment Share on other sites More sharing options...
K^2 Posted July 24, 2016 Share Posted July 24, 2016 3 hours ago, shynung said: Is building a fusion-powered rocket possible using late 1970s-early 1980s technology? I'm thinking of an alternate timeline where the US/USSR space race didn't end at the moon, but goes all the way to Saturn. Nuclear Pulse Propulsion, sure. See Project Orion. Economic feasibility is a separate issue, but basic tech was there. If you are looking for something more elegant, we don't have the tech even now. Quote Link to comment Share on other sites More sharing options...
PB666 Posted July 24, 2016 Share Posted July 24, 2016 7 hours ago, shynung said: Is building a fusion-powered rocket possible using late 1970s-early 1980s technology? I'm thinking of an alternate timeline where the US/USSR space race didn't end at the moon, but goes all the way to Saturn. I thought we already went to saturn,mthinking cassini. Problem is not thevdrive system, its the survival systems for manned flight. Quote Link to comment Share on other sites More sharing options...
shynung Posted July 24, 2016 Share Posted July 24, 2016 7 minutes ago, PB666 said: I thought we already went to saturn,mthinking cassini. Problem is not thevdrive system, its the survival systems for manned flight. I meant manned missions. The boots-and-flags kind. Quote Link to comment Share on other sites More sharing options...
peadar1987 Posted July 24, 2016 Share Posted July 24, 2016 37 minutes ago, shynung said: I meant manned missions. The boots-and-flags kind. We could probably launch a boot and a flag into Saturn without too many problems. It's quite a small payload compared to others we've sent to the outer solar system Quote Link to comment Share on other sites More sharing options...
PB666 Posted July 24, 2016 Share Posted July 24, 2016 5 hours ago, peadar1987 said: We could probably launch a boot and a flag into Saturn without too many problems. It's quite a small payload compared to others we've sent to the outer solar system Saturn, no boots on ground ever, no flag planted, ever. Its a gas giant Quote Link to comment Share on other sites More sharing options...
peadar1987 Posted July 25, 2016 Share Posted July 25, 2016 7 hours ago, PB666 said: Saturn, no boots on ground ever, no flag planted, ever. Its a gas giant Boots on the ground? That is old news. Boots exploding at hypersonic speeds in the upper atmosphere of a gas giant? That is something worth doing. Quote Link to comment Share on other sites More sharing options...
PB666 Posted July 25, 2016 Share Posted July 25, 2016 12 hours ago, peadar1987 said: Boots on the ground? That is old news. Boots exploding at hypersonic speeds in the upper atmosphere of a gas giant? That is something worth doing. Who were you planning on hypersonically disentegrating? Quote Link to comment Share on other sites More sharing options...
RainDreamer Posted July 25, 2016 Share Posted July 25, 2016 Assuming literal boots there, and not a person in those boots. Question. If you got a huge space farm going with a lot of cows, is it feasible to use bio gas they generate to generate power? In other words, can space farms run on cow farts? Quote Link to comment Share on other sites More sharing options...
Kryten Posted July 25, 2016 Share Posted July 25, 2016 Cows don't break conservation of energy, so no if there's no external power source. If you're using the sun to grow the plants, then that's just a convoluted solar power system and photovoltaics would be better. If you specifically need methane, then there are bioreactors that can convert biomass to methane more efficiently than cows, while being less fussy about the feedstock. But bioreactors don't break conservation of mass either, so hard to see why you wouldn't just ship in methane instead of fertiliser/water/oxygen et.c. for farming. Quote Link to comment Share on other sites More sharing options...
TheDestroyer111 Posted July 25, 2016 Share Posted July 25, 2016 (edited) My question is something like this. Imagine a situation: You have object A, which is standing still and has a mass of two kilograms. Now, object B has a mass of one kilogram and moves at a speed of 2 m/s. Now, B collides into A in such a way that B comes to a standstill while A absorbs B's movement. According to conservation of momentum, A should gain a speed of 1 m/s. With E=(mv2)/2 then before the collision, A has zero kinetic energy while B has 2 joules of energy. After the collision, B has 0 joules and A has 1 joule. The question is pretty obvious. Where the actual kraken did the second joule of energy go? We have the universal law of physics that no energy can be created or destroyed! Edited July 25, 2016 by TheDestroyer111 Quote Link to comment Share on other sites More sharing options...
PB666 Posted July 25, 2016 Share Posted July 25, 2016 A only absorbs part of Bs motion, since A weighs more than B, A accelerates but B reflects off of A. Quote Link to comment Share on other sites More sharing options...
TheDestroyer111 Posted July 26, 2016 Share Posted July 26, 2016 (edited) 10 hours ago, PB666 said: A only absorbs part of Bs motion, since A weighs more than B, A accelerates but B reflects off of A. Hmm... You mean, energy is always conserved here together with momentum by making things reflect off each other to certain speeds? Let's do a little calculation... no this is too complex even with simple numbers. Maybe I'll try, but not here and now. Edited July 26, 2016 by TheDestroyer111 Quote Link to comment Share on other sites More sharing options...
Kryten Posted July 26, 2016 Share Posted July 26, 2016 You can only have collisions where object A comes to a complete stop if both objects are of equal mass. Quote Link to comment Share on other sites More sharing options...
peadar1987 Posted July 26, 2016 Share Posted July 26, 2016 3 hours ago, TheDestroyer111 said: Hmm... You mean, energy is always conserved here together with momentum by making things reflect off each other to certain speeds? Let's do a little calculation... no this is too complex even with simple numbers. Maybe I'll try, but not here and now. Yeah, pretty much. Let's say two masses, A and B, collide head-on, each moving at 10 m/s. One has a mass of 10kg, the other a mass of 1kg. This lets you construct a set of simultaneous equations to solve for the velocities after the collision: (MA*VA1)+(MB*VB1)=(MA*VA2)+(MB*VB2) MA*(VA2-VA1)^2=MB*(VB2-VB1)^2 In our equation, our unknowns are VA2 and VB2. We can use the first equation to find one in terms of the other, and use the second to solve for that value. Plugging these values into Wolfram Alpha actually gives two possible values: http://www.wolframalpha.com/input/?i=90%3D(10*X)%2B(Y),+10*(X-10)^2%3D(Y-10)^2 Both these values hold mathematically, but one of them requires the lighter ball to pass through the heavier one, while transferring some degree of its energy, which doesn't actually work on a physical level For the record, both balls end up moving in the same direction, the lighter one at 19.25 m/s, the heavier at 7.70 m/s 24 minutes ago, Kryten said: You can only have collisions where object A comes to a complete stop if both objects are of equal mass. Or if the collision is not perfectly inelastic Quote Link to comment Share on other sites More sharing options...
peadar1987 Posted July 26, 2016 Share Posted July 26, 2016 20 hours ago, PB666 said: Who were you planning on hypersonically disentegrating? Boots explode perfectly well whether they are attached to a human or not. In fact, a useless human can often act as a heat sink, and delay or otherwise hinder the exploding process Quote Link to comment Share on other sites More sharing options...
RainDreamer Posted July 27, 2016 Share Posted July 27, 2016 What is the most information dense method of information streaming? As in, communicating by streaming information directly through whatever method like radio, lights and so on without relying on a information storage device like a usb. Quote Link to comment Share on other sites More sharing options...
peadar1987 Posted July 27, 2016 Share Posted July 27, 2016 7 hours ago, RainDreamer said: What is the most information dense method of information streaming? As in, communicating by streaming information directly through whatever method like radio, lights and so on without relying on a information storage device like a usb. At the moment, it's filling a vehicle with portable storage and delivering it directly: https://what-if.xkcd.com/31/ As Randall says, great bandwidth, lousy ping. If you don't want to rely on information storage, it will probably be fibre optics. 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.