/sci/ - Science & Math

>>12073355
fuel have mass and you need more fuel to send more mass into space

>>12073355
They use the absolute minimum amount of fuel possible to reach the destination, not what makes the journey fastest. That's why it's going to take several years for that one probe to fall closer to the sun, since it's using a bunch of gravity assists instead of using a bunch of fuel.

Blaa blaa delta V blaa blaa rocket equation

Most of the mass of a rocket is fuel, like 90%. The more you add, the more the rocket weighs, and more powerful engines are needed.

Brainlet here, saving you a thread so I ask here:

What if you make a giant rocket ship that holds ridiculous amount of fuel and you send it to fly out in space where it constantly accelerates more and more- will it reach near light-speed if it doesnt crash in anything? Why/why not?

>>12073772
yes. space is frictionless
ship may slow down or speeds up based on the gravitional pull of nearby celestial bodies though

>>12073355
Even without the friction, you still need energy to accelerate up to speed. Using hydrogen/liquid oxygen rockets, you would need an absurd amount of fuel - see picture related - to get even a 5 ton capsule up to 1 million miles per hour. Getting up to the ~3,500 mph speed need to reach the Moon in 3 days requires vastly less few, just a few tons for a 5 tons capsule.

>>12074035
is there a way to overcome this? space travel cant be slow as molasses forever.
Mars is 79 million miles away and the best we can do right now is get there in 9 months.

>>12074053
>is there a way to overcome this?
Find a more efficient way of turning fuel into acceleration, which is an engineering problem more then a physics problem. And don't forget you have to decelerate before you get to Mars.

>>12074053
Within the bounds of known physics, there are various flavors of nuclear rockets, both fission & fusion, that would be able to get you going much faster than chemical rockets, though they have their own limitations. Using big-ass solar panels near the sun to power big lasers to push solar sails is another option. There has also been some stuff with using superconducting loops to magnetize the sparse gases in space into a giant plasma sail that would be pushed by the solar wind, that has been being discussed lately.

>>12073355
It would take too much fuel to slow down, making it heavier, meaning it would take more fuel to speed up also.

>>12074053
muh ion drive

Space isn't a vacuum, fuck these posers.

Excitation of atomic energy via radio frequency may allow for unobstructed propulsion of aerial vehicles. This allows for revelation of opposing or attractive interpretive bullshit.

This is why we don't into science because it can't be done without dying for it.

The question remains; why didn't we all get along?

>>12074215
>why didn't we all get along?
what

>>12074215
based schizoposter

>>12073355
Idk

>>12074053
>is there a way to overcome this?
No
>space travel cant be slow as molasses forever
Why not?

>>12075146
are you saying the speed of light is half a billion miles an hour and we cant even build a spaceship capable of going a thousandth of that?

>>12075154
Yea pretty much

>>12074035
so basically we need to crank up that exhaust velocity. I wonder how fast you could eject mass with a solar powered railgun.

>>12073355
Play KSP and you'll have your answer

>>12075154
I mean is there a law that states that human progress always goes up? Just because things have gone well so far doesn't mean they'll always be like that

>>12074053
This.
Travel outside the solar system will never be worthwhile unless we find out how to go faster than light.
>>12075146
>Why not?
Because the rest of the universe may as well be in another dimension if we're stuck going so slow.

>>12075932
>the rest of the universe may as well be in another dimension if we're stuck going so slow
The practical scale we operate in is very small so in a way it basically is.

>>12073355
yeah why can't they go like eleventy GAZILLION miles an hour!!!

>>12074053
Take the nuclear rocket pill anon

>>12076025
ion drive?

>>12073355
acceleration takes a lot of energy

>>12076022
1 million mph is 1/600th the speed of light
people complain why cant we travel at the speed of light yet we cant even travel 1/100th that.

>>12078086
I don't care about space travel. This is humanity's purgatory, this is where it needs to be.

>>12075932
And if you go fast Earth might be ruled by dolphins by the time you get back from your trip. So why does it matter if your slow ship takes 5000 years to arrive somewhere? You'll have to plan millennia ahead anyway.

>>12078294
Yeah, that's why you need to find a way to go fast without fucking up time.

>>12073355
Also, space does have a little friction, which gets more relevant when you're going very fast. The worst part though is colliding with small particles at super high speeds.
Still, when talking about reaching these speeds the current main obstacle is getting fuel into orbit. Also, >>12074053
You can cheat this a little by doing gravitational assists I guess. Not sure by how much, but it's our current way of giving speed to things when we need to (as far as I understand).

>>12075102
thanks for the free games mate

>>12074035
and the real problem is that you also need fuel to slow down

>>12073355
we can't throw rockets hard enough yet.

>>12073355
The energy you put into your rocket drive per second is the factor of your thrust and your exhaust speed. Exhaust speed limits your final speed according to Tchaikovskys equation.

At a set amount of power (we're already putting A LOT of power into our rockets, a Falcon boosters produces more power than a giant nuclear powerplant) you can either have high thrust or high final speed, not both. You need high thrust both to leave Earth in the first place and to get to your final speed quickly. It's also really hard to get to gigawatt levels of power without chemical power sources, which are similarly limited to high thrust.

But don't listen to the retards who say we don't have the capability to reach high speeds. We do. You just need nuclear propulsion. Either pulsed or thermal, or a mix of both.

Why dont we have an explorer ship that uses solar and is designed to keep going faster and just do whatever it wants

>>12073355
They can, we just don't know how yet.

>>12080292
we do know, you room temp iq monkey
the reason we don't is because its fucking expensive

>>12075154
we may not find a way to move faster.
But we may find a way to bend space and get to places faster.
(although that would be extremely sci-fi)

>>12078105
Maybe for a dumbfuck like you, not for the rest of us, we will find a way

what if...

we attached all the planets...

by rails...

>>12080521
I will stop you.

>>12076002
the Milky Way may as well be a universe within a universe within a universe

>>12081808

>>12079009
>The worst part though is colliding with small particles at super high speeds.
Shields up

>>12079009
>The worst part though is colliding with small particles at super high speeds.
pic rel. the transverse speed of the particles probably doesn't matter at the speed the ship is going. flip side of that is dodging large debris would be a really high g maneuver.
frying it with a laser or something might be an option but Idk how you'd detect it fast enough considering the speed at which you're going.

>>12080236
Okay why don't we try to add speed before the ship leaves ground? Why can't we set up a rail gun on the side of the mountain? If we can get something going at least a few hundred mph before liftoff wouldn't that be a significant difference in weight of fuel needed? Even after it leaves ground, there could be some way to add more force. What if we had an ion thruster that used atmospheric gas and was powered by a laser or even a really long electric cable lol. It sounds stupid but if the craft is able to be just a few tons because it needs less fuel, a cable that stays with the craft for the first couple miles could work

>>12081928
space sails are kino

Anyone know about Bessel beams here? Its a method to stop lasers from dispersing at range, would be great for propulsion.

>>12073772
Yes but also consider you need even more fuel to slow down

>>12081813
Why couldn't I be born later? 21st century fucking sucks I'd rather be a medieval peasant than be aware of the universe I will never see

>>12084035
enjoy dying of flu when 20yo

>>12084035
21st century is better than you think

>>12074053
ion drives, project orion

im an absolute brainlet, once the fuel has burnt out - will the spaceship coast at that speed or continue to accelerate?

>>12087223
use your brain nigga

>>12073772

>>12080521
Optimistic cope.
There is no garuantee that a way exist's and if it doesnt, you will never find it regardless of how much you look.
The fact of the matter is, a way most likely does not exist, which is why we do not observe any galactic space civilizations in the universe.

>>12074053
>>12075218
>muh super advanced ufo spacecraft
[math]\frac{1}{2}\, (0.229 \, \text{ton})\, (10\, \text{Mm/s})^2 \approx 10^{16}\, \text{J}[/math]

>>12081825
what game?

>>12088202
ksp

>>12073355
look up electric pulse

>>12088202
Space Engine editor http://spaceengine.org/shipeditor/