If space travel has the problem that newer colony ship would overtake older colony ships, couldn't they just attach new engines to the old ships?

[Lemmingwiser]

So Ill take the devil's advocate position and posit that if you colonize other star systems with human colonists you are effectively condemning the human race to division and eventual war against itself.

Think of how tortoises on the islands of Galapagos diverged from each other after population groups get separated off for thousands of years.

Imagine how different we'll become from each other after tens or hundreds of thousands of years being lightyears away from each other? Imagine when these dispirate genetic mutations of humanity inevitably come to view themselves as different from each other even if the variations between them are ultimately surface level or trivial?

We should instead stand together, one humanity, sharing a single fate. Better that way

Human wars typically have a casualty rate of less than 5%(of entire population), while colonizing has the ability to more than double our human max capacity.

It's just cowardice. Like not having a second child because they might fight with her brother. Better to populate the worlds with friends and people invested in our well being. If some kind of dangerous entite might afflict one, perhaps the other can be saved by advance warning.

Colonizing US has been a UK advantage, even if they rebelled and they fought once.

 

[Zbk3VmLfujjzjxBd43tL]

You overestimate the strength of your spacecraft. Metal wears out. Going as fast as it needs to get to another star system means it's experiencing a absurd amount of G's. You also fail to consider it might need to make multiple burns, further increasing the wear. Also space debris goes fucking fast. A pebble might as well be a cannon shell.

You could accelerate to 10% of light speed while experiencing little to no Gs at all. Say you want to go 10% of light speed. 0.1 G of acceleration (not even 1 m/s2) will reach that speed in 354 days. At that point you'd be about 62 times the maximum distance of Pluto from the Sun. Admittedly, I've never heard of an engine that accelerates so smoothly outside of giant lasers pointed at a solar sail (which is the best way to go to another star system since it means you only need to carry fuel and giant engines to slow down).

But realistically you'd never want to do more than 1G of acceleration (and want a smooth ramping up to 1G like accelerating in a car) because that's uncomfortable for passengers, and plugging in the numbers gives a little over 35 days to reach 10% of light speed. That means to reach the nearest star at 4.24 light years away, the engine burns for 35 days at the start, 35 days at the end to slow down, and then is not used whatsoever for a little over 42 years. Maybe parts like the nozzle retract into the ship once it's done so it doesn't get damaged. Probably there'd be smaller engines for course correction around larger asteroids, since even a tiny change in course adds up over the course of days if you're going 10% of light speed.

 

[Cedric_Eff]

Let’s build either an O’Neill Cylinders or an PLANT Type Colony, or an Stanford Torus and colonize the Lagrange points!

 

[WelperHelper99]

You could accelerate to 10% of light speed while experiencing little to no Gs at all. Say you want to go 10% of light speed. 0.1 G of acceleration (not even 1 m/s2) will reach that speed in 354 days. At that point you'd be about 62 times the maximum distance of Pluto from the Sun. Admittedly, I've never heard of an engine that accelerates so smoothly outside of giant lasers pointed at a solar sail (which is the best way to go to another star system since it means you only need to carry fuel and giant engines to slow down).

But realistically you'd never want to do more than 1G of acceleration (and want a smooth ramping up to 1G like accelerating in a car) because that's uncomfortable for passengers, and plugging in the numbers gives a little over 35 days to reach 10% of light speed. That means to reach the nearest star at 4.24 light years away, the engine burns for 35 days at the start, 35 days at the end to slow down, and then is not used whatsoever for a little over 42 years. Maybe parts like the nozzle retract into the ship once it's done so it doesn't get damaged. Probably there'd be smaller engines for course correction around larger asteroids, since even a tiny change in course adds up over the course of days if you're going 10% of light speed.

Good in theory. But a lot of this is assuming things go as planned. We know precious little of what is out there. The ship might have to stop a few times and engage the main thrusters to avoid MASSIVE asteroids. Systems could fail out of the blue. Radiation from traveling between systems might fuck with the computers and METAL in unintended ways. Hell, ailen pirates could even be a factor. My point is, much like traveling the ocean, there is always a unknown risk when taking a voyage. I'd rather not retrofit a ship that has all that wear and instead build one harder better faster stronger.

 

[bango skank]

Real world space travel is so gay what with having to accelerate and decelerate and having everything operate on hair-thin margins including shit like mass and fuel I don’t think it’ll ever really happen. Unless we finally come up with infinite free energy and develop some sci-fi ftl where you just blink out of one spot and appear in another, we’re never leaving the solar system and are probably stuck with just Earth at that.

Outside of maybe resource mining operations there’s no reason to try and get people set up on uninhabitable balls of rock millions of miles away from the nearest livable biosphere.

 

[Zbk3VmLfujjzjxBd43tL]

Good in theory. But a lot of this is assuming things go as planned. We know precious little of what is out there. The ship might have to stop a few times and engage the main thrusters to avoid MASSIVE asteroids. Systems could fail out of the blue. Radiation from traveling between systems might fuck with the computers and METAL in unintended ways. Hell, ailen pirates could even be a factor. My point is, much like traveling the ocean, there is always a unknown risk when taking a voyage. I'd rather not retrofit a ship that has all that wear and instead build one harder better faster stronger.

Even today we can spot an asteroid the size of a house hours or even days before it impacts Earth. Future instruments in space without Earth's atmosphere would probably do better. At a few percent of light speed, even a marginal course correction method like firing a comparatively weak thruster would be enough to move out of the way.

Real world space travel is so gay what with having to accelerate and decelerate and having everything operate on hair-thin margins including shit like mass and fuel I don’t think it’ll ever really happen. Unless we finally come up with infinite free energy and develop some sci-fi ftl where you just blink out of one spot and appear in another, we’re never leaving the solar system and are probably stuck with just Earth at that.

Engineers solved a lot of these problems back in the 50s-70s. Shit like NERVA or Project Orion is the closest thing to lost technology out there, and it's incredible the engineers calculated that it would work with the primitive computers and inferior materials science they had back then compared to now. Now I think we probably could, but because it's all nuclear, it's pretty much illegal and a dying technology.

Outside of maybe resource mining operations there’s no reason to try and get people set up on uninhabitable balls of rock millions of miles away from the nearest livable biosphere.

Tourism too. There's plenty of people out there who would love to hike Olympus Mons on Mars. Over twice the height of Mt. Everest.

Other than that, the only thing that would go on in space is Wuhan lab-tier dangerous science (virology or future evil tech like grey goo or making IRL furries) and Space Epstein Island. Everyone who wants to get involved in that should be launched into the Sun.

 

[cigint]

Even today we can spot an asteroid the size of a house hours or even days before it impacts Earth. Future instruments in space without Earth's atmosphere would probably do better. At a few percent of light speed, even a marginal course correction method like firing a comparatively weak thruster would be enough to move out of the way.

It's the small asteroids at insane velocities that put the craft at real risk. But in any case, the way you worded that last sentence sounds like it's implying a high velocity makes it easier to dodge objects with a weak thruster, but it's the opposite. A high initial velocity makes an equivalent thruster, even if it is thrusting exactly perpendicular to your travel vector (= best turning), turn your travel vector less than if you had a lower initial velocity.

 

[WelperHelper99]

Even today we can spot an asteroid the size of a house hours or even days before it impacts Earth. Future instruments in space without Earth's atmosphere would probably do better. At a few percent of light speed, even a marginal course correction method like firing a comparatively weak thruster would be enough to move out of the way.

Possible. Doesn't change you MIGHT need to fire the main thrusters at some point due to human error. The Titanic didn't sink because people were aware after all.

And what about defensive systems? In some cases it might be better to blow up a asteroid than avoid it with something like a CWIS like this Myriad here:

While I'm sure you'll have lasers and missiles, nothing beats a gun in a lot of cases. The side effect being recoil and thus vibration on the frame. Missiles would do the same thing, which you would want, especially if you bumped into some aliens looking to steal your lunch. Point is a lot of things can put wear on the metal frame.

 

[HorseInTheWindow]

It's not easy to change direction in space because of how rockets work, so there's a very limited section of space where the ship could be. If they fired their own engines for even a second when pointed toward Earth, they would be even easier to see since any rocket big and powerful enough to travel to the stars could be seen from an insane distance away.

You are not in sea, you are in space. For easy comparsion let's take volume of space in radius from Earth to the Moon. Spaceship with volume of 2.378km³ placed in this volume would be the same as ant in London and we are talking about closest celestial object, others are much farther even in Solar System. It means you just can't point out in correct direction error even in 10⁻⁹ of degree gives you such great error on this distance that you won't be even close to the object.
As to possibility to see a spaceship, first of all the engine exhaust barely visible without an atmosphere, second of it is too small object to see on such distance. We can't properly see Pluto as a whole via Hubble, only blur image of a planet.

Or you know, just use a laser signal to beg Earth to send you a bigger rocket.

Do you remember that no signal can be faster than speed of light? Even we ignore the problem with accurately pointing out signals for messaging it will require decades of years to communicate. And with that you have another problem - technology gap. Technological advance don't stand still, imagine, for example, that you send info about modern engines to 20s. They wouldn't have needed materials, machinery or industry to built them.