Although I fully expect to be informed, here, that it’s been done before.
Anywho, I recently learned about the ‘Wait Calculation’. That’s the premise that that we should not do interstellar travel if we can’t get to our destination within 50 years because a slow spacecraft would probably be passed by another mission sent later with more advanced propulsion. By as many as hundreds or even thousands of years.
So here’s the scenario, earth foresees the end. They cobble together a spaceship and send out some brave souls to start a colony on an exoplanet in another solar system. As they plod along, 100 years later, earth gets a slight reprieve and a technological leap is made in propulsion and another group has set off.
They arrive first and set up a thriving colony. 100 years in, they become infected with a pathogen that threatens to doom the whole place. They need uninfected blood to work up a antidote. All is lost.
Until (!) they discover a ship is headed their way with untainted humans! But, are they still alive?
Anyway, that’s my idea. If I was only a writer, ha ha.
Side question, in the above scenario, would the two ships be on the same trajectory? As in, when the second ship overtakes the first one, would they be close to each other?
I think they might be close to each other - a scenario could probably be written that means they’re close to each other at some point, if that’s what the story needs. The hard part would be matching velocities - one would be going way, way faster than the other.
Not the exact same. Aiming where a star will be 50 years from now will be a different location from aiming where a star will be 500 years from now. For instance, if the target star was moving laterally 10 kps relative to the sun, that would be about a 130 billion mile diffence in endpoints.
This happened in Joe Haldeman’s The Forever War. In a war between Earth and some aliens, an Earth ship comes into contact with an enemy ship whose techology is far more advanced than demonstrated in a previous encounter. The Earthers figure out that because of relativity, even though it’s only been a few years from their perpsective, they may encounter the enemy in ships that are either far more advanced than they are or more primitive. It’s kind of a crap shoot.
You would also have to allow for possible perturbations from outside forces. All bodies are orbiting the center of the Galaxy along their own paths and at different speeds. Constant course corrections would be needed. Computing a single course a priori would be impossible. It would be an approximation at best, and probably not a good one. There are too many extraneous, random variables to consider.
Also a very similar plot in Heinlein’s ‘Time for the Stars’. Slow, sub-light ships are sent out to explore, and spend dozens of Earth-years in space only to be picked up by new FTL ships before they get to their final destination.
Larry Niven’s story “Like Banquo’s Ghost” touches on it.
A group of NASA officials, and one alien, are watching the first radio transmission from a space probe to the alien’s planet. The aliens had FTL, so the alien ambassador arrived on Earth before the probe’s radio signal.
Even if the ships do pass really, really close by each other, “really really close by”, by space standards, could still easily put them so far apart that they wouldn’t even detect each other (unless they’re trying to be detected).
This reminds me of a sci-fi comic book story I read as a kid (Weird Tales?)- humans had trashed Earth to the point it was practically unlivable, so a new Earth-like planet was located and an intrepid group of colonists determined to make a fresh start set out on the long journey, which required suspended animation, it would take so long to get there.
When they do finally get there, sure enough, not only had they had gotten leap-frogged, but the humans who beat them to it had time not only to build cities, but to trash them and pollute the new world just as badly as they had done to Earth.
Okay, how about a twist on the twist story. The Leapfroggers haven’t “trashed” the planet, they’ve just built it up into a nice, high-tech decent place to live, with good restaurants and other cultural things.
When the First Starship Folks arrive, the Leapfroggers thaw them out, since they’re nice guys that way, but there’s some trepidation; how will the FSF react to being leapfrogged?
It turns out, all that “We want to live on a virgin paradise!” stuff was just PR for the rubes. In reality, they all wanted to be on the first ship, in anticipation of someone else beating them there, and doing all that messy “pioneer dying in the wilderness” thing.
Except the language on the new planet had morphed to to point where the FSF couldn’t speak or understand it and so were outcasts and banished to the undeveloped side of the planet. They had to do messy “pioneer dying in the wilderness” thing, anyway.
I was thinking of a different backlash. “My great-grandfather didn’t die of Space Dysentery just so you lazy slobs could order sashimi and Chablis at 11PM!”
I think your outline is fine. You should write it.
Since there is no gravity or aeronautical drag in space, you might be able to keep accelerating quite easily, but you would need so much fuel the rocket could not lift off from earth.
Or, use an elliptical curve around a moon or planet to slingshot and get your speed up. But whatever you did, the speed of light should be the limit for mass to travel.
One of the things I wonder about is, since space does have objects in it, asteroids, satellites and such, if you are going super fast and encounter something like that, wouldn’t that be doomsday for the people and the craft? It seems to me that the further you travel, the higher the likelihood of running into something. Wouldn’t take much to take you out. At tens of thousands of miles an hour, a marble might do it. Look what a tiny pebble does to a car windshield on the highway at 65 mph.
Allen Steel’s “Coyote” series kind of does that, without the “Earth is doomed” aspect. A ship leave Earth, launched by the URA, (United Republic of America) a decidedly fascistic successor state to the USA. It is only on it’s destination planet for a few years when a faster ship, launched much later arrives. The ship is under control of the “Social Collectivists” (think Communism 2.0). These folks can’t win.