Your ideal Interstellar vehicle/system (no FTL)

[Duxwing]

A magsail beamrider infrastructure created by pioneering robots riding one-way antimatter rockets seems best. The antimatter rockets would comprise a massive charge before each payload, which would bear some NERVAs for orbital maneuvering. An orbital mass driver would magnetically accelerate the payload-charge complex and fire it towards the target, where the charge would fire to decelerate the craft.

-Duxwing

[Tommygun]

If we are talking a century or two from now, then I would go with a Fission-fragment rocket on a small DNA seeder ship.

The craft could be controlled through an artificial intelligence and self replicating machines.

Make the ships small and keep the cost down, but make as many as you can afford. Then send them anywhere that looks promising.

After it arrives the machines start mining and build more of themselves and then a colony.

After that they can use technology like DNA printers and 3D bio printers to produces human colonist and raise the first generation.

[Duxwing]

A magsail beamrider infrastructure created by pioneering robots riding one-way antimatter rockets seems best. The antimatter rockets would comprise a massive charge before each payload, which would bear some NERVAs for orbital maneuvering. An orbital mass driver would magnetically accelerate the payload-charge complex and fire it towards the target, where the charge would fire to decelerate the craft.

-Duxwing

[KASASpace]

It's faster than light in relation to whatever point of refference you choose to pick outside of the warp bubble.

But light speed is always the same, no matter what relative velocity or position. So, therefore, it actually isn't going faster than light at all. In fact, it's effectively staying still.

[SargeRho]

It's moving slower than light whithin its own frame of refference, aka inside the warp bubble.

But the bubble is moving faster than c, and you will get to your destination faster than light will. It is thus faster than light propulsion.

[jfull]

After that they can use technology like DNA printers and 3D bio printers to produces human colonist and raise the first generation.

Wouldn't it be more feasible to use artificial wombs to produce genetically engineered colonists that mature and learn at an accelerated rate? I just can't imagine it would be feasible to print a human being.

[KASASpace]

It's moving slower than light whithin its own frame of refference, aka inside the warp bubble.

But the bubble is moving faster than c, and you will get to your destination faster than light will. It is thus faster than light propulsion.

It isn't propulsion though. It's literally WARPING space and time to conform to you.

[cantab]

Can it get you from A to B faster than a pulse of light sent from A to B without the effects of your widget?

If yes, it's FTL travel. Simple as.

[KASASpace]

Can it get you from A to B faster than a pulse of light sent from A to B without the effects of your widget?

If yes, it's FTL travel. Simple as.

It's "FTL" when compared like that, yes.

But are any relativistic effects present?

NO?

Than it is no where near FTL, near c for that matter.

[Rakaydos]

"Faster than light" in no way implies relativity.

The classic fictional FTL drive, the "jump" drive, ignores relativity by reaching the destination directly, through setting-specific technobable. (a subset is the "hyperspace" drive, where the jump takes time, during which you are someplace outside our reality.)

[Tommygun]

Wouldn't it be more feasible to use artificial wombs to produce genetically engineered colonists that mature and learn at an accelerated rate? I just can't imagine it would be feasible to print a human being.

I'm not sure anymore. A few years ago a doctor created a working crude heart in part with a 3D bio printer.

Can you imagine describing a heart transplant to a doctor from two hundred years ago.

One to two hundred years from now, I can see it as possible. If nothing else, they could still print fertilized eggs for the artificial womb.

Some will have religious or philosophical issue with this approach, but this happened with the first organ transplants and other medical advancements.

If we still have slower than light travel at that time, I think this may be the only cost effective way of mass interstellar travel.

You don't even need to bring any organic materials on the ship. Just mine for raw materials locally, process them and then print on demand.

[jfull]

I'm not sure anymore. A few years ago a doctor created a working crude heart in part with a 3D bio printer.

Can you imagine describing a heart transplant to a doctor from two hundred years ago.

One to two hundred years from now, I can see it as possible. If nothing else, they could still print fertilized eggs for the artificial womb.

Some will have religious or philosophical issue with this approach, but this happened with the first organ transplants and other medical advancements.

If we still have slower than light travel at that time, I think this may be the only cost effective way of mass interstellar travel.

You don't even need to bring any organic materials on the ship. Just mine for raw materials locally, process them and then print on demand.

Current methods of organ printing require quite a bit of human cells to start with, which are then placed into a lattice.

In theory you could still print a person, but a printed organ may not be as efficient or as strong as a grown one. Plus, just arranging the proper cells in the right places is not enough. A fetus's brain forms connections as it grows and this results in a properly functioning brain.

I guess I'm just questioning the reason for the printing when the normal development of a fetus produces a perfect set of organs 99% of the time (thats actually pretty amazing if you think about it.)

[jfull]

Also, for the record, I considered Alcubierre/Warp Drive as an FTL technology when I started this thread.

In fact, it was the main thing I was trying to rule out by adding the "no FTL" condition.

Some people might have problems with this, but I think of it this way:

If an Alcubierre Drive is feasible, thats great and it will almost certainly be the method we use to travel to other stars. However, I have some doubts about whether it will ever be possible (The need for negative mass concerns me the most), so we may need to get very creative in our interstellar endeavors. This thread exists to discuss interstellar systems that use slower-than-light technologies.

[FREEFALL1984]

Hopefully at this point in humanities future we could invent a way to produce a material which could essentially block a gravitational field. That way a ship could be designed which could focus on a single gravitational field with the exclusion of all others. using that method we could "focus" the ship on key bodies on route to the destination and simply "fall" there without the need for any engines. Also the scale of the vessel would be unimportant because we could in theory launch anything without engines by simply "focusing" on a moon or passing planet. Of course the speed of acceleration would initially be very low but it would constant and increasing based on proximity and size of target body, the tough part of course would be stopping, since the vessel would still be effected by inertia, although in theory since the vessel could essentially use gravity assisted breaking using any object within line of sight, it wouldn't be too tough

[Acemcbean]

I always like to simplify things like this. If a rocket is simply a bomb with a nozzle at the end, then theoretically we could launch a rocket using a nuclear bomb. Slightly less of a controlled explosion, slightly way off topic, slightly the Kerbal way to do it. Perfect.

And as a side note, Antimatter rockets are phenomenal! (Just had to stay somewhat on topic...)

[architeuthis]

Say at some point we launch a seedship towards Tau Ceti which accelerates up to .1 c in a brachistochrone trajectory. It will take roughly 240 years (in Earth's reference frame) to get there. Then say 25 years after the seedship launches a technological breakthrough allows us build ships capable of accelerating up to .5 c. A seedship launched with the new technology now takes only 50 years or so to get to Tau Ceti so it will pass the older ship enroute and by the time the original seedship arrives it will find a 165 year old colony instead of the virgin territory they were expecting. This example has many simplifying assumptions but you get the idea: this is the basic problem with generation ships, and it only gets more and more extreme the farther away the destination is. Now if we are using a sufficiently powerful drive system, even if warp drive is miraculously invented, the people who leave early might only be a few decades rather than a few centuries late to the party.

What's my point? It is not likely that anyone is ever going invest the resources to build interstellar generation ships. Fission fragment, Orion, or even proton-proton fusion interstellar rockets would need totally absurd mass ratios to reach and decelerate from relativistic velocities, therefore they are effectively generation ships. And if you're fine with generation ships, why not just go with oort cloud osmosis and save having to strip mine the whole solar system to build one single phobos sized rocket that can still only manage a 100 ton payload?

The long and short is that Tsiolkovsky's rocket equation says there are only two ways to increase delta-v: increase your mass ratio, or increase your exhaust velocity. Untill we master the subtle art of building super star destroyers the latter option is where we have the most room to improve. Based on what we know now the magic eight ball of the future seems to be pointing towards "beam core antimatter or go home" ...(or don't bother with rockets).

Edited April 17, 2014 by architeuthis

[sp1989]

I think there is an incredible irony and potential with solar sails. We explored our world with sails it would be incredible and ironic if we can begin our exploration of the solar system and beyond with a sails. However due to the the low speed, we would need to perfect suspended animation or make it a generation ship. Still i think the concept is fascinating

[-Velocity-]

I think the solution for affordable interstellar travel and the settling of extrasolar systems is not to send humans at all. Send intelligent machines. Machines could probably be fine with 0.02 c or something similar, which should be "easily" achievable. If you really want Earth life at your destination, then grow the first generation of humans and any other desired critters in vats, once you've already reached your destination and prepped it a bit.

[KASASpace]

Wait, modern technology, or future technology?

Or most ideal in general?

[jfull]

Wait, modern technology, or future technology?

Or most ideal in general?

Any technologies that have solid theories behind them today.

Obviously not necessarily technologies that have been built yet though

[KASASpace]

Any technologies that have solid theories behind them today.

Obviously not necessarily technologies that have been built yet though

Okay then.

Let's look at antimatter:

Pros:

A lot of bang for the buck

Can get great thrust

Cons:

Hard to handle

Probably the most dangerous fuel there is

Needs an equal amount of matter to annihilate with

Takes ridiculous amounts of energy to create

But, it might exist over Saturn (and there's even some over Earth)

[Rakaydos]

Any technologies that have solid theories behind them today.

Obviously not necessarily technologies that have been built yet though

Ooh, does that mean generating complex vectors is allowed? :3

It is assumed for the purposes of relativity that your vector can be represented by a Real Number that is some fraction of the speed of light.

However, if it was possible (somehow) to generate a vector with an Imaginary component (that is, accelerating perpendicular to the speed of light), the math shows that the lightspeed singularity is only a infintismal point, blocking the Real numbers. The closer you get to this point, the more relativistic effects you get, but because you pass through "C+2i" or whatever instead of "C", your mass never goes infinite and you can keep accelerating past it.

[Chris P. Bacon]

I always like to simplify things like this. If a rocket is simply a bomb with a nozzle at the end, then theoretically we could launch a rocket using a nuclear bomb. Slightly less of a controlled explosion, slightly way off topic, slightly the Kerbal way to do it. Perfect.

Nuclear bomb you say? Then you might like the 'Thunderwell' concept or 'Project Orion'.

[FreeThinker]

On 16-3-2014 at 1:37 AM, SargeRho said:

Nuclear fusion pulse propulsion (Z-Pinch or Electron Beam Confinement), coupled with magnetic sails at first. These ships are used as first-wave colony ships. At the destination, some of the ships enter a low orbit around the target star, and being constructing particle beam emitter stations, that will emit particle beams for future ships to break on. Due to the absence of such beam stations, the initial colony ships would be slower than the ships that come later.

Once the beam emitters are all up and running, future ships won't be carrying their own interstellar engines. Instead, they carry only magnetic sails and small fusion engines for in-system travel. Since they have a beam to brake on, they are also accelerated to greater speeds than the colony ships before them, reducing the travel time significantly. The magnetic sails are also used as interstellar parachutes, more so by colony ships than by the regulars that come later.

The colony ships in turn, are sleeper ships. They carry a few hundred people, and thousands of frozen embryos, and all the equipment needed to build a colony (in the first wave) and additional supplies (later on). They might even carry fusion or fission-powered SSTO space planes, instead of blunt capsule landers, that go back and forth between the ships. The much greater mass of such a plane might be justified by not needing as many landers.

Shameless self-advertisement ahead:

Further into the future, we might develop antimatter engines and, more importantly, a way to produce antimatter in sufficient quantities. That would open up high relativistic speeds (In exess of 50% of the speed of light).

It would be realy nice if someone could convert this model into sperate KSP models, then I could integrate them into KSPI-E

Edited February 12, 2016 by FreeThinker

[Spaceception]

A Mini-mag or Medusa NPP starship to do a flyby of Proxima Centauri/Alpha Centauri, the speed would be 10-15% Light speed with a 100 tonne payload, and would get there in ~35-45 years