New Topic: Interstellar Systems?

Brett Davidson

Brett Davidson

ACCESS: Top Secret
Joined
26 September 2006
Messages
4,442
Reaction score
12,826
I was wondering if it's worthwhile to open up a dedicated topic on interstellar travel. There are a lot of serious studies brought up here, such as Icarus, Daedalus etc., but they're scattered about and it would be useful to have a one-stop shop.

Also, poor Winchell Chung's Atomic Rockets site still exists but is no longer being updated. Meanwhile, new studies and developments have emerged. Perhaps we can fill a little of the gap.

I've avoided 'starship' to avoid confusing searches with... Jefferson Starship and another thing. Moreover, the topic includes other aspects such as relativity, the interstellar medium, necessary genetic diversity in a population, very long-term autonomy etc., not just spaceships.

Insufficiently advanced technology only. No infinite improbability drives - by which I mean warp, wormhole, and jump unless there're solid studies. No wishful thinking along the lines 'in the future we'll be able to do x, y, z.' Well duh, okay, Archimedes couldn't have imagined laptops and yet today we have them, but if they can't be described, then discussion of vague imaginings without specifics is not informative. I draw an analogy with speculative evolution - Dougal Dixon (for that matter, HG Wells and Olaf Stapledon) et al came up with some pretty weird possibilities for the evolution of life in the far future but they weren't presented as certainties, all were based on expertise and were really no weirder than some things alive today. In other words, squibbons are apparently possible but dragons are not. https://en.wikipedia.org/wiki/The_Future_Is_Wild

Fictional starships would be excluded with only the exception of those solidly grounded in real research, for the purposes of discussing that research, NOT the fiction. For example, the VentureStars in the Avatar films are technically interesting and based on real research while the films are - to me - insufferable and irrelevant to the topic ('like a nightmarish furries convention' as film critic Mark Kermode put it). This is what I'm thinking of:
View: https://www.youtube.com/watch?v=VTCt00GzpFk

The VentureStar is a fictional presentation of the serious concept here: https://en.wikipedia.org/wiki/Project_Valkyrie

Now would Valkyrie actually work? That's the point.

Thoughts?
 
Last edited:
One concept I would like to see are sublight trains as it were.

Say you have a star system 20 light years away, you might want 40-80 container ships at half light speed or below, if you use even more ships.

The goal is to have a colony get two deliveries of the most used items per year.

Craft at NAFAL velocities are essentially FTL from the perspective of the crew aboard-- but from the colony's perspective, they are receiving the equivalent of a FTL freighter every six months.

Loved ones are frozen before transport, on ship and off.

You just time it so people on the ground and in space wake up together with no time elapsing from their vantage points.

The drive systems aren't as important as the spacing
 
Last edited:
Must admit, that I love ram-augmented interstellar rocket (RAIR) concept; circumventing the problem of Bussard ramjet by gathering only the reaction mass from interstellar medium (energy to accelerate the gathered hydrogen is either stored as fuel onboard - for example, antihydrogen, injected into reaction mass flow - or beamed onboard from home system laser array)
 
I only like a) Orion nuclear pulse drive and b) wormholes because they work around the speed of light limit.
 
It's not just about the speed of light; there are also many side problems.

Let's remember the early days of aviation: they were so eager to take off that they forgot to find safe ways to land. The engines did not have enough power for extra equipment, then it was necessary to develop one by one all the instruments, the retractable landing gear, the radio, the radar, the radar altimeter, the anti-icing system, the parachute, the ejectable seat, the pressurized cabin, the oxygen equipment, the hydraulic servo controls, the flight by wire... and even airplanes are not safe!

Suppose it is possible to create a bubble in which the conditions of space-time do not act, and we find a way to cancel out the structure of space by making a hole in the gravitational lattice. In theory, the spaceship would glide unopposed through hyperspace at speeds greater than the speed of light, but the problem is knowing when to stop to return to normal space, lacking sensors and hyperspace navigation systems. How can we avoid materializing inside the Oort cloud of another star system, or in an asteroid belt?

At relativistic speeds, the impact of a grain of sand is equivalent to a significant fraction of Hiroshima, it is not only a matter of developing a protective energy field but of absorbing an enormous amount of impact energy.

One solution would be to completely nullify inertia by materializing at zero velocity with respect to the previous position… but not at the speed and angle at which the other solar system moves.

It would be more prudent to make small jumps stopping at a safe distance from the system to study its characteristics and choose the optimal point of re-materialization.

How would all these changes affect our biological clock and navigation systems?

It would also be necessary to develop a very powerful electromagnetic motor to reduce flight time within the system and develop an adequate power source.

We will never solve those problems without the help of very powerful AI systems.

There will be failures, ships will be lost, preferably manned by robots, but in the end, we will succeed because there is no alternative.
 
Michel Van said:
sound nice
but were to put in this Forum ?
I proposed as untertopic in Propulsion
Click to expand...
I regret the intrusion, I had understood that it was about interstellar travel and I was trying to draw attention to the technological level necessary for interstellar flight, in my opinion it is a problem that includes all known scientific fields and perhaps some that we have not yet developed. The engine is important, but it would be suicide to use only the propellant without having everything you need to survive and return.
 
Justo Miranda said:
It's not just about the speed of light; there are also many side problems.

Let's remember the early days of aviation: they were so eager to take off that they forgot to find safe ways to land. The engines did not have enough power for extra equipment, then it was necessary to develop one by one all the instruments, the retractable landing gear, the radio, the radar, the radar altimeter, the anti-icing system, the parachute, the ejectable seat, the pressurized cabin, the oxygen equipment, the hydraulic servo controls, the flight by wire... and even airplanes are not safe!

Suppose it is possible to create a bubble in which the conditions of space-time do not act, and we find a way to cancel out the structure of space by making a hole in the gravitational lattice. In theory, the spaceship would glide unopposed through hyperspace at speeds greater than the speed of light, but the problem is knowing when to stop to return to normal space, lacking sensors and hyperspace navigation systems. How can we avoid materializing inside the Oort cloud of another star system, or in an asteroid belt?

At relativistic speeds, the impact of a grain of sand is equivalent to a significant fraction of Hiroshima, it is not only a matter of developing a protective energy field but of absorbing an enormous amount of impact energy.

One solution would be to completely nullify inertia by materializing at zero velocity with respect to the previous position… but not at the speed and angle at which the other solar system moves.

It would be more prudent to make small jumps stopping at a safe distance from the system to study its characteristics and choose the optimal point of re-materialization.

How would all these changes affect our biological clock and navigation systems?

It would also be necessary to develop a very powerful electromagnetic motor to reduce flight time within the system and develop an adequate power source.

We will never solve those problems without the help of very powerful AI systems.

There will be failures, ships will be lost, preferably manned by robots, but in the end, we will succeed because there is no alternative.
Click to expand...
> How can we avoid materializing inside the Oort cloud of another star system, or in an asteroid belt?

That might not be the showstopper you think it is. Real-life Oort clouds and asteroid belts Objects are separated by many millions of miles; there's plenty of space between.
 
tgharris said:
> How can we avoid materializing inside the Oort cloud of another star system, or in an asteroid belt?

That might not be the showstopper you think it is. Real-life Oort clouds and asteroid belts Objects are separated by many millions of miles; there's plenty of space between.
Click to expand...
That's true with planetesimals but... How many rocks are the size of a refrigerator, a suitcase or a soccer ball are there in the universe?

We already had a vision of the future when Armstrong went into manual control because the automatic landing system directed the lunar module into an unprogrammed crater.

Or the German paratroopers who were impaled to death in the reed beds of Crete.

Or the thousands of ships that were lost on coral reefs before we could map them.

Some system must be developed so as not to fly blind.
 
Justo Miranda said:
Suppose it is possible to create a bubble in which the conditions of space-time do not act, and we find a way to cancel out the structure of space by making a hole in the gravitational lattice. In theory, the spaceship would glide unopposed through hyperspace at speeds greater than the speed of light, but the problem is knowing when to stop to return to normal space, lacking sensors and hyperspace navigation systems. How can we avoid materializing inside the Oort cloud of another star system, or in an asteroid belt?
Click to expand...
First of all, would you even have the inertia after FTL flight? I may be wrong there, but AFAIK the movement of Alcubierre bubble (or other warp models) is a pseudomotion - no actual change in relative velocity, and as soon as bubble collapsed, the ship would have the same relative velocity to the designation point as it was before FTL.

So basically to avoid problem of high-velocity collisions, the ship should reduce its velocity relative to its designation BEFORE entering FTL. Which is much simpler to do, because starting area would likely be well-mapped and trajectories safe from dust could be identified. Moreover, such trajectories could be pre-seeded with fuel and/or reaction mass (fusion pellets launched by railgun), so the ship would have less troubles accelerating/desselerating.

Imagine that you need to FTL from Sol system to the star system, which is - relatively to Sol - moving "left" at 50 km/s. So before leaving the Sol system, you should accelerate your ship "left" to 50 km/s relative to Sol, and then enter FTL flight. When you would arrive, your velocity relative to target system would be zero (you already "burned" the difference). And since you started from Sol, you could use laser sails, pre-seeded trajectories, ect. to make safe acceleration.
 
tgharris said:
> How can we avoid materializing inside the Oort cloud of another star system, or in an asteroid belt?
Click to expand...
To take an example form science fiction ; in the 'BattleTrch' universe , the JumpShips that travel between the stars travel to a Jump Point situated at a considerable ( it varies with stellar mass , volume , and luminosity ) distance from the star , and either 'above' the .star's 'North' pole ( zenith ), or below the 'South' pole (nadir ) . This keeps them clear of the vast majority of small objects in the star system . The JumpShips carry as their payload DropShips , which then complete the journey to the planetary destination . The JumpShips remain at the jump point , recharging their drives , until the DropShips return , then move on to the next stellar destination .

cheers ,
Robin .
 
I thought most of this ended up getting dropped into Space Projects? At least the theoretically-practical ones. Crud, even Alcubierre-Warp drives are there.
 
Dilandu said:
First of all, would you even have the inertia after FTL flight? I may be wrong there, but AFAIK the movement of Alcubierre bubble (or other warp models) is a pseudomotion - no actual change in relative velocity, and as soon as bubble collapsed, the ship would have the same relative velocity to the designation point as it was before FTL.

So basically to avoid problem of high-velocity collisions, the ship should reduce its velocity relative to its designation BEFORE entering FTL. Which is much simpler to do, because starting area would likely be well-mapped and trajectories safe from dust could be identified. Moreover, such trajectories could be pre-seeded with fuel and/or reaction mass (fusion pellets launched by railgun), so the ship would have less troubles accelerating/desselerating.

Imagine that you need to FTL from Sol system to the star system, which is - relatively to Sol - moving "left" at 50 km/s. So before leaving the Sol system, you should accelerate your ship "left" to 50 km/s relative to Sol, and then enter FTL flight. When you would arrive, your velocity relative to target system would be zero (you already "burned" the difference). And since you started from Sol, you could use laser sails, pre-seeded trajectories, ect. to make safe acceleration.
Click to expand...
I totally agree: no inertia, no acceleration, just going through Alice's mirror slowly until it materializes somewhere else. A space-time bubble that passes through the gravitational web unaltered, like a submarine.

But the submarine has sonar to avoid collisions.... although some have also been lost for unknown reasons.

There are those who speak of underwater waves of extraordinary power.

Who knows what awaits us out there and how many ships it will take to find out?

Better if they are robot ships.
 
One 'gotcha' of the Bussard and other inter-stellar material-harvesting systems is our location within 'Local Bubble'.

IIRC, the local density is ~~10 % of 'typical' galactic beyond our super-nova puffed region.

Out there, 'Bussard' and related 'heroic' tech *might* work, but we are in what you could term the 'Doldrums'. Where, IIRC, the density is generally a factor of five too lean...

It's an unsettling solution to 'Where Are They ??', another being the 'severely inimical' nature of the Local Bubble's still-expanding 'Great Fire-Wall'...

Note that when Sol-system's galactic orbit swung into Local Bubble about 5 million years ago (YMMV), a seriously scary spike of Supernova decay products arrived, evidence now buried in deep ice cores...

Disclosure: I was in 'British Interplanetary Society', with particular interest in Terraforming and 'Interstellar Studies', from 1980~~2003. Sadly, the cost / benefit faded...

Tangential: For my 'Convention' Sci-Fi tales, I 'resolved' the multiple Alcubierre 'impossibles' by crafting a 'Double Bubble'.
Ships ride within pocket of a 'Limaçon of Pascal'...
;) ;) ;)
 
robunos said:
To take an example form science fiction ; in the 'BattleTrch' universe , the JumpShips that travel between the stars travel to a Jump Point situated at a considerable ( it varies with stellar mass , volume , and luminosity ) distance from the star , and either 'above' the .star's 'North' pole ( zenith ), or below the 'South' pole (nadir ) . This keeps them clear of the vast majority of small objects in the star system . The JumpShips carry as their payload DropShips , which then complete the journey to the planetary destination . The JumpShips remain at the jump point , recharging their drives , until the DropShips return , then move on to the next stellar destination .

cheers ,
Robin .
Click to expand...
Replying to my own Post and also Justo's Post #5 , In 'BattleTech' , the JumpShips don't 'move' when jumping . They are stationary with respect to their environment prior to jumping , then jump to the destination star system , and on completion of the jump are again stationary with respect to their environment .

cheers ,
Robin .
 
Nik said:
One 'gotcha' of the Bussard and other inter-stellar material-harvesting systems is our location within 'Local Bubble'.

IIRC, the local density is ~~10 % of 'typical' galactic beyond our super-nova puffed region.

Out there, 'Bussard' and related 'heroic' tech *might* work, but we are in what you could term the 'Doldrums'. Where, IIRC, the density is generally a factor of five too lean...

It's an unsettling solution to 'Where Are They ??', another being the 'severely inimical' nature of the Local Bubble's still-expanding 'Great Fire-Wall'...

Note that when Sol-system's galactic orbit swung into Local Bubble about 5 million years ago (YMMV), a seriously scary spike of Supernova decay products arrived, evidence now buried in deep ice cores...

Disclosure: I was in 'British Interplanetary Society', with particular interest in Terraforming and 'Interstellar Studies', from 1980~~2003. Sadly, the cost / benefit faded...

Tangential: For my 'Convention' Sci-Fi tales, I 'resolved' the multiple Alcubierre 'impossibles' by crafting a 'Double Bubble'.
Ships ride within pocket of a 'Limaçon of Pascal'...
;) ;) ;)
Click to expand...
It's why the Valkyrie starship from the Avatar movies makes sense until we get out of the Local Bubble.

Or until we develop Alcubierre drives or some wormhole drive/access.
 
Project Valkyrie among others require the ship to turn midway for break burn. This puts stress on the frame, requires powerfull RCS, exposes the whole ship to collision without shield protection and introduces re-alignment problems. There are older designs that do not need or require this risky process: like a bi-directional drive design.
 
Seragina said:
Project Valkyrie among others require the ship to turn midway for break burn. This puts stress on the frame, requires powerfull RCS, exposes the whole ship to collision without shield protection and introduces re-alignment problems. There are older designs that do not need or require this risky process: like a bi-directional drive design.
Click to expand...
skew-flip turn so the ship is constantly under main thrust and therefore keeping the tether taut.
 
publiusr said:
It might be best to tailor spacecraft to the solar system's surroundings
https://dailygalaxy.com/2025/12/astronomers-find-interstellar-tunnel-linking-star-systems/
That corridor for non RAIRscoops perhaps.
Click to expand...

Sounds like https://en.wikipedia.org/wiki/Interplanetary_Transport_Network
It's good to have but ultimately increases travel time. Another good thing this could improve thether power generation and propulsion. Not a lot but still better than nothing.

So from the paper:
local bubble LHB:
~0.1 keV (~10^6 K) plasma
electron density of n_e= ~4 × 10^–3 cm^–3
tunnel:
n = 1.92 n_e

If I'm reading it right it seems matter density is just shy of 2x so it won't really matter for a bussard scoop design.
Currently, a bussard scoop design needs a nagnetic field of 1 AU forward. We would need at least 100x better density to get to a manageable planetary size field...
 
Since I'm at it allow me to illuminate a few other finer detail problems with interstellar travel.
I'll cite from memory so it's not 100% accurate.
Radiation/shield problem: space is filled with radiation / particles (gamma, alpha, beta). The faster a ship goes the more it will get hit from the front and sides.
Let's say a ship goes at 0.998 c ... compared to a stationary ship with 1 m^2 and an iso 1 m^3 of space volume radiation/second it would be hit by almost 300 milllion times more radiation that would occupy the volume in its path. However, the real radiation rate on the ship is higher due to time dilation. at 0.998 c that's 19.54974 x on top.
At that speed it seems a 0.01 m micro meteorite will rip a 404 m hole into solid rock armor (2.86 × 10^10 Joules).
For meteoroids (0.01 m), the maximum flux is 8.36 impacts/m^2/yr (stationary).
Let's say we would want to detect and use some laser to vaporize larger than 0.01 m micrometerites.
Against a common supernova remant travelling @ ~25000km/s and a 90s warning time the detection distance needs to be about 106061.1 light seconds forward (signal travel time, time dilation etc.). That's 3.181833e+10 km or larger than the solar system's diameter.
Against an interstellar matter @ 333 km/s that's down to 89929.8 light second.
The sensor arc needs only to be ~10.014°. The computation needed ~6.75e22 FLOPS a bit more than all current supercomputers on Earth :p.
 
Another reason to stay in that corridor.

If humanity does get some better drive systems...you might want to build up speed in that corridor just to lessen the likelihood of hitting dust and such at speed, and hope there are some dead stars ahead you can use like Jupiter to redirect your course.

It could be that we have to do this even if where we want to go is in another direction

I have given up hope for any FTL system...so the focus should be tether development and using those to Tarzan through space....dangle one towards a collapsar and cut it during the turn.

Automated probes only.
 
Well, alternatively quantum teleportation might be more easily attainable than FTL.
But the range has to be at least 12 light hours. So if it takes a day to complete a move (in part or whole) that would equate 0.5 c for a reasonable traveltime. But as a real replacement the range needs to be at least 0.5 lightyears... yeah, too much to ask for.
 

Similar threads

Back
Top Bottom