What is Interstellar travel: Definition and 41 Discussions

Interstellar travel refers to the travel by interstellar probes or crewed spacecraft between stars or planetary systems in a galaxy. Interstellar travel would be much more difficult than interplanetary spaceflight. Whereas the distances between the planets in the Solar System are less than 30 astronomical units (AU), the distances between stars are typically hundreds of thousands of AU, and usually expressed in light-years. Because of the vastness of those distances, practical interstellar travel based on known physics would need to occur at a high percentage of the speed of light; even so, travel times would be long, at least decades and perhaps millennia or longer.The speeds required for interstellar travel in a human lifetime far exceed what current methods of space travel can provide. Even with a hypothetically perfectly efficient propulsion system, the kinetic energy corresponding to those speeds is enormous by today's standards of energy development. Moreover, collisions by the spacecraft with cosmic dust and gas can be very dangerous for both passengers and the spacecraft itself.A number of strategies have been proposed to deal with these problems, ranging from giant arks that would carry entire societies and ecosystems, to microscopic space probes. Many different spacecraft propulsion systems have been proposed to give spacecraft the required speeds, including nuclear propulsion, beam-powered propulsion, and methods based on speculative physics.For both crewed and uncrewed interstellar travel, considerable technological and economic challenges need to be met. Even the most optimistic views about interstellar travel see it as only being feasible decades from now. However, in spite of the challenges, if or when interstellar travel is realized, a wide range of scientific benefits is expected.Most interstellar travel concepts require a developed space logistics system capable of moving millions of tonnes to a construction / operating location, and most would require gigawatt-scale power for construction or power (such as Star Wisp or Light Sail type concepts). Such a system could grow organically if space-based solar power became a significant component of Earth's energy mix. Consumer demand for a multi-terawatt system would create the necessary multi-million ton/year logistical system.

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  1. Strato Incendus

    Writing: Input Wanted Revisiting the Enzmann Starship Design: A Sixty-Year Perspective

    The dumbbell design of my fictional generation ship Exodus, as I’ve recently discovered, bears some similarity to the Enzmann starships, proposed by Dr. Robert Enzmann in 1964. I’ve even gone so far as to label the ship part of the “Enzmann class” within my setting...
  2. Strato Incendus

    Writing: Input Wanted Can a Gamma-Ray Burst Affect Communication Devices?

    There have been quite a few threads on gamma-ray bursts already, so I’ll make this one as specific as I need it for my WIP sci-fi story: Can a gamma-ray burst that affects the entire solar system, among others, damage the majority (if not all) devices capable of interstellar communication? For...
  3. A

    B Any Feasible Faster-Than-Light Interstellar Travel?

    I'm not talking sci-fi, not talking "10yrs to the next solar system" speeds, and not including things we don't even know actually exist (like exotic matter). I'm talking interstellar travel like star ships, speeds one day comparable to what you see in sci-fi now, such as Star Trek? While my...
  4. Strato Incendus

    Writing: Input Wanted Turning an interstellar ship around before reaching coasting speed?

    This is a follow-up question emerging from another thread in the Sci-Fi Writing and World Building forum. Specifically, @DaveC426913 had criticised another book in which the plot is set in motion by a plan to turn an interstellar colony ship around and return back home. In my setting, a similar...
  5. Josh S

    B Trying to understand what "time" is (layperson)

    Hi Everyone, Just a disclaimer, I'm not a physicist or a physics student, just a layperson with an interest in physics. So please forgive any lack of understanding on my part :). Anyway, I recently started trying to gain a better understand of what time is in the real world, because some...
  6. Erik1801

    Realistic fast Interstellar Propulsion Methods

    This is my first time posting, so please excuse any mistakes. I am grasping at straws here. I am working on a Hard-Sci Fi novel, plot, arcs, characters etc. are all worked out and i decided to take the deep dive in terms of Realism. For instance, there are no Fusion reactors. All that is...
  7. Strato Incendus

    Wall thickness of ring habitats for radiation shielding

    This is a topic that will be relevant for anyone who plans to use "realistic" artificial gravity (of the centrifugal kind, rather than the "acceleration-based" kind) in their stories - be it on spaceships or space stations: How much of the ring walls has to be dedicated to radiation shielding...
  8. Strato Incendus

    What can realistically go wrong on an interstellar journey?

    Alright, since I’m still stuck on my sci-fi story because I can’t exactly outline the mid-point plot twist with a realistic catastrophe on board an interstellar spaceship, I thought I’d widen the scope a little — towards full-on open brainstorming: What, if anything, can realistically go wrong...
  9. Strato Incendus

    Wood as a precious resource on spaceships

    A lot of fictional examples of interstellar spaceships, be they generation ships or sleeper ships, have some sort of arboretum. However, those often just tend to be places for recreation, like a forest for joggers. Or, if the ship is transporting any animals, too, those might inhabit the...
  10. D

    Exploring Electron Rockets for Interstellar Travel

    Hi all, Why not build an electron rocket? Why won't this idea work? Seems like someone could just hitch an electron gun onto a spaceship. Boom! Electron Rocket. I was thinking about ion thrusters. These use ions to achieve thrust. They are problematic for achieving a high delta V because...
  11. Giovanni Cambria

    A Is this solution for interstellar travel viable?

    I have in mind a way to enable FTL travel. Is this way viable? In the paper: "Weighing the vacuum with the Archimedes experiment" we can see the dependency of the gravitational repulsion exerted by Casimir Vacuum on the energy between the plates. The force goes as E / c^2. In the papers...
  12. K

    I Interstellar Travel vs Universe Expansion: Is Andromeda Reachable?

    I read in a so called sci-fi website from my country that as the universe is expanding we may not be able to get to certain galaxies in a possible interstellar travel. That information seems ok for me. But then there was a comment by a reader concluding from the website post that there is coming...
  13. Y

    I Interstellar Travel Without Propulsion or Time Dilation

    I hope this is the right forum for this question. Imagine alien tech allows them to travel 1 million light years to Earth instantaneously. No thrust, vector, propulsion was involved. They didn't have to approach the speed of light, with its attendant increase in mass. Having arrived at earth, in...
  14. LaurelAnnyse

    Questions about space travel

    Hey there! My name is Laurel, and I'm working on a short story with a friend about, among other thing, space travel. I've just got some questions about exiting the atmosphere in order to fly a spaceship around looking for other stuff. I don't want you to feel you have to over simplify things...
  15. Ranvir

    B Why is interstellar travel so hopelessly difficult?

    So, I have been thinking about TRAPPIST-1 and how far away that system is from us. It is 40ly away from Earth, according to our frame of reference. This is often put in a way that makes one think that even at speeds close to that of light, it will take almost 40 years to get there. The muons in...
  16. Wrath_of_sloths

    A problem with interstellar travel

    Hi guys, I am writing an undergraduate screenplay about physicist. The physicist is working on a mission with the aim to fly a spaceship with human crew to an extremely distant planet with an environment suitable for humans. Its really not that important for the story, because the film is...
  17. Steven Hansel

    I Will interstellar travel become more possible in future

    Let's say we already colonized some of the planets and moons in our solar system. Mars,Moon, Europa and etc. Planets like Mars and other has less gravity than earth, so the resource needed for space travel in our solar system will reduce by a lot if we launch spaceships there. Say, that we...
  18. H

    B Time Dilation, Interstellar Travel, and "The Forever War"

    Dear community, I have no formal education in physics, but I think I have understood some of the basic concepts and ideas in SRT. I am currently trying to find a solution to a problem that came up during my reading of Joe Haldeman's "The Forever War", a Sci-Fi novel that deals with the impact of...
  19. Jigsaw674

    I Interstellar travel/centrifugal couching

    Given: original project Orion https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) My idea is the addition of a centrifugal couch to regulate gravity to crew during the acceleration and deceleration phases of the trip. The Orion concept, for an interstellar ark concept, relies on...
  20. B

    Debunking Interstellar Travel: Separating Fact from Fiction

    Hi Folks, What is your opinion on this article? It suggest that interstellar travel is a fantasy. http://www.scientificamerican.com/article/interstellar-travel-as-delusional-fantasy-excerpt/# Yet, I read articles about institutions like NASA investing in various conceptual propulsion...
  21. T

    Interstellar travel and Special Relativity

    I always ask myself this question, and I think it is better to ask people that really know about this. Due to the impossibilities that Special Relativity poses, such as any object with mass not being able to travel at the speed of light. If we don't manage to at least scratch that speed, I...
  22. T

    Question about interstellar travel

    My physics professor told us something about interstellar travel, which I have a question on. He told us that scientists figured out a way to send objects into space and frequently increase velocities. He said they do this by sending probes and aiming them at planets and large bodies in space...
  23. GiantSheeps

    Is a warp drive possible? How long until we develop one?

    Is a warp drive actually possible to create? If so, how long until we can develop one? Is it at all possible that they could be developed during our lifetimes? I'm asking because of this article...
  24. M

    Movies on interstellar travel

    After doing my own research I would like to know if anyone can recommend a good Sci-Fi movies on mankind's first interstellar voyage, besides the movie 'Interstellar', which I have seen?
  25. C

    Interstellar Travel: Exploring Nearby Stars with Advanced Technology

    Hi, I am writing a piece which involves interstellar travel to nearby stars (Epsilon Indi being the one I will use in the following example.) It will be via a beam/ sail craft accelerated/ decelerated by solar-powered lasers (and lenses along the route). The craft will use constant...
  26. C

    How to interstellar travel in a very hard SF universe

    While I enjoy space opera (Star Trek, Star Wars, etc) my favorite fictional genre is the rarer hard science fiction, stories that involve science and engineering which doesn’t yet exist, but, unlike soft SF and fantasy, don’t can be rigorously explained as possible by present-day science, making...
  27. BitWiz

    Is interstellar travel impossible due to kinetic energy magnitude?

    This has been bugging me. Several respected propulsion scientists at the 2008 Joint Propulsion Conference claimed that interstellar travel within a human lifetime was impossible. The KE of a rocket traveling at a significant fraction of c would be enormous via KE=0.5 * m * v^2 and that...
  28. U

    Novel way for interstellar travel

    Suppose there was a ring of some material (steel? future carbon nano tubes?) around the sun. The ring would have a diameter of 2*10^9th meters. If a solar sail were placed attached to the ring with the reflector at a 45 degree angle) then the solar sails velocity would only be limited by the...
  29. D

    Interstellar travel is impossible, moore's law is finite, the heat dea

    Yeah, all of those things, multipled by five thousand, and there we have the current cosmic predicament for human beings. Is there any way in which we can do something about this? Or will Schopenhauer have the last laugh?
  30. F

    Time dilation and interstellar travel

    Homework Statement Plans are made to send a spaceship from Earth to a nearby star 10 light-years away and at rest with respect to Earth. The light support systems within the spacecraft will last for a year. (a) what is the minimum speed of the spacecraft relative to the Earth-star system if...
  31. J

    Interstellar Travel Tables

    Using information and calculators I found online, I have put together a series of tables illustrating the energy, fuel mass, and time requirements (both Earth and ship time, at 1 g acceleration) for a spacecraft to reach various percentages of light speed...
  32. X

    [Novel] On usage of charged black holes for energy production and interstellar travel

    Hello! I'm redesigning my never-to-be-finish sci-fi novel, yet another futile to come up with scientifically based interstellar travel propulsion. My latest consideration is based on article[1] and possible extensions of those ideas. Anyway, I'm looking for an independent opinions on the...
  33. MattRob

    Photon Sails in Interstellar Travel

    I might get a bit of a reputation for space talk, here :P So, I'm familiar with the concept of Photon Sails, but I was wondering how effective these would be? To make sure we're on the same page, I'm talking about using a highly reflective surface to propel a spacecraft by hitting it with a...
  34. S

    What are the limits of interstellar travel?

    For simplicity consider an unmanned probe to a star in our neighbourhood say 10 to 20 LY. Most discussions of this concentrate on speed and power. But what is the fastest realistic velocity? 40,000 MPH (~ 1/10 of 1% of light speed)? Even at this speed interstellar dust banging away at the...
  35. R

    Length contraction and interstellar travel

    Interstellar travel is always a problem in science fiction: you can't have the hero hibernate for millions of years whenever he or she wants to travel to another star, but it's annoying when spaceships just magically move faster than light. However, wouldn't length contraction from special...
  36. J

    Time Dilation and Future Interstellar Travel

    Hello all, I am new to the Forum and have no formal Physics training. I have an interest in the subject mainly due to other pursuits. I am reading Joe Haldeman's The Forever War. I would definitely recommend this book to anyone with an interest in Time Dilation or Humans vs Aliens at...
  37. vincentm

    Difficulties with interstellar travel

    According to Relativity, if a ship traveling at nearly the speed of light through interstellar space diffuse atoms (mostly Hydrogen, becase simply that is the most abundant atom in the universe, right?) would strike the front of the ship with increased mass, causing radiation. My question is how...
  38. L

    Interstellar Travel: Theorical Force to Stabilize Wormhole

    Theorically speaking, what force could stabilize a wormhole?
  39. P

    Relativity interstellar travel question

    well the textbook question is (transfer me over to hmwk help its ok) 2 Civilizations are evolving on oppposite sides of our galaxy (d = 10^5 ly) at time t = 0 in the galaxy frame of reference, civilization A launches its first intersteller spacecraft , 50,000 years later, measured in the...
  40. B

    Interstellar Travel: Reaching Alpha Centauri

    How long will it be before we reach alpha centauri, i was on a thread on Fark.com yesterday about going to Mars and it interstellar travel came up. I figured you guys (and girls) would prob have a better idea on what ideas are out there right now. this was my post: do you know how impossibly...
  41. T

    Exploring the Possibilities of Interstellar Travel in Physics Coursework

    (read *lost* in general discussion- thought itd be better if i posted this again here) interstellar travel. i wanted to know the possibility of it actually being able to happen. iv got coursework to do, and it can be on anything we want it to be on, as long as its got summat to do with...