Proxima Express

Tom Kalbfus · 2016-08-28 10:33:27

After doing a comparison between terraforming Mars and interstellar Travel, this has got me to thinking, what can we do, that is on a similar scale to terraforming Mars that would make Proxima b more accessible, and the idea hit how about a linear accelerator. One that is 300 AU long which can accelerate a starship up to 10% of the speed of light, and then another and another and another! The problem with beamed propulsion, such as a laser sail for instance, is you can accelerate 1 light sail within a laser beam, but if you accelerate another light sail with that same beam, it may shadow the first one. There is only so much area within the beam for accelerating light sails. A linear accelerator however can accelerate multiple objects at once, in different parts of the accelerator. The other part is how do you slow down? We may use a Daedalus space probe to do that, it is said to be capable of reaching 12.5% of the speed of light, so it can slow down from 10% of the speed of light and have 6750 km/sec of delta-v for maneuvering around the system to do some explorations. The other problem is how do we build something that is 300 AU long? If we are capable of building a Daedalus, we are certainly capable of building a more modest spaceship, say one that can go up to 1% of the speed of light and then slow down again.
4b8911e4c22fbcce9751be3c235466a4_large.jpg?1370200124

This blueprint states that the Daedalus probe is 190 meters long by 110 meters wide so we need an accelerator with a tunnel that at least 120 meters wide to accommodate the Daedalus spaceship. We probably would want multiple tubes, we'll give each one an external diameter of 150 meters, with a total of 8 linear accelerators in parallel and in the center we have the power conduit and fusion reactors. You see part of the tunnel's functionality it s to deliver fuel to the various fusion reactors along the length of the accelerator to power it, the accelerator acts as the transportation system to keep those reactors fueled, probably from a source such as the planet Neptune.
The whole apparatus would be 450 meters wide and 30 AU long! How much mass are we talking here? Lets say a cubic meter weighs a ton. A cross section which is 450 meters by 450 meters by 1 meter would weigh 202,500 tons before we cut out the holes for the tubes. There are 8 holes we are cutting out. The area of a circle 120 meters wide is 11,309.73 square meters, since this cross section is 1 meter wide, it is also 11,309.73 cubic meters and 11,309.73 tons. We cut out 8 of these circles for a total of 90,477.84 tons, subtracting that from 202,500 tons we get 112,022.16 tons. Now an AU is about 150,000,000,000 meters and 30 A is 4,500,000,000,000 meters multiply that by 112,022.16 tons and we arrive at the mass of this accelerator which is 504,099,720,000,000,000 tons or 5.04*10^20 kg.
Tethys has a mass of 6.22*10^20 kg. Charon would be more convenient, with a mass of 1.7*10^21 kg, this is more than 3 times the amount of mass that we need, and it also is far away from he Sun, just the sort of place we would want to build our linear accelerator. how how to we build it. We would obviously need a fleet of spaceships deployed along the length of the accelerator we propose to build. The orbital velocity of Pluto is around 4.74 km/sec. If we had 450,000,000 spaceships about the size of Daedalus we could put each one in charge of constructing 100 kilometers of accelerator at 1% of the speed of light it would take 1,500,000 seconds to travel the length of the accelerator or about 17.361 days excluding time to accelerate and decelerate. So each on of those ships gets into position and starts building its part of the accelerator. Lets say it takes a decade for each one to build 100 km of track.

So now we have a track capable of accelerating a Daedalus probe, both stages to 10% of the speed of light, and each probe expends 1 stage to slow down, and uses most of its remaining fuel to slow down into the Proxima system, and using material in that system, another linear accelerator can be constructing using another 450,000,000 spaceships to build another accelerator that is 30 AU long, and some guidance probes guides incoming spaceships precisely so they enter the decelerator and can slow down t match the velocity of the Proxima system, and then we can open up public access to Proxima b. The journey should take 42.5 years. the 110 meter wide spaceships can be rotated to provide gravity, or they can be attached together to form a larger wheel, 30 of them would make a wheel 1050 meters in diameter. The wheel would then rotate 1.305 times per minute to produce 1-g of centripedal acceleration. These wheels then break up on approach to the Proxima linear accelerator for precise positioning to decelerate within.

GW Johnson · 2016-08-28 17:37:10

(1) just how do we build structures measured in AU and of what? (2) just how do we take ices and minerals and turn them into real engineering materials that we can actually use? (3) just how do you propose to move all this mass where it needs to go?

Near-term, this is a fallacious and unrealistic fantasy, precisely because there exist no answers to my three questions.

"Near term" is the next several decades. This applies to space habitats made from asteroid materials, space elevators, etc. Until there are answers to my three questions, these things cannot be done.

Far term, all bets are off. Far term is centuries hence.

GW

Last edited by GW Johnson (2016-08-28 17:39:00)

JoshNH4H · 2016-08-28 21:38:24

As I said in the previous thread, I think lightsails are the way to go when it comes to interstellar transit. Assuming a reflective lightsail and a 10,000 tonne ship, accelerating at 0.1 m/s^2 (This will get you from 0 to 0.1 c in 10 years), total intercepted power needs to be 1.5e14 W (150 terawatts). This is a whole lot of energy, but the sun burns brightly. At 0.2 AU, the solar constant is about 34 kW/m^2.

I'm going to assume that only 10% of the light intercepted by this mirror actually makes its way to the interstellar craft. Therefore the primary mirror needs to intercept 1.5e15 W or 1.5 Petawatts. At 34 kW/m^2, the primary mirror will need to have an area of 4.4e10 square meters. This corresponds to a square with a side length of 210 km.

This mirror would not be in orbit. Instead, it would use light and solar wind pressure to counterbalance the effects of the Sun's gravity. A perfectly reflective mirror pointing straight back into the Sun should mass 1.5 g/m^2 to maintain its position. This is true no matter how far from the Sun it is because both insolation and gravitational acceleration fall off with the inverse square of distance.

Light that is being concentrated cannot be used to hold position. If 50% of the mirror surface is used to hold position and another 50% is used to concentrate, the sail can only mass .75 g/m^2. This is about an order of magnitude lower than what we have now but should be achievable short-to-medium term if we really wanted to.

Rather than building one giant concentrating mirror, I would create an array of separate mirrors operating together. This would make it possible to gradually expand capacity. It would also reduce the structural stresses inherent to megastructures.

The secondary mirror would be mounted on a relatively large body out at the solar focus. It will use the Sun's gravitational field to focus the light it receives onto a small area where the ship is. Depending on the accuracy and stability of the primary mirror array, a series of concentrators might help to narrow down the beam area.

Tom Kalbfus · 2016-08-28 22:37:55

GW Johnson wrote:

(1) just how do we build structures measured in AU and of what? (2) just how do we take ices and minerals and turn them into real engineering materials that we can actually use? (3) just how do you propose to move all this mass where it needs to go?
Near-term, this is a fallacious and unrealistic fantasy, precisely because there exist no answers to my three questions.
"Near term" is the next several decades. This applies to space habitats made from asteroid materials, space elevators, etc. Until there are answers to my three questions, these things cannot be done.
Far term, all bets are off. Far term is centuries hence.
GW

Near term you stick to 1% of the speed of light or less, and you build seeder ships cheaply, and it turns out, when it comes to interstellar travel, "Near Term" is also Far Term, because technologically the kinds of starships we can build in the near term would take thousands of years to reach the nearest star. I so happen to think that artificial intelligence is a near term technology, that is it will be developed in the next several decades. The first thing we can do with AIs is send them out on seeder ships, AIs can more easily get past the time barrier, that is they can wait a long time and complete the mission, growing humans in artificial wombs and acting as their parents upon arrival at the stars. If you are in a hurry however, its going to take more energy and materials, whether its giant lasers in space or linear accelerators.

To build the accelerator, we need AI which can replicate itself as many times as needed to build this accelerator in parallel, we need to get the constructor robots in position along the 30 AU where the linear accelerator is going to be built. We probably need to build shorter versions of this accelerator to move materials into position. We can build 31 linear accelerators our of cometary material each one is 0.03 AU long and accelerates material at 1000-gs Human cargo requires a long accelerator, but rocks and dirt do not!. So you build one accelerator near Charon, where you get your material, and you accelerate the rock and dirt to 10% of the speed of light to 30 difference locations along the construction site of the accelerator, at each of those positions an accelerator slows the incoming material down, the material from there is transported by freighter to the locatipns where they are needed, and the locations parts and pieces of the main accelerator are manufactured, and then the parts are assembled into the linear accelerator at 450 million different locations along the construction site. That should answer questions 1 and 3 as for 2, there is enough material in the Solar System, and even the outer solar system bodies are not all ice, the ice by the way can go to fuel the fusion reactors that power the manufacturing process and the linear accelerators. Eventually we can extend the accelerator or build another one that is 4.25 light years long. to do that we need about 90 times the mass and 90 times the spaceships and robots, and it would take 424 years to get all the robots into position along the route to begin assembling this longer accelerator, which would allow us to make the trip to Proxima in 3.54 years subjectively for the passenger and 5.87 years for the rest of us.

Tom Kalbfus · 2016-08-28 23:19:59

JoshNH4H wrote:

As I said in the previous thread, I think lightsails are the way to go when it comes to interstellar transit. Assuming a reflective lightsail and a 10,000 tonne ship, accelerating at 0.1 m/s^2 (This will get you from 0 to 0.1 c in 10 years), total intercepted power needs to be 1.5e14 W (150 terawatts). This is a whole lot of energy, but the sun burns brightly. At 0.2 AU, the solar constant is about 34 kW/m^2.
I'm going to assume that only 10% of the light intercepted by this mirror actually makes its way to the interstellar craft. Therefore the primary mirror needs to intercept 1.5e15 W or 1.5 Petawatts. At 34 kW/m^2, the primary mirror will need to have an area of 4.4e10 square meters. This corresponds to a square with a side length of 210 km.
This mirror would not be in orbit. Instead, it would use light and solar wind pressure to counterbalance the effects of the Sun's gravity. A perfectly reflective mirror pointing straight back into the Sun should mass 1.5 g/m^2 to maintain its position. This is true no matter how far from the Sun it is because both insolation and gravitational acceleration fall off with the inverse square of distance.
Light that is being concentrated cannot be used to hold position. If 50% of the mirror surface is used to hold position and another 50% is used to concentrate, the sail can only mass .75 g/m^2. This is about an order of magnitude lower than what we have now but should be achievable short-to-medium term if we really wanted to.
Rather than building one giant concentrating mirror, I would create an array of separate mirrors operating together. This would make it possible to gradually expand capacity. It would also reduce the structural stresses inherent to megastructures.
The secondary mirror would be mounted on a relatively large body out at the solar focus. It will use the Sun's gravitational field to focus the light it receives onto a small area where the ship is. Depending on the accuracy and stability of the primary mirror array, a series of concentrators might help to narrow down the beam area.

To accelerate multiple objects at once, you need a very wide laser beam, so instead of having a very long linear accelerator, you have a very wide laser aperture, plus the fact that it takes 10 years, whereas it takes 3,000,000 seconds (34.7 days) to accelerate something to 0.1 c at 1-g acceleration. Linear accelerators can also be improved to cover the entire trip between Sol and Proxima with constant acceleration/deceleration for a trip 3.541 years subjectively and 5.866 years objectively. Of course you would need 8914.176 times the mass and 4 trillion starships capable of 1% of the speed of light, and it would take 424 years to get them all into position. Of course we can begin mining an sending construction material to the constructors at once, so when they arrive at their prearranged positions, they can begin construction at once, and it would take another 10 years to build it for total of 434 years to construct, and it probably would take another 4.24 years for the light to reach sol so we can verify that he accelerator is complete and we can begin using it.

There is also the little detail that Proxima Centauri is moving closer to us, that means the accelerator needs to be able to shrink in length so that one end can match the velocity of Proxima while the other matches the velocity of Sol!

RobertDyck · 2016-08-28 23:29:42

List of nearest stars and brown dwarfs

JoshNH4H · 2016-08-28 23:31:24

To accelerate multiple objects at once, you need a very wide laser beam

One could also have multiple beams. Also (minor terminology point) as there are no lasers involved the system I'm proposing is just a regular beam, not a laser beam.

...plus the fact that it takes 10 years, whereas it takes 3,000,000 seconds (34.7 days) to accelerate something to 0.1 c at 1-g acceleration.

Let's be honest with ourselves and admit that we both pulled the specs for our systems out of thin air. You pulled a bigger number out of your hat, but I could just as easily have done the same. Anyway, when your trip time is 40-50 years it doesn't make that much of a difference if you accelerate over ten years or ten minutes.

Linear accelerators can also be improved to cover the entire trip between Sol and Proxima with constant acceleration/deceleration for a trip 3.541 years subjectively and 5.866 years objectively. Of course you would need 8914.176 times the mass and 4 trillion starships capable of 1% of the speed of light, and it would take 424 years to get them all into position. Of course we can begin mining an sending construction material to the constructors at once, so when they arrive at their prearranged positions, they can begin construction at once, and it would take another 10 years to build it for total of 434 years to construct, and it probably would take another 4.24 years for the light to reach sol so we can verify that he accelerator is complete and we can begin using it.
There is also the little detail that Proxima Centauri is moving closer to us, that means the accelerator needs to be able to shrink in length so that one end can match the velocity of Proxima while the other matches the velocity of Sol!

I think you've gone a bit off the deep end here. While a 30 AU linear accelerator might become possible eventually (as absurd as it is given that 30 AU is about the size of the solar system) one that stretches between stars is absurd beyond absurd and four orders of magnitude longer.

Tom Kalbfus · 2016-08-29 09:05:36

What you need is self-replicating machines.. I think all the parts of a 4.24 light year accelerator could be built and fit within this Solar System. So lets see, a light second is 300,000 kilometers, and there are 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, 365 days in a year, and 4.24 light years between Sol and Proxima Centauri, this comes to about 300,000 * 60 * 60 * 24 *365 *4.24 = 40,113.792,000,000 kilometers so if each one of my 4 trillion ships is 10 km long, that ought to do it! Each 1 meter cross-section of each ship is 202,500 tons before we add the fuel, 10 km is 10,000 meters so each one of those ships would weigh 2,025,000,000 tons.
1 becomes 2, 2 becomes 4, 4 becomes 8, 8 becomes 16, 16 becomes 32, 32 becomes 64, 64 becomes 128, 128 becomes 256...
2^45 = 35,184.372.088,832,
2^45.2 = 40,416,230,340,044
So 45.2 replications of that starship should bring you to the correct number, and 40 trillion times 2 billion tones equals 80,000,000,000,000,000,000,000,000 kg 8 * 10^25 is 13.3 Earth masses, this is just under the mass of Uranus, if we consume one or two of the outer gas giants, that might be enough t build this linear accelerator, There also might be some planets in the Alpha Centauri system, but if we were to do this, we might as well build our own planets. Your point well taken, The question is, would it be worth sacrificing two gas giants to build this thing? Maybe if it was only to the Alpha Centauri system it wouldn't be, but there are planets in the Centauri System as well, some of those could be disassembled to lead to other systems. Over time we could create a transportation network, one could flit from system to system, and could there be a safer way to travel up to 95% of the speed of light than within a tube? The tube keeps all things the ship may hit out of the path of the starship. The trip would still take years, but really it would be the safest way to do interstellar travel, baring new physics such a wormholes and other such stuff.

Last edited by Tom Kalbfus (2016-08-29 10:12:26)

Tom Kalbfus · 2016-08-29 10:35:42

We might want to consider building this thing from other star systems, Not sure I'd want to sacrifice Uranus and Neptune, but what about some other system that we don't care about, one that is not likely to yield life bearing planets, How about Sirius?

https://en.wikipedia.org/wiki/Sirius
It is about twice as far as Alpha Centauri, the inconvenient orbit of Sirius b just about rules out life bearing planets, but these are massive stars, I wonder how many gas giant could be orbiting this system. When Sirius b blew out its outer layers, there might hae been some material left behind to form planets, some of which could be quite massive. There could be some stable orbits close in to Sirius A, too hot for life, but an abundant source of construction material. So we can build a bridge to Sirius, import some of the material there and use that to build a bridge to Alpha Centauri. There might be some material in the Alpha Centauri system as well.
nearest-stars-121218g-02.jpg?interpolation=lanczos-none&downsize=600:*

The Procyon system is another system we might obtain building materials from
https://en.wikipedia.org/wiki/Procyon
It is 11.46 light years away. One thing we might consider when transporting material from these systems is that material is less fragile than people. We could simply accelerate mass towards the Sol System and from there we can build a bridge to Alpha Centauri and other systems we may want to visit or colonize. We could build short stubby accelerators an decelerators economizing on materials used. Procyon like Sirius has no stable orbits in its habitable zone, it is also nearing the end of its life, we might as well use its materials for something that is useful to us.

It seems rather obscene the waste of matter or energy We can use light, and waste energy using only the momentum of photons or we can waste matter and build giant physical objects that mass greater than many planets to get us from one star system to another. Another idea is an elongated beam of light, something that is 10,000 km thick, 150,000,000 km wide, and 4.24 light years long. A light sail then moves outwards and diagonally starting at one end of the beam accelerating away from the Sun and moving sideways while doing so, then another light sail is pushed away and it moves diagonally away, at the mid point the light sails separate in two, the greater part reflects the light beam back at the smaller part that was formerly in the center slowing it down and continuing towards Proxima Centauri, by the time each sail has reached its destination it has moved 1 AU sideways. Assume it takes 3.54 years subjectively to make this trip and it moves sideways 1 AU so it moves at a rate of 4837 km/hour, lets call it 5000 km/hour, each sail is 5000 km wide, and each hour a new sail is launched, over the course of a year 8760 light ships are launched.

Last edited by Tom Kalbfus (2016-08-29 13:18:52)

Antius · 2016-08-29 17:32:01

As Josh stated in a neighbouring thread, the critical problem with all interstellar engines is mass power density. To achieve high acceleration and high ISP the engine needs very high power density and exhaust velocity. Basically, the power of an engine is the product of thrust and exhaust velocity. And power density is limited by the heat transfer capabilities of matter.

If the propellant is photons and the source is stationary, then this is optimum in terms of achievable mass power density for the vehicle. The downside is that the stationary laser must be very powerful in order to accelerate even a small payload to relativistic velocities. And the optics must be good enough to maintain a tight focus over billions of km. The mission proportions that I have seen involve 100's GW of ground based lasers accelerating payloads weighing grams to 20% C.

Last edited by Antius (2016-08-29 17:37:53)

Antius · 2016-08-29 17:52:22

Bringing the discussion back to a practical scale of engineering; how about a fission-fusion hybrid nuclear rocket? Basically, liquid deuterium contained in small spherical thorium spherical pellets, maybe a few mm in diameter. We fire a dozen such spheres towards the focus of a hemispheric chamber. As the spheres converge, we hit the central sphere with an ultraviolet laser, heating it to several million K. The deuterium fuses liberating fast neutrons, which cause fast fission in the pellet thorium shell. As the thorium atoms fast fission, the fragments deposit their energy into the deuterium, heating it up and accelerating the fusion, producing even more fast neutrons, etc, resulting in a self-accelerating positive feedback. The other pellets in proximity, would initially provide reflection, as fast neutrons escaping the first pellet would result in fast fission in their shells. If the pellets are in close enough proximity, fusion in the inner pellet would produce enough fast neutrons to pop-corn the outer pellets.

For the engine to work, multiplication factor is essential. If too many fast neutrons escape the assembly without yielding fission, then the reaction will fizzle out. If it does work, then exhaust velocity shoukd be ~10% C in a relatively compact engine configuration. To direct the plasma, the hemispherical thrust chamber would be ringed with a superconductor. The field lines would direct escaping plasma along the axis the nozzle.

The concept is basically a mini-orion, but ignites sub-critical assemblies using lasers to provide a burst of neutrons in the fusable charge. After laser ignition, it relies upon coupling and feedback between the fissile and fusible charges. I don't know if it would work and couldn't begin to model it. But the need to minimise neutron leakage suggests a minimum critical size for the assembly in terms of the number of pellets, a critical density in terms of their proximity at the point of ignition and their size, as fission products must reliably tunnel through the fusible charge heating it and generating feedback.

A starship propelled by such an engine could be relatively compact and relatively cheap to build, as thorium and deuterium are abundant elements, assuming it works.

Last edited by Antius (2016-08-29 18:15:39)

JoshNH4H · 2016-08-29 18:35:23

If your math is right and your answer is wrong, there's a problem with your assumptions.

In this case, you assumed that the most important consideration is kinematic in nature, and the biggest limiting factor is the acceleration that the payload can withstand. From there, you did some simple kinematics and arrived at your answer.

Kinematics aren't really the limiting factor here though because there are other considerations. For example, power consumption. Even ignoring your multi-lightyear linac proposal and focusing on your 50 billion km linac, the power consumption is huge. Accelerating 10,000 tonnes moving at 0.1 c at an acceleration of 10 m/s^2 will use 3,000,000,000,000,000 W, or 3 PW. This is about 200 times more power than is used by our entire civilization. Where's this going to come from? How much is it going to cost? You say that you'll use self-replicating machines, but even given that it's a tremendous project. Surely we could use the mass of Neptune for something better?

One of the best things about using concentrated light is that you sidestep generator requirements in favor of mirror area.

On top of that benefit, you can actually stage a lightsail to slow down when you reach your destination. The bulk of the mass (70-80%?) needs to be dropped as part of the reflecting stage, but that's really not such a bad staging ratio for an interstellar craft.

Tom Kalbfus · 2016-08-29 20:12:15

There are also rogue planets, and with self-replicating probes, we can detect them, in fact we could probably detect a good many of them with telescopes. There are the planets within our Solar System, but I wouldn't want to use those. There are also rogue planets out between the stars, chances are they are more numerous than red dwarf stars. We can search the 4 cubic light years of space between Sol and Alpha Centauri for some, send out 4 billion replicating probes, and space them out each one thousandth of a light year from one another in a cubic rectilinear arrangement and have them shine lasers on each other to measure their distances from one another precisely, if there is a rogue gas giant somewhere in those 4 cubic light years, it will be detected, then the spaceships will close in on that gas giant, self-replicate from its material and its moons and tear it apart to build the accelerator, the hydrogen would be used to fuel the fusion reactors and so forth.

My idea is to make interstellar travel cheap and commonplace, not something for an elite core of astronauts supported by a vast army at the homebase. We would probably need artificial intelligence to do most of the heavy lifting in this, but that is how it always would have been.

RobertDyck · 2016-08-29 20:35:22

I am reminded of a movie called "The Black Hole". It had a silly Hollywood plot, the interesting point was a giant starship sent using state-of-the-art propulsion technology. It had hibernation, automation, and systems to allow humans to live on the ship for the century long trip. During the century of isolation, all sorts of dramatic things happened on the ship. Before it arrived at its destination, Earth developed new propulsion technology. A small ship zipped there in a couple weeks. Of course there's more silly Hollywood stuff, but my point is a trip that takes excessively long will probably find Earth develops new technology before they arrive at their destination. If that new propulsion technology can arrive first, then the first ship is a waste of time and money. That is a "trope" that appears in a couple science fiction books. This is in Star Trek as well; according to "canon" in 2050 a series of ships were launched to stars within 15 light years, but only the one to Alpha Centauri reached its destination before being overtaken by second generation ships. I know it's only fiction, but considering the extreme travel times and the rate technology is advancing today it is highly plausible that a new drive would be developed before the first ship reached its destination.

A point of trivia for nerds. Matt Jefferies was the artist who designed and built models for the Enterprise. His first proposal was rejected by producers. That design was later recycled as the first generation ships mentioned above. And that first proposed design just happens to look a lot like designs for Alcubierie Drive.

XCV-330 Enterprise:
180?cb=20141124041444&path-prefix=en

Alcubiere drive:

Tom Kalbfus · 2016-08-30 08:02:27

We have no examples in nature of anything traveling faster than the speed of light, we do have examples of things coming close to the speed of light, such as cosmic rays, and things accelerated by our particle accelerators, the linear accelerators I'm talking about are simply larger versions of that. Now if we live in a universe where travelling faster than the speed of light is impossible, we just have to make the best of things as they are, living within the physics as we know them today, if a sudden discovery should occur, fine, then what we did prior to that point may have been a waste or resources, but we don't know that until it happens.

Funny thing happened when I was looking up diagrams and specs for this starship.
Dan+Uyeno+Daedalus+class+1.jpg
I kept on getting this one, and in fact there were more images of this one, than the one of Project Daedalus of a real starship proposed by the British Interplanetary Society. Now the thing is, Star Trek's starships aren't going to get us anywhere because they are not based on real science.

Eventually we may have a network of linear accelerators spanning across the galaxy. Maybe use antimatter ships to establish the beach heads in other systems, begin constructing each link and open up new systems to mankind. For the cost in matter though, we just find sunlike stars and build our own planets where there isn't one already.

Last edited by Tom Kalbfus (2016-08-30 18:03:01)

SpaceNut · 2017-02-02 18:10:09

Its not a starship but maybe a way to make the SLS useful....

Using the SLS for outer Solar System exploration?

Use the tankage to push it out to the destination faster in hopes that we could get there within a life time....

elderflower · 2017-02-03 05:23:06

Star Trek ships make a noise in the vacuum. How annoying is that?

Tom Kalbfus · 2017-02-03 08:09:20

elderflower wrote:

Star Trek ships make a noise in the vacuum. How annoying is that?

Not in the classic series, the only time the Enterprise made noise was when it fired its phasers or photon torpedoes, it warp and impulse engines were very quite, though there was music going on in the background!

elderflower · 2017-02-03 09:25:00

It wasn't the music of the spheres, was it?

Tom Kalbfus · 2017-02-03 10:41:02

elderflower wrote:

It wasn't the music of the spheres, was it?

Well you got to have some background music, you can't just have silence, because then people would be adjusting the volume nobs of their television sets and complaining that they aren't getting any sound! They will switch to other channels and get sound, then they would switch back and then call up the station and complain that they aren't broadcasting any sound. The music just lets the viewers know that there isn't anything wrong with their television sets, or with the station that's broadcasting, there just is no spaceship sounds to broadcast.

Mars_B4_Moon · 2023-03-15 16:33:39

maybe not Project Daedalus?

NASA and DARPA will build a nuclear rocket by 2027
https://www.space.com/nasa-darpa-nuclea … ocket-2027

Column: Future of nuclear power growth lies outside Europe and N. America
https://www.reuters.com/business/energy … 023-03-08/

Mars_B4_Moon · 2023-10-07 06:49:40

Space Force approves funding for nuclear fission-powered spacecraft

https://interestingengineering.com/mili … spacecraft

New Mars Forums

Announcement

#1 2016-08-28 10:33:27

Proxima Express

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Re: Proxima Express

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Re: Proxima Express

#22 2023-10-07 06:49:40

Re: Proxima Express

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