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Is this shit possible? I don't think so honestly. But w

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Is this shit possible? I don't think so honestly. But what does /sci/ think? Can you build one?

Picture related, it's called the "solar express"

A concept on a train that would hurtle through space nonstop. Never decelerating at all. Using various small ion thrusters and the gravity of large celestial objects to adjust or change course.

http://www.sciencealert.com/meet-solar-express-the-space-train-concept-that-can-get-to-mars-in-two-days
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>>8302560
better have some retardedly good brakes
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>>8302577
it doesnt stop, so it never needs brakes thats the idea. It would meet up with smaller vessels to pick up and drop off.
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>>8302560
Why, specifically, do you think it wouldn't work?
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>>8302560
>solar express
I'M A DIGITAL CYBERDEMON
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>>8302588
No i'm just curious what you guys think of this. What would it take to make this baby run. besides millions upon billions of dollars and or debt.
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>>8302603
well it would take living in a completely different universe where physics works totally different for starters

When you are well over solar escape velocity, how do you turn around? You are just gonna shoot out of the solar system no matter what you do.

>"In space, the most expensive portions of travel are the acceleration and deceleration phases. The energy required for those portions is tremendous,

If space travel was measured in the energy cost for delta V, then it would be cheaper than trains or planes.
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It's a cycler. It'll work. The craft docking and departing it would need a lot of fuel for the massive change in Delta V.
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It's just an Aldrin cycler but going at sanic speed.

The idea is that you put your big heavy habitat in a cycler orbit that regularly passes between the two planets. Accelerating the habitat is a one-time deal, then you can bring your crew and supplies up to dock in small spacecraft.
The crew/supply craft will still have to match the velocity of the cycler in order to dock, but since they're relatively small and light it requires less fuel to reach the required velocity.
It's still really expensive, but ultimately more efficient than packing enough fuel to accelerate to Mars, decelerate at Mars, then accelerate to Earth, and decelerate again at Earth.

It could work technically, but doing it in 2 days is setting the bar extremely high.

https://www.youtube.com/watch?v=qCVfUlFZQ4U
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it's not a new concept, even if it didn't leave the pulp scifi books or drawing boards in the last century

It just takes a monstrous amount of fuel/force to maintain that dV for any long period of time. Every ion-propelled craft has basically worked to a limited extent on gravity slingshots and very low thrust/dV to make the most of their fuel, or to be able to operate on solar energy. So they'll keep accelerating somewhat constantly but with thrust numbers in the grams. So not really at all that high of speeds

But to go interplanetary in a matter of 2 days is WEW LAD
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>>8302616
Its not more efficient in any way, in fact its completely stupid & pointless

Also it would be slow as shit.
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>>8302625
>backupyourfactsretard
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>>8302625
nice post
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>>8302627
takes more delta-v just to match a stupid fucking cycler than to go to mars in the first place.

What purpose does a cycler serve? Just go straight to mars if you want to go to mars.
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>>8302625
It's significantly more efficient, but only if you use it many times over a long period of time.
The first missions to Mars won't use a cycler, but if we eventually get to the point of permanent or semi-permanent Mars bases/space stations that require regular missions back and forth, it would be worth doing.
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>>8302639
It allows you to have a large habitat for the crews to live in during their trips without having to accelerate and decelerate it at each planet.
Again, the 2 days thing is very unrealistic, 3-4 months is more plausible, and with that long of a trip, a larger habitat is necessary.

One obvious downside is that is something goes wrong and the crew fails to rendezvous with the cycler for whatever reason, they're shit out of luck.
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>>8302643
? It has years of downtime, thats not efficient at all
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>>8302664
Once you get it into it's orbit it's set though.

With a accelerate/decelerate method you'd have to have engines that could withstand being ignited many times, and refuel it in orbit, which isn't easy. Plus you have to the rocket equation to deal with when you start packing more fuel for the additional acceleration and deceleration burns.
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>>8302676
Why are you doing deceleration burns when both planets have an atmosphere?
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>>8302607
That's the point, m8. This is one of the designs of a generation so meant for interstellar travelling at sub-light speeds.
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>>8302681
Whoops
Meant generation ship.
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>>8302677
Aerobraking alone when you're going really fast is a good way to die
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>>8302677
Because aerobraking a large transfer vehicle is really difficult.
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>>8302686
>>8302685
Aerobraking will ALWAYS be better than spending 90% of the mass of your vehicle in fuel doing deceleration

I don't think its difficult at all, the only reason the shuttle was problematic was because it was a stupid design & done before automation.
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>>8302664
No it doesnt. It literally never stops. There is absolutely no downtime. Read the article you hasbeen faggot.
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>>8302696
>muh pop-sci article that gives no specifics
>mars in 2 days! for free!
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>>8302693
You arenall idiots. Its not supposed to brake at all. The concept is to KEEP GOING. fucking retards the lot of you ibwish i never came here this board is worse than cancer. Its like if hiv had a kid with cancer. Thats what you are ugh.
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>>8302693
Aerobraking alone at the kind of speeds this thing is proposing will cause you to burn up, you have to drop below escape velocity in one pass or you miss and dont get another chance
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>>8302698
THE SOURCES ARE IN THE ARTICLE ACTUALLY READ FUCKBOI
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>>8302699
go read a book on how space travel works, it aint' fucking rocket science, its relatively simple & straight forward

This pop-sci bullshit from OP's article has nothing to do with reality.

muh space trains FUCK OFF
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>>8302560
I cant even imagine how you would accelerate/decelerate the smaller craft that go back and forth to 1% C fast enough to catch it
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>>8302705
>it aint' fucking rocket science
Kek, but seriously explain precisely why the concept wouldnt work
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> it never decelerates
>Sci starts talking about deceleration methods
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>>8302709
because cyclers have fixed speeds linked to specific orbits, and spend the vast majority of their time looping back around in deep space.

Theres no speeding up a cycler, or you would just fly off into space.
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>>8302730
You have to speed it up to get it into its desired orbit though. I dont understand your point, the whole idea is that you dont speed it up or slow it down once you have it on the orbit you want it on
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>>8302738
ur dumb fucking article quotes 3000 km/s which is obvious nonsense
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>>8302741
Yes, but can you explain why it couldnt work in principle
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>>8302741
>ur dumb fucking article quotes 3000 km/s which is obvious nonsense
Well yeah, but the article is stupid.
Everyone but you is just using it as an excuse to talk about cyclers.
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>>8302751
Go watch some youtube video on cyclers

Whatever this solar express is supposed to be is just some guy talking out his ass.
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>>8302761
I'm still waiting for an explanation
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>>8302763
>I'm still waiting for an explanation
The absurd cycler in the article won't work, because it's moving far to fast for planet's gravity wells to significantly change its course. It would just shoot past any planet and fly off into interstellar space.
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>>8302776
Its not intended to change its course
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>>8302783
well then, ETA to alpha centauri 400 years at 1% of c
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>>8302789
No you see because it uses magic to stay on a regular orbit at absurd speeds
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>>8302783
Q: What do you call a boomerang that doesn't come back?
A: A stick

Q: What do you call a Aldrin cycler that doesn't come back?
A: ???
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>>8302827
Its like you dont even understand the concept of "magic"
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>>8302827
a solar express
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>>8302581
>>8302560
Basically, just flying around on a circuit then?

Once it reaches x speed, it maintains that and essentially orbits the sun or something?

Then ships from Earth can dock with it on its way to x destination. They just need to match its speed, but in a tiny ship instead of a massive ship like the train.

I can see the benefits. Less fuel needed to get to a final destination repeatedly while having really nice accommodations for the trip. This would work really well, if the speed is correct, which it isn't....

>>8302741
>3000 km/s

So, 6,710,809mph or 1% of c. That's too fast for a ship to reach and too fast to use planet's/sun to steer properly. It'd fly off into space too far for the engines to compensate. The fastest man made object only reached 90,000mph (0.01% of c) and that was the Juno satellite that is orbiting Jupiter now.

>>8302783
But, its purpose is to stay in the solar system as a mass transit. That is what the article says. I wonder how much it decelerates over the course of its circuit; every gravity well in the solar system will be pulling on it after all.
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>>8302677
mars' atmosphere is way too thin
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>>8303379
Lithobreaking then.
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>>8303382
brake not break
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>>8302693

>the only reason the shuttle was problematic was because it was a stupid design & done before automation.

even Apollo could be run in an automated mode, this is how it was tested
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>>8302560
so... a man made comet?

It would need to be a highly elliptical orbit. Someone would need to maintain the space train as it reaches apogee. Could someone survive that far out in space?
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>>8302560
The thing in the article is completely retarded and written/"thought" by someone who doesn't understand aerospace engineering. It is basically a designer just doing it for viral marketing, although usually they just design a silly looking yacht or something.

The reason it is retarded is because 1% of the speed of light would be an enormous achievement, which basically impossible to be done with chemical engines. Even so, 1% of the speed of light is many times over the Sun's escape velocity, so this thing is going out of the system and beyond unless it turns, except "turning" in space is acceleration, so it definetly does not "keep going either". And also, no, no planet's gravity can turn like this an 1% of light thing. Not even the sun can.

That said, the overall concept is somewhat similar to a cycle, which is a real thing. Except that in this case, the frigging thing would be an interstellar cycler more likely so that it would manage to turn. And keep in mind that 1 star probably wouldn't be enough. You'd probably need to swipe it by 4-5 suns before you managed it to u-turn it towards sol again.
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>>8302560
>> 1% C
oh fuck no
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>>8302581
If the smaller vessels have to be accelerated to match speed then what's the fucking point?

Am I missing something here?
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>>8304595
The smaller vessels don't require as much energy to accelerate.
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>>8304635
Yes but what's the point of having the larger vessel at all?
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>>8304692
More living space. You can't live in a small capsule for months.
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>>8303379
mars atmosphere is ample

it just means u have a higher terminal velocity
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>>8304692
>Yes but what's the point of having the larger vessel at all?
Having it means that the small craft don't have to be much bigger than a Soyuz.
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>>8303379
No it isnt we have aerobraked shitloads of stuff into mars orbit
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>>8302560

>Aldrin Cycler
>just really fast
>doesn't mention Buzz in the article
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>>8303881
Yeah, this is a napkin sketch idea from someone who lacks the physics background to see why it wouldn't work, or why, if it did work, it wouldn't make any sense.

The idea of a cycler is that, since you're going to spend a long time travelling to Mars, you need a big, heavy vehicle with lots of radiation shielding and life support stuff. It would be nice if you could use that for more than one trip. So instead of accelerating a long-term habitat to Mars for each trip, you just have to accelerate the people to catch up with the habitat on its orbit.

If your cycler takes two days to get to Mars (setting aside that this is ludicrous), it serves no purpose. If your transfer vehicle can catch up to a cycler moving that fast, it can get to Mars in two days on its own. In fact, by the time it docked with the cycler, it would probably be time for it to undock already.

Anyway, that's way too fast for aerobraking, so it would need to propulsively stop itself at Mars.

On top of that, accelerating to 3 million meters per second even at an uncomfortable 3g would take 100,000 seconds, or 27 hours, and decelerating to land would take just as a long.

This is all ignoring the obvious impossibility of this thing working as described (i.e. getting up to this speed by slingshot maneuvers and turning around by gravity alone).
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>>8303819
I meant more about automation involved in stuff like maintaining the heat tiles, which took an army of interns instead of some machines.
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>>8305147
AKA pretty much exactly what the big spaceship in the Martian ended up doing
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>>8305186
You mean the idea of a cycler? Yeah, the ship in "The Martian" was normally supposed to be a transit habitat repeatedly shuttling between Earth orbit and Mars orbit using nuclearthermal-electric propulsion, but they improvised a cycler-like trajectory using two fly-by rendezvous (a resupply at Earth then a pick-up at Mars) to make an emergency return to Mars and pick-up.

Incidentally, that was an insane plan. In the setting, they would have had nothing prepared for a flyby resupply rendezvous, and they had to throw it together in a rush and launch it on an unfamiliar Chinese rocket. If they missed it, the whole crew and the ship would be lost (as could also have easily happened in the crazy events of the pick-up rendezvous).
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>>8302560
kek file name
>>
I don't get it. If the idea is to save on the costs associated with accelerating and decelerating cargo, don't you still need to accelerate the cargo to the speed of the train to load it?
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>>8305290
Because you only have to accelerate your cycler, which contains your living space and all the infrastructure for the months long journey one time.
You're going to need all that infrastructure no matter what, so it's more efficient to set up a cycler and re-use it for multiple trips than to bring enough fuel to make the additional burns to park the thing in Mars orbit and then bring it back to Earth.

The 2 days thing is sci-fi though. Realistic cyclers still take a few months to get to Mars and then have to swing out to deep space before coming back to Earth.
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>>8302560
Thumbnail looked like a vibrator from afar
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>>8305186
Well... no

You see they needed to move an ENTIRE big spaceship back around, not just the solid stage booster that had all of their food on it.
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>>8302705
>space travel aint' fucking rocket science
L0L good one
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>>8305373
>so it's more efficient

Whats more efficient, save peanuts on fuel costs, or leave your 400 million dollar spacecraft looping around for 2 years after the earth -> mars trip

Is that an efficient use of hardware & manpower? Nope
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>>8305406
>You see they needed to move an ENTIRE big spaceship back around
Yeah thats how a cycler works, a big spacecraft that can support people and cargo for a long time continually shuttles back and forth without stopping
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>>8305445
>Whats more efficient, save peanuts on fuel costs, or leave your 400 million dollar spacecraft looping around for 2 years after the earth -> mars trip
As opposed to what, launching an entirely new one each time?
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>>8305461
as opposed to going back and forth like a plane, since the tonnage needed for a habitat is not really significant compared to all the cargo that needs to be shipped.
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>>8305505
refueling and re-igniting engines in orbit isn't that easy
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>>8305579
I think SpaceX is going to be showing us the optimal & sane way of doing things
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Do people here understand basic orbital mechanics? You can't have a cycler going inside Solar systems at 1% of c, it would fly straight out to the interstellar space.
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>a Montreal-based innovator,
Also known as I don't know what the fuck I'm talking about.
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>>8305383
When you are a hammer everything is a nail
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>>8305734
Perhaps, but right now SpaceX is only really working on launch vehicles. They can restart their engines but they do the entire thing within a few minutes. Then they go through a bunch of servicing before they get fired again.
Having an engine that can go months before being re-ignited, and be refueled and serviced in orbit is harder. Cryogenic propellants like LH2/LOX can't be kept cold that long, so hypergolic propellants have to be used for long missions, which are corrosive as fuck and very rough on the engines.

The Apollo ascent engine for example had to be rebuilt after each test fire because the fuel was so corrosive. So when they ignited the one to get off the moon, it was the first time it had ever been fired.
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>>8306607
Well, they are working on their spaceship to go to mars too. And will relase their architecture to do so later in september.

Storing cryogenic propellant in space/restarting engines at mars will all need to be solved.

As far as I understand all the successfully landed stages could have been launched again immediately, they aren't space shuttles, they don't need to be taken apart & refurbished.
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