Is it time to give interstellar travel a shot?

[landeTLS]

If one could travel at 1/10 of the speed of light. Have enough dv to slow down the craft when on final approach (to achieve solar/planetary orbit, and if manned still have the ability to refuel on site or enough dv to Accelerate back to 1/10 lightspeed plus establish orbit with earth ) if manned Could support the crew for the entire trip (food,recycling,oxygen, artificial gravity etc.)

Travel time also depends on how fast the craft can accelerate, if it is halfway to the other star before it reaches target speed then the travel time will be a lot longer than if the acceleration was more quick.

A lot of these things are not possible today and the travel time would probably be too long for humans that where not "preserved" via scifi tech.

But an unmanned non return flyby could be possible in the forseeable future afaik. Possibly also an orbit. All ofcource if it was practical to achieve 1/10th the speed of light with some concievable nearfuture tech (the possibilities are probably an "orion" nuclear pulse propelled engine. Or a laser sail. Fusion propelled rockets are more theoretical/scifi but could also be a possible option)

Edited March 13, 2014 by landeTLS

[78stonewobble]

In this thread.

http://forum.kerbalspaceprogram.com/threads/40866-When-Gimbal-Lock-Is-A-Bad-Thing/page6

We could go for a mechanical computer.

[rkman]

Microwave is not radio, though they're adjacent parts of the EM spectrum. Radio waves penetrate Earth's atmosphere, microwaves don't.

That's a pretty arbitrary definition of "radio".

"Radio is the wireless transmission of signals through free space by electromagnetic radiation" http://en.wikipedia.org/wiki/Radio

"Microwave radio relay" http://en.wikipedia.org/wiki/Microwave_transmission#Microwave_radio_relay

[LtHeckard]

I do believe that a space craft developed for interstellar travel could be possible, but it cannot go any faster than .1c because even the smallest particle of dust would shatter the spacecraft.

[SargeRho]

Whipple shields and impact shields (would) exist for a reason.

[Red Iron Crown]

That's a pretty arbitrary definition of "radio".

"Radio is the wireless transmission of signals through free space by electromagnetic radiation" http://en.wikipedia.org/wiki/Radio

"Microwave radio relay" http://en.wikipedia.org/wiki/Microwave_transmission#Microwave_radio_relay

By the first definition, a laser is a radio. "Microwave radio" is a commonly used misnomer.

The definitions of the different parts of the EM spectrum are arbitrary, and there's some overlap, but I don't think it's right to call microwaves radio.

Here's a useful diagram of what I'm talking about.

[rkman]

By the first definition, a laser is a radio.

If used for communication, i'd say yes it is.

"Microwave radio" is a commonly used misnomer.

Only if you think microwave is not radio.

I don't think it's right to call microwaves radio.

Microwaves are regularly used for all kinds of wireless communications, which by definition makes it radio.

google: microwave ham radio

https://www.google.com/search?q=microwave+ham+radio

[nhnifong]

Let's forget the idea of going 0.1c and just send a bunch of super light probes at nearby stars at speeds of merely 30 to 50 km/s using traditional chemical rockets. Our descendants in 30 thousand years will thank us, and it won't even be that expensive.

[SargeRho]

Radio in this context refers to a specific range of wavelengths, not wireless telecommunication. Microwaves are waves in the 300 Mhz to 300Ghz range. I think they actually fall within Radiowaves, but I don't know for sure.

[Red Iron Crown]

If used for communication, i'd say yes it is.

Only if you think microwave is not radio.

Microwaves are regularly used for all kinds of wireless communications, which by definition makes it radio.

google: microwave ham radio

https://www.google.com/search?q=microwave+ham+radio

I guess we're going to have to agree to disagree. If you're going to define radio as any EM signal transmission, that's fine, enjoy your smoke signal radio.

I'll stick with the definition NASA uses.

[Seret]

Microwaves are waves in the 300 Mhz to 300Ghz range. I think they actually fall within Radiowaves, but I don't know for sure.

No, microwave is a separate part of the spectrum from RF.

[Rakaydos]

No, microwave is a separate part of the spectrum from RF.

That might be a relatively recent revision- I lerned it as overlapping, but that was 10 years ago.

[Nuke]

In this thread.

http://forum.kerbalspaceprogram.com/threads/40866-When-Gimbal-Lock-Is-A-Bad-Thing/page6

We could go for a mechanical computer.

i dont think we would need to go that far back. besides complex mechanical devices tend to be maintenance hogs.

one thing is different memory technologies are more suitable to use in space than others. dram and its derivatives are know for its tendency to bit flip when exposed to chargeed particles, sram is a bit more robust. im not sure how flash does in space. i was reading about fram the other day, which is essentially core memory on a chip, would work great in space. mram would be another one. thing is every time we invent a new kind of memory it takes a few decades for moors law to play out.

Edited March 14, 2014 by Nuke

[Seret]

That might be a relatively recent revision- I lerned it as overlapping, but that was 10 years ago.

In practice the gear and the principles are similar enough that they might as well be considered the same thing. RF people are quite happy working with microwave gear, they're taught together and work the same way. It's not like there's a sharp cutoff frequency where the principles change radically. So the distinction is a bit arbitrary.

[rkman]

If you're going to define radio as any EM signal transmission, that's fine, enjoy your smoke signal radio.

You do realize performance does not depend on how you define it, do you?

[Red Iron Crown]

You do realize performance does not depend on how you define it, do you?

I have no idea what this post means. Can you clarify?

[rkman]

Maybe i misunderstood what you mean by "smoke signal radio". Does not sound like it is a particularly effective way of radio communication, and you seem to think it is related to my defining microwave as radio.

[Red Iron Crown]

I meant that by the definition you're using, sending smoke signals is using radio, too.

I think we're just using different definitions of what "radio" means. The definition I've been using is in reference to a specific part of the EM spectrum, which by most definitions excludes microwaves (though, as you say, this is arbitrary). The differences in properties between radio waves and microwaves are great enough that they shouldn't be considered equivalent.

I think you're using the definition "any device which transmits information wirelessly using EM". I consider this a misnomer, as not all of those devices use radio frequency, but it has crept into general usage.

[Seret]

as you say, this is arbitrary

That was me actually.

[rkman]

I meant that by the definition you're using, sending smoke signals is using radio, too.

I can't think of a non-convoluted argument as to how smoke signals are EM waves.

If my definition of radio is a misnomer, it is so only according to arbitrary definition.

But really, this has gone to far already. I propose a cease-fire.

[Red Iron Crown]

But really, this has gone to far already. I propose a cease-fire.

Agreed.

[DonLorenzo]

I can't think of a non-convoluted argument as to how smoke signals are EM waves.

If my definition of radio is a misnomer, it is so only according to arbitrary definition.

But really, this has gone to far already. I propose a cease-fire.

Really? But.... how will you send smoke signals without the fire?

I'll see myself out

[Seret]

I can't think of a non-convoluted argument as to how smoke signals are EM waves.

Visible light is an EM signal. Your eyeballs are electromagnetic receivers.

[78stonewobble]

i dont think we would need to go that far back. besides complex mechanical devices tend to be maintenance hogs.

one thing is different memory technologies are more suitable to use in space than others. dram and its derivatives are know for its tendency to bit flip when exposed to chargeed particles, sram is a bit more robust. im not sure how flash does in space. i was reading about fram the other day, which is essentially core memory on a chip, would work great in space. mram would be another one. thing is every time we invent a new kind of memory it takes a few decades for moors law to play out.

Yeah... and anything mechanically advanced could probably weigh as much as proper shielding would anyway.

Still, if it is a manned ship, we might come to the conclusion that we would not be able to trust conventional computer to endure everything and we might send along some kind of mechanical helping device as a sort of backup. Even if it's just a glorified calculator.

Just like even in this day and age of GPS, sailors, soldiers, pilots and so on are still trained in alternative ways of navigation, in the event of emergency.

[Nuke]

you are going to have a number of math people on hand to solve problems as they arise. sota like mission control in the early days of space program. never underestimate a room full of geeks with slide rules. besides your ship is going to be so big that the time neccisary to orient the ship for a maneuver will be long enough to do any math you need. there will be computers but they wont be the powerhouse you are used to using.

Edited March 15, 2014 by Nuke