The future of manned space travel.

[jsluder]

Or, worded another way, how do you navigate really long distances with no point of reference at all?

Just like we do on Earth: choose an arbitrary origin for an arbitrary coordinate system.

[monkey587]

Or, worded another way, how do you navigate really long distances with no point of reference at all?

The same way we did with the Mars Rover?

[djm]

Your point of reference is your starting point. We'll just mark it here with a big red X. Now we just leave a trail of breadcrumbs, and look back over our shoulders every parsec or two, and we should be right as rain ... er ... in space ....

djm

[Coffee]

how do you navigate really long distances with no point of reference at all?

--James

The one word answer? Calculus.

We might not have fixed points of reference, but we do have moving ones. As long as we know where those objects are, their current speed and trajectory, we can still get about just fine.

[peeplj]

how do you navigate really long distances with no point of reference at all?

--James

The one word answer? Calculus.

We might not have fixed points of reference, but we do have moving ones. As long as we know where those objects are, their current speed and trajectory, we can still get about just fine.

What happens if your ship breaks?

If you lose track of your position, how do you re-establish it?

Mind you, I think that not only is it possible, I think we'll do it one day.

Using technologies that we don't even dream could exist, yet.

--James

[Denny]

Using technologies that we don't even dream could exist, yet.

people were dreamin' 'em before I was born!

[mutepointe]

When I used to swim laps, I lost count a lot. So, every time I completed a stroke, I'd say, "1" "1" ...til I got to the next lap, then I'd say, "2" "2"... If I lost count once, i could think back and get back on track, once I lost count twice, I had no clue.

If you're out in space lightyears from earth, does it really matter if you know where you're at? It's not like you know where you're going and it's not like you're going back to where you started. Just enjoy the trip.

[peeplj]

Anytime this subject comes up, a song by Urban Tapestry comes to mind, called Starsoul.

I still can't listen to this song without getting tears in my eyes.

To me, this song makes the argument far more eloquently than I ever could.

Here are the lyrics:

The ship is untried and you say she won't fly,
The chances are good she will not reach the sky,
But she has to be tested for space is the prize,
If you think none will take her just look in my eyes.

(chorus:)
So show me the gantry, give me the ship,
Give me the fuel and I'll go on that trip.
Now if I return you can say I was bold,
But my place is in space as the heavens unfold.

I know I may die, that I may not return,
But just strap me in and I'm ready to burn,
My life I will pledge if my life be the fare,
For I need the long dark and the stars past the air.

(chorus)

If I live I'll be glad but that's not why I go,
For my heart is afire with the rocket's red glow;
My body knows grief although I have not been
To my home in the sky with the worlds never seen.

(chorus)

And if I should die in a bright burning flare,
Just take what you find and throw it in the air.
Don't grieve for my death, don't ask why for ten years,
Just build one more ship and ask for volunteers.

So show us the gantry, give us the ship,
Give us the fuel and we'll go on that trip.
Now if we return you can say we were bold,
But our place is in space as the heavens unfold.


--- o --- O --- o ---

damn fine song.

--James

[BillChin]

how do you navigate really long distances with no point of reference at all?

--James

The one word answer? Calculus.

We might not have fixed points of reference, but we do have moving ones. As long as we know where those objects are, their current speed and trajectory, we can still get about just fine.

What happens if your ship breaks?

If you lose track of your position, how do you re-establish it?

Mind you, I think that not only is it possible, I think we'll do it one day.

Using technologies that we don't even dream could exist, yet.

--James

If you ever watched TV, you would know the answer is to triangulate . Seriously, as long as you are in known space with charted stars, it is a relatively easy task to stop for a moment and figure out exactly where you are. It is the same principle that the old navigation tool, the astrolabe works on, measure the angles that known star systems appear at. In layman's terms a person would look at various stars of known position to draw enough lines on a 3-D star chart to get a point of intersection. Not hard, even by hand and a simple 3-D astrolabe type of tool, much less with computers and modern optics.

For more on astrolabes
http://www.astrolabes.org/mariner.htm

Now compare that with sailing ships of the Columbus era. They could only determine their latitude with an astrolabe. For longitude, they used logs with average speed for the day, and dead reckoning if they came upon any landmarks. If they were in the middle of the ocean they had little idea how far they had gone, because their primitive measurements were only best guesses.

The longitude prize is one of the great stories of science. A little known person widely regarded as a quack by the establishment was awarded the prize. Isaac Newton was convinced the task was impossible. It is an example of how some technological break throughs come from virtually unknown sources. So it will be with space exploration, when more people can get into the game with relatively small amounts of money. It is amazing that despite "proof" the scientific experts of the Newton era, deemed what had been accomplished pure luck, and not science. So it will be again, with some future innovations.

from
http://itotd.com/articles/532/the-longitude-problem/
>>
Nothing could be more important to a captain than knowing the ship’s location, but without landmarks, this was an amazingly difficult puzzle a couple of centuries ago.
...
an unknown clock maker named John Harrison was busy ... constructing a clock that was far more accurate than any available at the time and able to maintain that accuracy even after weeks of being tossed around on a ship
...
The clock performed flawlessly (and well within the range stipulated for the prize). But the judges on the Board of Longitude—which included Isaac Newton—were convinced that no mechanical device could ever solve the longitude problem. So this success, they concluded, must have been a fluke. They demanded (and got) a second trial, which showed similar accuracy but still didn’t convince the Board.

Eventually Parliament took up the matter, and agreed to give Harrison and his son half the prize money, with the other half to be delivered if other watchmakers could duplicate his design and produce the same results. Three years later, William, frustrated by the Board’s continued heel dragging, appealed to King George III, who tested H4 himself. He found it as accurate as had been claimed and, outraged that the Board had kept Harrison’s rightful winnings from him, threatened to appear personally before Parliament if they didn’t hand over the rest of the prize money.

In 1773, at age 80 and after more than 40 years of work, Harrison finally received both the prize money and the recognition of having solved the longitude problem. He died three years later, on his 83rd birthday.
>>

[WyoBadger]

What happens if your ship breaks?

Well, you just need one of these, and a whole lot of this.

Tom

[Dale]

I bought a flashlight last night and nearly cut off my thumb trying to get it out of that plastic packaging. As I always do, I asked myself why NASA doesn't line the bottom of the space shuttle with this incredible polymer. I'm going to build a house out of it.

[fearfaoin]

All those planets and starts aren't just sitting still out there. They are moving at...well...astronomical speeds.

My Chem prof once went on a rant about Star Trek. He would get particularly
annoyed when Picard would say "Come to a Full Stop". Relative to what!?!?

As I always do, I asked myself why NASA doesn't line the bottom of the space shuttle with this incredible polymer. I'm going to build a house out of it.

What makes you think they don't?

[Nanohedron]

I bought a flashlight last night and nearly cut off my thumb trying to get it out of that plastic packaging.

Here you go: