How would you navigate in space? Say you lived on planet x. And grandma lived on planet k, and it was Christmas and you and the family were invited for dinner. You load the presents into you new 'faster than light Mustang space cruiser and headed off to granny's for some Christmas ham and homemade pie. Now planet k is 14 light years away from planet x and between planets k and x looms a massive star. As you zip past that star, it's gravitational force pulls ever so slightly on your Mustang, changing it's trajectory by .005mm. Lets say that this happens 4 lightyears away from home. You can't see planet k, but it's still 10 lightyears away which means that you might miss it by millions of miles. That's the scenario, silly maybe but it does address a dilemma. How do we navigate in space, if we ever get there?
We calculate and change as needed to compensate. Just as we do for wind on airline flights, but in advance rather than in flight.
Yes, orbital mechanics are fairly straightforward (it's all just gravity, for the most part) and so are highly predictable. Which is why we can send robotic probes to Mars, make only a few engine burns, and know they'll arrive three years later, even though both planets will have circled the sun several times by then. It's also why we can model the history of the solar system to a degree -- rewinding the orbits of the planets to see what was going on thousands or millions of years ago.
They would likely navigate the same way we navigate space probes we send out now. Scientists and Astronomers know the gravitational force of objects in space for the most part so they are able to compensate for things like that. Or use it to their advantage. Even as I grew older and learned more about astronomy and astrophysics I still find it absolutely astonishing that they are able to get all of the trajectories, gravity sling shots, timing, etc just right to be able to throw a probe from our little planet and manage to somehow land it right on target some 3 billion miles away. Needless to say, those guys and gals are pretty damn smart.
The Apollo 11 guidance computer had a processing speed of 1MHz and a memory of about 4kb. Your average smartphone meanwhile, used by folks to send selfies, and playing angry bird has a processing speed of 1.3GHz and 64GB of memory. I would think interplanetary navigation would be a piece of cake given access to the incredible computing power available today...who knows what the future will bring, factoring in Moore's law of course.
Yep, as I understand it, the programs are straightforward enough that calculating orbital trajectories is pretty simple nowadays. Assuming, of course, that everyone is working off of the same measuring system: http://articles.latimes.com/1999/oct/01/news/mn-17288
Oh, absolutely. It's kind of embarassing to be one of just three countries in the world that aren't on the metric system -- the other two being Liberia and Myanmar. If tradition is so powerful that we can't move to something as sensible as the metric system, it brings into question our openness to new ideas, period.
I guess that an interstellar civilization will have a dynamic simulation of the galaxy in the computers on board of the space vessel. They would rely on that simulation to know exactly which is the right direction in any single moment of the journey [we should keep in mind that in a space travel, the problems are not the known object which affect the trajectory of the vessel, but eventual unknown objects and in interstellar travels a vehicles can deal with giant nomad comets, nomad planets, not detected vagabond black holes ...]. I go further imagining they will be able to see a simulation in real time of the sector of the galaxy with the position of the starting point, the vessel and the point of arrival.
There will be errors in everything. So you will need to plan for course corrections. One way to find your position in space is to look at neutron stars. You will know the positions of these and so will be able to work out your own position from them. Also you would be able to look at the stars you are coming from and going to. Reasons for needing to do this include 1. leakage of material from the craft 2. collisions from other objects 3. errors in what you do.
The last resource would be the active research of the target solar system by analyzing the spectrum of the stars. The spectrum of a star is like the DNA of an individual, if you are aiming to the star "IB-G2/4" and you are not that sure that your rout is correct, you can scan the space in front of you looking for the spectrum of that star ...
