I recently came across Could pulsars really act as "lighthouses" to help in interstellar travel?, asked a week ago. The author was trying to figure out if pulsars could be useful for interstellar FTL travel, because they could be used to find a craft's position; the answer was, of course, yes. I had some reservations, though. My main issue was that it seems, from an engineering standpoint, not very feasible. Here's my thought process:
- To be certain of successfully triangulating your position to a high degree of accuracy, you'd need to have probably half a dozen or more candidates to observe from any one location.
- Observing a pulsar isn't easy. The issue is that if you make a random jump out of hyperspace, you won't know where any pulsar should appear unless you can quickly determine a general location. This means that you'd need to do a lot of guessing, and essentially discover pulsars all over again.
- This in turn means that you'd need a large radio telescope, and that's not really easy to attach to a typical spacecraft. Optimally, the dish is over 100 meters in length.
Let's say that we overcome various other technical hurdles, and need to attach a 100-meter parabolic radio telescope (although I'm open to other designs, if you can make a very convincing argument otherwise) to an interstellar spacecraft, for the purposes of finding and monitoring pulsars for navigation. I'm concerned as to whether or not the telescope could survive sub-lightspeed travel for any extended period of time. By this I mean acceleration for perhaps two weeks to a speed of maybe $0.01c$, staying at constant speed for three months, then decelerating for two weeks. Propulsion would likely be from chemical rockets.
- Will the telescope survive the harsh conditions of space, including micrometeoroid impacts?
- Will there be any physical stresses from the motion of the ship that could damage it?
- Are there any other potential dangers to the telescope itself, and can they be overcome?
So far, nobody's actually addressed the original scenario in as much detail as I'd like. I'd love answers that do that; it's why I asked the question. However, I wouldn't be totally opposed to answers that suggest different but related options, such as using a different type of telescope, or using pulsars a different way. But you'd have to make a really good case for doing so, and you'd still have to justify that this option would survive the spaceflight.
My motivation for asking this is that I've considered using pulsars for this purpose in several stories, but I've always gotten hung up on how to solve this sort of problem.