Studying for a master's in Computer Science after a bachelor's in Physics I am currently in my penultimate (third) year of a master's degree in Physics (in the UK). The degree is set up such that you have four years of a taught degree and graduate with a master's without ever actually receiving a bachelor's. However, it is still possible for me to switch to a bachelor's degree in Physics.

I have been considering whether it would be advantageous to switch to a one year master's degree in Computer Science instead of Physics since I have developed a substantial interest in programming and software development over the last two and a half years of my Physics degree. I have taken programming modules as part of the degree and I completed a software development internship last year that was related to geographical information services in the space industry. I also try to get involved in software projects in my free time when I can but I don't have particularly extensive experience.

After getting involved with some student space organisations and undertaking research into careers, my goal is to work in a software related position within the information sector of the space industry - something I have developed a strong interest in. Jobs like these require software skills but do also specify that a bachelor's or master's degree in Physics would be valid for entry.

So, I have the choice of continuing with a master's degree in Physics or switching to a master's degree in Computer Science. I find the latter more interesting and along with the broader principles of Computer Science I would learn from it (i.e. not just programming), it may give me an advantage when it comes to applying for the jobs I am interested in. However, the primary drawbacks to switching would be adapting to a new university and course structure when I may be able to self-teach the key skills that I would learn from a Computer Science master's.

It is possible to undertake a year-long software development project as part of a Physics master's, although this would of course be accompanied by Physics-centred taught modules.

Any advice about the benefits of such a switch to Computer Science would be greatly appreciated.
Given you can get a first in your BSc in Physics I think it is OK to move. You have a strong written indicator that you know your Maths for an industry person. In addition, you can legitimately claim you left because you liked something else more rather than you leave suspicions you left because you could not handle it.

Having said that, I would personally stick for an MSci in Physics because: 1. It is significantly less common than CS and 2. a Mathematics/Physics education is much harder to acquire later in life (To put it bluntly: People don't catch-up on their PDEs). You say you have the opportunity for a year-long software development project. This is very good and gives you a great foot-hold for future SW development work.

Finally it is important to note that "a software related position within the information sector of the space industry" is a rather broad thing. If you want to do information security, image recognition or something equally specialized you should definitely focus on a specialized MSc. If you want to do simulations, reliability, controls, etc. actually sticking to your MSci might be a better thing (given you know how to code :) ).