So I've recently started a job and there is this female co-worker that I really like. I would really like to ask her out, sooner rather than later. However there is one big problem: We're going on a business trip, just the two of us, after 3 weeks of starting work and I wouldn't want to ask her out beforehand, potentially get rejected and then just create unnecessary tension during the business trip. Bear in mind that we would have to travel together.
Is it best that I just wait after the business trip to ask her out even if we would have already worked around 4 weeks together?
P.S. I do not care about the outcome, if I get rejected I'll just tell her that'll it'll not compromise our working relationship, but that I'd prefer not to be "just friends" either as I don't tend to be friends with woman that I'm attracted to. (Edit: On further reflection this is in fact a really bad thing to say, instead I would say, "We should keep this relationship strictly professional", if I do in fact get rejected.)
Edit: It's in the UK and her position is temporary (for 1 year), whilst I'm there permanently. Just for some extra context.