How can I politely tell a professor that I'm too busy to do research with him this term? I'm an undergraduate. I sent two emails to professors regarding potential research work. Both responded positively, which I didn't expect, and I started work with one of the profs last term. As for the other, I think his work is incredibly interesting but I simply don't have the time for two research projects at once. However, I would really like to work with him eventually. 

How can I tell the other professor that I'm too busy this quarter but would like to work with him at some point in the future? It seems a bit awkward to mention the other professor so I'm not sure how to explain it.
Just say so directly! He will value your directness and honesty – 'beating around the bush' gets rather tiresome. There's enough of that from management...


  I'm sorry that I don't have time to work with you this term, as I have now started on a research project with Prof A that I am committed to finishing. However, I would still really like to work with you in the future. Since I aim to finish my current project in a few months, around the end of June, would you mind if I contact you again then?