I recently had a very similar project for my on-line Master's program. Given that the project was heavily weighted, I was very worried about my partners (either they would not pull their part, or I would not be at their level).
In order to make sure everyone was happy with the progress, we set deadlines, reviewed the work of everyone, and spoke a lot about what needed to be done, revised, and completed.
One can easily tell about another person's commitment to education, even if one does not meet face-to-face. Email the person, discuss the plan, ask for input. Depending upon their response, you will be able to tell how "urgent" he or she is as well.