No matter how new the technology may be, no matter how unpredictable the research may be, you can still break down any project into discrete and finite steps. First identify the steps that you have a high degree of certainty of achieving. Then identify the steps where you have a medium or low degree of certainty. If possible, perform the riskiest steps first. Commercial managers usually have a better aptitude for breaking a project into steps than do scientists.
Scientists are great conceptual thinkers but they are often weak in project management skills.
For most commercial managers, this is their strong suit. A commercial manager knows how to break a task into practical steps. Steps should not be confused with milestones. A milestone is simply one way to measure the completion of a step. Other ways include dollars spent or results achieved.