Email from Keith, May 17, 2017 (underline by SH): “Team X can do a single spacecraft mission study in about two days (I just had two for HabEx – Telescope and Starshade – in four days). If a second option is a variation on the first option (e.g., slightly heavier or more power hungry payload, change the propulsion system from bi-prop to SEP) it can be handled in the study with a third day. We are holding three days for your mission study. Furthermore, if you make small changes outside of Team X (e.g., drop or add an instrument) we can get a Team X systems engineer to update the sheets with the new information to get the correct mass and power and cost without holding another Team X session. You will not get a new configuration or a new report but sometimes you just need a new MEL and cost estimate. There is a good deal of flexibility with the instrument design team too. When you know what you would like to study then you, me and Amy should sit down and work out a Team X plan. Right now I have a three day mission study (February), two instrument studies (December and January) and a short A Team architecture study in the plan. Again, we have a good deal of flexibility in where to put the work but how much work we do is a fixed.”