OK - @DCDC I found the discussion. #284. Sportsball starts it but you can look at what they replied to Soodad - and then read down from 284.
Perhaps you can add to their discussion or correct if needed.
I guess the genesis I got from it - and we had years ago for my daughter who wanted regularly to go into DC - was that it wasn’t realistic on a regular basis.
Thanks for adding your input - and to the other thread too. I still say - given one is going to intern during the summer, it wouldn’t be a factor for me. But OP can decide. Also, NASA Goddard doesn’t appear to be in DC - but East of UMD in Greenbelt MD (maybe it’s easier??) Public transport shows 1 hr 32 right now. UMD to DC shows 1 hour 4 but maybe because it’s a weekend.