Was performing a manned Duna return mission with Bill, Bob, Jeb, and Val. Being their was only 3 seats in the capsule I put one of the kerbals into a hitchhiker module thinking that I could just ferry the extra Kerbal back down to Kerbin once I'd returned. Long story short, I underestimated my fuel expenditure and my only option was to either ditch the hitchhiker (extra weight, no heat shield on hitchhiker) and just barely get an aerocapture into Kerbin via rcs, or go dancing off into space because I wouldn't have enough fuel to circularize. Needless to say one Kerbal wouldn't be returning home. Jeb bravely took on the task, and is now orbiting for eternity in solar orbit.