sentences:  While working at Caltech, Parsons was admitted to evening courses in chemistry at the University of Southern California (USC), but distracted by his GALCIT workload he attended sporadically and received unexceptional grades.By early 1938 the Group had made their static rocket motor, which originally burned for three seconds, run for over a minute.In May that year, Parsons was invited by Forrest J Ackerman to lecture on his rocketry work at Chapter Number 4 of the Los Angeles Science Fiction League (LASFL).