Geoffrey Landis works at NASA and has made many contributions to advanced space concepts. In particular to laser pushed sails.

The interstellar distance issue was summarized

Moon                   0.5 million kilometers
Mars                  50 million kilometers (100X Moon distance)
Jupiter              600 million kilometers (12X Mars distance)
Pluto              6,000 million kilometers (10X Jupiter distance)
Oort Cloud     7,000,000 million kilometers (1200X Pluto distance)
Nearest Star 130,000,000 million kilometers (19X Oort cloud distance)