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)
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.