Powering our spacecraft
Powering our spacecraft
John Peck's excellent Sept. 11 editorial concerning the twin Voyager spacecraft traveling in the outer solar system reminds us of American technological prowess and our drive to explore. That drive remains alive today - witness also the arrival of rover Curiosity to Mars and NASA's resurgent popularity.
A first point, perhaps not fully appreciated in John's editorial, is the national resource that makes these missions possible. Why do Voyagers continue to have electrical power after 35 years that far out in deep space? With the sun merely a bright point of light billions of miles removed, solar panels are useless. The only realistic power option in 1977, and now, for this type of unmanned explorer, remains radioisotope-powered generators.
These ultra-reliable, nuclear-fueled power sources are built by the Department of Energy for NASA's missions. Well-known missions packing "RTGs" include the Voyagers, New Horizons (arrives at Pluto in July 2015), and the now hugely celebrated Curiosity rover. Although not absolutely needed on Mars, the on-board radioisotope power system (RPS) enables a far more capable and durable rover than otherwise possible.
Secondly: having first-hand experience with RPS as a former employee of both NASA and DOE, this legacy capability to provide RPS for U.S. spacecraft has come close to disappearing (see details at space.com/15184-plutonium238-spacecraft-fuel-production.html).
We need to support funding of these missions and the RPS technology they depend upon.
Dr. B. Alan Harmon
Hard & helpful lessons
This "you better not do that again" diplomacy doesn't work. I know from experience.
When I was in about the eighth grade there was a student named Ed who loved to beat
up on my friend Bruce and me. He laughed at our, "you better not do that again."
So Bruce and I tried a different diplomacy.
I got in a face-to-face argument with Ed, Bruce got behind him on all fours, I made a lunge for Ed and down he went over Bruce's back. We jumped on him and with lunch pails
and school packs we beat him up pretty good.
When Ed got to school the next day he looked awful. Black eye, cuts and bruises everywhere.
All the kids knew what had happened, and I suspect the teachers also knew.
Ed never bothered anyone again. Last I heard he was a successful businessman.