Nerva, courtesy Adrian Mann.


Solar System Exploration: The Missing Drive

by admin

This guest blog is a contribution from Glenn Thornton. Glenn is recently retired from a career at Los Alamos National Laboratory. He worked on underground nuclear testing at the Nevada Test Site for four years and then joined the Lab’s satellite design group. He made important contributions to several satellite projects, some NASA funded projects among them. He designed the data acquisition systems for the Lab’s neutron spectrometers that flew on Lunar Prospector and a similar instrument for Mars Odyssey. Lunar Prospector was the first orbiting lunar probe to use remote sensing (neutron spectrometer) to definitively identify water ice deposits in the permanently shadowed craters at the lunar poles. Mars Odyssey is still orbiting and returning data from Mars. It has produced detailed global maps of subsurface ice deposits on Mars. The neutron spectrometer can see about a meter deep and identify the percentage of water ice within a “footprint” that the instrument sees as it travels over a region. Glenn currently lives with his wife Pam and their mischievous cat, Tilly, in Santa Fe, New Mexico.

A year before I was born and a full decade before Sputnik, one of the pioneers of modern science fiction had his first novel published – the year was 1947. In a world that still struggled to recover from the horrors of the Second World War, the author depicted an optimistic future. Ironically, the backdrop for his vision was the V2 rocket; Nazi Germany’s most destructive Vengeance Weapon. He was able to look past its dark origin and see the V2 as a promising technology. Previous developments, military or otherwise, were nothing more than upgraded fireworks in comparison to the V2. The V2 was the first rocket to reach suborbital space, but to Robert A. Heinlein, it did much more; it pointed to the Moon and beyond…

Perhaps a bit giddy about the promise of the V2, Heinlein envisioned a world where the chemical rocket was in everyday use. He saw rockets zooming around the planet, delivering mail, freight, and passengers. The rocket was simply the next step in high speed transportation and he expected it to be adopted as quickly as the train, automobile, propeller aircraft, and the jet. After jet comes rocket; what could be more logical? Yet, as inspired and optimistic as he was, he still couldn’t see chemical rockets taking us beyond the Earth, not even to our nearest neighbor.

Heinlein understood the energy density and efficiency problems that confronted the chemical rocket. He realized that even a trip to the Moon would require a monstrous tower of fuel and oxidizer. It was too extreme for serious consideration, but he couldn’t foresee Sputnik; the Soviet first strike that put a priority on advanced rocket technology and launched the Space Race. Spurred on by the heat of the Cold War, NASA and Wernher von Braun constructed that tower of chemical propellants and engines, stretching three feet higher than the entire length of a football field, including end zones. The Saturn V was both an amazing achievement and a definitive statement about the limitations of chemical rocket technology.

Read more: Solar System Exploration: The Missing Drive | Icarus Interstellar.

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