We Must Think Outside the Rocket Equation

The rocket equation contains three variables. Given any two of these, the third becomes cast in stone. Hope, wishing, or tantrums cannot alter this result. Although a momentum balance, these variables can be cast as energies. They are the energy expenditure against gravity (often called delta V or the change in rocket velocity), the energy available in your rocket propellant (often called exhaust velocity or specific impulse), and the propellant mass fraction (how much propellant you need com...

 Astrochicken

The basic idea of Astrochicken is that the spacecraft will be small and quick. I do not believe that a fruitful future for space science lies along the path we are now following, with space missions growing larger and larger and fewer and fewer and slower and slower as the decades go by. I propose a radical step in the direction of smallness and quickness. Astrochicken will weigh a kilogram instead of Voyager's ton, and it will travel from Earth into orbit around Uranus in two years instead ...

 Two Examples of Leaping to Conclusions without the Facts

Let me give you two examples of leaping to conclusions without the full facts. Back in the 1890’s, a certain California newspaper was apprehensive about the harmful effects the railroads would have on the environment. If the trains crossed the Mojave to get to the Pacific, this newspaper editorialized, “the huge iron rails will reverse the Earth’s magnetic field with catastrophic effects.” Now that’s real science! One hundred forty years ago, the Royal Society in England warned agai...

 Randal Monroe on Space Flight

The universe is probably littered with the one-planet graves of cultures which made the sensible economic decision that there's no good reason to go into space--each discovered, studied, and remembered by the ones who made the irrational decision.