"It's the velocity," explained Don. "Venus Equilateral is traveling at the same speed as Venus, of course. A spacecraft hits it up in the hundreds of miles per second. Say two hundred and seventy miles per second, which is about ten times the orbital velocity of Venus Equilateral. Then with a given dispersion of meteors throughout space, any spacecraft has ten times the possible chances of encounter because the ship covers ten times the volume in the same time. Besides, truly missing meteors is a hypothetical problem."
"How so?"
"To avoid only those whose courses will intersect yours would demand some sort of course predicting gear that would read the course of the oncoming meteor and apply it in a space problem to the predicted course of the ship. That's just too much machinery, Doug. So spacecraft merely turn aside for anything that even looks close. They don't take any chances at all," said Don Channing. "They can't afford to."
"Suppose that the ship ducked a big shower and it went so far out of course that they missed Mars?"
"That's out, too," laughed Channing.
"Why?"
"A standard ship of space is capable of hitting it up at about four G all the way from Terra to Mars at major opposition and end up with enough power and spare cathodes to continue to Venus in quadrature. Now the velocity of the planets in their orbits is a stinking matter of miles per second, while the top speed of a ship in even the shortest passage runs up into four figures per second. You'd be surprised at what velocity you can attain at one G for ten hours."
"Yes?"
"It runs to slightly less than two hundred and fifty miles per second, during which you've covered only four million miles. In the shortest average run from Venus to Terra at conjunction, a skimpy twenty-five million miles, your time of travel is a matter of twenty-five hours odd, running at the standard two G. Your velocity at turnover—or the halfway point where the ship stops going up from Terra and starts to go down to Venus—is a cool five hundred miles per second. So under no condition would the ship miss its objective badly enough to cause its complete loss. Why, this business is run so quickly that were it not for the saving in time and money that amounts to a small percentage at the end of each flight, the pilot could head for his planet and approach the planet asymptotically."
"You know what you're doing, don't you?" asked the reporter.