This Scientific American article looks at how landings on Mars have gotten more and more precise, shrinking the “landing ellipse” from 300 km × 100 km (Viking) to 7.7 km × 6.6 km (Perseverance), which enables landings in places other than wide undifferentiated plains. Some locales will be still be off-limits for some time: “For instance, scientists cannot propose landing on high-altitude features such as Olympus Mons because the atmosphere overhead is too tenuous to sufficiently slow down a spacecraft. Regions with very rough terrain or steep slopes are also off-limits, even with [Terrain Relative Navigation]. Furthermore, features such as polar ice caps, canyons, lava tubes and sand dunes offer poor prospects for wheeled rovers and would require alternate forms of mobility.”
How Mission Control’s Giant Displays Worked
In a 19-minute YouTube video, Fran Blanche explains how those big screens at Mission Control worked during the Apollo era. Stop and think about it: they were displaying information in ways that computers wouldn’t be able to do for decades. The displays were produced mechanically, by multiple projectors using glass slides to project images on the screen. The projectors could move spaceship icons across the screen like a graphical sprite, or use plotters to scratch a flight path across a slide to represent a flight path, using telemetry data processed in real time by mainframe computers. [Boing Boing]
Further Reading on the Apollo Program
We marked the 50th anniversary of Apollo 11 last week, which means that the next step is to put all our moon-landing related nostalgia away until the next milestone anniversary, or until another of the remaining Apollo astronauts dies.1
If, on the other hand, all this attention has piqued your interest in the moon landings, the Apollo program, and the history of crewed spaceflight generally speaking, I have some suggestions as to what you should watch and read next. There are, of course, plenty of books and documentaries on this subject, but these will give you a general overview, with increasing levels of detail.