There’s no shortage of ways a satellite in low Earth orbit can fail during the course of its mission. Even in the best case scenario, the craft needs to survive bombardment by cosmic rays and tremendous temperature variations. To have even a chance of surviving the worst, such as a hardware fault or collision with a rogue piece of space garbage, it needs to be designed with robust redundancies which can keep everything running in the face of systemic damage. Of course, before any of that can even happen it will need to survive the wild ride to space; so add high-G loads and intense vibrations to the list of things which can kill your expensive bird.
After all the meticulous engineering and expense involved in putting a satellite into orbit, you might think it would get a hero’s welcome at the end of its mission. But in fact, it’s quite the opposite. The great irony is that after all the time and effort it takes to develop a spacecraft capable of surviving the rigors of spaceflight, in the end, its operators will more than likely command the craft to destroy itself by dipping its orbit down into the Earth’s atmosphere. The final act of a properly designed satellite will likely be to commit itself to the same fiery fate it had spent years or even decades avoiding.
You might be wondering how engineers design a spacecraft that is simultaneously robust enough to survive years in the space environment while at the same time remaining just fragile enough that it completely burns up during reentry. Up until fairly recently, the simple answer is that it wasn’t really something that was taken into account. But with falling launch prices promising to make space a lot busier in the next few years, the race is on to develop new technologies which will help make sure that a satellite is only intact for as long as it needs to be.
Continue reading “Why Satellites Of The Future Will Be Built To Burn”
Hackaday readers are well aware of the problems caused by materials left exposed to the environment over time, whether that be oxidized contact pads on circuit boards or plastics made brittle from long exposure to the sun’s UV rays.
Now consider the perils faced by materials on the International Space Station (ISS), launched beginning in 1998 and planned to be used until 2028. That’s a total of 30 years in an environment of unfiltered sunlight, extreme temperatures, micrometeoroids, and even problems caused by oxygen. What about the exposure faced by the newly launched Tesla Roadster, an entirely non-space hardened vehicle on a million-year orbit around the sun? How are the materials which make up the ISS and the Roadster affected by the harsh space environment?
Fortunately, we’ve been doing experiments since the 1970s in Earth orbit which can give us answers. The missions and experiments themselves are as interesting as the results so let’s look at how we put materials into orbit to be tested against the rigors of space.
Continue reading “Lost In Space: How Materials Degrade In Space”
Thanks to the seminal work of Howard and Hanks et al, the world is intimately familiar with the story behind perhaps the most epic hack of all time, the saving of the crippled Apollo 13 mission. But Apollo 13 is far from the only story of heroic space hacks. From the repairs to fix the blinded Hubble Space Telescope to the dodgy cooling system and other fixes on the International Space Station, both manned and unmanned spaceflight can be looked at as a series of hacks and repairs.
Long before the ISS, though, America’s first manned space station, Skylab, very nearly never came to fruition. Damaged during launch and crippled both electrically and thermally, the entire program was almost scrapped before the first crew ever arrived. This is the story of how Skylab came to be, how a team came together to fix a series of problems, and how Skylab went on to success despite having the deck stacked against her from the start.
Continue reading “Hacking When It Counts: Much Space Station Hacking Saved Skylab”