Posts Tagged

space tech

Space Items We Won’t Get Back

Elizabeth Technology September 22, 2022


Why launch a telescope into space when the ones on the Earth aren’t limited by launch weight restrictions? There are many reasons, but the biggest one is that Earth’s atmosphere and pollution get in the way. When you get to the sort of deep field imaging the Hubble is doing, any infrared fuzz from other sources at all will blur the photo and reduce the telescope’s range. The atmosphere contains and reflects a lot of radiation, all across the spectrum, so it naturally obscures quite a bit of what you’d see if you were just outside of it.

As a result, NASA uses satellite telescopes to see the farthest reaches of our universe! While Hubble was not the first of its kind (the 60s had the Orbiting Solar Observatory) it is one of the most technologically advanced, and it remained the pinnacle of space-based telescope tech for most of its life so far, receiving regular upgrades and repairs until 2009. It consists of the same ‘mirrors reflecting lights onto a central point’ that many long distance telescopes do, but without all the fuzz of the atmosphere in the way, it was able to catch an astonishing amount of detail and distance not previously seen by telescopes on Earth! While this is no longer the most powerful telescope in space thanks to the James Webb, it’s still provided tons of valuable, useful research material. It’s central mirror can capture 40,000 times more light than a human eye could. You may notice that stars in Hubble’s pictures have a distinct halo with four points of light – that’s thanks to how the side mirrors are arranged around the central one.

Cassini and the Golden Disk

Most of the stuff people send into space isn’t expected to make it back to Earth, at least in one piece – there’s not a great way to retrieve large objects from space. However, most of the objects we send out are expected to stay in orbit, or burn up. James Webb and Hubble are in orbit (although the Webb telescope is actually orbiting the sun).

The Cassini space probe, launched in 1997, is not in orbit, at least not anymore. Cassini’s original goal was to learn about Saturn and its moons. It maintained an orbit around Saturn from 2004 to 2017 when it’s orbit decayed (on purpose) so it could descend into Saturn and hopefully learn a little more on its way out of this material realm. And learn it did!

Even more far-reaching are the Golden Records, sent out on the Voyager spacecraft in 1977. Voyager was not launched towards one particular star; the closest it’s going to get, barring any encounters with space debris on the way, is a lightyear and a half away from a star in 40,000 years. The records contain sounds and sights from the planet Earth, intended as a message in a bottle, for anyone or anything that finds it. It uses pulsars, long-lived remnants of stars that ‘flash’ or ‘pulse’ EM waves at a constant rate, to orient the map, since anything complex enough to spot Voyager would also be able to see them, thus providing a reference point.

Did you think the Mars Curiosity probe singing happy birthday to itself was sad? We’ll never see Voyager again. There’s no promise anything will.

James Webb

The James Webb telescope is one of the most technologically impressive things humankind has ever managed to make. It took several hundred millions of dollars and years of hard work to make it happen. The images coming back right now (as of this article, July 14th of 2022) cover an area of the sky approximately the size of a grain of sand from our perspective on Earth. The universe is huge! That one little point shows an enormous amount of galaxies, including ones whose light has been warped as it traveled to us by something in between us and them, all different angles and distances away from us. It also captured higher-quality images of planetary nebulas and the like that we had from Hubble, but even more detailed! None of this, of course, would have been possible without Hubble coming first, and the images Hubble captured are equally impressive – the Webb scope’s design simply allows it to see further and gather more light in order to actually ‘see’ the things out there in space. Webb’s images of stars also have halos, but it has six points of light instead of four like Hubble, a result of a different and improved mirror focusing design.

When you’re dealing with such huge distances, your telescope has to begin compensating for something known as ‘Red-shifting’ – especially with things that are moving away from you or your telescope. Red-shifting means that the waves of light will begin stretching out. Wider wavelengths of light are redder than narrower ones, and so everything begins trending towards infrared light when it gets far enough away from us. If those galaxies have aliens looking back at us, they’d see us as redder than we are, too! As such, both Webb and Hubble captured information from Infrared all the way up to X-Ray bands. We can’t see X-Rays either, and have to compensate there as well.

Technology on Our End

Not all of that compensation is happening in the telescope itself – a lot of it is happening in the data processing back on Earth. The same thing goes for the Hubble. Many of the complex images of planetary nebulas or gas clouds are the result of weeks’ worth of light catching and data combining. Some celestial bodies are bright, others are dim, some gasses that compose nebulae are not visible to the human eye, etc. and so all must be visually adjusted so that we, on the other side of that enormous void, can actually put together an image we understand. This doesn’t mean the images are ‘fake’, although they’re not always the pretty colors shown in the images by NASA. NASA often color codes things to indicate where one kind of gas cloud ends and another begins, for example, or differences in density and temperature that the telescope could see in X-Ray but we couldn’t.

Just as the telescopes have gotten better, so too has the technology receiving the images back on Earth. 

Starlink Stuff is Kind of In The Way Sometimes

Elizabeth Technology March 21, 2022


China’s Tianhe space station is a lot like the ISS – it’s modular, it’s in low-Earth orbit, and it’s got enough living space for three crew members at the moment. Unlike the ISS, it’s not complete, and is slated to receive more modules in the upcoming years. Eventually, it’s going to have life support, and it’ll ideally be able to do a lot of what the ISS does but completely under China’s control. Astronauts and scientists are already using the central Tianhe module for experiments, and of course to do so they’d need to be inside it, which is part of China’s current annoyance with SpaceX – adding human life into spacecraft maneuvers that wouldn’t have been necessary if not for new satellites intercepting the path adds ethical danger to the already political issue at hand.

The Outer Space Treaty of 1967 allows for basically everybody to peacefully explore outer space as long as they abide by a set of pretty reasonable rules, meaning China has the right to hang out in outer space so long as they’re not building a WMD up there, same as anyone else. (China’s previous issues with sliding into the ISS’s orbit are a problem, but not one that violates the treaty as long as it’s accidental, or ‘accidental’.) However, not much governs exactly where stuff is supposed to go except for data. Establishing orbit is very complicated – establishing orbit with other countries’ projects in the way is even more complicated. Because Earth has an atmosphere, things that are too close will eventually be dragged back down via friction with the little bit of air up high. Things that are too high may not perform as expected, or begin to drift away. There are sweet spots for projects, and those sweet spots have a surprising amount of stuff in them already.  

China has had to perform evasive maneuvers twice to keep their Tianhe module away from Starlink satellites crossing into their path. This is really, really annoying in space for a couple of reasons. Number one, fuel is limited. Number two, people were on board, and China is in the middle of a fit of nationalism – countries take a lot of pride in their experts, from Olympic athletes to leading scientists, so disturbing or potentially risking those kinds of people when a country is invested in proving it’s the best with said people is not ideal. China responded well, all things considered.


Surveys are being affected by the Starlink Satellites. Sky surveys can be contentious – the best spots to put the survey sites are places with good weather and low light pollution. Equatorial areas tend to meet this conditions, but some places – like Hawaii – would rather not give up even more precious (and sometimes sacred) land for these telescopes. Thus, survey sites are limited.

The survey site discussed in the article that first noted the phenomenon is the Zwicky Transient Facility in deep Southern California, a facility dedicated primarily to finding near-Earth asteroids and other cool things. Having stuff interfere with the pictures isn’t dangerous, because the odds that something would fit behind the satellite streak is near zero, but it is annoying and sometimes distracting.

Surveys are essentially long-exposure photos of the sky, with the telescope adjusting gradually to account for the Earth’s rotation. The satellites, which move at speed, appear as streaks across the photos. The last article I read on the matter says Starlink now has 1,800 or so satellites orbiting at a distance of 550 kilometers above the surface, with a final goal of 10,000 or so. ZTF says at that rate, every photo they take could have a satellite’s streak in it.

Progress takes time, and it takes bug-fixing. Right now, this is a major bug to fix.

For the Future

There’s a potential problem caused by space trash: Kessler Syndrome. This, if started, cannot be stopped. A cascade event where one satellite crashes into another, which causes that to break apart and then crashes into more satellites, and then on and on. We’ve already got enough space trash for this to be a potential problem, and unfortunately satellite launches come with a lot more stuff alongside the satellite that can end up in orbit. It’s not just the big stuff, either – while the big stuff is certainly dangerous, small pieces at great speed can also be extremely dangerous.

On Earth, if you throw a ball, it will eventually stop. The Earth’s gravity pulls it downwards, and air (or other materials in the way) gradually slows the object down until it comes to a complete stop. In space, if you throw a ball, it will go in that direction at that speed forever. If that ball is tossed into a stable orbit, the same applies. Now, picture throwing that ball at a normal speed in one direction. Other stuff in orbit is not moving at normal ball-throwing speeds. The ISS orbits the earth every 90 minutes – it moves about 4 miles every second. Things need to be moving at that speed to resist gravity, because if they slow down they start falling towards the Earth. If that ball hits something big that’s moving at that kind of speed, the speed difference may mean that ball goes straight through whatever it hits, or at the very least damages it. If it knocks pieces off, those pieces go at their own speed, and maintain some momentum from the bigger object. Now you have a handful of tiny bits of metal to track and pray they don’t end up hitting something else important. Space trash has the potential to really, really screw up major projects.

How do we handle space trash? Starlink, with it’s 10,000 satellite plan, will hopefully have an answer before it turns into a serious problem.