2017 marked the 60th anniversary of Sputnik's successful launch into space. But the past successes of space launches have had an unanticipated consequence: space debris.
There are actually two kinds of space debris: natural (like meteoroids) and artificial (ie: man-made). Natural space debris generally orbits around the Sun, while man-made debris orbits around the Earth. The Earth-orbiting, human-made space junk is also referred to as orbital debris.
While it is not something we civilians think about when space travel comes to mind, NASA's chief scientist for orbital debris, Nicholas Johnson, says, “The greatest risk to space missions comes from non-trackable debris.” There are over 500,000 pieces of tracked orbital debris orbiting the Earth at up 17,500 miles per hour, and that is not even including the debris that is too small to track from Earth. According to NASA's website, "Even tiny paint flecks can damage a spacecraft when traveling at these velocities. In fact a number of space shuttle windows have been replaced because of damage caused by material that was analyzed and shown to be paint flecks."
Luckily, no disasters of the proportion of Gravity (starring Sandra Bullock) have taken place. But it's only a matter of time. And once some large piece of debris hits another large orbiting body, that collision will create even more orbital debris. And then that debris will hit other debris, and create more debris, and so on and so forth.
This doomsday scenario is called Kessler Syndrome. As far back as 1978, NASA scientist Donald Kessler predicted that someday there could be such a high density of orbital debris that collisions create only more debris that increase the probability of further collisions. If this threshold is reached, it could doom humans to the Earth forever.
Yet we still dream of the stars. SpaceX just successfully launched its Falcon Heavy rocket booster, propelling a Tesla into space. And, this company alone is planning to launch 11,943 satellites into space. In the current environment of orbital debris, this may not work out well, but fear not: people are already thinking up solutions.
Aerospace Corporation has created Brane Craft, a blanket-like, metal sheet that is supposed to wrap around space debris and pull it back into the atmosphere to burn up. Another (more exciting) approach proposed by the Air Force Engineering University in China is to blast debris with lasers. Yet another solution, from Japan's Aerospace Exploration Agency, suggests using an electrodynamic tether (pictured below). It's basically a magnetic chord that uses electromagnetic force to redirect objects into the atmosphere.
Space junk is a problem for future extraterrestrial travelers, but it is not an unsolvable one. Hopefully, future generations, too, will have the chance to explore space: the final frontier.
Sources:
https://www.nasa.gov/mission_pages/station/news/orbital_debris.html
https://en.wikipedia.org/wiki/Kessler_syndrome
https://www.wired.com/story/spacex-wants-to-launch-thousands-of-satellites-what-for/
https://www.space.com/38105-ultrathin-craft-could-destroy-space-junk.html
https://www.space.com/39412-china-satellite-lasers-clean-space-debris.html
https://www.space.com/38984-tiny-space-debris-sensor-to-station.html
Images:
https://www.npr.org/sections/thetwo-way/2016/12/09/505020386/japan-sends-long-electric-whip-into-orbit-to-tame-space-junk
What an interesting post! I had never really thought about space debris or Kessler Syndrome, but it definitely makes a lot of sense how this would be the case considering the space travel processes that have been able to occur. As new innovations regarding space travel continue to be created, like SpaceX, it is crucial to consider their lasting effects so that there can continue to be more developments in space travel. Creations such as Brane Craft that are meant to combat this issue are so fascinating. When doing some more research to learn about some specific details of Brane Craft in particular, I found out that the physical spacecraft is actually thinner than a human hair and extremely lightweight. It definitely surprised me to picture these spacecrafts that can be used to potentially create a solution to the issue of space debris as described in the article below, because when I thought about them, I initially thought of something much larger that would be sent into space to pull the space debris back into the atmosphere to burn up.
ReplyDeletehttps://www.popsci.com/space-debris-clean-up-spacecraft#page-3
Anya — your post took a very interesting perspective on the possibly dangers of space expeditions! I was never really aware of the danger that debris orbiting the Earth could very possibly threaten our lives due to heightened collisions. I found the fact that even paint flecks could significantly damage spacecrafts fascinating because it really isn't something we'd see as a threat to our safety. It's good that people are already developing ways to get rid of the debris, either by sending it into the atmosphere to burn up or shooting at them with lasers. I did some more research into the lasers and I found that the idea behind it is that the radiation from space-based lasers can affect the orbital path of the debris. The goal is to use this radiation to redirect the path of the debris into the atmosphere. It seems like the majority of the solutions involve moving the debris from orbit to be destroyed in the atmosphere, which is pretty interesting.
ReplyDeletehttps://www.space.com/39412-china-satellite-lasers-clean-space-debris.html
Anya- thanks for such an interesting and insightful post. Often times, as we have seen in American history, the repercussions are not considered until it is nearly too late. This incident reminded me of the Love Canal Disaster that we recently learned about. Although chemicals and the chemical industry symbolized the opportunity for American growth through jobs, scientific discovery, and even furthering the individual American dream, the discovery of the environmental impacts did cause a pushback. In Love Canal, the chemical residues from Hooker Chemical Company was "mostly composed of products such as "caustics, alkalines, fatty acid and chlorinated hydrocarbons resulting from the manufacturing of dyes, perfumes, and solvents for rubber and synthetic resins". Following the movement of the people of Love Canal to get their homes cleaned up, over 30,000 chemical waste repositories were found in the US. People became fearful of the "ground under their feet" - as the documentary said. I think that the 1970s was in important part of history not only because of the technological advancement, but also the government's increasing role to protect the environment in the midst of this development. I think its sad that we have often wrecked our homeland in the name of making money. Even with Space Travel, I think that the environmental effects should be greater publicized instead of romanticizing growth. Thankfully people are working to clear up the space debris, though!
ReplyDeletehttps://en.wikipedia.org/wiki/Love_Canal