Tiangong-1’s Death Throes

The astronomy news sites, like Space.com, have been filled with information about Tiangong-1, a Chinese space station tumbling out of control towards Earth this weekend. On the one hand, space trash entering the atmosphere and burning up is not really news. It happens all the time, particularly since estimates put orbiting debris at around 170 million items smaller than a centimeter, 670,000 bits between 1 and 10 cm, and about 29,000 larger bits (Wikipedia par 2). These small bits of shielding, tools, a lost glove, and other small bits burn up when they renter the atmosphere. It is scary to realize that these numbers do not include the 17,852 objects being tracked by the United States Strategic Command, of which only 1,419 are operational satellites.

Tiangong-1

Tiangong-1

Credit CMSA. An artist’s rendition of the space station. From Space.com

For example, Tiangong-1 (Heavenly Palace in English) is not small. This station is a smallish 9.4 tons and the rough size of a school bus, so  is possible that some fragments might make it all the way to the ground even after it breaks apart upon re-entry. People shouldn’t worry about these fragments though, since experts say the chances of getting hit with the debris is extremely unlikely. One fun fact though is that a popular television show, Dead Like Me, was based on the comedic premise that the main character was killed by a re-entry toilet seat from space. And this space station isn’t even the largest thing to streak earthward. The Russian space station Mir came down in 2001 and weighed 120 metric tons. The biggest difference is that Mir was controlled when it hit the atmosphere whereas Tiangong-1 will not be.

Space Station History

Tiangong-1 was China’s first small station. It was launched in 2011 with the purpose to perform docking practices and living in space tests in 2012 and 2013. It orbited the earth at an altitude of 217 miles. Although it provided useful planetary data for the Chinese space agency, this station’s service ended in 2016 (Howell).

Waste of Resources

An object of this size coming down from space is an unusual event but not necessarily a dangerous one. What strikes me as the real crime here is that, when it flames out of existence, so will so much steel, glass, gold, aluminum, platinum, and other elements. Yes, some of them, particularly the more valuable ones, might only be a few grams in weight but they will no longer be recoverable. Such a small amount may seem like less than a drop of water in an overflowing bucket that represents Earth’s resources, but we all know even that bucket has limits.

We are drilling deeper for oil and gas and digging deeper for coal. We know Helium is running out, and there is no alternative to its use in industry or medicine. For most folks, this means using MRI machines may eventually become rare or stopped altogether because the users don’t have enough helium to cool the superconducting magnets (Quora). We use up and destroy resources because they have always been plentiful but some day they won’t be, a lesson we seem to keep having to learn over and over.

space debris

Computer generated image of Earth with her trash. Credit: NASA. From Wikipedia.com

In that regard, this means rarer metals like platinum, gold, iridium, palladium that are put into spacecraft will never make it back to the Earth to be recycled. Picture a world in the not too distant future where we can’t go to space anymore because we lack some kind of specialized wires or rare-earth semi-conductors to run the equipment. In addition, we can’t make any more since they are elements. This potential future grows even more likely every time a spacecraft, satellite, or station disintegrates as it returns to its mother planet.

Being Better Resource Managers

The wiser move for reducing space trash in the future is two-fold. Consider an international standardization of space equipment so old stations can form parts of new stations. Perhaps this is already in place. It just seems to me that having a five-year mission for a station, such as for Tiangong-1, represents a waste of resources when it could be somehow shifted and attached to future, larger endeavors.

The second part of the plan is to look into research to clean up our heavens and bring the debris down for recycling. It may initially be costly, but it would save money in protecting our operational satellites as well. According to Wikipedia, five satellites have collided with space trash as of December 2016, resulting in more debris. One can’t help but wonder if that number will rise as we continue blasting new projects skyward.

Bringing the debris down would allow us to extract valuable metals and help preserve what limited resources we have. It would also create safer zones of operation as man continues to press forward through the solar system. To make these changes though, humanity has to get rid of the “out of sight, out of mind” mentality on space garbage and begin to create plans to reduce or reuse our resources better. One possibility of that is using reusable rockets, which many agencies and companies are pursuing.

Future Vision

In addition, more than one man’s fortune was made in garbage historically. It is easy to imagine a world where the Earth’s orbit is just a stepping stone to the Moon and Mars. During that time, it might become cheaper and more feasible for a company to rake in all that junk, sort it, reprocess the elements and become wealthy doing so. I can even picture a recycling center in space since lifting things in and out of Earth’s gravity well is part of the overwhelming cost of space exploration.

Heavenly Show

Tiangong-1 flight path

Tiangong-1’s predicted fall path. Credit: Aerospace Corporation. From Space.com

On the other hand, Space.com predicts that this first Chinese space station will make quite a show as it hurls downward. They offer live coverage which started on March 28th at The Virtual Telescope Project. The big show will be somewhere between March 30th and April 1st. The flight path covers the southern part of the US, most of South American and Africa (Howell 2).

So if you are out watching the night sky and notice a a thin streak much like a large meteor crossing the sky, give a moment of silence to this complex distant machine as it goes through its death plunge. It represents yet another step taken in the path leading man to the stars.

References

“Space Debris” Wikipedia.com 25 March 2018. https://en.wikipedia.org/wiki/Space_debris.

Letzter, Rafe. “China’s Out-of-Control Space Station is Nowhere Near the Biggest Thing to Fall From Space” Space.com 26 March 2018. https://www.space.com/40097-china-space-station-tiangong-crash-how-big.html.

Quora. “Why We are Running out of Helium and What we can do About It.” Forbes.com 1 Jan 2016. https://www.forbes.com/sites/quora/2016/01/01/why-we-are-running-out-of-helium-and-what-we-can-do-about-it/#71c825b157ad

Howell, Elizabeth. “Tiangong-1: China’s First Space Station” Space.com 26 March 2018. https://www.space.com/27320-tiangong-1.html

Howell, Elizabeth “Watch China’s Tiangong-1 Space Station in Real Time as It Nears its Demise” Space.com 28 March 2018. https://www.space.com/40111-watch-chinese-tiangong-1-space-station-demise.html

 

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