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

 

Oumuamua: Interstellar Visitor that Sparks the Imagination

Last fall, an ancient visitor wandered through our solar system, setting the astronomy world aflutter with excitement. Headlines read something like “First Interstellar Asteroid visits…” which of course is wrong. Since our system is billions of years old, I think it is safe to say that Oumuamua isn’t the first to fly through. It is only the first that we’ve actually noticed.Oumuamua

Ice or rock?

Still this starry visitor engages the imagination. We’re used to comets whizzing through from beyond Pluto but they’re pretty easy to spot because of the elongated tail and fuzzy coma. Not so Oumuamua. Its orbit originally looked like that of a comet, but its lack of cometary characteristics soon marked it as an asteroid or meteor. A closer look at its path through the solar system left astronomers scratching their heads. Asteroids follow closed loops around the Sun, traversing the same path over and over again. Oumuamua is on a one-time trip through out system, zooming in and back out again on its way to the interstellar depths.

The shape of this rocky traveler is surprising as well, elongated and relatively smooth, at least according to the artist’s rendition. I’m sure I’m not the only one who sees the spaceship nature in these photos since asteroid-skinned ships have been theorized in science fiction for years.

A visitor just passing through?

But consider this. What if Oumuamua really was an alien spacecraft? Some scout ship or alien ark passing through our small system on its way to a new home? What if they noticed our intelligent presence, which would be easily seen from our thousands of satellites and space trash orbiting around the Earth? Would they say, “look! another space-faring species”? Or would it be more like, “Hey, change directions just a little and don’t slow down”?

I imagine that visiting our planet might seem like a socialite driving near a filthy mobile home at the end of a run-down trailer park. You know what I’m talking about. The one where empty beer cans decorate the yard and an old refrigerator sits outside the door not far from an overstuffed chair with rips in the seat.

And like the socialite, the extraterrestrial would be, “Don’t look. Don’t answer if they call out.” We are still so primitive compared to what we could be, and the trash around our planet reflects that. One day we’ll have to clean up all the floating debris, which will only increase as we continue to push away from our Earthly ties. Yes, most of it can burn up on reentry but some items are too large to do so. Some have made it to the ground and caused damage. In addition, such massive amounts of space trash endanger our other satellites.

Economics of Space Trash

In addition, a great deal of money is spent every year monitoring the trash. Many organizations are looking at ways to clean up all of this debris, but the efforts are not cheap or simple when considering the physics of objects travelling at high speeds in orbit. However, since many of these old vehicles and defunct satellites include rare metals, the recycling rewards could be well worth the efforts.

So it is easy to imagine a space-faring future where ships of all kinds, from pleasure crafts and shuttles to independent family units and huge shippers, could fill the system. When interstellar visitors like Oumuamua come through again, we’ll be ready to explore or mine them for their resources. And if they are an alien space ship out for jaunt, we don’t want them to think we are the trashy, diseased-filled neighbors. We must clean up our world as we go forward.

Future Men

Therefore, as humanity spreads to Mars and beyond, so will the space trash unless we find ways to clean it up. “Rag and bone men,” small entrepreneurs living aboard their own ships, could make a living gathering and recycling old garbage back into precious metals before delivering them to one of the many space ports. After all, we have organizations now that strip down old technology for the gold, platinum, silver and more. Not everyone in the space faring age is going to be a Captain Kirk or Zapp Brannigan. Some will be miners or shippers, merchants or corporate management, and many will have never seen Earth’s blue skies. Some will live on the edges with antiquated technology, trying to make a living the best they can on the scraps scattered across the vastness.

And they will all have stories worthy of telling.

“Space Debris FAQs” Aerospace, http://www.aerospace.org/cords/all-about-debris-and-reentry/space-debris-faq/  March 22, 2018.

Bennett, Jay “Interstellar Asteroid ‘Oumuamua Likely Ejected From a Binary Star” Popular Mechanics, https://www.popularmechanics.com/space/deep-space/a19494278/interstellar-asteroid-oumuamua-likely-ejected-from-a-binary-star-system/  March 22, 2018 (photo from the same source).