Starman & Roadster: Automotive Polymer Adventures in Outer Space

Nearly two months ago, Elon Musk launched a Tesla Roadster (with Starman, the driver) into space with the first Falcon Heavy rocket. “For science,” supposedly. The red Roadster and its dedicated dummy pilot will (hopefully) orbit around the sun, with only hypothetical plans to bring it back to Earth next time it’s close enough.  

This is the first car to be sent into space, so naturally we’re all curious about how long the car could survive in the extreme deep space environment. With no protection from UV radiation or the extreme temperatures, how will the car survive?

On Earth, assembled cars go through a lengthy series of tests to see how environmental elements and road conditions impact their drivability and use. Even before that, however, car materials undergo aging tests before they’re able to be used on a production line. This is standard practice, because the outside world is a punishing place for the polymers found in paint, rubber, and plastics. The Roadster, like all automobiles, went through multiple rounds of aging studies, where its materials were subjected to a variety of extreme elemental conditions in order to determine degradation rates.

Through these studies, scientists have determined that elemental factors will, in the long term, damage the car. UV radiation, in particular, “causes photooxidative degradation which results in breaking of the polymer chains, produces free radical and reduces the molecular weight, causing deterioration of mechanical properties and leading to useless materials, after an unpredictable time.” It’s not just UV rays that damage: oxygen, heat, and cold will also adversely affect polymers. In order to stave off these disastrous effects, scientists have created stabilizing agents to counteract degradation, discoloring, and embrittlement. Things like UV absorbers and peroxide decomposers allow cars to live long & healthy lives provided they aren’t crashed.

But, space is an entirely different playing field. Factors like atomic oxygen (oxygen in the upper atmosphere that has reacted to UV radiation), particulate radiation (like cosmic rays), and space plasma aren’t dealt with on Earth, but can destroy materials easily. Atomic oxygen, for example, reacts with carbon, nitrogen, sulfur and hydrogen bonds, eroding a vast array of polymers.  And then there are factors that we experience on Earth–temperature changes and UV radiation–that are taken to extremes in space. Temperatures fluctuate between -120? and +120?, although they can be even more extreme than that depending on distance from the sun, and without an atmosphere like Earth’s, there’s no protection from damaging UV rays. If you thought Earth was punishing to polymers, space is torturous.

Spacecraft developers subject potential materials to their own environmental tests to evaluate space-readiness. While some can be performed on Earth in crafted, controlled environments, some must be taken into space for testing. The Roadster did not undergo space testing for its materials, meaning the car sent into space is made of usual car materials: tested for functionality on Earth, but not for space.

Interestingly enough, scientists don’t agree on how quickly the car will fall to pieces. The only worry Musk and some scientists have is a collision (yes, it’s possible that the car will crash into Mars, Earth, the Sun, or an asteroid, which leads to fascinating questions about whether or not it was sanitized in order to prevent contamination). While human life cannot be sustained in open space, a car and the dummy driver should be fine. The biggest cosmetic issue is that the paint will fade, faster than it would on Earth, from increased UV exposure.

Other scientists, however, say the car won’t last even a year. The extreme conditions and radiation alone will disintegrate the organic materials (leather, rubber, paint) rapidly. There’s also a chance for the car to be struck by micrometeoroids. Micrometeoroids are tiny particles of rock & metal broken off of larger bodies. While their alone size is unsubstantial, their speed (22500 mph) means these small pieces can do serious damage to spacecrafts, akin to that of a sandblaster. The Roadster, without proper protection from micrometeoroids will incur quite a bit of damage. Its frame, once stripped of all organic materials, will have a longer lifespan, but probably not for the billion of years Musk claims.

Scientists aren’t sure exactly how long The Roadster will stay afloat in the Milky Way (Musk said “a billion years”, but most scientists suggest someone will fly out and salvage it after 50-100, if it isn’t destroyed by then). Regardless, it’ll be a cool experiment to see if our on-Earth polymer aging tests can compete with the extreme conditions of outer space. In the meantime, you can trust us at Polymer Solutions to complete your Earthbound material testing. Contact us today to talk more about our capabilities.

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