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Sustainable Space Travel: Is it Possible? By Neelam Bhohi

As an astronomy student, I have always seen space exploration as one of the most fascinating and exciting areas of science, and I’m not the only one. We often see headlines of NASA’s latest mission, or Elon Musk’s last SpaceX endeavour. However, in a society more conscious of climate change and the environment, I must wonder: are we destroying our world in our quest to explore others?

Why is the environment a concern when discussing space exploration? If you watch one of the many rocket launch videos on YouTube, you will see why. The loud roars, and the colossal eruption of fumes, are awe-inspiring…and worrying. But despite this, space exploration is still considered to be a necessity, and many space agencies claim that space travel contributes more to the sustainability of the planet than it hinders it.

One way that space exploration has improved sustainability here on Earth is the creativity required to produce the technology needed for humans to survive in space. In space, there are limited resources, and the tech needs to reflect that by being less wasteful and more energy efficient. NASA has developed water filtration systems, air purifiers and solar cells, and many of these inventions have been incorporated into our daily lives. NASA has also been hugely involved in the advancement of alternative energy systems and were pioneers in the development of wind power, solar power, and electric cars.

A common argument for the importance of space travel is that many people believe that for humanity to survive in the long term, we need a way to colonise another planet. With fossil fuels running out and climate change getting worse by the minute, the damage to the planet may become too irreversible for humans to thrive on Earth. This has inspired many space agencies, most notably SpaceX, to try to get astronauts on Mars in the near future.

However, we must consider the negatives to space technology, for which there are many. According to the Smithsonian museum, carbon dioxide emissions are an obvious problem, especially when one considers the fact that most rockets are 95% fuel in mass. There have been some innovations in creating cleaner fuels, such as a liquid hydrogen fuel often used by NASA, but some recent launches have been a reason for concern. The launch of SpaceX’s first Falcon Heavy rocket was widely publicized and praised back in 2018 by fans, even though it used a kerosene-based fuel called RP-1, with a 34% carbon content as established by the Smithsonian.

One may argue that space launches are too uncommon to have any real impact on the environment, especially in comparison to global industry emissions. However, advancing technology has allowed space launches to occur more easily and frequently than ever. For example, two more Falcon Heavy rockets have been launched since the first in 2018, and Musk has stated he is aiming for a record 48 space launches in 2021 alone.

There are other contributions to climate change outside of carbon dioxide emissions. NASA has been known to use a solid rocket fuel containing aluminium powder, commonly used in pyrotechnics and fireworks. The ‘explosion’ that gives rockets enough energy to launch is created by combining the aluminium powder with ammonium perchlorate, producing aluminium oxide and a range of other products into the atmosphere. Aluminium oxide has been linked to global warming because of its ability to absorb terrestrial, long-wave radiation, which heats up particles and consequently heats up the planet. The use of ammonium perchlorate also leads to an emission of significant amounts of hydrochloric acid, that can potentially have a huge impact on the pH of water. In fact, NASA found a reduction in the number of plant species surrounding NASA’s Kennedy Space Centre due to these hydrochloric acid emissions.

Unfortunately, the problems don’t end there. On Earth, littering causes many issues regarding pollution, and humans have somehow managed to extend this issue to above the atmosphere. There are huge amounts of junk orbiting the Earth, and this space junk, normally referred to as space debris, is becoming more and more prevalent. The ESA Space Debris Office determined there is an incredible 128 million space debris objects less than the size of 1cm orbiting the Earth, and 34 thousand bigger objects greater than 10cm in size (and one of these is a car – Elon Musk’s Tesla Roadster!). More space debris means more chances of collisions with satellites – which then results in more space debris. The renowned NASA scientist Donald J. Kessler believed that increasing amounts of space debris will render the Earth’s orbit useless for space science and satellites. This scenario is called the Kessler Syndrome and naturally has great implications on satellite usage.

However, it should be noted that space agencies are fully aware of these problems and the impact they have on the Earth’s environment and are working to improve things. In a bid to make the company more eco-friendly, NASA has a sustainability policy which states that it will only work in a way that avoids compromising the Earth’s resources for future generations. And they are doing this; as mentioned before, NASA has already been using greener rocket fuels that leave a smaller carbon footprint. There have also been recent developments in reusable launch systems by both NASA and SpaceX, to make space travel less wasteful and more cost effective. In terms of space debris, there have been a wide range of interesting technologies that have been created or proposed. One of these includes RemoveDEBRIS, a satellite with a giant net to catch space junk - built by the Surrey Space Centre at the University of Surrey!

There is no doubt that space travel will always be one of the most fascinating areas of science, and a great showcase of the incredible capabilities our modern-day technology has. But being in a generation with growing concerns of global warming and diminishing fossil fuels, it’s also valid to be a bit wary. Nevertheless, the beauty of technology is that it’s always changing and improving, so it is possible that one day, we will develop the means to explore our universe sustainably without jeopardising our future.

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