Challenges for deep space travel and colonisation

Tuesday 19th November, 2019

Our speaker for the evening was Dr Martin Braddock who works for a research-based pharmaceutical company trying to develop treatments for conditions such as cystic fibrosis, COPD and asthma. He came to talk to us about "Challenges for Deep Space Travel and Colonisation" as he said that clinical science is essential to enable space travel; whether that be in our own Solar System or beyond into interstellar space.

He began by saying that any time longer than a month spent in space presented problems for our human physiology and the isolation due to long duration missions would also impact on mental health. He mentioned a quote from Charles Darwin that said: "It is not the strongest of the species that survive nor the most intelligent but the one most responsive to change."

Dr Braddock then continued by listing a number of benefits that exploring space would bring to the human race. There would be advancements in both pure and applied science as well as engineering that could then be applied back on Earth. This has already happened with the Apollo programme and research taking place aboard the International Space Station. He also thought that it would help with the current climate crisis as any long trips in space would need to be in a sustainable environment where supplies were reused and recycled. He added that it may be needed should the global population exceed the ability of the Earth to support us or if there was another extinction event, such as the one that killed off all the dinosaurs.

Currently, all astronauts develop motion sickness when they first experience microgravity. For, although it is commonly assumed that they experience no gravity, as they are in freefall around the Earth they do feel a small amount of gravity. As humans have evolved to adapt to the gravity of Earth our bodies can suffer when no longer in that environment. Apart from the nausea, astronauts experience a redistribution of bodily fluid and it rises into the head and chest areas leading to symptoms similar to a head cold. Over a long period their muscles will waste, bone density will reduce, and problems develop with their cardiovascular systems. One worrying symptom that had been noted recently in two astronauts is reverse blood flow in the left internal jugular vein. This vein is one of two that normally move blood out of the head when we are lying down.

Dr Braddock said that to counteract these symptoms of very low gravity pressure suits have been developed but these are uncomfortable to wear for long periods. So, a better solution is actually to engineer a spacecraft to simulate gravity, using some form of rotating structure. The only snag with this fix is that humans, like most animals, cannot cope with fast rotation speeds. This means that to reproduce Earth's gravity the diameter of the rotating section would need to be a couple of kilometres across.

He ended his talk by saying that future deep space exploration may initially be done by robotic spacecraft but be followed by forms of human hibernation or multi-generational spaceships. There is also the question of how astronauts could be protected from the deadly radiation in space.