The physiological and psychological impact of spaceflight.
Words by Nicola Simcock
Given the chance, would you go to space?
Put on a space suit, strap into a shuttle and get blasted 7 miles per second into earth’s orbit or beyond?
For the audience at July’s SciBar around half would jump at the chance! But, do they really know what they are getting themselves into? Luckily, PhD student Jonathan Laws was on hand to explain exactly what our eager audience could expect after being propelled miles above the earth’s surface.
Jonathan’s research, in the Aerospace Medicine and Rehabilitation Laboratory at Northumbria University, is focussed on analysing the physiological and psychological impacts of spaceflight. Combining virtual reality studies with astronaut physiological data, Jonathans research will illuminate our understanding of spaceflight at low-earth orbit and beyond. An increasingly valuable resource, as humanity’s first mission to Mars looms!
As you can imagine spaceflight is fraught with difficulties, however Jonathan narrowed this down to 3 key challengers: Micro-gravity, Sleep deprivation and, Isolation and confinement.
We’ve all seen the videos, astronauts (and cosmonauts) floating weightlessly, doing somersaults and generally making space look like every child’s (and adult’s!) dream. The video of Tim Peake (European Space Agency astronaut) playing water ping pong with two hydrophobic paddles certainly reinforced the ‘super-fun’ side of micro-gravity. But Jonathan soon brought us back to earth (so to speak), by highlighting the physiological issues that come with all that orbital tomfoolery.
The human body, unsurprisingly, is adapted to life within earths gravitational field. Our muscles and bones are structured in such a way to ‘push-back’ against gravity, to keep us upright and moving around. On the international space station (ISS), astronauts are continuingly falling towards and around the earth in a microgravity environment. Over an extended period of time this leads to two major physical problems: muscle and bone wastage.
On a 6-month mission, astronauts could expect to lose up to 40% muscle mass and 20% bone mass, particularly in the lumbar-pelvic area (with astronaut-dependent variation). This is problematic as ─ despite all the floating around ─ working aboard the ISS is a physically demanding job. Whether it’s carrying out maintenance, performing experiments, or conducting a spacewalk, for life in space, functioning muscles (and bone!) are necessary.
To combat these losses astronauts are prescribed a gruelling exercise regime ─ up to 2.5 hours, 6 days a week. As if that wasn’t bad enough, due to microgravity the exercises themselves are fairly limited. Astronauts can only use equipment they can be strapped into, providing resistance to work the muscles. A good example is the treadmill that Tim Peake used in space to run the London marathon ─ orbitally accompanying the many participants down on earth in 2016.
2. Sleep deprivation
For many of us microgravity is a foreign concept, whereas sleep deprivation is much more relatable ─ particularly during these sticky summer nights! When we lose sleep, we often become irritable and suffer cognitive impairments such as loss of concentration and memory. In space, where mistakes can cost lives, these impairments could be fatal. Down here on earth most of us need around 8 hours sleep per day to function well. Data collected on astronauts indicate that on average, they only achieve 6 hours. The reason for this is not totally clear but there are some likely contributors.
Firstly, noise. Unsurprisingly, spacecraft are noisy places, as Jonathan described it: “like sleeping next to a running washing machine”. So as you can imagine, this can be quite disruptive. Every. Single. Night!
Secondly, light. The ISS orbits the earth at an astonishing 17,000 miles per hour. The sun rises on the ISS every 90 minutes and the astronauts experience 16 sunrises (and sunsets), for every 1 we experience here on earth. As the human sleep-wake cycle is closely linked to the earth’s day-night cycle this drastic change in ‘day-length’ can be very disruptive. Going to sleep at ‘night-time’ isn’t really an option for an ISS crew member!
To help combat the noise and light disturbances the astronauts are provided with sleeping pills to help them sleep, and stimulants to help them wake ─ as well as an eye mask and ear plugs! However, research is ongoing to try and extend the astronauts sleep average towards a more restful 8 hours.
3. Isolation and Confinement.
The ISS orbits the earth on average 400 miles above the surface. That’s 400 miles from friends and family and of course, your pets! It can be a lonely place. Although, as Jonathan pointed out, not too lonely as the ISS is small and relatively full. Imagine working in a confined, messy office, with 5-6 co-workers and at the end of the working day, you can’t leave. Now imagine this for months at a time! For many of us this would be unbearable, but this is a challenge that comes with spaceflight. While the ISS may be considered snug, the spacecraft proposed to carry the next humans to the moon, or beyond (Orion spacecraft) is even smaller!
Coping with isolation from earth and its inhabitants, along with continuous confinement are aspects that the current astronaut selection procedure addresses. However, the popularity of commercial spaceflight is growing and ways to deal with these issues, for non-astronauts, need to be investigated.
By the end of Jonathan’s talk, despite now knowing the risks they face, none of the audience seemed concerned about rocketing off to space. Hopefully, if Jonathans research goes well ─ and much more like it ─ our audience might have less to worry about when they finally get there.
To end, Jonathan left us with one of our favourite passages from the excellent Astrophysicist Carl Sagan. Asking big questions is what science is all about, and research like Jonathans can help to remind us that…
“The earth is a very small stage in a vast cosmic arena” – Carl Sagan
Join us next moth when we hear from the Newcastle University PhD student Holly Middleton Spencer as she explains the mysterious mathematics of finding the coldest temperature possible, Wednesday 19th August 2019. The Old George, 7pm.