Dr Don Pettit is one of NASA’s great science pioneers. A chemical engineer, he is the veteran of multiple missions, including two long-duration stays aboard the International Space Station (ISS), and a 6-week meteorite-hunting expedition to Antarctica.
Back in 2002 when he was science officer on Expedition 6, he hosted the now gloriously retro science series Saturday Morning Science, where he conducted an array of experiments in the ISS’ microgravity.
He is also known as an inventor, having built a barn door tracker out of ISS parts on the same mission. The device compensates for the ISS’ movement relative to Earth, allowing for the crisp images of the world below we now get from orbiting astronauts. Plus he invented the zero-g coffee cup, which allows astronauts to enjoy a caffeinated pick-me-up without the need for a straw.
Pettit is above all, however, a frontrunner to a horde of future researchers and scientists who will expand our knowledge of science in microgravity, which, as he pointed out when I spoke to him at the European Space Agency’s event Space for Inspiration, currently only scratches the surface of what’s possible.
You’ve spent a total of 370 days living and working onboard the International Space Station. What’s it like to be up there?
It’s an incredible experience. You’re going into a frontier environment that we have no innate intuition about, and so every day you’re learning new things. Not everything is wonderful, but the environment is wonderful.
What excites you most about the potential of research in space?
It’s not one specific factoid that we are learning, it’s the whole avenue of human beings expanding into a frontier where our normal intuition from life on Earth does not apply, and things that are just unimaginable happen.
You will make an observation and we will have insufficient knowledge to predict what was going to happen, but after we make the observation we can use our pre-existing knowledge to explain what happens. And sometimes our pre-existing knowledge is insufficient, and that means you’re truly working in a frontier situation.
That’s the exciting part of going into space. It’s not any single experiment; it’s not just looking at Earth; it’s not the feeling of weightlessness; it’s the idea that you are truly doing exploration, exploration that only about 550 people have ever done, have ever gone into space out of the 7 billion people on this planet.
That’s something that we need to change right there; we need to figure out how to do the engineering and make machines so that we can get more people going into space. That’s going to dramatically increase the rate of our knowledge, our discovery, and expansion into the solar system.
Do you anticipate a rapid expansion of knowledge as the private space industry expands?
Yeah. It’s bound to happen. Take the discovery of the laser. At first it was a large complicated piece of equipment you could only keep running in a laboratory, and it was highlighted as being a discovery waiting for an application. Because it was a real neat piece of physics, but nobody knew what to use it for.
It took literally 30 years before lasers started to become useful, and now you can hardly go anywhere without a laser being somewhere in your life. You’ve got a laser in your smartphone there; you’ve got lasers in the grocery store; lasers are all around us and lasers are a fundamental part of our life now.
Space is kind of like that: it’s slow to take off because of access, but just like lasers were slow to take off because they were large and bulky and complicated, it will be inevitable that human beings will expand into space both for continued exploration and for commercial ventures.
There’s also talk of the ISS being privatised – do you anticipate that creating more opportunities for new experiments?
Experimentation is what human beings are good at doing
Of course, and experimentation is what human beings are good at doing. It doesn’t matter whether it’s a government-run programme or a commercially-run programme, they’re all good and we need both. The kinds of questions that a government research lab asks and does research on are typically different than the kind of questions that private industry would do, and they go hand-in-hand.
Are there any untapped research areas that you would like to see prioritised in future ISS experiments?
There are areas that are rich for potential discovery. Fluid mechanics is one; dealing with the flows involving gases and liquids along with free surface interfaces.
These are complex and difficult to deal with, and a classic example of this is a toilet: how do you make a toilet that works? We’ve got toilets on the space station but they’re always breaking down, and it’s in parts dealing with a mixture of air and liquids and bubbles and droplets and all these things moving together and how do you deal with that?
So that’s one field. Another field is anything dealing with the life sciences. If you look at life evolving on Earth – temperatures, pressures, chemical compositions – these things have swung all over, but the magnitude of gravity has remained constant for billions of years.
Ever since Earth became a planet its gravity has basically been constant; life has always known constant gravity and now we can take life organisms including ourselves into an environment where we change the magnitude of gravity by a factor of a million.
That’s what microgravity is: you change it by a factor of a million. You change almost any other environmental factor by a million and see how long it’ll take your nematodes to curl up and die. The fact that we can change the magnitude of gravitational force by a factor of one million and life still continues on, that in itself is an amazing discovery.
But then we’re finding there are all kinds of subtle things that happened with living organisms when we take them into a microgravity environment and likewise tertiary effects on human physiology. And so this is another field that is ripe for discovery.
How do much do we currently know about humans’ response to microgravity situations?
We know a lot about how the human body responds, but we don’t know why.
I like the analogy of sailors getting scurvy when they go on transoceanic expeditions in the 14th, 15th, 16th centuries – thousands and thousands of sailors died from something that now grade school kids know the solution to. But the concepts of vitamins and diets hadn’t even been thought of [back then]; that there were small quantities of complex organic material that you needed by the milligram dose every day in order to maintain health, and without them you would die.
Around 1750, the Royal Navy figured out that if you suck on citrus you won’t get scurvy, and that was the empirical solution to the problem of scurvy, but they didn’t understand the fundamental basics as to what causes scurvy for another 150 years, when vitamins and their role in your diet and human health were discovered.
That’s where we are now with so many of the things we’re learning about human physiology.
Now you look at just one of the many things that happened to human beings in space environments: bone decalcification. We have an empirical remedy for that now, it’s called exercise, and we exercise for two and a half hours a day. In some respects a trip to the space station is like spending six months at health camp, because you come back stronger than you were before you launched.
This exercise preserves your bones, and the rate of bone density loss now is minuscule. So this is the equivalent of the Brits figuring out if you suck on citrus you won’t get scurvy. But we haven’t the foggiest as to what is going on with our bones in a weightless environment, what are the details of the biochemistry?
We’re working on that now, and just like vitamins and diet that allowed these nasty vitamin deficiencies to be solved for everybody on the continent that never went on a sea voyage, if we understand the fundamentals of bone density loss, everybody on the planet that doesn’t travel into space, they will benefit from this.
So it’s the same story of scurvy but it’s being replayed in a different venue, in a different century, with a different human malady and this story is also being repeated for eye retinal issues; the cardiovascular issues we find; the immune system deficiencies that we’re finding.
We’re finding that as all of these disease-like symptoms that are being instigated in healthy people in the middle of life simply because you go into space, and it’s going to be an amazing venue to help decipher what’s going on with these diseases for everybody on the planet.
It’s really exciting; I could talk about this stuff for hours.
For those who are keen to become future researchers in microgravity, what advice would you give on becoming an astronaut?
The secret to becoming an astronaut is: you put in an application. A limousine is not going to pull up in front of your house and men in black come out and give you a secret handshake and now you’re in the astronaut program.
The only way you will become an astronaut is to put an application in for the program and if the first time you put your application in it doesn’t work out, you can’t take no for an answer and you just keep trying, and trying and trying.
I was rejected three times. I interviewed [to become an] astronaut four times over a 13-year period and three of those times I got the ‘thank you very much’ letter, and the fourth time I got the ‘welcome to the astronaut program’ letter. You just don’t take no for an answer if it’s something you really, really want to do.