Winter Sky Setting at Dinosaur Park Panorama
Orion and the winter stars set on a spring evening at Dinosaur Provincial Park in Alberta. High haze and aircraft contrails (one at centre) add to the natural star glows. (Alan Dyer)
Limits of the sky

Managing editor Allendria Brunjes talks about limits — limits in the sky, in space, of our machines and bodies.

I love the skies. When I’m not putting this magazine together, one of my hobbies is flying gliders. Up there in the cockpit, I often have to think — what are the limits?

It is on my mind when I am slicing beneath clouds and riding currents around 10,000 feet in altitude. Up there, there’s less to breathe. Without a tank of oxygen, even a short time at that height can alter a person’s perceptions of reality, making flight operations dangerous. Without liquids, dehydration can set in. And if I forgot my sandwich, hunger can become an irritating distraction. I always have to think — what are the limits of the human body?

Elizabeth Howell examined this same question in her story about space health, a precursor to the 20th anniversary of the first crew launch to the International Space Station.

It is harsh up there, 400 kilometres above sea level. She writes that living in space can push the limits of the human body, leading to osteoporosis, vision problems and the effects that come with increased radiation exposure.

When piloting, another very important focus is the aircraft. If you fly incorrectly, like if you pass the never-exceed speed, your plane could fall apart mid-air. We have to think — what are the limits of the aircraft?

Ivan Semeniuk’s story about the attempt to collect a sample from the asteroid Bennu includes a note that the more precise of two lasers mapping the body stopped working in February. The laser altimeter still managed to get close to 10 times more data than was expected, but mission scientists will be deprived of a final round of surface mapping at the highest resolution.

Out there, we really do test the limits of our hardware. There’s extreme heat and cold, an ultra-vacuum, atomic oxygen and high-energy radiation. That our Earthly designs can withstand off-planet intensity is an amazing feat, keeping in mind there is often little one can do to fix a mechanical problem occurring outside of our planet’s orbit.

While breakable little me is floating around in my winged tin can, I also have to watch out for the invisible walls and ceilings that delineate airspaces.

Before editing Dan Falk’s piece about satellite constellations, I had never really thought about what’s going on far above me. Where does airspace end? How high does “Canada” go, for that matter? What are the upper limits?

Working on this edition, we found there is no consistent law marking where Earth ends and the freedom of space begins.

“This issue has been floating around for the last 60 years, and there’s no solution to that problem,” said Ram Jakhu, associate professor in McGill University’s Institute of Air and Space Law.

And so we put limits in place almost as quickly as we dismantle them. With new technology and a constantly evolving knowledge base, humanity is endlessly discover- ing, pushing, testing and expanding its boundaries.

That’s one of the great things about curiosity — it knows no bounds.

As Canadian comet sleuth David Levy said: “Just look at the sky and see what happens.”

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