The ISS was photographed by Expedition 56 crew members from the Soyuz spacecraft after undocking. Photo: Reuters
Every time it passes overhead and I'm there to watch, some pedestrians want to know about my index finger. "Look," I said to them. "See that bright object moving?" Many people stop and stare, often in astonishment and excitement.
But there are others who refuse to search. The face is set in a gloomy mask, without looking at me, they push past and continue walking. Somehow, they have been convinced that seeing something in the sky is dangerous, both for their health or their soul or both. "This is the International Space Station (ISS)!" I will say when they graduate. "It's not often we can see it like this!" I might also talk to octopuses, for all the effects I have on them which quickly recede. I know they have their beliefs, but all the irrationality – irrationality, in dealing with the ode to the intelligence of the people who advance up there – always makes me a little sad.
But not for long. Because the others are more than just make up. We will stand there together, our heads tilted backwards, watching what happened for a few minutes, the brightest object not the Moon race in the night sky. Of course, it was just a glittering white dot, but those moments were filled with almost inexplicable excitement, the strange feeling of somehow connecting with the brave astronauts on the spaceship was somehow part of this most extraordinary human effort.
"Hey, did you see Sunita Williams waving?" I will ask, and "yes right!" It seems to me like a layer of ice on it.
The ISS passes in front of the Milky Way, in Wales, England. Photo: Alamy
Every few weeks, Nasa tells me from a close meeting that will come with the space station. This factoid never failed to impress my fellow observers when I told them— "Are you working for Nasa? Wow! "- but it sounds much heavier than it really is (no, I don't work for Nasa). Anyone in the world can register for this alert in seconds, and you can get it via email or SMS. That's how I know when to look for it.
Nasa notification appears when there will be an ISS flyby (called "flyover", which usually makes me smile) in the next 24 hours, but only if it will happen at dusk or dawn. Why only at that time? However, the ISS surrounds the planet at any time, completing the orbit every 90 minutes or more. I mean, I wrote these words at 1:00 a.m. and I knew from the direct map that the station had passed almost an hour less than an hour ago. Why doesn't NASA remind me of the flyover? Why don't I see the ISS even if I see it at the right time?
Well: during the day – or more precisely, when the space station flies over parts of the planet bathed in sunlight – the sun itself is so bright that it sinks anything in the sky that might emit or reflect light. When the ISS sailed through the darkness, the sun was on the other side of the planet and the station was too close to the surface of the earth to get sunlight to reach it. So only at a few moments between moments that the angle is right and we can see the ISS, through sunlight that reflects us as if using a giant mirror. If you have registered to get the ISS mark, NASA will check whether the ISS will fly above your location on earth during dazzling dusk or dawn for hours. If so, you will get a message like this:
Place the station. Time: Wednesday, May 19, 19:05, Visible: 3 min, Max Height: 41 °, Appears: 30 ° above W, Disappear: 22 ° above S
This is the problem. I got this notification and I went out a few minutes before 8.05, looking west. At exactly 8.05 a night – not 8.04, not 8.06 – bright spots appeared from that direction. Unlike anything in the sky, it moves, it certainly moves faster than anything in the sky that is not an airplane. It becomes a little brighter because it's getting higher in the sky. Exactly 3 minutes after it appeared, it disappeared.
US astronaut Scott Kelly inside the ISS cupola. Photo: Reuters / NASA
This is how it feels, every time I walk to an open place to see the ISS.
The precision is impressive, amazing. But it shouldn't be too surprising. Even if the ISS orbits the earth quickly, we know exactly where it is at a certain time. There are websites that track their movements in real time. We know that the path shifts with each orbit, and you can see that happening on the tracking site. You learn that the trip is above 27,500 km / hour, about 400 km above us. You can find out about upcoming sightings in your location. In my case, the next one will be on November 15, with the time and direction and altitude registered exactly as I know it will be in the email that will arrive on November 14. There is even a feed from the camera installed at the station, so you get an idea of what our planet is from up there (hint: it's pretty).
Yes, the accuracy is very impressive. But if you think about it, that's what should happen. Space exploration is impossible without such precision. To understand what I mean by that, consider just one example.
ISS in London. Photo: Alamy
As you know, we have sent spacecraft to Mars; Indian property Mangalyaan has been orbiting the planet for more than four years now. How do we manage this achievement, given that on average, Mars is around 220 million km from the earth? Let's say we aim at Mars on a cool night, imagine a straight line connecting planets, and send it Mangalyaan shooting towards Mars like firing weapons at the target. What would happen if you even had a small fraction in your goal – a thousandth of a degree, say? With a unique weapon and target, such an error will have no effect at all. Your bullet will still hit the bull's eye. But with certain red planets that are 220 million km away, you will drive almost 4,000 km. That is, with such an error, Mangalyaan will fly comfortably over Mars and go to the vast empty space outside. Let's face it: we can't pay for such mistakes.
In fact, this is not at all like how we send spacecraft to Mars, or anywhere. Because both planets move, because we have to take into account and even make use of each other's gravitational fields, because we also have to take advantage of that time when Mars and the earth swung closer than 220 million km, because the host is another factor – say the way Mangalyaan taking to reach Mars resembles a straight line like saying my tennis game resembles Roger Federer (hint: no). After launch, Mangalyaan make a number of elliptical orbits which continue to widen around the earth, the latter then basically throwing it on a long track to where it is now – circling Mars. Straight line? Not in your life.
But the complicated path itself is also a reflection, the appreciation, the same idea of the accuracy of space travel. Think of the calculations needed to calculate gravity. Or to get it Mangalyaan orbit the earth, but wider each time. Or settle it into orbit around Mars. Get it even a little wrong and the plane will fall back to earth, or go into space, or even explode.
In some cases, this is why I signed up for the Nasa ISS warning. This is why I go out to watch the station, the one I hear most often will be seen. This is why it never failed to thrill me when it appeared. This is why I encourage other people around me to see that bright spot too, because the speed passes over it overhead.
Spinning on the sea off Mumbai, captured by retired Canadian astronaut Chris Hadfield. Photo: Twitter / @ Cmdr_Hadfield
Because it's more than just a bright moving point, it's quite like that scene.
The way I see it: Down here on earth, we have the irrationality and killing strife and dirty rivers and lying leaders and meaningless monuments, and quite often, all of which make me down because I'm sure that makes you disappointed . But then you can see and admire that point, a symbol of the best quality of our species. Everything about the ISS – from the accuracy of its path to the path it has built, from all of it trying to achieve the courage of the people in it – speaks to me about the wonders of generous science and humanity.
When the International Space Station completes 20 years in orbit, it is something to think about.
Want to register for a warning? Go to http://spotthestation.nasa.gov