By Jaime Yarbrough – Science Editor – January 22, 2021
What am I about to read? Why do I need to read it? How will it make my life better?
I thought about other questions like ‘who am I?’ ‘where did I come from?’ but the first is too broad and the second too deep for ‘general information’ that might be of use in a ‘friendly conversation.’
Today, because I started out with the article on the International Space Station (published December 24, 2020) I would follow up with some general information about space and man’s space history. You already have some information from the ISS article but what you may not know is how truly vast it is and how important this tiny area we call “Low Earth Orbit” is to our everyday modern existence.
The beginning of “outer space” is roughly around 62 miles above sea level. There are several layers of our “atmosphere” that ‘thin as the skin on a peach’ envelope that contains at least some breathable ‘air.’ Even though no one would be able to breath most of it due to below freezing temperatures and extremely low pressures.
“LEO” starts ‘around’ 99 miles and goes “out” to ‘around 1200 miles (160km-2000km). So, in Del Norte county terms from a low of from here to Fortuna to from the Smith River boarder to Mexico. I used the term “out” because once you enter “outer space “up” looses much of it’s importance. UP is mostly a convenient term we use to use in relation to the surface of the earth. Up in the sky, down in the ocean, etc. It is also useful when talking about the effects of gravity. So, once you have escaped earth’s gravity, and have gone beyond the ‘observable’ sky you are ‘out of this world’ and IN space.
Currently there are over 1900 satellites in LEO. Most of these are photographic satellites taking terrain and weather photos. There are a new number of ‘mini-sats’ recently placed in orbit by Elon Musk for potential communications including the internet. Several countries first ventures are often into LEO. The Russian Sputnik launched in 1957 was in LEO for 3 months before most of it burned up upon re-entry.
It only took 3 ½ years from the launch of Sputnik for there to be 115 satellites in orbit. The benefits of having our technology ‘off world’ has profoundly changed our existence. At first it seemed novel and awesome that we could see the ground from that perspective. To see continents, to see weather patterns, and most spectacularly throughout time. To see seasonal changes, migrations of animals, changes in vegetation, even the movement of people and industry.
There have been tremendous military observations and implications. While there were the purely scientific forces that drove man into space with the invention of the rocket itself the military has been and will always be a part of the mix. Our satellites prevented a WW III opportunity during the Cuban Missile crisis in 1962 only 5 years after the first launch.
Man has always looked to the stars. In fact the term “astro” we use in reference to our off world activities (e.g. astronaut) comes from the Greek “Astron”, meaning “star.” From our earliest times we have observed the motions of the ‘heavenly bodies. Even before the invention of the telescope elaborate use of these motions have been used to tell time, predict seasons and from which to navigate.
We knew a lot about ‘space’ even before we went there. What used to be called “celestial mechanics developed into ‘orbital dynamics’ because the objects in space had been placed there by human beings. Of course, orbital mechanics also addresses the motion of moons and planets around stars (which we know as ‘suns’ – yes, our sun is actually ‘a star’!)
Next time I will delve more into the vastness I mentioned, geosynchronous orbits, the satellites placed and found there before we explore more of the “how we got there.” If this has created any questions you want to ask, please do. I will do my best to answer, find the answer or find a path to the answer.
Keep looking to the sky.