Since moving to the space coast of eastern Florida, my attention to the launches from the Kennedy Space Center have inevitably led me to a heightened curiosity about the ISS (International Space Station).  It is quite easy to forget about the ISS when you’re not faced with launches that you can see from your backyard. But at least half of the launches I have been fortunate enough to witness, have something to do with the ISS. 
As of March 2019, 230 individuals from 18 different countries have visited the ISS. The ISS has been continuously occupied since November of 2000. An international crew of six have lived and worked while traveling five miles per second, orbiting Earth every 90 minutes. In a 24-hour period the ISS makes 16 orbits of Earth that entails 16 sunrises, and 16 sunsets.
Peggy Whitson set the record for spending the most total time in space, when on Sept. 2, 2017, Peggy completed a total of 665 days. The ISS is larger than a six-bedroom house, it also contains six sleeping quarters, two bathrooms, a gym, and a 360-degree view from the bay window. 
 I was listening to a NASA employee discussing the dangers of CO2 levels in space craft.  Obviously the smaller the air space, the closer this has to be monitored.  He was talking about how much they have learned on the ISS. This information will play a vital role as astronauts move into smaller vehicles like Orion.  
I have been learning about the vulnerability of humans to CO2 levels as low as 900-1000 PPM (parts per million).  Decision-making, and human cognition can be greatly affected at these low levels.  Most Americans are exposed to these levels of CO2 regularly in cars, offices, homes, and planes.  When I look at the delicate onion-peel appearance of our atmosphere, it really is a cause for pause; ruminating on the delicacy of the very air we depend on to breathe is almost overwhelming.
Before we take our next breath, I would encourage us all to be grateful for the miracle planet on which we live. The incredibly delicate balance it takes to keep life sustained on this planet is quite sobering.  We need to all be more cognitive to this simple reality. The human race has the ability to destroy, or save this planet.  I think the answer should be pretty universally in favor of saving it.
May God help us all,
RHM