historyfeels
NASA
wanted to know what actually happens to spacecraft materials when you
leave them exposed to space for years, so they attached an enormous
materials experiment directly to the outside of the International Space
Station.
This particular experiment contained 41 different types of polymers. Because many were stacked several layers deep, there were 205 individual pieces of material in total.
They remained outside the ISS for nearly four years.
During that time, the samples endured radiation, thousands of hours of sunlight and roughly 22,800 cycles of heating and cooling.
But one of the biggest threats was something that sounds surprisingly harmless: oxygen.
In low-Earth orbit, ultraviolet light breaks oxygen molecules apart, creating highly reactive individual oxygen atoms.
As the ISS travels around Earth at roughly 17,000 mph, exposed surfaces repeatedly slam into these atoms. Over years, the effect can literally erode certain materials away.
The difference in the before-and-after photographs shows just how severe that damage could become. Six of the 41 polymers were partially or completely eroded through.
Added fact: One material performed particularly badly. NASA reported that all four layers of its polybenzimidazole, or PBI, sample were completely eroded away during the experiment.
This particular experiment contained 41 different types of polymers. Because many were stacked several layers deep, there were 205 individual pieces of material in total.
They remained outside the ISS for nearly four years.
During that time, the samples endured radiation, thousands of hours of sunlight and roughly 22,800 cycles of heating and cooling.
But one of the biggest threats was something that sounds surprisingly harmless: oxygen.
In low-Earth orbit, ultraviolet light breaks oxygen molecules apart, creating highly reactive individual oxygen atoms.
As the ISS travels around Earth at roughly 17,000 mph, exposed surfaces repeatedly slam into these atoms. Over years, the effect can literally erode certain materials away.
The difference in the before-and-after photographs shows just how severe that damage could become. Six of the 41 polymers were partially or completely eroded through.
Added fact: One material performed particularly badly. NASA reported that all four layers of its polybenzimidazole, or PBI, sample were completely eroded away during the experiment.
I've heard and read this from many, many different doctors.
There is not a SINGLE fetal or maternal condition that requires a third trimester abortion.
Zero. None.
Delivery? Yes. Abortion? No.
There is not a SINGLE fetal or maternal condition that requires a third trimester abortion.
Zero. None.
Delivery? Yes. Abortion? No.
ZERO.
