The Four Favorite Facts From the Last Seven Days

In the 1970s NASA employees had to walk around holding broomsticks in front of them to detect invisible fires. This is because NASA uses liquid hydrogen for lots of their rockets and since the 1950s they've been using it as a fuel. It's incredibly flammable, it's a great fuel for a rocket, it burns at 5000 degrees Fahrenheit, it's ultra-explosive. But of course hydrogen, first atom first element in the periodic table, it's tiny. The atoms are incredibly small and it's very flammable and because the atoms are so small it leaks. Even if you've welded two plates of metal together,. It can leak even ifyou've weld