What obstacles did john Glenn face?

Why did my dog stare at the full moon then act strangerly? What did Neil Armstrong and Buzz Aldrin do on the moon in 1969? What does heliosensitivity mean? What planet orbits around the sun the fastest? What mizar and alcor made up of? Why is Hades sort of happy? How long was it before the universe became transparent? What is the diameter of a rainbow? What do you call the point in a satellite's orbit farthest from its planet? How does fire come out of a rocket at lift off? What is onoscope in ballistic? How did harry hess's hypothsis explain seafloor movement? Did Gemini 7 land on the moon? One of many rocks in a belt between mars and Jupiter? What gas makes about 21 percent of the atmosphere? When vapor condenses into water droplets? Can a solar oven work in a cloudy day? What is Leo's birthday month? What are some physical characteristics for Annemarie in Number the Stars? Is the solar system stable?