Why is it hard to walk in outer space?

Sensors inside our ears, which are part of the vestibular system that controls balance, are thrown off — often causing astronauts to feel dizzy or queasy the first few days in space. Once they get back to Earth, it takes a while for their bodies to readjust. Hence, the walking problems.

satellites are frequently used to make observations of the orbit on earth

i'm guessing this is from edg enuity so the answers would be, from top to bottom,

theodor schwann

matthias schleiden

robert hooke

rudolph virchow

anton van leeuwenhoek