LET'S CLEAN UP THE SPACE TRASH

May be you did not know, but there are thousands of small and big pieces of astronauts equipment left in the space.  Researches are suggesting different methods for  cleaning up the space.
After watching this video answer: (In your notebook. Reading section)
What are the five methods that researches suggest? make draws according to the information you understood.
What do you think is the best? Why?
Write almost 10 words related with the vocabulary listened and write the definition.