Answer:
what happened after that
Explanation:
and y did she walk to the hospital
"The space shuttles is the subject."
Simple formula: find the verb of the sentence then ask the question "who or what performs the verb" and the answer to that question is the SUBJECT of that sentence!
In your sentence; ask the question;
"Who or what have made travel to the International space station convenient and possible?
Answer: The space shuttles (that's your subject)
The author's purpose for including this paragraph is to explain the resistance that Branch Rickey willingly took on in an effort to being the process of ending segregation in Major League Baseball. This paragraph serves to explain that there were people off the field who also helped revolutionize the game.