Definition: Generate a correct and concise answer for the question based on the words in the context.
Input: Context : The Boeing 601 (sometimes referred to as the BSS-601, and previously as the HS-601) is a communications satellite bus introduced in 1987 by Hughes Space and Communications Company. 
Question : What year is Boeing 601 associated with?
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
1987