Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Humans have sent spacecraft up to study our star. The SOHO spacecraft has been in operation since 1996. The craft orbits the Sun in step with Earth but closer to it. SOHO has sent back amazing images. Onboard instruments have also sent back mountains of data. The data is mostly about the Sun's outer layers. Answer: 1996
Output:
What year did the soho spacecraft first started to operate?