Answer:
Scientists replicate other scientists' experiments to test if the result of the original investigations being tested should become a law, therefore, meaning if it should be generally accepted or discarded.
However, using different conditions than the conditions used in the original investigations is a method employed by scientists usually to:
1. Check if the values, equipment, used by the original investigations can give similar results if the values are lowered or increased and to also test if the result of the original investigations can be the same even if conditions are adjusted.
2. Check the accuracy of some experimental results especially when those original investigations are the first to speak about a new topic/finding. Definitely, other scientists would use different conditions to provide a broad knowledge and a general acceptance.
Galileo's investigation on the moon rejected popular beliefs of the content of the moon paved the way for further investigations by other astronauts. Galileo performed his investigations with equipment centuries back, coupled with the fact that his investigation didn't support an existing belief that paved the way for his investigation to be replicated by other astronauts.