Clark N. answered 03/22/19
Introductory astronomy, including Keplerian orbital mechanics
When the ISS is on the "night side" of the Earth, the sky looks like what you would see from the top of a very high mountain at night, where most ground-based observatories are. It was found during the early days of spaceflight that stars are not visible if sunlight illuminates any nearby object or structure in your visual filed. Likewise, peering out from an illuminated space in the ISS makes it difficult to see stars. Stars are MUCH LESS bright than even a fairly dim light source in a room. The Hubble Space Telelscope incorporates features that prevent any sunlight, or reflected sunlight from enetering its optical path, even when it is on the "day side".