90s SciFi TV show, pilot/marine searches for his sister who landed on an alien planet before him [duplicate]

Question

I have looked everywhere but can't find a TV show I am having flashbacks of! Here is what I remember

• Based in space on an alien planet
• there is conflict with any alien race
• the main character is a pilot? Marine?
• the big thing I remember is the main character's sister is missing, she landed on the planet before him. Finding her is the long-running story arc
• late nineties, aired on a major network
• the whole series felt like it was filmed at night

Answer 1

As mentioned in comments, this is almost certainly Space: Above and Beyond.

• Based in space on an alien planet

The main characters were based on a "space carrier" the USS Saratoga, but many episodes were set on alien planets

• there is conflict with any alien race

The Chigs

• the main character is a pilot? Marine?

The main characters were members of the 58th Squadron Space Aviator Cavalry, United States Marine Corps

• the big thing I remember is the main characters sister is missing, she landed on the planet before him. Finding her is the long running story arc

Lt. Nathan West had a fiance who travelled to a colony world that was then attacked by the aliens before he arrived.

• late nineties aired on a major network

First screened on the FOX network in the USA between 1994 and 1996

• the whole series felt like it was filmed at night

There were a lot of scenes in space and a some on alien worlds at night