NASA is set to fly the first test flight of its tiny Ingenuity helicopter on Mars Sunday, marking the advent of drones for space exploration.

Why it matters: If successful, this flight will be the first time a human-built aircraft has flown on a world other than Earth, opening the door to new means of exploring planets far from our own.

Catch up quick: Ingenuity flew to Mars with the Perseverance rover, which landed in February.

• The helicopter detached from the rover's underbelly earlier this month and survived its first frigid Martian night solo, paving the way for its first flight Sunday.
• When it takes off, Ingenuity will rev up its rotors and climb to about 10 feet in the air for 30 seconds, collecting photos and engineering data along the way before coming back to the ground.
• The flight is expected to occur at about 10:54 p.m. ET on Sunday, and NASA should have some indication of whether the test was successful by early Monday morning.

The big picture: NASA thinks helicopters like Ingenuity would be invaluable as the space agency continues to explore Mars, in part because drones can do reconnaissance work that isn't possible with just rovers, landers and orbiters.

• Unlike orbiters, helicopters could give scientists and even astronauts on Mars high-definition views of various areas of a planet in context with other regions.
• "We have robotic assistants that are paired with astronauts today like on the International Space Station, and so there has been quite a bit of work done in how humans and robots could work together for exploration purposes," Bobby Braun, director for planetary science, at NASA’s Jet Propulsion Laboratory, said during a press conference.
• These types of spacecraft can also move from one place to another relatively quickly and easily, unlike rovers, which take a large amount of planning for a drive.

Yes, but: Ingenuity is a proof-of-concept, and it's possible the helicopter won't be able to make it off the ground at all.

• The atmosphere on Mars where Ingenuity is flying is only 1% as dense as Earth's, making it difficult for the helicopter's rotor blades to loft it into the air.
• Communications with the helicopter via Perseverance — which acts as a relay station between Earth and Ingenuity — are also difficult because of the time delay in sending signals to and from Mars, forcing scientist to give directions to Ingenuity and then let the little spacecraft work autonomously.

What's next: If all goes well with this flight, Ingenuity is expected to take to the Martian skies again and again over the course of the next month to prove out its technology.