News at CNN [cnn.com]:
Jezero Crater, an ancient lake bed on Mars and the current site of the Perseverance rover and Ingenuity helicopter, can drop to temperatures of minus 130 degrees Fahrenheit. That's low enough to do significant damage to the helicopter's electrical and battery components.
The 4-pound helicopter finally separated on April 3 from the belly of the Perseverance rover, where it has been stashed since before the rover launched from Earth in July.
Ingenuity went through a series of movements to unfold from beneath the rover, which looked like the metamorphosis of a butterfly, before dropping the final 4 inches to the Martian surface.
"This is the first time that Ingenuity has been on its own on the surface of Mars," said MiMi Aung, Ingenuity project manager at NASA's Jet Propulsion Laboratory in Pasadena, California, in a statement. "But we now have confirmation that we have the right insulation, the right heaters, and enough energy in its battery to survive the cold night, which is a big win for the team. We're excited to continue to prepare Ingenuity for its first flight test."
When Ingenuity does fly, which could happen as soon as April 11, it will be the first powered, controlled flight on another planet. In a nod to the first such feat conducted on Earth, Ingenuity carries a swatch of fabric [cnn.com] from the Wright brothers' plane, Flyer 1.
Ingenuity, the first rotorcraft sent to Mars, presented a challenge to the engineers who designed it for several reasons. It needed to be small enough to tuck up under the rover without endangering Perseverance's mission, which is the first to search for evidence of ancient microbial life on Mars.
April 11, or 4-11! Or later.