NASA's Ingenuity Mars helicopter is scheduled to lift off no sooner than April 14 in the first-ever attempt at powered, controlled flight on another planet, a delay from its initial planned launch date.
While lift-off was initially targeted for Sunday, April 11, the agency announced the delay on Saturday afternoon.
In a release, NASA's Jet Propulsion Laboratory (JPL) explained that the decision was made based on data that arrived late Friday night.
"During a high-speed spin test of the rotors on Friday, the command sequence controlling the test ended early due to a 'watchdog' timer expiration. This occurred as it was trying to transition the flight computer from ‘Pre-Flight’ to ‘Flight’ mode," they explained. "The helicopter is safe and healthy and communicated its full telemetry set to Earth."
The watchdog timer oversees the command sequence and alerts to any potential problems. It also helps the system stay safe by not proceeding if an issue is observed.
"The helicopter team is reviewing telemetry to diagnose and understand the issue. Following that, they will reschedule the full-speed test," they said.
In a pre-flight news conference on Friday, representatives from both JPL Ingenuity and Perseverance Mars rover teams vocalized their excitement for the historic event.
Thomas Zurbuchen, an associate administrator for science at NASA Headquarters, said a selfie image taken of the rover and rotorcraft showed the team was "ready" and that the flight would "really change the trajectory of what's possible" in space exploration.
Ingenuity Project Manager MiMi Aung gave an update on Ingenuity's pre-flight progress, noting that the autonomous helicopter had been successfully recharging its solar-powered battery and communicating with Perseverance.
She said the team had fully confirmed it has enough energy and power to perform the flight test and that they had examined thermal models, turned on sensors and computers and finished testing rotor blade operation.
One final checkout test to spin Ingenuity's rotors at full speed to the flight RPM (revolutions per minute) was scheduled for Friday and after that they would be "set to go."
"And, we will test, prove and learn regardless of what the outcome is in this first attempt," said Aung.
The whole flight will last for around 40 seconds. If all final checks and atmospheric conditions look good above the Jezero Crater flight zone, Ingenuity will lift off climbing at a rate of 3 feet per second, rotate, take images with a 13-megapixel camera and hover at 10 feet above the surface.
"So, we're really excited. It could be an amazing day. We're all nervous, but we have confidence that we put in the work and the time and we have the right people to do the job," Tim Canham, Ingenuity operations lead, said speaking after Aung.
Success is not a certainty and Ingenuity Chamber Test Engineer Amelia Quon pointed out that the red planet's extremely cold and thin atmosphere could present challenges for the endeavor.
"It's about one percent of the density of Earth's atmosphere at sea level. That's the equivalent of about 100,000 feet of altitude on Earth or three times the height of Mt. Everest," she explained. "We don't generally fly things that high."
Aung said that they had picked their flight time with atmospheric hurdles and weather conditions in mind, though Malin Space Science Systems Mastcam-Z Uplink Operations Lead Elsa Jensen said they knew there would still be surprises.
"We hope everything will go well on Sunday, but we know there will be surprises. That's what we trained for," she said.
"It gives me the chills sitting here and thinking about the fact that on Sunday my team and I are going to be taking images and video of you guys flying on Mars." said Jensen, smiling.
The helicopter team has a period of 30 Martian days to take up to five flights, each with chances to record additional data.
A post-flight briefing is expected to take place at 11 a.m. EDT on April 12, though JPL noted in a release earlier last week that timing for events is subject to change as needed.