For the first time, the Ingenuity team on Earth lost contact with Ingenuity in suns 427 and 428, or Martian days corresponding to May 3 and 4. Engineers on the small helicopter spent a week investigating what could have caused the communications blackout.
The team found that the loss of contact occurred because the Ingenuity experienced an insufficient battery charge as night fell. This reduced voltage reset the mission clock, causing the helicopter’s system to be out of sync with its companion, the Perseverance rover. Although Ingenuity has returned to reliably transmit messages to Earth via the rover, the team hopes this problem could happen again.
That’s because it’s early winter on Mars. Winter on the red planet will last until September or October. During the Martian winter, dust is thrown into the atmosphere and obscures the light needed to charge Ingenuity’s solar panels.
So far, Ingenuity has logged 6.8 kilometers on 28 different flights.
The helicopter remains healthy and has resumed operations, albeit slightly modified, and the team remains optimistic that Ingenuity will soon make its 29th flight. But there is no doubt that Ingenuity is on borrowed time.
“We are now operating far beyond the limits of the original design. Historically, Mars has been very challenging for spacecraft (particularly solar-powered spacecraft). Every sun could be Ingenuity’s last.”
Martian winter is coming
With Mars wintering, Ingenuity will experience more dust in the air and falling temperatures – both of which can wreak havoc on the helicopter’s ability to stay powered, warm and operational.
As a result, Ingenuity will no longer be able to keep your battery and electronics at a programmed temperature limit of minus 13 degrees Fahrenheit (minus 25 degrees Celsius) using heaters.
Instead, the air vehicle will experience nighttime temperatures of minus 112 degrees Fahrenheit (minus 80 degrees Celsius), which can pose a risk to any electronic components. So far they are holding their ground and have not suffered damage during the cold nights.
Each morning, as the helicopter warms up and recharges, the previous night’s blackout misaligns the mission clock.
Perseverance has to be a little more creative now when communicating with Ingenuity. Basically, the rover has to allow the helicopter to “sleep” and wake up at the wrong time because of the clock problem. Using its onboard Helicopter Base Station, Perseverance can talk to Ingenuity every day and reset the helicopter’s mission clock for that day.
The Ingenuity team cannot predict how Ingenuity’s main electronics module components will behave over the winter, but “soaked electronics are believed to have caused the demise of the Opportunity and Spirit Mars missions,” Tzanetos wrote in the update.
Currently, Ingenuity arrives at sunset on Mars with about 68% of its battery charge state. The helicopter needs at least 70% to keep its heaters, clock and core electronics powered overnight, JPL engineers estimated.
“Our 2% deficit (state of charge) is expected to grow to a 7% deficit when we reach the winter solstice (sol 500 in July), when conditions will begin to improve,” Tzanetos wrote.
Preparing for the future
Retrieving data from Ingenuity, including its flight performance logs and color images from the eight previous flights, became a top priority. Next, the mission team will determine if the helicopter is ready for another flight and have the helicopter perform a high-speed spin of its rotors.
If Ingenuity is able to make a short flight to the southwest, the small helicopter will be in a good position to communicate with the Perseverance rover as it studies and samples an ancient river delta.
The flight software team is also working on updates to Ingenuity’s advanced navigation features to help it fly over the river delta and continue operating as an aerial scout for the rover.
“Perseverance and Ingenuity’s operations teams have done an extraordinary job of re-establishing reliable communications with Ingenuity,” Tzanetos wrote.