On Thursday, Might 5, mission controllers at NASA’s Jet Propulsion Laboratory obtained affirmation that the company’s Ingenuity Mars Helicopter had re-established communications with the Perseverance rover. Earlier within the week, the rotorcraft had missed a deliberate communications session with the rover – for the primary time in over a yr of operations on the Mars floor. Ingenuity depends on Perseverance as the bottom station that permits it to ship knowledge to and obtain instructions from Earth. Whereas extra knowledge downlinks and evaluation are wanted, the Ingenuity and Perseverance groups consider they’ve decided a explanation for the anomaly in addition to a plan to return to regular operations.
Ingenuity turned the primary powered plane to function on one other world on April 19, 2021. Designed to carry out as much as 5 experimental check flights over a span of 30 Martian days (sols), or near 31 Earth days, the rotorcraft has flown over 4.2 miles (6.9 kilometers) throughout 28 sorties and operated from the floor of the Pink Planet for over a yr.
Information downlinked signifies that the communications dropout on Might 3, Sol 427 of the Perseverance rover’s mission at Mars, was a results of the solar-powered helicopter coming into a low-power state, doubtlessly because of the seasonal improve within the quantity of mud within the Martian environment and decrease temperatures as winter approaches. The mud diminishes the quantity of daylight hitting the photo voltaic array, lowering Ingenuity’s potential to recharge its six lithium-ion batteries. When the battery pack’s state of cost dropped under a decrease restrict, the helicopter’s field-programmable gate array (FPGA) was powered down.
The FPGA manages Ingenuity’s operational state, switching the opposite avionics parts on and off as wanted to maximise energy conservation. It additionally operates the warmers that allow the helicopter to outlive frigid Martian nights, maintains exact spacecraft time, and controls when the helicopter is scheduled to get up for communications classes with Perseverance.
When the FPGA misplaced energy in the course of the Martian evening, the helicopter’s onboard clock – which designates the time that communications with Perseverance happen – reset. And Ingenuity’s heaters, so important to maintaining electronics and different elements inside operational temperatures – turned off. When the Solar rose the subsequent morning and the photo voltaic array started to cost the batteries, the helicopter’s clock was now not in sync with the clock aboard the rover. Primarily, when Ingenuity thought it was time to contact Perseverance, the rover’s base station wasn’t listening.
To ensure Perseverance would hear a name, Perseverance mission controllers at JPL commanded the rover to spend virtually all of Sol 429 (Might 5) listening for the helicopter’s sign. It got here at 11:45 a.m. native Mars time. The information transmitted was restricted to intentionally protect battery cost, however the helicopter’s important well being and security knowledge had been nominal. The radio hyperlink between Ingenuity and Perseverance was secure, spacecraft temperatures had been inside expectation, the photo voltaic array was recharging the battery at a fee anticipated for this season, and the battery was wholesome, containing 41% of a full cost.
However one radio communications session doesn’t imply Ingenuity is out of the woods. The elevated (light-reducing) mud within the air means charging the helicopter’s batteries to a stage that can enable necessary elements (just like the clock and heaters) to stay energized all through the evening presents a big problem.
Every evening for the previous three sols, Ingenuity’s heaters have kicked in when its battery temperature was under 5 levels Fahrenheit (minus 15 levels Celsius). Whereas on, the warmers stored the temperature of significant helicopter elements from dropping farther – right down to the ambient environmental temperature of minus 112 levels Fahrenheit (minus 80 levels Celsius). However the crew believes that the battery couldn’t maintain the vitality draw of the onboard heaters all through the evening.
“We’ve all the time recognized that Martian winter and dirt storm season would current new challenges for Ingenuity, particularly colder sols, a rise in atmospheric mud, and extra frequent mud storms,” mentioned Ingenuity Workforce Lead Teddy Tzanetos of NASA’s Jet Propulsion Laboratory in Southern California. “Each flight and each mile of distance flown past our authentic 30-sol mission has pushed the spacecraft to its limits every sol on Mars.”
The Ingenuity and Perseverance groups have designed a plan they hope will make a distinction. Their objective is to assist the helicopter’s battery accumulate sufficient of a cost in the course of the subsequent few sols in order that it may assist all vital spacecraft methods in the course of the chilly Martian evening. Uplinked yesterday, the brand new instructions decrease the purpose at which the helicopter energizes its heaters from when the battery falls under 5 levels Fahrenheit (minus 15 levels Celsius) to minus 40 levels Fahrenheit (minus 40 levels Celsius). The helicopter then shuts down shortly, relatively than consuming the battery cost with the warmers. The crew hopes this technique will enable the battery to retain no matter cost it collected in the course of the day. The Ingenuity engineers hope that after a number of days of the helicopter’s array soaking within the restricted rays, the battery may have reached some extent the place the spacecraft can return to regular operations.
Permitting the warmers to stay off in a single day will preserve vital battery vitality however may even expose elements to the chilly of Martian evening. Developed as a expertise demonstration to show that powered, managed flight on Mars is feasible, the 4-pound (1.8-kilogram) rotorcraft carries many business off-the-shelf elements that weren’t designed for the chilly of deep house operations.
“Our high precedence is to keep up communications with Ingenuity within the subsequent few sols, however even then, we all know that there will likely be vital challenges forward,” mentioned Tzanetos. “I couldn’t be prouder of our crew’s efficiency over the past yr, not to mention our plane’s unbelievable achievements on Mars. We’re hopeful that we will accumulate battery cost with a purpose to return to nominal operations and proceed our mission into the weeks forward.”
