Ingenuity Mars Helicopter successfully completed its fourth flight on Friday, going farther and faster than in the previous three flights.
Its fifth flight is expected in about a week. After that, NASA said Ingenuity will begin a new operations demonstration phase to show how future aerial craft can aid future missions.
On that fifth flight, Ingenuity is expected to make a one-way trip to discover a new landing strip on the Martian surface and then perform flights every two weeks or so to explore new locales and possibly other landing areas. After a month, the helicopter team will assess its flight operations and will then decide whether to continue more flights until no later than the end of August.
The main reason for the slower cadence of flights is to focus on the Perseverance rover and its main mission of collecting Martian rocks with a special mechanical arm, then caching them onboard. Scientists are hoping to fly the rocks back to Earth in 2026 or 2028 to examine them for evidence of microscopic ancient life. The first collection of rocks is scheduled for some time in July.
NASA had not planned on an operations phase for Ingenuity until recent days, and only expected to conduct its five technology demonstration flights. The four-pound copter was only designed to withstand one month of operation on Mars and includes commercial parts that are not specially designed for a long-term space mission.
For example, the four spindly legs supporting Ingenuity were designed only to take 100 landings. “A solder joint could snap,” said Ingenuity Chief Engineer Bob Balaram. Also the dust in the atmosphere could eventually pose problems. “Right now, it’s healthy, but it’s not designed for a long mission,” he said in an online news conference on Friday.
The fourth flight had been expected to occur on Thursday, but “a little gremlin prevented going into flight mode,” Balaram said. There was a small chance, about 20%, the failure to transition to flight mode would happen as it did before the first flight. A bug prevented the first flight in mid-April which NASA circumvented with a workaround in which engineers “exploited ways to fool the system to be OK and accept the transition to flight,” he said. “It worked well three times, but yesterday it didn’t work.”
It turns out, however, it also worked on Friday for the fourth flight.
In addition to that workaround, engineers also have designed a software fix to prevent the inability to transition to flight mode. It would take days to install and test it, which is why it hasn’t been used. With future flights, Balaram said engineers “might try the more permanent approach so we don’t have to play this dice game every time.”
The fourth flight went more than 870 feet roundtrip and lasted about two minutes, up from the 90 seconds of the third flight.
The transition to the operations phase for Ingenuity follows successful completion of all the goals intended for the technology demo, including the transmission of vital data to Earth that can be used to design future missions and rotor craft. It will also provide “a treasure trove of data for other aspects of the [current] mission,” he said.
Balaram gave a close-up view of the kind of hard core data received by engineers from Ingenuity, using an animation of “what Ingenuity sees” on the surface of Mars with its black-and-white navigation camera. (The animation from the second flight and his description start at 19 minutes into the entire news conference embedded below:)
"There’s a lot of engineering performance that’s fantastic,” Balaram explained. With the navigational camera, Ingenuity was able to pick out rocks and features, marked in green and constantly updated. Red marks were used for “outlier” features that Ingenuity would ignore, such as its own shadows.
The data showed that Ingenuity knew where it was within two inches as it flew along and landed within a foot of where it was programmed to land, he said. It did so while riding Martian winds and “taking off great,” he said. “Everything was working very well, all the engineering systems: solar, battery, radio, all the avionics and computers just went fantastic.”