Ingenuity, NASA’s little Mars helicopter that could still fly, will be able to fly even more.
A week and a half ago, the little flying robot made history as the first powered airplane to take off from another world. On Friday the fourth flight went further and faster than ever.
That wasn’t the only good news NASA had about the helicopter on Friday.
In a press conference earlier in the day, the space agency announced that it would extend Ingenuity’s life for another 30 Mars days and move the mission into a new phase. After Ingenuity engineers demonstrate that flying is possible in the air of Mars, they will investigate how it can be used as an aerial scout for its larger robotic companion, the Perseverance rover.
“It’s like Ingenuity is finalizing the tech demo phase,” said MiMi Aung, Ingenuity’s project manager, during a news conference on Friday.
Before that, it seemed like the helicopter’s lifespan was rapidly coming to an end. The 30 Mars days reserved for Ingenuity test flights were due to expire next week, and then the plan was to abandon them and never fly again.
Ingenuity – just 1.6 feet tall, 4 pounds in weight – is an 85 million dollar expansion of Perseverance, NASA’s newest $ 2.7 billion rover that landed on Mars in February. The helicopter is the first to fly like an airplane or a helicopter in another world.
The extension of Ingenuity’s flights reflects not only the success of the helicopter, but also the desire of Perseverance scientists for the rover to explore its current environment near its landing site in February. The rover is located in a 45 km wide crater called Jezero, which was once a lake. Scientists expected to head straight away for an ancient, parched river delta, which is a promising place to look for signs of Martian past life.
“We ended up in a random location,” said Kenneth Farley, professor of geochemistry at the California Institute of Technology who serves as the project scientist for Persistence, in an email. The place, he said, “gave us a great opportunity to examine some rocks that we would otherwise probably not have seen or visited.”
These rocks appear to be the oldest in the crater, and scientists want Perseverance to collect at least one sample that will become part of a collection that would bring a latter robotic mission back to Earth. The age of the rocks would put a limit on how young Mars was when the lake first filled with water.
Dr. Farley said he expected the persistence to spend several hundred Martian days – perhaps an Earth year or more – exploring this piece of Jezero, which is just a mile from the rover’s current location.
Even if Ingenuity isn’t left behind for now, the focus for Perseverance’s mission managers will shift to conducting scientific observations. This means, for example, that Perseverance will no longer take pictures and videos of Ingenuity in the air.
“We pampered the helicopter,” said Jennifer Trosper, assistant project manager for the rover, during the press conference.
On the fourth flight, Ingenuity used its camera to find a new base for future flights. On its fifth flight, it will make a one-way trip to the new location. There may be another flight or two from there in May.
Ms. Aung said the helicopter could conduct reconnaissance to plan where Perseverance will go, capture images of areas too rough for the rover, and create stereo images to depict the heights of the Martian landscape.
“The lessons from this exercise will be hugely beneficial to future aerial platform missions,” she said.
Ingenuity launched on Friday in the middle of Mars day – on Earth it was 10:49 a.m.Eastern time. After reaching a height of 16 feet, it headed 436 feet south, flying over rocks, sand waves, and small craters. It floated, took photos with its color camera, and then flew back to its starting point, which NASA has named Wright Brothers Field.
The flight was more than twice as long as the previous trip five days ago. This time Ingenuity also flew longer – 117 seconds compared to 80 seconds on the third flight – and faster, reaching a top speed of 8 mph.
The success followed an aborted flight attempt on Thursday. The cause was a recurrence of a problem that occurred earlier this month.
During an April 9 test that spun the helicopter’s rotors to full speed without a take-off, take-off activities took longer than expected and Ingenuity’s computers instead turned off the engines instead of going into “flight mode”.
During a week of troubleshooting, the engineers came up with a software fix but decided not to install it on Ingenuity as the likelihood that a bug in the new software would cause even bigger problems, as did upgrading your operating system, is slim Computer can crash the software.
The stakes are even higher when the computer is on another planet 187 million miles away.
Instead, the engineers opted for a simpler solution: the software on Ingenuity was left untouched, but the commands sent from Earth to Mars were modified. That largely fixed the problem, but it wasn’t a perfect solution. Tests on Earth showed that timing errors still occurred 15 percent of the time.
However, the engineers also knew that if the error recurred, they could try again the next day and the second attempt would most likely be successful. That’s exactly what happened on Friday.
If Ingenuity continues to work and prove useful, NASA could further extend its lifespan.
Ms. Aung and Bob Balaram, Ingenuity’s chief engineer, said the helicopter was only rated for 30 Martian days and that they couldn’t say how long it would stay in good working order. Dr. However, Balaram also said that Ingenuity’s lifespan is not limited in itself. The helicopter charges its batteries using solar panels so that it doesn’t run out of fuel, for example.
A top speed of 8 miles per hour may not seem particularly fast, but the robotic helicopter has to fly over an alien landscape without the help of engineers on Earth. It uses a downward facing camera to map the landscape below. If it flies too fast, it can lose track and potentially crash.
Ingenuity, however, has not flown any higher than the 16 feet of the last three flights, though its two four-foot wide counter-rotating blades generate enough lift to land higher above the ground. This is largely a limitation of the altimeter, which measures altitude by bouncing a laser off the ground and recording the time it takes for the reflected light to return to the sensor.
Dr. Balaram said the 16-foot height is a “sweet spot” that provides good resolution for the images used for navigation.
“I wouldn’t be surprised if at a certain location we were asked to go to a higher vantage point,” said Dr. Balaram. The helicopter could fly up to 32 feet without causing altimeter problems and “provide some panoramic images that may be useful to the rover operators or the scientists.”