Why the loss of a photo affected the 6th flight of the helicopter to Mars

For its sixth flight, the ingenious helicopter encountered some obstacles. The reason? A photographic problem, thankfully not serious.

Once, the test campaignIngenious helicopter On May 22, it encountered an incident that, fortunately not seriously, disrupted the quality of its aerial program on Mars soil – this is the sixth time the aircraft has been operated by NASA’s Rotorcraft. In this case new height, speed and trend objectives were set.

Five days after the plane was found to be in disarray, the US space agency returns to the matter In a brief article Released May 27. If the first step of the journey went well (i.e. moving 150 meters 10 meters above the ground), we know that the rest of the program was affected by the strange behavior of the helicopter.

In fact, the ingenuity began to oscillate in the plane, tilting back and forth. ” Before landing safely, Howard Griff, a leading pilot of handicrafts at the Jet Propulsion Laboratory, explains On-board sensors indicate that the rotorcraft has experienced roll and pitch motions above 20 degrees, significant control inputs and power consumption peaks. »

You have not found an image, everything has changed

Today, NASA knows why these unexpected maneuvers occurred: because it lost an image taken by an ingenious photographer during its flight. 54 seconds after the flight, details Howard Grip lost a snapshot of an error in the processing chain of images provided by the navigation camera, causing a change in the timestamp of the following photos.

« Therefore, the navigation algorithm always runs on an incorrect database of when a correction was made based on a navigation image and when it was taken. The resulting discrepancies drastically reduced the information used to fly the helicopter, leading to constantly revised estimates. », He mentions.

The helicopter uses an on-board depression measurement unit to detect how it is moving. But the navigation system uses a camera to confirm and correct passive measurement unit functions – this alone is not enough, “he said. Bugs will form quickly, and the helicopter will eventually get lost .. So the camera is used to redesign the aircraft.

However, find out when the camera’s pictures were taken and help guide the algorithm to determine if the trajectory is the same as expected – by analyzing the terrain taking into account previous photos. How the helicopter can adjust its estimates of position, speed and attitude. But still it is essential that the flow of images is constant.

The good news is that this failure does not endanger intelligence. The craft was able to land within five meters – very close to the planned landing. One reason was that NASA had a good idea of ​​allowing margins to add potential errors without making an aircraft impossible or unpredictable. With this error tolerance, the timestamp error has been overcome.

Continuation in the video