VIPER — short for Volatiles Investigating Polar Exploration Rover — said it has recently completed another successful round of rigorous testing of the agency’s first robotic moon rover’s ability to leave the Astrobotic Griffin lunar lander and land on the lunar surface. This multi-hour operation, called the Exit, is one of the most important and challenging parts of VIPER’s 100-day mission. This can be even more difficult if VIPER landings on the Moon are too steep or inclined due to rough terrain.

Recent tests using prototypes of the VIPER rover and Griffin lander, conducted at NASA’s Ames Research Center in California’s Silicon Valley, are designed to push VIPER’s systems to their limits to keep the rover functioning properly during its science mission. By launching the VIPER MGRU3 prototype, short for Lunar Gravity Representation Unit 3, down the launcher’s ramps in a series of test configurations at the Ames facility, engineers gain a better understanding of how the rover will perform in both normal and unconventional modes. scenarios.

Unlike large rigs that deliver vehicles by rolling them off standard ramps on the trailer, the geometry of the lunar lander’s ramps changes dramatically depending on how the surface is when the moon arrives at its destination atop the flat-topped Mons mountain. Mouton near the Moon’s south pole. Depending on the terrain around the lander, the angle of the ramps may be particularly steep, creating a risk of losing traction and shifting the rover, or one ramp may be steeper than the other, requiring the VIPER control team to actively compensate. for this tough terrain.

“With this series, we tested all the ‘limiting’ cases of VIPER’s lunar mission,” said Jasper Wolf, Ames VIPER test leader. “This included a worst-case high-grade scenario using the steepest – and scariest – ramps, a worst-case scenario using the steepest ramps, and a worst-case scenario using a combination of slope and grade.”

The photo above shows a key moment in the tests focused on the physical interface between the rover and the lander. Critical testing features included software that specifically handles VIPER output and changes to the physical components of both rover and descent ramps. The team carefully checked that the MGRU3 had sufficient clearance and correctly engaged the ramps as it rolled from top to bottom.

“We ran these test cases with MGRU3 to ensure that VIPER can do this on the Moon,” Wolff said.

Completion of these tests means that the VIPER can successfully exit the lander even if it touches the ground in a difficult position; this is an important step towards flight.

“We are breaking new ground with VIPER,” said Wolfe. “And it’s very exciting to reach that milestone.”