NASA has offered the first full update on the Perseverance rover’s seven-month voyage to Mars, and the news is good.
Coming less than a day after United Launch Alliance’s Atlas V rocket blasted into the sky from the Cape Canaveral launch site in Florida on Thursday morning, the team in charge of the mission confirmed it’s receiving detailed data from the spacecraft and can send up commands as it hurtles toward the red planet tens of millions of miles away.
From his base at NASA’s Jet Propulsion Laboratory in Southern California, Matt Wallace, the mission’s deputy project manager, said in an online update that the spacecraft is healthy, and well and truly on its way to Mars.
There were, however, a couple of issues that emerged shortly after launch, with one fixed and the other under control.
Communications
The first involved a minor communications problem with NASA’s Deep Space Network (DSN), a global array of radio antennas that provide contact between a spacecraft and its team back on Earth.
Wallace explained that the proximity of the spacecraft to Earth immediately after launch saturated the ground station receivers of the DSN, disrupting the transfer of information.
“This is a known issue that we have encountered on other planetary missions, including during the launch of NASA’s Curiosity rover in 2011,” Wallace said. “The Perseverance team worked through prepared mitigation strategies that included detuning the receivers and pointing the antennas slightly off-target from the spacecraft to bring the signal within an acceptable range. We are now in lock on telemetry after taking these actions.”
Spacecraft temperature
The other issue concerned the temperature on the spacecraft.
“The mission uses a liquid freon loop to bring heat from the center of the spacecraft to radiators on the cruise stage (the part that helps fly the rover to Mars), which have a view to space,” Wallace explained. “We monitor the difference in temperature between the warm inlet to the radiators and the cooler outlet from the radiators.”
Shortly after launch, the spacecraft entered into a shadow when Earth temporarily blocked the sun, causing the outlet temperature to drop, and the difference between the warm inlet and cooler outlet to increase.
“This transient differential tripped an alarm and caused the spacecraft to transition into the standby mode known as ‘safe mode,’” Wallace said.
The team had predicted that something like this could happen during this early part of the mission, and had set the limits for the temperature differential “conservatively tight” for triggering the safe mode.
“The philosophy is that it is far better to trigger a safe mode event when not required, than miss one that is,” Wallace said. “Safe mode is a stable and acceptable mode for the spacecraft, and triggering safe mode during this transitional phase is not problematic for Mars 2020.”
He added that the team is currently conducting the necessary work to move the spacecraft out of safe mode and back into normal cruise mode.
When it reaches the Martian surface in February 2021, NASA’s Perseverance rover will search for signs of ancient life, gather rock and soil samples for return to Earth at a later date, and collect data for future human exploration of the faraway planet.
