The spacecraft carrying the Perseverance rover, en route to Mars, experienced technical difficulties as it passed through Earth's shadow, forcing it to pass in "safe" mode. NASA still wants to be reassuring.
Did Mars ever harbor extraterrestrial life? This is the question that the Perseverance rover will try to answer. Its launch by a United Launch Alliance Atlas V rocket took place this Thursday, July 30 at 1:50 p.m. French time, from Cape Canaveral in Florida. Its arrival in the Martian system is scheduled for February 18, 2021 . It will then be the fifth rover to make the trip since 1997.
In the meantime, NASA has had a little scare. Indeed, shortly after 8 p.m. on Thursday, the agency recorded several technical problems. Matt Wallace, of NASA's Jet Propulsion Laboratory and the mission's deputy project manager, just shared the details.
First, the spacecraft's proximity to Earth just after launch temporarily overloaded the ground station receivers of NASA's Deep Space Network. "This is a known issue that we have encountered on other planetary missions, including the launch of NASA's Curiosity rover in 2011 », explains the researcher.
The Perseverance team had to point the antennas slightly away from the target (spacecraft) in order to bring the signal back into an acceptable range. Thanks to these maneuvers, the operators were able to obtain telemetry data from the ship, as expected.
“The second issue was a transient event involving the temperature of the ship , continues Wallace. The mission uses a loop of liquid freon to bring heat from the center of the craft to the radiators installed on the cruise stage (the part that helps fly the rover to Mars), which directly overlook the space .
Mission managers constantly monitor the temperature difference between the hot and cold inlets of the radiators. But when the craft entered the Earth's shadow, sunlight was temporarily blocked and the exit temperature dropped .
“This caused the difference between hot and cold radiator inlets to increase , explains the researcher. This transient differential triggered an alarm, eventually causing the spacecraft to enter safe mode ". In other words, for the past few hours, the ship has only been operating using its essential functions.
This switch to safe mode was more or less planned. Indeed, during the launch tests carried out on Earth, NASA had not been able to simulate the same environment as that crossed by the spacecraft at the time of its passage in the shadow of the Earth. The researchers also couldn't rely on Curiosity's flight data, as its trajectory hadn't been the same.
“So we set the temperature differential limits conservatively , continues the researcher. In our opinion, it is indeed far better to trigger a safe mode when it is not necessary, than to miss one .
Flight operations have since resumed as planned. "With the release of safe mode, the team is now dedicated to interplanetary cruising , reassured Matt Wallace. Next stop, Jezero Crater”.
