WASHINGTON — Less than a week after full science operations began, a processing glitch aboard a new NASA Mars orbiter forced the craft to temporarily shut down all of its science instruments, the agency said in an online post Nov. 20.
Operators on the ground were attempting to send commands to the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft Nov. 19, when “a timing conflict between commands” triggered an automatic shutdown of the orbiter’s three science instruments. MAVEN has been orbiting Mars since Sept. 22.
“Two different processors got out of synch with each other, so that the relative timing of commands was incorrect,” Bruce Jakosky, principal investigator for MAVEN at the University of Colorado in Boulder said Nov. 20 via email. “Think of it as two computers that have to talk with each other but realize that they’re not keeping the same time; they lose the ability to talk to each other. In that instance, they recognize the problem but don’t know how to recover from it, so they send the spacecraft into safe mode.”
Six of MAVEN’s eight science sensors are grouped together on an instrument known as the Particle and Fields package built by the University of California, Berkeley, Space Sciences Laboratory. MAVEN’s other instruments are the Remote Sensing package provided by the University of Colorado Laboratory for Atmospheric and Space Physics, and the Neutral Gas and Ion Mass Spectrometer, built by NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
MAVEN remains in contact with controllers on the ground, Jakosky said.
The $571 million orbiter, built byof Denver, is studying Mars’ upper atmosphere in an attempt to figure out why the planet, once thought to be habitable, is now a cold, barren desert. MAVEN’s mission had been in full swing only for a few days when the automatic shutdown occurred.
“We had declared start of science over the weekend,” Jakosky said Nov. 20.
Here’s NASA’s Nov. 20 statement:
MAVEN went into safehold mode on Wednesday, Nov. 19. The spacecraft goes into this state autonomously, when it detects a problem with its operations, to ensure that it stays safe and in contact with Earth. Safehold was triggered by a timing conflict between commands. This is part of learning how to operate the spacecraft in a new environment, as this is the first time the spacecraft has been in its full science-operations scenario. The instruments have all been turned off and are safe, the spacecraft is healthy and in high-data-rate contact with Earth. The spacecraft operations team is currently developing the schedule to return MAVEN to science operations.