Mars Exploration Rover Opportunity has been discovering the Martian surface for over 10 years — that is an astonishing ten years longer than the 3-month primary mission it started in January 2004. However, with its extraordinary victories, inexorable age-related issues have surfaced and mission architects are consistently tested by an undeniably upsetting spell of rover “amnesia.”
A Decade On Mars: Opportunity’s First Sols
Opportunity uses two types of memory to record mission telemetry as it investigates the Meridiani Planum district. Sister wanderer Spirit, which tragically succumbed to the Martian components in 2010 after 6 years of discovering Mars, utilized the same framework. The two types of memory are known as “volatile” and “non-volatile.”
Mars Exploration Rover Project Manager John Callas, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif said, “The disparity is non-volatile memory recalls everything though you power off, in volatile memory everything goes away. So, volatile memory is similar to the conventional RAM you have in your computer; non-volatile memory utilizes flash memory technology.”
Generally, all telemetry information is stocked up in the flash memory, so that when the rover shuts down amid the Martian night or reboots, the information stays saved — like when you turn off your digital cam, the photographs stay stored to the cam’s flash card. Any information saved in the wanderer’s RAM, nonetheless, is lost as it powers off.
Flash memory may be incredible for saving information when the wanderer’s hardware are shut down, “however flash memory has a confinement on how often you can read and write it,” Callas told Discovery News. “It ‘wears out’ with utilization.”
Mars Rover Opportunity to Have Memory Wiped
Furthermore, after 10 years of constant use, its the rover’s flash memory that mission specialists have recognized as the cause of lost information and sudden reset events that are tormenting the rover’s surface mission.
Old Rover Memory Glitches
“The issues set off genuinely considerate, however now they’ve gotten to be more severe — much like a sickness, the indications were mild, yet now with the series of time things have ended up more severe,” Callas added.
“So now we’re having these events we call “amnesia,” which is the rover attempting to utilize the flash memory, yet it lacked the capacity, so in its place it utilizes the RAM … it stores telemetry information in that volatile memory, however when the wanderer goes to rest and awakens, all (the information) is gone. So that is the reason we call it amnesia — it overlooks what it has done.”
Opportunity uses NASA’s veteran Mars Odyssey satellite as a communication hand-off between the Mars and Earth, so at whatever point Odyssey makes an orbital pass, commands are sent down to the rover and telemetry is channeled once again to Earth.
Alien Robots That Left Their Mark on Mars
However, should an orbital pass be occupied until the wanderer has shut down and afterward rebooted the next day, the rover group observed that information was consistently lost — the wanderer had been experiencing the flash memory error and after that storing it to RAM, evading the flash memory simultaneously. As the wanderer shut down, the RAM was wiped and the information was gone the next day.
Christmas Blues
The flash memory problem has developed into a more serious issue than losing important information, though.
As the wanderer endeavors to store information to the flash memory, and is over and over unsuccessful, its software compels the wanderer to reboot. If a series of commands is sent to the wanderer, it will continue rebooting again and again, overlooking what the past command taught the wanderer to do.
“Actually the wanderer stops what it was doing as it wasn’t certain what created the reset,” said Callas. “So that intrudes on our science mission on the surface of Mars.
“It’s similar to you’re attempting to drive on a family tour — the car stalls out repeatedly. You don’t make much movement that way!”
And now the wanderer group’s more terrible dream has raised its monstrous head — Opportunity quit speaking with Earth over the Christmas break.
Rover Opportunity Celebrates Mars Spring Power Boost
As the NASA crew went into the Christmas holidays, a succession of 3 sol (Mars day) plans gave the wanderer a series of commands to deal with. On the 1st sol, the wanderer would work as anticipated, however come the 2nd and 3rd sols, not just would the wandere not execute the rest of the commands, it quit conversing with mission control.
Akin to any space mission, when Opportunity quits communicating, “we get, extremely stressed,” said Callas.
Luckily, after sending commands to the wanderer, it sent a consoling “beep” in answer and proceeded with its guidelines.
Software Fix?
It appears the hotspot for all these issues lead back to one specific bank of flash memory. 7 banks are utilized by Opportunity and its the seventh bank that is setting off the information loss, wanderer resets and communications glitches.
Presently the offender has been recognized, JPL software architects have created a method that will compel the wanderer’s software to overlook the seventh bank and use the other 6 obviously sound banks. As per Callas, his group is likely a few weeks away from finishing the software change so it can be transferred to Opportunity.
Distant from this upsetting events, Callas is astonished at the strength of the rest of the rover’s hardware, yet he stays practical about Opportunity’s future.
“The wanderer has been amazingly healthy considering the extent to which we’ve utilized it … we thought the mobility framework would have exhausted a long ago however its in incredible condition.
“However, anything could fall short at any minute,” he said. “It’s similar to have an aging parent, that is overall healthy — possibly they try for a little run consistently, play tennis every day — yet you never know, they could have a hard stroke right amidst the night. That’s why we’re always vigilant that something could happen.”
