Posted on 19 August 2018
NASA & # 39; s Opportunity rover has been quiet since June 10, when a planet-encroaching dust storm cut off solar energy for the nearly 15-year-old rover. Now that scientists think the global dust storm is "decaying" – meaning more dust is being released from the atmosphere than it is being fed back into – it can quickly become clear to him that the solar-powered rover is reloading and trying "to house
The picture above shows a dust storm on Mars that is growing on June 6, 2018. The blue dot is the estimated location of Opportunity.
No one will know how the robber is busy until it speaks. team notes that there is reason to be optimistic: they have carried out several studies into the state of the batteries before the storm and the temperatures at the site, because the batteries before the storm were relatively healthy, not too much deterioration, and because duststorms usually heat the environment – and the 2018 storm happened when the Opportunity on Mars location was in the summer – the rover should have stayed warm enough to live.
What will engineers at the Jet Propulsion Laboratory at NASA in Pasadena, California be? looking for – and what do those signs mean for recovery efforts?
Dust storms on Mars block the sunlight to reach the surface, raising the level of a measurement called "tau". The higher the tau, the less sunlight is available; the last tau measured by Opportunity was 10.8 on 10 June. For comparison, an average tau for its location on Mars is usually 0.5.
JPL engineers predict that Opportunity needs a tau of less than 2.0 before the solar-powered rover is able to recharge its batteries. A wide-angle camera on NASA's Mars Reconnaissance Orbiter will look for surface features that become visible when the sky becomes clear. That will help scientists to estimate the tau.
Two ways to listen to possibilities
Several times a week, technicians use NASA's Deep Space Network, which communicates between planetary probes and the earth to try Opportunity to talk. The massive DSN antennas ping the rover during scheduled "wake-up" times and then search for signals sent from Opportunity.
In addition, JPL's radio science uses special equipment on DSN antennas that offer a wider range of frequencies. Every day they register every radio signal from Mars during most of the rover's daylight hours and then search the recordings for the "voice" of Opportunity.
When Opportunity experiences a problem, it can go into so-called "error modes" where it takes automatic action to maintain its health. Engineers prepare for three important error modes if they do hear from Opportunity.
Low-power error: technicians assume that the robber went into a power outage shortly after he no longer communicated on June 10th. This mode causes the rover to go into sleep mode, assuming it will wake up in a time when there is more sunlight for charging.
Clock fault: Critical for use during Hibernation is the built-in clock of the rover. If the rover does not know what time it is, do not know when to try to communicate. The rover can use instructions from the environment, such as an increase in sunlight, to make assumptions about time.
Increase error: if the rover has not heard from the earth for a long time, it may go into an "up-down" error – a warning that its communication equipment may not work. When it experiences this, it starts to check the equipment and tries different ways to communicate with the earth.
After the first time engineers hear something of Opportunity, there may be a delay of a few weeks for a second time. It is as if a patient is coming from a coma: it takes time to fully recover. It may take some communication sessions before engineers have enough information to take action.
The first thing you have to do is learn more about the state of the robber. The Opportunity team will ask for a history of the battery of the rover and solar cells and their temperature. If the clock has lost time, it will be reset. The rover would take photos of itself to see if dust could be caked on sensitive parts and test actuators to see if dust is sliding in, which affects the joints.
Once they have collected all this data, the team would perform a poll or they would be ready to try a full recovery.
Even if engineers hear back from Opportunity, there is a real possibility that the robber will not be the same. The robber's batteries could have discharged so much power – and have remained inactive for so long – that their capacity has been reduced. If these batteries can not hold that much charge, this can affect the continuous operation of the rover. It can also mean that energy-bleeding behavior, such as using the heating in the winter, can cause the batteries to turn brown.
Dust is usually not a problem. Earlier storms plastered dust on the camera lenses, but most of them were repelled over time. All remaining dust can be calibrated.
The Daily Galaxy via NASA Opportunity