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A.J.S. Rayl • November 5, 2018
Sols 5221-5251
October came and disappeared without a signal from Opportunity, a silence that was still not a surprise for some, but a bit daunting for other members of the Mars Exploration Rovers team (MER).
"We're still waiting," said Steve Squyres, MER's chief investigator at Cornell University, summarizing the month.
But when ghosts and goblins were preparing to visit the streets around the world, NASA headquarters gave good news. The MER team now has the green light to continue "in the foreseeable future" of its dual-track active listening and commanding strategy to find an Opportunity signal and passively listen to the most sensitive radio receivers (DSNs) to try to contact the rover.
NASA / JPL-Caltech / Cornell / ASU / J. Sorenson
work in progress
This is a color panorama with which Opportunity has even worked on several solos or Martian days
before the planet's dust event (PEDE) stops all scientific and induced operations
geologist from the robot field to close and enter the sleep survival mode in June 2018. James
Sorenson processed this picture in real color. From the black sections you can see that it was a rover
I'm still working on it. "I hope that when or" if "it turns out that there is a chance that she can continue to do so,"
said Sorenson. "He still has work to do!" There is a team of scientists and engineers and
MER supporters all over the world who agree with all their hearts.
The announcement that appeared on the main page of the MER mission on October 29thit was the best "treat" that the MER team could have hoped for Halloween, and that reduces the pressure. This means that operational engineers will be able to continue looking for opportunities for dust cleaning when the Martian winds have historically cleared the rover's solar systems.
"We know that the time frame from November to January 2019 corresponds to the annual dust cleaning period on the Opportunities page of the Endeavor Crater," said Squyres. "Such active listening through January is an increased chance of hearing from the rover if the boards are now very dusty."
The storm of monsters – called PEDE – caused the planet's abyss – it caused Opportunity to stop working in Perseverance Valley, shut down and enter the survival mode at the beginning of June. Although officially announced in September, the secondary or disappearing phase of PEDE, in which all dust ejected high into the atmosphere settles back onto the surface, can continue.
The atmosphere and sky over Opportunity have disappeared almost to a normal, foggy summer. Still, the rover continues to dust. "When you're out of the dust purification season on Mars, the dust accumulates on the rover," said John Project Project, John Callas of the Jet Propulsion Laboratory (JPL), the original home for all NASA spacecraft.
It's unmistakable to say, but atmospheric scientists MER and members of the Power team are confident that Opportunity is dust-covered, maybe more than ever before, and that the rover needs serious dust cleaning, as we wrote in the previous MER Updates. In this case, the solar-powered rover will not receive enough sunlight to generate the energy needed to charge the batteries, wake up and call home.
"I have the impression that most of the dust has probably been raised and fell on the spot," said MER Athena Science team member and atmospheric scientist Mark Lemmon of the Space Science Institute. "This applies to most of Mars. Curiosity covered dust, and even vertical surfaces were dusty, especially Opportunity, in the epicenter of a storm."
Curiosity has caused that from September 14 cleaning a little dustth and October 25thAt that time he had an anomalistic memory problem that required the Mars Science Laboratory (MSL) team to switch from one computer to another, confirmed deputy designer MSL, Joy Crisp. "What Curiosity noticed was that a lot of fine material – gray powder from a shallow drill and a dark red-brown loose regolith – was blown out where we were trying to drill the Inverness goal," she said. "We do not know when exactly the clearing occurred during this period, because we had few photos obtained during the anomaly of the rover."
NASA / JPL-Caltech / Malin Space Science Systems
Divination for Oppy?
Curiosity suffered memory anomalies in mid-September and Mars Science
The laboratory team (MSL) did not see the work area and the purpose of the rover, Inverness, for more than
month. "There were surprises for us!" Melissa Rice, collaborator of MER, and
MSL Participating Scientist, wrote on the MSL blog. Mastcam, stone on the above photos
it was covered in gray waste, but when the team looked again on October 25th, voila!
The litter and a lot of dark brown earth and reddish dust have disappeared. "The winds were
moving, sweeping the workplace clean, "noted Rice from Western Washington University
on the other side of Mars, Opportunity is waiting for the wind to clean its solar systems.
Although curiosity is on the other side of the planet, its happiness is a reminder that there is still summer, and therefore still a sandstorm and a dust season in the southern hemisphere of Mars. And the images of this rover prove that the Martian winds are indeed kicking here and there.
Is it possible that the wind is already blowing in Endeavor, and will soon begin the dust cleaning season in Meridiani Planum, the region where the Crater and the Chance of Endeavor are located? Time and maybe the rover will tell you in the coming weeks.
The Martian winds and the upcoming dust cleaning season were key elements of the MER team's recommendation for agency officials who can continue actively and passively listening to the rover, as it was from the beginning of September.
In the last week of October, in a teleconference interview, MER Mission Manager Matt Keuneke, going to Callas who was on vacation, gave a review of what the team had done so far, and the ops engineers' argument for continuing their current strategy through January 2019. With Squigie , deputy chief investigator, Ray Arvidson, and deputy designer MER Abby Fraeman, director of Mars exploration Mars Fuk Li, director of the Mars exploration program at NASA headquarters Jim Watzin, we have heard and agreed.
A few days later, the team found out that he had obtained the consent of NASA. "We are pleased that we will continue to make all reasonable efforts to restore contact with the Chance," said Keuneke.
The pursuit of further lapping and listening, as it happened, greatly raised the morale. "It really made us alive," said Michael Staab, space systems engineer and flight director who has been working on various aspects of the recovery strategies of the MER ops team for months. "I think there are a lot of dust on the boards and the rover was not able to wake up and talk to us yet, we just have to wait for the dust cleaning season and now we can do it," he said.
"Of course, we're pleased that NASA wants us to do everything in our power to try and get the vehicle back," added Callas at the end of the month. "If we hear from the rover, it will be fantastic." This will be a phenomenal achievement, and we will all enjoy it. "At the moment we have no data," he added, softening his words. "We only have speculation and it carries confidence."
It is safe to say that everyone in the world hoped that NASA-JPL would already hear the rover sound, even those who believe that the Opportunity solar probes are densely covered with Martian dust. "We were hoping to hear something and did not hear anything at the moment" – admitted Rich Żurek, lead scientist of the Mars program at JPL, who is also a Project Scientist with the Mars Reconnaissance Orbiter (MRO). "But there are still a few things to try and the dust cleaning season should start soon."
Angela George, (on the left); Jim Summaria (right), both by Creative Commons Wikimedia
The Who supports MER, inspired by Mel Brooks
Opportunity and MER team received support from The Who (right) and they inspired
one and only Mel Brooks (left) in October. Brooks (left) is a filmmaker, actor, comedian and
an outstanding composer whose film Spaceballs motivated MER ops engineers. The Who –
Roger Daltrey, John Entwistle, Keith Moon and Pete Townshend in the photo from the concert in
1975 in Chicago – began in 1964 in London and performed at Woodstock in 1969. Although
The moon died in 1978, not long after MER Update the author celebrated Who you are on
listening with the band on the set Battlestar Galactica at Universal Studios and Entwistle
He died in 2002, Daltrey and Townshend continue to lead The Who on the road.
Meanwhile, the whole world is watching – even The Who, one of the most influential and influential rock bands & nolla, and the only, unique filmmaker-comedian Mel Brooks. When October 20, Staab published a song awakened by the band, aimed at murder and beatingth– The Who & # 39; s classic, "I Can See For Miles" – the band answered two days later: "Wake up, Mars The Who are here!"
And as Staab, he prepared himself until 24 October for active listeningthinspired by Brooks' 1987 film Spaceballs and again called "Sweep, Beep and Creep" for fun on his Twitter account, Brooks reacted immediately.
The additional time granted by NASA does not mean that the mission team can relax and unwind, even though Christmas is approaching. By the time the rover returns home, the team members will remain in a state of increased vigilance and alertness that DUSTCON 1 will call, a term they have adapted from the DEFCON system of the US military with five degrees of defense readiness.
"DUSTCON 1 is not an official designation" – said Jennifer Herman from JPL. "It's just something that some of us in the operational team have prepared for fun and inspiration to remind ourselves that we're ready," she said. "We have not heard from our spacecraft, so our tactical readiness is still in a state of high readiness. When we hear about the possibilities and return to nominal operations, we can lower it."
Rover and the fate of the mission can be on Mars. For the moment, the team is about continuing preparations, sustaining faith and believing in opportunities, just as they did from the very beginning. But team members are losing Opportunity, the world's longest robot on Mars. "It's a bit of a problem," said Matt Project Scientist Matt Golombek. "It was awfully long, and the rover is like part of our family."
Everyone agrees that hearing this sound from Mars and regaining Opportunity on the Internet and re-wandering will be a triumph like no other and do everything in their power to make it happen. "We do not want to throw our hands away and go:" Well, it was a sandstorm, we tried, "said Herman, repeating the feelings of other team members as well as supporters around the world."No. We want to get her back! "
JPL-Caltech, B. Barker
DUSTCON 1
When the chairman of MER Power Team Jennifer Herman suggested the team's readiness
A rating scale similar to the American army of DEFCON, the operational engineer of the JPL Brian Barker
creatively designed the graphics that appeared in Herman's workspace the next day. "DUSTCON
1 is not an official sign, "remarked MER Jennifer Herman, JPL." That's just right
something that some of us in the operational team have prepared for fun and inspiration to remind
let us be ready, "she said, our tactical readiness is in a state of high readiness."
It had been almost five months since the MER band had heard about Opportunity for the last time, and the telemetry she had returned was staggering. In this feedback, which the team received on June 10, 2018, Łazik showed that it produces only remarkably low 22 watt-hour energy, and the atmospheric opacity was 10.8, the highest ever recorded on the surface of Mars. But there was not enough telemetry to determine the amount of dust on the sun tables with data from June 10th down, said Herman.
This PEDE turned out to be the worst global storm on Mars since 2001, according to Bruce & c. Cantora from Malin Space Science Systems, who has since been observing the Mars storms. The huge event finally entered the decay phase at the end of August and ended in September, as stated in the latest issue MER Update.
During the disintegration phase of these PEDEs, all the dust that has been raised high to the Martian atmosphere returns to the surface of the planet. By the end of September the sky had clearly cleared, but not quite. Tau, which the team calls the measurement of dust in the atmosphere, reflected in the range of 1.1-1.3, and perhaps a bit higher in October, according to Cantor, who uses photos from Mars Color Imager (MARCI) on board the MRO along with models for estimate. Although the sky is still foggy, these measurements are "typical for cloudless conditions" during late spring and summer on the Red Planet, "he said.
NASA / JPL-Caltech / MSSS / UA / supplements L. Crumpler (left) / P. Stooke (right)
A long and winding road Opportunity
The golden line in the image on the left shows the Opportunity route from the Eagle Crater
landing place for Cape Tribulation, which is located north of its present location in Perseverance
Valley. The basic map image is a mosaic of images taken by the context camera
on board the MRO. Larry Crumpler, from the Museum of Natural History in New Mexico
Learning, provided the route. The right graphics show the rover's moves up to Sol 5100
(May 29, 2018) and its approximate current location. Phil Stooke, author The
The international volume of Mars exploration 1 and 2(Cambridge University Press),
from the University of Western Ontario, Canada, documented this graphics with a solo and a page
annotations. The basic image was taken by the HiRISE camera also on the MRO board.
October turned out to be very similar to WRC in terms of active dragging and listening, listening and commanding to try to find an Opportunity signal and get the rover to react, as well as passively listening to the global Deep Space Network (DSN) array of transmitters and receivers around the Earth , explained in detail in the latest issue MER Update.
Ops engineers continued their experiments throughout the month to search more DSN space and on different frequencies during several "drag and drink" signals that engineers are doing in an hour of DSN each day. "We only have one broadcasting session assigned per day, because DSN is very much sought after," said Staab. "But when we do dragging and sending signals, we'll send many commands in one session."
In October, they tried something new, just in case, if it is possible Engineers and Opportunity may not communicate in the same wave configuration.
"There are two signal modes, which are called left circular polarization (LCP) and right circular polarization (RCP)" – said Żurek. On the right circular polarization, the vector rotates in the right-hand sense with respect to the direction of signal propagation, and has left a circular polarization in which the vector rotates in the left-hand sense. "We usually use the right circular polarization, because this is what all spaceships use for command, and the DSN sets it routinely."
There are, however, several scenarios and error modes in which Opportunity may try to call home on the right circular polarization and for some reason the engineers on Earth have not heard it, so the rover switched to the left circular wave polarity and then started to switch between them.
NASA / RadioFan / Creative Commons Wikimedia
JPL Space Ops Mission Control
This image shows a panoramic view of the Space Operations Center on Jets
Driving laboratory (JPL) in Pasadena, California. Here are the mission engineers and
scientists communicate and track the space vehicles of their mission through NASA Deep
Space Network (DSN). DSN is just an international network of antennas that provide
communication links between the mission team on Earth and the spaceship and
rovers on Mars. The network consists of three communication devices in space
approximately 120 degrees around the world: in Goldstone, California
Mojave Desert; near Madrid, Spain; and near Canberra, Australia, a strategic destination
which enables the spacecraft to be observed constantly when the Earth rotates on its own axis.
That's why engineers switch to LCP to see if they can get a response from the rover. "If Opportunity is on the opposite polarity, maybe that's why we did not hear from him," said Staab.
Engineers have to stay with one polarization when dragging and hitting, so they have to plan ahead in advance which tracks will prove the LCP, and which ones will lead the RCP, Staab summed up.
On Sunday, October 21ulafter changing the configuration of receivers and DSN transmitters, the team switched from RCP to LCP to generate significant signals, said Staab, who works as a flight director in cooperation with engineers known as Aces who monitor and communicate with spacecraft through DSN with JPL. "I have a tracking spreadsheet when we send commands, and most of our attempts are in the sweet place of the window where we think the rover may be conscious and we're pretty good with coverage until now. But again, it's probably a bit too early to wake up because of the amount of dust on the solar panels, "he said.
What's more, according to Staaba, Chance can wake up "about an hour" every day. "It's optimistic, if it's serious no dirty – he said.
This reality puts you in the chances of catching this one window, an hour when you can get a rover command, only about 10%, Staab estimates. "At the moment, we are dealing with a situation in which we are very focused," he said. "If we get cleaning, the chances will increase dramatically," he said.
But it may happen that Opportunity is not able to wake up and stay long enough to receive commands. "It's possible that Opportunity wakes up for two minutes and then it shuts off, and that's not enough time to put in the command," Staab said. "At the moment, we may not even have one each time to get a command to the rover. But that's what we expect now. All that dust, which rises down, falls and drops on the rover. The fact that we have not heard anything yet, suggests to me that Opportunity is really dirty. "
NASA / JPL-Caltech
Listening to the occasion
At the end of October 2018, the NASA headquarters gave the MER team the green light "for
in the foreseeable future, "continue its two-track strategy both actively and passively
listening to find the Opportunity signal. "It really revived us," said the space ship
Systems engineer / flight director Michael Staab, who has been working for months
various aspects of the mission repair strategy.
One thing the team is now convinced about is that the rover released three faults: a low power error; timer error up-loss; and mission clock error. "The clock of the mission has long passed, so the rover does not know what time it is, and maybe wake up in unusual times, due to the way the algorithm works," said Golombek.
Nevertheless, JPL Science engineers and Mission mission managers and / or flight directors should be able to receive the Opportunity signal through passive mid-day listening on Mars. Every day they look like a rover signal in a wide range of times and frequencies recorded by DSN receivers, the most sensitive radio receivers in the world. "We listen passively to virtually every DSN track going to Mars, and we see how the rover tried to say" hello ", even if we did not listen actively – Golombek reminded.
While power models suggest that there should be enough energy to let the Opportunity sometimes wake up, all assumptions about the extreme dusty state of the rover suggest that it needs a good breeze to remove some of the accumulated dust from its solar systems before it can call home or answer the sweeping signals. For researchers, MER October was a September repetition. "Every day we received an update from the engineers and it was basically a template in which only the number of soles changed," said Arvidson of Washington University. Louis.
There were many discussions about other possible reasons why Opportunity might not have called home, without being laden with dust. No wonder that the members of the operational team, as well as the people who had been following the mission from the beginning, wondered whether the two connected batteries of the rover can be lowered or damaged in some way, or worse, dead.
However, it is unlikely that the batteries are completely dead, said Marshall Smart, the main member of the technical staff at the JPL Group of Electrochemistry. "The batteries are quite solid." Although the batteries can be discharged and frozen for several months, if they are properly heated and charged, they will probably run smoothly, although they can be degraded, "said Smart, a chemist who together with Kumar Bugga Chief member and an advanced MER (Li-ion) lithium-ion battery engineer has developed an electrolyte that goes into battery cells to withstand the brutal temperatures on Mars.
Spirit batteries had a similar voltage under them, and to a lesser extent, when they were over-discharged, due to "flash anomalies" within the first month of the original rover's mission, said Bugga. "But after some time they got better and they did a great job," he said. "Another episode of low voltage occurred with the protoflight batteries at Curiositywhere, where several cells were discharged below 1 volt." However, the batteries recovered and supported System Integration and Testing operations, although with reduced performance, higher impedance and less capacity, "he said.
NASA / JPL-Caltech / Cornell
Oppy body, brain, heart and power pack
The diagram on the left shows the basic layout of the Mars Exploration Rovers scientific package
instruments. The diagram on the right shows the interior of the rover's body, otherwise Warm
Electronics Box (WEB) that protects the brain and heart of the rover and is located just under
"winglets" of solar panels. Shows the location of the RAD6000 computer that serves as a robot
brain. Along with a parallel lithium-ion battery (bottom left), which powers the rover and others
The electronics are in the Rover Electronics (REM) module, which is located inside the WEB
protected from cool Martian nights.
Therefore, it is likely that Opportunity batteries will regain their efficiency and will work again when they receive a suitable electric charge from the solar panels, said Bugga. "Although there may be a loss of performance due to their deep discharge, these losses can be much lower in the current" frozen "state."
So, although Opportunity did not have the energy to use its heaters to keep the battery warm during a global storm, the batteries should still work. This does not mean that they can not be damaged. "If the batteries are really cold and you try to charge them too quickly, it can be harmful to your health, for example by covering reactive lithium on the surface of the carbon anodes," Smart said.
"But this litmation is unlikely in a fully discharged battery, the batteries are more likely to not accept charging because of their high impedance at these low temperatures. This can cause the battery to warm up to higher temperatures, where charging is possible from the point of view of kinetic "- explains Bugga.
If the battery voltage has dropped too low, which can reduce the capacity and performance of the battery, said Smart. "If the voltages in the batteries and inside the cells are drained to very low values, a degradation mode may occur which will lead to permanent loss of power and an increase in impedance."
Therefore, even if the batteries are heated and charged with grace, they may show deteriorated performance compared to their health before drying and freezing, "as observed in the Protoflight Curiosity batteries," Bugga noted.
Can the mission clock work through some or even PEDE and constantly drain the batteries until they are effectively killed?
NASA / JPL-Caltech
MER batteries: dynamic duo
Despite some murmurs that Opportunity batteries may be dead or damaged
use, JPL experts from their own battery MER, Kumar Bugga and Marshall Smart, who have developed
the electrolyte that goes into the battery cells to withstand the brutal freezing
temperatures on Mars, I do not think that any scenario would be probable. If the battery voltage
however, they dropped too low, which could reduce battery capacity and performance
speak. But that does not mean that the rover can not continue to wander when it is healed and
return to nominal status.
"This is less likely due to the low currents required for the mission clock, which results in less-striking under-voltage effects, especially at these low temperatures," Bugga said. Intelligent conclusions: "I do not think this scenario will damage the battery." As mentioned above, allowing the battery to be very low voltage is not healthy for the battery and will probably lead to a loss of performance, but this one-time occurrence should not be catastrophic. to low voltage are not so dramatic at very low temperatures, because the rate of degradation, which involves the dissolution of the anode current collector from copper, will be slower. "
There is also the possibility that something somewhere on the rover broke down. "We have to accept the fact that it is a fourteen and a half year old rover," said Callas. "Remember my analogy, it's the difference between a 17-year-old nephew outside without a jacket and a 97-year-old grandmother outside without a jacket. We're a 97-year-old grandmother."
Although there is no evidence or reason to believe that something has burst in the rover, there is simply no way to find out the data from the Opportunity. In addition to the catastrophe or mission catastrophe, everything seems to be reduced to dust. Much more confusing, there is simply no way to prove with certainty how much dust has fallen on this rover. Considering that PEDE literally covers the whole planet, it is hard to get into the rover no Be dirty with dust.
"Yes, it was a gigantic sandstorm, and there was a lifting center nearby, but it is not known how much of it actually falls on site, and what is globally mixed with the atmosphere, which may or may not be the main factor." Golombek said. "Because there no To get enough power to recharge the battery at least enough to wake up, it would have to be extremely dusty on the solar panels, probably more than we've ever seen in the past.
This is what Lemmon, Herman, Staab and others have been thinking for several months. "I believe that if something is not broken, the Opportunity solar systems must be covered with a lot of dust, so much so that they block over half of the light that hits them, maybe as much as 80% or 90%," Herman said.
"I think it's more than half because of the results of some of the power simulations I've been conducting," Herman continued. The input data were known items of the rover and Mars, as well as Tau estimates from orbiter. "I assumed different amounts of dust for solar panels, with enough dust to block 10% of sunlight enough to block 90% of sunlight," she said. "If less than half of the sunlight is blocked by dust, the boards should produce enough energy to let us now hear from Opportunity." So the only thing that makes sense – besides something that's broken – is that more than half Sunlight hitting the boards is blocked by accumulated dust, "she said.
W rzeczywistości burza mogła wyskoczyć z dużych cząstek, które mogły się osadzić na tablicach łazika, a te duże cząsteczki mogą być częścią powodu blokowania światła słonecznego, jak podano w ostatnim numerze Aktualizacja MER. "Wiele dokumentów sugeruje to i pokazują one, że większe cząsteczki osiadają blisko obszaru podnoszenia", powiedział Lemmon.
NASA / JPL-Caltech / Cornell / ASU
Klątwa i pocałunek marsjańskich wiatrów
Okazja wykorzystała jej Pancam do wykonania autoportretów powyżej, w styczniu 2014 r. (Po lewej),
kiedy jej panele słoneczne pokryto pudrowym marsjańskim pyłem, a pod koniec marca 2014 r
(po prawej) po tym, jak wiatry Marsa wyrzuciły dużo kurzu z tablic. Jako
Wiatry marsjańskie dają, one również zabierają. Zarówno przekleństwo, jak i błogosławieństwo, wiatry Marsa
umożliwiły roverowi długie życie i prosperowanie. Jak teraz jest brudna Szansa
as a result of the fallout from the planet-encircling dust storm that churned up in June
July, and August 2018, no one knows. But the Martian winds should start kicking up and
blowing through Endeavour when the dust-cleaning season begins in mid-November.
Since Opportunity is believed to have been very close to a lifting area for days, if larger stuff was lifted as proposed by those atmospheric scientists, that stuff may well have settled on and around the rover. While this supposition is still in the 'model' area, not the 'data' area, “I think it is likely,” said Lemmon.
Another factor to consider is that “Opportunity has always needed and gotten dust cleanings around this time of the Martian year whether there was a dust storm or not,” said Herman, who did the historic dust-cleaning research that informed the team.
Without any incoming data from the rover on the ground, all the team has had to go on is the orbital HiRISE image taken in September. As to what can actually be determined from that image depends on whom you talk to. While some scientists on the MER team think the rover looks as dusty as its immediate surroundings, others disagree.
The High Resolution Imaging Science Experiment, or HiRISE, is a camera onboard the MRO. The 65-kilogram, $40-million instrument, built under the direction of the University of Arizona's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corporation, has been producing stunning imagery for more than a decade.
The HiRISE image of Opportunity in Perseverance Valley, which cuts the western rim of Endeavour, was acquired after the dust storm settled down and the Tau was around 1.5. “It shows that the top of the rover looks really bright,” said Arvidson. “But what’s interesting is that the surrounding areas don’t look particularly bright. The area actually doesn’t look much brighter overall pre and post-PEDE. Still, the deck itself looks really bright so it may have trapped more dust than the surrounding areas.”
Initially HiRISE Principal Investigator Alfred McEwen, of the University of Arizona, interpreted that most of the fallout from the storm settled at latitudes higher than Opportunity's coordinates. “Butsince then, we have seen evidence for extensive dust fallout in some equatorial regions as well, such as in Valles Marineris,” he said.
“What is clear is that the dust deposition is very non-uniform, in spite of the fact that the atmospheric dust looked uniform at the peak of the PEDE,” said McEwen, who is a planetary geologist and director of the Planetary Image Research Laboratory (PIRL) at the Lunar and Planetary Laboratory, at the UA.
NASA / JPL-Caltech / University of Arizona
When the sky first cleared
The MER team saw Opportunity for the first time in months when HiRISE, a high-resolution
camera onboard NASA's Mars Reconnaissance Orbiter took this image in late
September 2018, after the sky over Endeavour cleared from the monster global storm
called a planet-encircling dust Event (PEDE). The image shows that the rover is still
hunkered down at her site about halfway down Perseverance Valley, which cuts the
western rim of Endeavour Crater. But to untrained and unknowing eyes, the golf cart
size rover could be mistaken for a boulder. The square highlighting the rover is about
one kilometer (a half-mile) across.
“The west rim of Endeavour Crater looks remarkably similar in color and albedo patterns as an image with similar lighting acquired before the PEDE, with the exception of some small streaks extending south from topographic knobs on the crater floor, McEwen added. “This suggests that some dust was deposited on the nearby crater floor, then removed by surface winds except where protected by topographic obstacles.” [See animated HiRISE gif in this report].
As for what the images tells us about Opportunity? “I don’t think we can say much about the brightness of the rover itself, given the unique photometric geometry of this image compared to previous images of the rover, and the fact that atmospheric opacity was still higher than normal,” McEwen said.
The rover’s solar arrays only occupy a few HiRISE image pixels. “So doing an analysis of how bright the arrays are relative to the surroundings is beset with problems associated with small numbers of samples, and therefore relatively large errors in estimates of the amount of dust on the panels relative to the surroundings,” Arvidson elaborated.
There are, however, plans for HiRISE to take another image. In fact, a shoot had been scheduled in late October as a ride-along with the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) observation that Arvidson, a CRISM co-investigator, proposed. But that was deferred because of troubleshooting a relay problem between MRO and Curiosity.
October proved to be a tough month on Mars. In addition to Oppy’s situation and Curiosity’s memory problem, that troubleshooting required the MRO team to turn off MARCI, CRISM, along with other instruments onboard for a couple of weeks. “Because we’re troubleshooting this relay issue on the MRO, we’ve powered down the instruments temporarily, except for HiRISE, which doesn’t seem to have any of this interference,” said Zurek.“We have had some relay glitches as we were trying to work through with Curiosity, and we’re all getting ready for InSight because it’s not very far away and we’ll be landing shortly after Thanksgiving.”
The objective was to make the environment as quiet as possible as the engineers worked to resolve the anomalous interference with the MRO relay. “We’ll reschedule CRISM for after the InSight landing,” said Zurek.
While you can’t see even see the rover at all in a CRISM pixel, the MER scientists will be able to check out the scene around Opportunity. “With CRISM’s 18-meter per pixel spatial resolution, it is impossible to see the rover,” said Arvidson. “Instead the intent is to estimate the amount of dust that has accumulated on Endeavour Crater’s rim overall as another constraint on what may have accumulated on the rover’s solar arrays.”
NASA / JPL-Caltech / University of Arizona
Now you see the dust, and now you don’t
This gif shows that dust on the floor of Endeavour has been whisked away, indicating
there is wind activity at least on the floor of the crater. Initially HiRISE Principal
Investigator Alfred McEwen, of the University of Arizona, interpreted that most of the
fallout from the storm settled at latitudes higher than Opportunity's coordinates. “But
since then, we have seen evidence for extensive dust fallout in some equatorial regions
as well,” he said.
So the MER team won’t have to wait for InSight to land for HiRISE to take another image. “We will probably try again for the cycle that executes between Nov 11th–24th, said McEwen. “This should be a much better image with clearer air, unless a regional storm kicks up before then, which is common in summer in the southern hemisphere of Mars.”
With NASA’s approval, the MER team is pressing on positively. Work will soon begin on the extended mission plan, beyond 2019. “It’s due in the second week of February,” said Arvidson. “We still have to submit a plan about the science we would do assuming the rover wakes up. We have to do it. It would be weird if on February 1ulthe vehicle responds because the dust has been blown off and, despite being 15 years old, it’s survived on its own for nine months or so and us no have a proposal ready.”
The extended mission would essentially pick up where the PEDE stopped MER in its tracks. Opportunity would continue the science campaign in Perseverance Valley and then drive down into the crater.
First, of course, the robot field geologist has to wake up and the team has to recover her, fix the faults that have been tripped and attend to anything else it would take to put the veteran robot back in the saddle. “Even if we reestablish contact with Opportunity, it will still take a month or more to get the rover under complete Earth control and back to business, and we have to have that in the proposal too,” Arvidson said.
“There is a lot of hope that the vehicle can survive this long and not be communicating with us, because of the dust cover, and then the wind blows off enough dust and we get Opportunity up and running again – that’s the pro side,” Arvidson said. “The con side is – geessh, she’s going on 15 years old. I mean it’s not like we just bought the vehicle. But who knows? We all hope Opportunity comes back.”
Both Opportunity and her twin, Spirit, were “warrantied” for 90-day primary missions on the Martian surface. The expectation was that Mars’ extreme winters and dust storms would take them out. While Spirit, which landed in the harsher region of Gusev Crater, succumbed sometime in 2010, Opportunity has been like the energizer rover ever since, carrying on it seems with the power of two.
In the immediate future, the team will continue the routine of the last month and half. “I don’t suspect there will be much difference in what we do over the next few months,” said Golombek.
NASA hasn't set any deadlines for the mission. The only plan it seems now is that the team will appear before the Mars Program officials at JPL and the powers-that-be at the space agency again for a reassessment sometime in January 2019. “No one has mentioned deadlines recently,” noted Golombek. “Perhaps it’s because of the popularity of the rovers.”
S. Lever
“Until we hear”
MER Mission Manager Scott Lever decided the day after the rover shut down to wait out
the storm to begin growing a beard, and will continue to let it grow “until we hear from
Oppy or give up trying.” The selfie on the left was taken shortly after the team lost
contact. The one on the right was taken on Sep. 26, 2018, after 108 days of silence. The
image on the right was snapped, after coiffing, at the end of October. Like everyone else
on the team, he’s looking forward to getting that ‘phone call’ from Mars.
Grateful and relieved to have NASA’s approval to continue with both active and passive listening, the MER ops team is focusing all eyes and all efforts like a laser beam on the prize. “We will be much happier when finally hear from her,” said Keuneke.
Silent as Oppy was in October, with NASA’s go-ahead, the month of All Hallow’s Eve brought a welcomed kind of fall color to the team. “It’s great that NASA is continuing to use the best available tools for communicating with the rover through January,” said Lemmon. “If there is no signal by then, I'm not sure how we'd get a signal. But between now and then is when we expect the winds, and this is a time when it is still warm at Opportunity’s site.”
Meanwhile, Staab has started to work on what the team calls Hail Mary scenarios, “our last-ditch efforts,” he said. “We’re trying to identify all the scenarios that could have happened, and then which ones we can actually do something about, and how we would actually go about commanding to rule out those scenarios have occurred.” [More on that next issue.]
Time however sets it’s own deadline. Summer will be transitioning into fall in the coming months and fall of course turns to winter. “As we move past summer, solar insolation will be decreasing and temperatures will be decreasing, and unless we get some dust cleaning, dust will continue to accumulate on the solar arrays,” said Callas. “Since the storm, dust has probably continued to settle out of the atmosphere and has probably accumulated even more on the rover, so it is concerning. We just don’t know. The rover hasn’t talked to us, and that is the thing that will tell us what’s going on.”
While the MER team members simply do not know the state of their rover, Opportunity is cherished, and many are choosing to believe, at least for now. That’s not surprising. Belief in themselves and in their rovers put this team into the history books again and again and again, and along the way they succeeded in taking the world on NASA’s first overland expedition of Mars.
These human Mars explorers have bonded with this “Little Miss Perfect” rover in a way that no previous robotic planetary mission ever has – and that is no doubt a key factor in how and why this 90-day mission has gone on for nearly 15 lat. “If we could bring Opportunity back just with the strength of our emotions,” said Herman, “she would be back already.”
MER optimism prevails and with luck the mission’s lucky star is still shining. “There is no reason to think yet – we haven’t heard from Opportunity, that means it’s gone,” said Staab. “We’re not even to the point where cleaning season historically begins. So there’s no reason to give up yet. We’re not at that point yet.”
S. Atkinson
Not this day
Author and astronomy outreach educator, Stuart Atkinson, who has been following MER since
the beginning used Google’s Aragorn meme generator to create this graphic. The images are
from the 2003 movie version of J.R.R. Tolkien’s The Lord of the Rings: The Return of the King.
directed by Peter Jackson. Atkinson frequently contributes images to The MER Update i ma
his own blog that has tracked Oppy’s travels since her journey to Endeavour Crater began. See
his The Road to Endeavour.
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