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Spirit (rover)

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MER-A ("Spirit") is the first of the two Mars Exploration Rover Missions. It successfully landed on Mars on January 3, 2004 at 20:35 PST (04:35 UTC on January 4). Its twin, MER-B ("Opportunity"), landed successfully on Mars on January 24, 2004.

Landing site: Columbia Memorial Station

MER-A landed in Gusev crater about 10 km from the center of the target ellipse at latitude 14.5718° S ± 30 meters, longitude 175.4785° E ± 0.5 meters [1]. The rover, parachute, heatshield and several bounce marks are visible in a picture taken by Mars Global Surveyor.

A panorama [2] shows a slightly rolling surface, littered with small rocks, with hills on the horizon up to 27 km away. The MER team named the landing site "Columbia Memorial Station", in honor of the seven astronauts killed in the Space Shuttle Columbia disaster.

On January 27 NASA memorialized the crew of Apollo 1 by naming three hills to the north of "Columbia Memorial Station" for Gus Grissom, Ed White and Roger Chaffee. On February 2, the astronauts on Columbia's final mission were further memorialized when NASA named a set of hills to the east of the landing site the Columbia Hills Complex, denoting seven peaks in that area Anderson, Brown, Chawla, Clark, Husband, McCool and Ramon. (NASA has submitted these geographical feature names to the IAU for approval.)

Events and discoveries

Sleepy Hollow

"Sleepy Hollow," a shallow depression in the Mars ground near NASA's Spirit rover, was targetted as an early destination when the rover drove off its lander platform. NASA scientists were very interested in this crater. It is 9 meters (30 feet) across and about 12 meters (40 feet) north of the lander.

File:Sleepyhollowsmall.jpg


First 3-D panorama of landing site: the crater under the sun is "Sleepy Hollow" received on January 5. (Enlarge image)

"Just as the ancient mariners used sextants for 'shooting the Sun,' as they called it, we were successfully able to shoot the Sun with our panorama camera, then use that information to point the antenna," said JPL's Matt Wallace, mission manger.

First color photograph

Below is the first color image of Mars taken by the panoramic camera on the Mars Exploration Rover Spirit. It is the highest resolution image ever taken on the surface of another planet. "We're seeing a panoramic mosaic of four pancam images high by three wide," said camera designer Jim Bell of Cornell. There are actually 12 million pixels in this image, it's 4,000 high by 3,000 wide. This, however, is only the tip of the iceberg, as this image, received on January 6, 2004, is about one eighth of a single pancam panorama and isn't stereo.

 
Part of the first color photograph sent from Spirit. The depression known as "Sleepy Hollow" is visible at the right of this photograph. (Enlarge image)

Adirondack

Adirondack is the nickname for rover's first target rock. Scientists chose Adirondack to be Spirit's first target rock rather than another rock, called Sashimi, that would have been a shorter, straight-ahead drive. Spirit traversed the sandy martian terrain at Gusev Crater to arrive in front of this football-sized rock on Sunday, Jan. 18, 2004, just three days after it successfully rolled off the lander.

The rock was selected as Spirit's first target because its dust-free, flat surface is ideally suited for grinding. Clean surfaces also are better for examining a rock's top coating. Scientists named the angular rock after the Adirondack mountain range in New York. The word Adirondack is Native American and is interpreted by some to mean "They of the great rocks." Spirit's Moessbauer spectrometer detected a mineral called olivine, which does not survive weathering well. The lack of weathering suggested by the presence of olivine might be evidence that the soil particles are finely ground volcanic material. Another possible explanation is that the soil layer where the measurements were taken is extremely thin, and the olivine is actually in a rock under the soil.

File:Adirondacwide.jpg
(enlarged image)

Spirit has also returned microscopic images and Mössbauer spectrometer readings of Adirondack taken the day before the rover developed computer and communication problems on Jan. 22. Both are unprecedented investigations of any rock on another planet.

The microscopic images indicate Adirondack is a hard, crystalline rock. "If you had a hammer and whacked that rock, it would ring," Arvidson said.

The peaks large and small in the spectrum reveal that the minerals in Adirondack include olivine, pyroxene and magnetite. That composition is common in volcanic basalt rocks on Earth, said science-team member Dr. Dick Morris of NASA's Johnson Space Center, Houston.

January 21 computer failure

On January 21 (sol 18), Spirit abruptly ceased communicating with mission control. The next day the rover radioed a 7.8 bps beep, confirming that it had received a transmission from Earth but indicating that the spacecraft believed it was in a fault mode. This was described as a very serious anomaly, but potentially recoverable if it was a software or memory corruption issue rather than a serious hardware failure. Spirit was commanded to transmit engineering data, and on January 23 sent several short low-bitrate messages before finally transmitting 73 megabits via X-band to Mars Odyssey. This suggested difficulties with the rover's high-gain antenna. The rover had also been in a processor reset loop of some type since Wednesday, in which the processor would repeatedly wake, load the flight software, and uncover a condition that would cause it to reset. The processor was not resetting immediately, however, with a delay of up to an hour. Indications were that the cause of the reset was not always perceived by the rover's diagnostics to be the same each time.

On January 24 the rover repair team announced that the problem was with Spirit's flash memory and the software that wrote to it. Spirit was placed in "crippled mode", operating using RAM instead of flash. In this mode, the rover obeyed commands about communicating and going into sleep mode. Spirit communicated successfully at 120 bits per second for nearly an hour. The flash hardware was in fact believed to be working correctly but the file management module in the software was "not robust enough" for the operations the Spirit was engaged in when the problem occurred, indicating a software bug as opposed to faulty hardware.

Dedication to the Apollo 1 crew

The crew of Apollo 1 perished on January 27, 1967 in a flash fire during a launch pad test of their Apollo spacecraft at Kennedy Space Center, Fla. NASA memorialized the Apollo 1 crew -- Gus Grissom, Ed White and Roger Chaffee -- by dedicating the hills surrounding the Mars Exploration Rover Spirit's landing site to the astronauts.

Newly christened "Grissom Hill" is located 7.5 kilometers (4.7 miles) to the southwest of Spirit's position. "White Hill" is 11.2 kilometers (7 miles) northwest of its position and "Chaffee Hill" is 14.3 kilometers (8.9 miles) south-southwest of rover's position.

File:55172main apollo hills.jpg
large image

History's first grinding of a rock on Mars

The round, shallow depression in this image resulted from history's first grinding of a rock on Mars. The rock abrasion tool on NASA's Spirit rover ground off the surface of a patch 45.5 millimeters (1.8 inches) in diameter on a rock called Adirondack during Spirit's 34th sol on Mars, Feb. 6, 2004. The hole is 2.65 millimeters (0.1 inch) deep, exposing fresh interior material of the rock for close inspection with the rover's microscopic imager and two spectrometers on the robotic arm. This image was taken by Spirit's panoramic camera, providing a quick visual check of the success of the grinding. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.


"The RAT performed beyond our expectations," beamed Steve Gorevan, of Honeybee Robotics, New York, lead scientist for the rock abrasion tools on both rovers. "With the docile cutting parameters we set, I didn't think that it would cut this deep. In fact, when we saw virtually a complete circle, I was thrilled beyond anything I could have ever dreamed. Following up that glorious circular brushing - it's like back-to-back homers."

 

Timeline

Note: Days on Mars are called Sols and last 24 hours 39 minutes 35.244 seconds. The solar day on which Spirit landed is designated Sol 1. The local time of the event was in the early afternoon, or at 14:34 according to the LST-A timekeeping system used by the MER team. (When referring to MER-B, however, Sol 1 means its landing date, which is offset 20.5 sols behind Sol 1 of MER-A).

Announcements of MER-A achievements were made at daily press briefings at the NASA Jet Propulsion Laboratory, usually held at 09:00 PST (12:00 EST, 17:00 UTC). The briefings typically discussed activities during the most recently completed sol and plans for the upcoming sol. The following chronology uses the dates of announcements, and references to "this morning" or "tonight" are often in reference to JPL local time (PST).

2003

  • June 6 - June 8 - Two launch attempts cancelled due to weather conditions at Kennedy Space Center.
  • June 8 - NASA announced that Mars Exploration Rover A will henceforth be known as "Spirit". Its companion probe MER-B will be known as "Opportunity". The names were selected by means of an essay contest open to American school children; the winning essay was submitted by Sofi Collis of Arizona.
  • June 10 - Spirit was successfully launched aboard a Delta II rocket.

2004 January

  • January 3-4 (Sol 1 ends 2004-01-04 14:15 UTC) JPL Images from 1/3/2004
    • 20:35 PST - MER-A landed in Gusev crater, however not exactly at its appointed landing spot within the crater (believed by scientists to once have been a crater lake). It later became apparent that the rover had landed six miles downrange from its planned landing site, but has landed in an area possibly even more favorable for the tests scientists want the rover to perform.
    • A few hours after landing, first photography is received via relay thgough Mars orbiter.[3] Three descent images showed its progress as it came down. [4].
  • January 5 (Sol 2 ends 2004-01-05 14:55 UTC) JPL Images from 1/5/2004
    • The lander locks on its high-gain antenna and begins transmitting color photographs directly to Earth.
    • The first 3D Stereogram images are sent back from Spirit.
    • Four of five planned tests on scientific instruments on MER-A have been successful, the fifth instrument test is expected to occur later tonight. See Scientific instuments on the rovers.
  • January 6 (Sol 3 ends 2004-01-06 15:35 UTC) JPL Images from 1/6/2004
    • 08:00 PST - U.S. President George W. Bush calls JPL to congratulate the MER team for a successful landing.
    • The first high resolution, full color image is received from Spirit. [5]
    • Throughout the day, a series of high quality color images were sent from Spirit to NASA. During a news conference about the day's events Steve Squyres, science chief of the MER mission said "This is just a tiny taste of what's to come", refering to the first color images coming back.
    • 12:15 PST - The MER team decides to name the specific spot that Spirit landed on within the Gusev Crater "Columbia Memorial Station", in honor of the seven astronauts killed in the disaster. [6]
  • January 7 (Sol 4 ends 2004-01-07 16:14 UTC) JPL Images from 1/7/2004
    • 09:00 PST - Daily news briefing broadcast from JPL over NASA TV. A few new images are released, mainly polished versions of earlier images. Events from Sol 4 are reviewed, including a diagnostic test of a high gain antenna motor voltage spike (which occurred on Sol 2), which did not show any problems and was attributed to debris in the antenna machine housing. Airbag retraction was continued on Sol 4. Sol 5 activities are discussed, scientists and engineers on the MER team are anxious to get Spirit separated from its lander and moving around the martian surface.
    • A plot is released by JPL showing the "Dust Optical Depth" of the Gusev Crater and Meridiani Planum areas of Mars. The plot shows a measure of the amount of dust in the martian atmosphere as taken by instruments on the orbiting Mars Global Surveyor satellite. Recent dust storms in December and January on Mars have greatly increased the amount of dust in the atmosphere around Meridiani Planum, the expected landing site of MER-A's sister rover Opportunity, landing 1/24/2004. It is unknown at this point if this increased dust activity will hinder Opportunity's mission. [7]
  • January 8 (Sol 5 ends 2004-01-08 16:54 UTC) JPL Images from 1/8/2004
    • 09:00 PST - Daily news briefing from JPL, apparently the activities to further retract the airbag under Spirit's lander were unsuccessful. On Sol 6 JPL engineers will try 6 rotations to try and force the partially deflated airbags fully under the lander. If this attempt fails, Spirit may have to turn itself around on the lander and attempt egress via another route.
    • Engineers will also begin Spirit's two step lifting process to "stand up" on the lander. Step 1 is to raise Spirit up on its back 4 wheels, and Step 2 is to deploy the currently retracted front wheels.
    • It is predicted that the airbag problem will delay Spirit's egress from the lander to January 14 or later. Currently the plan is to lift landing petal on the lander that Spirit is preparing travel down and attempt to tuck the excess airbag material under the petal. [8]
  • January 9 (Sol 6 ends 2004-01-09 17:33 UTC) JPL Images from 1/9/2004
    • During the night of Sol 6 Spirit successfully completed parts one and two of the "stand up" operation and now has its front wheels deployed and is almost ready to egress. Parts three and four of the stand up operation will be executed tonight. [9]
    • Images of data from Spirit's Mini-TES were released [10]
    • Another attempt to pack the inflated airbags under the ramp petals of the lander failed. Now JPL engineers will attempt to turn the rover around while still on the lander and egress down one of the other ramps on the lander. This activity has been practiced before MER mission launch and is expected to work.
  • January 10 (Sol 7 ends 2004-01-10 18:13 UTC) JPL Images from 1/10/2004
    • The Spirit Rover completed its stand up operation and is now standing with all six wheels deployed and locked, with one final connection between the lander and Spirit remaining.
  • January 11 (Sol 8 ends 2004-01-11 18:52 UTC) JPL Images from 1/11/2004
    • At the conclusion of Sol 8 the Spirit Rover's science arm, which features tools for digging into and taking close up images of rocks, was moved from its stowed launch position to its forward "drive" position.
  • January 12 (Sol 9 ends 2004-01-12 19:32 UTC) JPL Images from 1/12/2004
    • During Sol 9 the Spirit Rover performed science activities and returned data from the Pancam, completing the 360 panoramic image it took of its surroundings last week. Mini-TES data suggests more evidence that the Gusev site may have been a water filled lake.
    • Engineers plan the egress operation Spirit will begin on Sol 10 using a replica of the Spirit rover and lander. The tests go well, and no problems are expected.
  • January 13 (Sol 10 ends 2004-01-13 20:12 UTC) JPL Images from 1/13/2004
    • Sol 10 activities included successfully cutting the last link between the Spirit rover and lander. The first 45 degree turn was successful and the rover is preparing for egress. On Earth, mission details for the rover's exploration of the martian surface are being planned now that it is known exactly where Spirit is within Gusev.
  • January 14 (Sol 11 ends 2004-01-14 20:51 UTC)
  • January 15 (Sol 12 ends 2004-01-15 21:31 UTC) Images from 1/15/2004
    • Spirit leaves the launch vehicle.
  • January 16 (Sol 13 ends 2004-01-16 22:10 UTC)
    • A 3-D perspective image [11] is taken by the panoramic camera onboard the Mars Exploration Rover Spirit showing "Adirondack," the rover's first target rock.
  • January 20 (Sol 16 ends 2004-01-20 00:09 UTC)Images from 1/20/2004
    • NASA Mars Rover?s First Soil Analysis Yields Surprises Among these suprises, is the detection of olivine, which does not survive weathering well.
  • January 21 (Sol 17 ends 2004-01-21 00:49 UTC)
    • Spirit stops transmitting data and no longer responds to commands.
  • January 22 (Sol 18 ends 2004-01-22 01:28 UTC)
    • The rover radioed a 7.8 bps beep Thursday morning confirming that it had received a transmission from Earth. The 7.8 bps indicates that the spacecraft believes it's in a fault mode. Still, it has not returned any data since early Wednesday. Flight-team engineers for NASA's Mars Exploration Rover Project are working to diagnose the cause of communications difficulties.
    • Pete Theisinger at the Jet Propulsion Laboratory in Pasadena, Calif., described the situation as "a very serious anomaly." He did say however that "If this problem on Spirit is somehow a software corruption issue, or memory corruption issue that's reflecting itself in software, and there's not a serious power fault, Spirit can go for quite a long time and we can pick up the pieces again."
    • Steve Squyres, the Cornell astronomy professor who heads the Mars mission's science team, said "It's cause for concern, certainly, but it's not cause for alarm. I've been in this business for almost 25 years now, and I've been involved in over a dozen different planetary missions. I don't know of a single one that hasn't had a problem like this somewhere along the line, and I include in that list missions like Voyager and Magellan that were spectacular successes. This kind of thing is part of the business of operating complicated spacecraft far from Earth." He continued stating that "This vehicle knows how to protect itself when something goes wrong, and can do so for long periods of time." He concluded saying "I'm very optimistic that we'll get this straightened out, and get back to the business of exploring Gusev crater."
    • The NASA team plans to instruct the craft to send back engineering data from Spirit's onboard memory (for diagnostic purposes) and possibly send commands to restore normal communication at around 6 a.m. EST tommorow.
    • On NASA Television, JPL Director Charles Elachi said "We are cautiously encouraged," and added "It is a pretty smart machine that we have up there and the key thing that we are going to do next is to communicate with it tomorrow morning and ask it to send us some data down so we can do a diagnostic of what's the problem"
  • January 23 (Sol 19 ends 2004-01-23 02:08 UTC)
    • NASA's Spirit rover communicated with Earth in a signal detected by NASA's Deep Space Network antenna complex near Madrid, Spain, at 12:34 Universal Time (4:34 a.m. PST) this morning. The transmissions came during a communication window about 90 minutes after Spirit woke up for the morning on Mars. The signal lasted for 10 minutes at a data rate of 10 bits per second. Mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., plan to send commands to Spirit seeking additional data from the spacecraft during the subsequent few hours. [12]
    • The flight team for NASA's Spirit received actual data from the rover in another communication session that began at 13:26 Universal Time (5:26 a.m. PST) and lasted 20 minutes at a data rate of 120 bits per second. [13]
    • Shortly before noon, controllers were surprised to receive a relay of data from Spirit via the Mars Odyssey orbiter. Spirit sent 73 megabits at a rate of 128 kilobits per second.
    • At a news briefing, Pete Theisinger said, "The software is in X-band fault mode. We surmise it got there because of some problem with the high-gain antenna pointing, and that is why the second high-gain antenna pass on Wednesday did not work. It gives us a little bit of a tale-tell for what is going on with the processor now. But as I pointed out to you, the flight software is not functioning normally. The two times we have gone and communicated with the system, we have gotten different flight software behaviors. Therefore we do not have assurance the next time we go and ask for it we will get either one of those two behaviors or perhaps a third behavior. " Later Theisinger said that the Spirit is in "critical condition" and stated that "We do not know to what extent we can restore functionality to the system because we don't know what's broke. We don't know what started this chain of events. I think, personally, that is a sequence of things. And we don't know, therefore, the consequences of that. I think it is difficult, at this very preliminary stage, to assume that we did not have some type of hardware event that caused this to start. Therefore, we don't know to what extent we can work around that hardware event and to what extent we can get the software to ignore that hardware event, if that is what we eventually have to do. "
    • An anomaly team has been formed, completely separate from the Opportunity team. They will be working a schedule that will look like 0500 Mars Time to about 1500 Mars Time.
    • At the press conference, Theisinger said that Spirit "has been in a processor reset loop of some type, mostly since Wednesday, we believe, where the processor wakes up, loads the flight software, uncovers a condition that would cause it to reset. But the processor doesn't do that immediately. It waits for a period of time - at the beginning of the day it waits for 15 minutes twice and then for the rest of the day it waits for an hour - and then it resets and comes back up." He added that Spirit's central computer has rebooted itself more than 60 times over the past two days. Theisinger also noted that "The indications we have on two occasions is that the thing that causes the reset is not always perceived to be the same."
    • At the press conference, two computer animations of Spirit's landing were released.[14], [15] Also released was an image of Spirit's landing site taken by the Mars Orbiter Camera on the Mars Global Surveyor. [16] [17]
  • January 24 (Sol 20 ends 2004-01-24 02:48)
    • At a press conference which started at 3:00 EST, Theisinger says that the there is a problem with Spirit's flash memory and the software that writes to it. The Spirit is in crippled mode and can operate using RAM instead of flash. In this mode, the rover has obeyed commands about communicating and going into sleep mode. Spirit communicated successfully at 120 bits per second for nearly an hour.
    • "The rover has been upgraded from critical to serious," said Mars Exploration Rover Project Manager Peter Theisinger
  • January 25 (Sol 21 ends 2004-01-25 03:27 UTC)
    • At a press conference, Theisinger says that the NASA team been able to successfully run the first master sequence since the anomoly prevented the completion of a task on Wednesday. He adds that the team is moving towards regarding the situation as a "guarded condition" as opposed to the current "serious condition." He says that the flash hardware is in fact believed to be working correctly but the file management module in the software is "not robust enough" for the operations the Spirit was engaged in when the problem occurred, indicating a software bug, as opposed to faulty hardware.
  • January 27 (Sol 23 ends 2004-01-27 04:46 UTC)
    • At today's 12:00 EST press conference, Jennifer Trosper explains the current situtation regarding Spirit: "First comm window of the day is happening as we speak. Not a lot of new data yet. Subsystems all nominal. Batteries are in good shape. No degradation from discharge a couple nights ago. Thermal working. Today our intent was to try to get a trace of the task causing the problem. We don't have that data yet. Maybe at a later comm today. We've done some analysis of data we already had on ground plus some testing in testbed. One data is the position of the HGA based on potentiometers. Rover doesn't rely on that, just for measurements. HGA was active when we started to get problems. We got info that in the mooring of sol 18 our comm dropped out 10 minutes early. As a result we attempted to command a HGA session. We saw nothing. It had a calibration where we move to hardstop and then track earth. Position now indicates that it only moved through calibration half way. Important because activity that started the reset was not in the HGA because it moved fully to the correct position after the reset problem. That's good news. The other information we got was a result of running tests in our avionics test environment. Loading up a bunch of files. Couldn't reproduce it fully. Got some key aspects of the problem. Looking forward to getting more data down. Continuing to dump out the flash memory, get that data down. Yesterday only about 18.5 megabits. Expect to get 80 megabits today."
  • January 29 (Sol 25 ends 2004-01-29 06:05 UTC)
    File:Sol25-flhaz th100.jpg
    Spirit's extended arm
    • NASA's Mars Exploration Rover Spirit took and returned this image on January 28, 2004 (Sol 25), the first picture from Spirit since problems with communications began a week earlier. The image from the rover's front hazard identification camera shows the robotic arm extended to the rock called Adirondack. As it had been instructed a week earlier, the Moessbauer spectrometer, an instrument for identifying the minerals in rocks and soils, is still placed against the rock. Engineers are working to restore Spirit to working order so that the rover can resume the scientific exploration of its landing area.

2004 February

  • February 1 (Sol 28 ends 2004-02-01 08:04 UTC)
    • After intensive diagnostic work, the working hypothesis is that Spirit's problems were caused by the contents of the flash memory it uses for mission data storage causing Spirit to use all of its available RAM when mounting the flash memory. Work has commenced on fixing the problem.
  • February 6 (Sol 33 ends 2004-02-06 11:22 UTC)
    • After further diagnostics, and some other problems with the flash memory, Spirit's flash memory used for mission file storage has been completely reformatted. This appears to have cured Spirit's problems. Scientific work has resumed. Spirit has used the brush from the RAT to remove dust from the surface of the "Adirondack" rock, and sent back pictures.
  • February 8 (Sol 35 ends 2004-02-08 12:41 UTC)
    • Today the Spirit performed history's first grinding of a rock on Mars. The rock abrasion tool on NASA's Spirit rover ground off the surface of a patch 45.5 millimeters (1.8 inches) in diameter on Adirondack during Spirit's 34th sol on Mars, Feb. 6, 2004. The hole is 2.65 millimeters (0.1 inch) deep, exposing fresh interior material of the rock for close inspection with the rover's microscopic imager and two spectrometers on the robotic arm.
  • February 9 (Sol 36 ends 2004-02-09 13:21 UTC)
    • Spirit began moving again last night, passing over Adirondack and traveling 6.37 meters. The drive tested the rover's onboard navigation software and hazard avoidance system for the first time on Mars, which allow the rover to evaluate and navigate itself past obstacles. The drive, intended to test the traverse commands, was extremely precise, taking Spirit to its intended goal - the rock called White Boat. Later tonight commands will be sent to command the rover to move toward the small crater Bonneville. (In the coming sols, Spirit will continue its drive toward Bonneville Crater.) Before leaving the rock Adirondack, Spirit took images and collected miniature thermal emission spectrometer data from the hole ground by the rock abrasion tool.
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