MER-A

MER-A ("Spirit") isfirst oftwo 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.

Note: Days on Marscalled Solslast 24 hours37 minutes. The landing date (January 3, 2004)MER-Acalled Sol 1. When referringMER-B, however, Sol 1 means its landing date.

Tablecontents

1 Landing site: Columbia Memorial Station 2 Eventsdiscoveries 2.1 Sleepy Hollow 2.2 First color photograph 2.3 Adirondack 2.4 January 21 computer failure 2.5 Dedication toApollo 1 crew 3 Timeline 3.6 2003 3.7 2004 4 Related articles 5 External links

Landing site: Columbia Memorial Station

MER-A landedGusev crater about 10 km fromcenter oftarget ellipse at latitude 14.5718° S ± 30 meters, longitude 175.4785° E ± 0.5 meters [1]. The rover, parachute, heatshieldseveral bounce marksvisible inpicture taken by Mars Global Surveyor.

A panorama [1] showsslightly rolling surface, litteredsmall rocks,hills onhorizon up27 km away.The MER team namedlanding site "Columbia Memorial Station",honor ofseven astronauts killed inSpace Shuttle Columbia disaster.

On January 27 NASA memorializedcrewApollo 1 by dedicatinghills surrounding "Columbia Memorial Station"Gus Grissom, Ed WhiteRoger Chaffee.

Eventsdiscoveries

Sleepy Hollow

"Sleepy Hollow,"shallow depression inMars ground near NASA's Spirit rover, was targetted as an early destination whenrover drove off its lander platform. NASA scientists were very interestedthis crater. It9 meters (30 feet) acrossabout 12 meters (40 feet) north oflander.

Image:sleepyhollowsmall.jpg
First 3-D panoramalanding site:crater undersun"Sleepy Hollow" received on January 5. (Enlarge image)

"Just asancient mariners used sextants'shootingSun,' ascalled it, we were successfully ableshootSunour panorama camera, then use that informationpointantenna," said JPL's Matt Wallace, mission manger.

First color photograph

Below isfirst color imageMars taken bypanoramic camera onMars Exploration Rover Spirit. It ishighest resolution image ever taken onsurfaceanother planet. "We're seeingpanoramic mosaicfour pancam images high by three wide," said camera designer Jim BellCornell. Thereactually 12 million pixelsthis image, it's 4,000 high by 3,000 wide. This, however, onlytip oficeberg, as this image, received on January 6, 2004,about one eighth ofsingle pancam panoramaisn't stereo.

Another detailed photograph, this one fromcenter ofGusev Crater, showingmostly flat, reddish expanse,relatively small greyish rocks litteringfieldview, taken bySpirit rover (NASA)
Part offirst color photograph sent from Spirit. The depression known as "Sleepy Hollow"visible atrightthis photograph. (Enlarge image)

Adirondack

Adirondack isnicknamerover's first target rock. Scientists chose Adirondackbe Spirit's first target rock rather than another rock, called Sashimi, that would have beenshorter, straight-ahead drive. Spirit traversedsandy martian terrain at Gusev Craterarrivefrontthis football-sized rock on Sunday, Jan. 18, 2004, just three days aftersuccessfully rolled offlander.

The rock was selected as Spirit's first target because its dust-free, flat surfaceideally suitedgrinding. Clean surfaces alsobetterexaminingrock's top coating. Scientists namedangular rock afterAdirondack mountain rangeNew York. The word AdirondackNative Americanis interpreted by somemean "They ofgreat rocks." Spirit's Moessbauer spectrometer detectedmineral called olivine, which does not survive weathering well. The lackweathering suggested bypresenceolivine might be evidence thatsoil particlesfinely ground volcanic material. Another possible explanationthatsoil layer wheremeasurements were takenextremely thin, andolivineactually inrock undersoil.

image:Adirondacwide.jpg
(enlarged image)

January 21 computer failure

On January 21 (sol 18), Spirit abruptly ceased communicatingmission control. The next dayrover radioed7.8 bps beep, confirming thathad receivedtransmission from Earth but indicating thatspacecraft believedwas infault mode. This was described asvery serious anomaly, but potentially recoverable ifwassoftware or memory corruption issue rather thanserious hardware failure. Spirit was commandedtransmit engineering data,on January 23 sent several short low-bitrate messages before finally transmitting 73 megabits via X-bandMars Odyssey. This suggested difficulties withrover's high-gain antenna. The rover had also been inprocessor reset loopsome type since Wednesday,whichprocessor would repeatedly wake, loadflight software,uncovercondition that would cause itreset. The processor was not resetting immediately, however, withdelayupan hour. Indications were thatcause ofreset was not always perceived byrover's diagnosticsbesame each time.

On January 24rover repair team announced thatproblem wasSpirit's flash memory andsoftware that wroteit. Spirit was placed"crippled mode", operating using RAM insteadflash. In this mode,rover obeyed commands about communicatinggoing into sleep mode. Spirit communicated successfully at 120 bits per secondnearly an hour. The flash hardware wasfact believedbe working correctly butfile management module insoftware was "not robust enough" foroperationsSpirit was engagedwhenproblem occurred, indicatingsoftware bug as opposedfaulty hardware.

Dedication toApollo 1 crew

NASA memorializedApollo 1 crew -- Gus Grissom, Ed WhiteRoger Chaffee -- by dedicatinghills surroundingMars Exploration Rover Spirit's landing site toastronauts. The crewApollo 1 perishedflash fire duringlaunch pad testtheir Apollo spacecraft at Kennedy Space Center, Fla.

Newly christened "Grissom Hill"located 7.5 kilometers (4.7 miles) tosouthwestSpirit's position. "White Hill"11.2 kilometers (7 miles) northwestits position"Chaffee Hill"14.3 kilometers (8.9 miles) south-southwestrover's position.

Image:55172main apollo hills.jpg
large image

Timeline

2003

• June 6 - June 8 - Two launch attempts cancelled dueweather conditions at Kennedy Space Center.
• June 10 - MER-A ("Spirit") was successfully launched aboardDelta II rocket.

2004

• January 3 (Sol 1) JPL Images from 1/3/2004
  • 20:35 PST - MER-A landedGusev crater, however not exactly at its appointed landing spot withincrater (believed by scientistsonce have beencrater lake). It later became apparent thatrover had landed six miles downrange from its planned landing site, but has landedan area possibly even more favorable fortests scientists wantroverperform. Three decent images showed its progress ascame down. [1]
  • It returns blackwhite photographs viarelay through Mars-orbiting satellites.
• January 4 (Sol 2) JPL Images from 1/4/2004
  • MER-A starts its first day"work", receivingrespondingcommands from NASA.
• January 5 (Sol 3) JPL Images from 1/5/2004
  • The lander locks on its high-gain antennabegins transmitting color photographs directlyEarth.
  • The first 3D Stereogram imagessent back from Spirit.
  • Fourfive planned tests on scientific instruments on MER-A have been successful,fifth instrument testexpectedoccur later tonight. See Scientific instuments onrovers.
• January 6 (Sol 4) JPL Images from 1/6/2004
  • 08:00 PST - U.S. President George W. Bush calls JPLcongratulateMER team forsuccessful landing.
  • The first high resolution, full color imagereceived from Spirit. [1]
  • Throughoutday,serieshigh quality color images were sent from SpiritNASA. Duringnews conference aboutday's events Steve Squyres, science chief ofMER mission said "Thisjusttiny tastewhat'scome", refering tofirst color images coming back.
  • 12:15 PST - The MER team decidesnamespecific spot that Spirit landed on withinGusev Crater "Columbia Memorial Station",honor ofseven astronauts killed indisaster. [1]
• January 7 (Sol 5) JPL Images from 1/7/2004
  • 09:00 PST - Daily news briefing broadcast from JPL over NASA TV. A few new imagesreleased, mainly polished versionsearlier images. Events from Sol 4reviewed, includingdiagnostic test ofhigh gain antenna motor voltage spike(which occured on Sol 2), which did not show any problemswas attributeddebris inantenna machine housing. Airbag retraction was continued on Sol 4. Sol 5 activitiesdiscussed, scientistsengineers onMER teamanxiousget Spirit separated from its landermoving aroundmartian surface.
  • A plotreleased by JPL showing"Dust Optical Depth" ofGusev CraterMeridiani Planum areasMars. The plot showsmeasure ofamountdust inmartian atmosphere as taken by instruments onorbiting Mars Global Surveyor satellite. Recent dust stormsDecemberJanuary on Mars have greatly increasedamountdust inatmosphere around Meridiani Planum,expected landing siteMER-A's sister rover Opportunity, landing 1/24/2004. Itunknown at this point if this increased dust activity will hinder Opportunity's mission. [1]
• January 8 (Sol 6) JPL Images from 1/8/2004
  • 09:00 PST - Daily news briefing from JPL, apparentlyactivitiesfurther retractairbag under Spirit's lander were unsuccessful. On Sol 6 JPL engineers will try 6 rotationstryforcepartially deflated airbags fully underlander. If this attempt fails, Spirit may haveturn itself around onlanderattempt egress via another route.
  • Engineers will also begin Spirit's two step lifting process"stand up" onlander. Step 1 israise Spirit up on its back 4 wheels,Step 2 isdeploycurrently retracted front wheels.
  • Itpredicted thatairbag problem will delay Spirit's egress fromlanderJanuary 14 or later. Currentlyplan islift landing petal onlander that Spiritpreparing travel downattempttuckexcess airbag material underpetal. [1]
• January 9 (Sol 7) JPL Images from 1/9/2004
  • DuringnightSol 6 Spirit successfully completed parts onetwo of"stand up" operationnow has its front wheels deployedis almost readyegress. Parts threefour ofstand up operation will be executed tonight. [1]
  • Imagesdata from Spirit's Mini-TES were released [1]
  • Another attemptpackinflated airbags underramp petals oflander failed. Now JPL engineers will attemptturnrover around while still onlanderegress down one ofother ramps onlander. This activity has been practiced before MER mission launchis expectedwork.

• January 10 (Sol 8) JPL Images from 1/10/2004
  • The Spirit Rover completed its stand up operationis now standingall six wheels deployedlocked,one final connection betweenlanderSpirit remaining.
• January 11 (Sol 9) JPL Images from 1/11/2004
  • AtconclusionSol 8Spirit Rover's science arm, which features toolsdigging intotaking close up imagesrocks, was moved from its stowed launch positionits forward "drive" position.
• January 12 (Sol 10) JPL Images from 1/12/2004
  • During Sol 9Spirit Rover performed science activitiesreturned data fromPancam, completing360 panoramic imagetookits surroundings last week. Mini-TES data suggests more evidence thatGusev site may have beenwater filled lake.
  • Engineers planegress operation Spirit will begin on Sol 10 usingreplica ofSpirit roverlander. The tests go well,no problemsexpected.
• January 13 (Sol 11) JPL Images from 1/13/2004
  • Sol 10 activities included successfully cuttinglast link betweenSpirit roverlander. The first 45 degree turn was successful androverpreparingegress. On Earth, mission details forrover's exploration ofmartian surfacebeing planned now that itknown exactly where Spiritwithin Gusev.
• January 14 (Sol 12)

• January 15 (Sol 13) Images from 1/2/2004
  • Spirit leaveslaunch vehicle.
• January 16 (Sol 14)
  • A 3-D perspective image [1]taken bypanoramic camera onboardMars Exploration Rover Spirit showing "Adirondack,"rover's first target rock.
• January 20 (Sol 17)Images from 1/20/2004
  • NASA Mars Rover?s First Soil Analysis Yields Surprises Among these suprises, isdetectionolivine, which does not survive weathering well.
• January 21 (Sol 18) Spirit stops transmitting datano longer respondscommands.
• January 22 (Sol 19)
  • The rover radioed7.8 bps beep Thursday morning confirming thathad receivedtransmission from Earth. The 7.8 bps indicates thatspacecraft believes it's infault mode. Still,has not returned any data since early Wednesday. Flight-team engineersNASA's Mars Exploration Rover Projectworkingdiagnosecausecommunications difficulties.
  • Pete Theisinger atJet Propulsion LaboratoryPasadena, Calif., describedsituation as "a very serious anomaly." He did say however that "If this problem on Spiritsomehowsoftware corruption issue, or memory corruption issue that's reflecting itselfsoftware,there's notserious power fault, Spirit can goquitelong timewe can pick uppieces again."
  • Steve Squyres,Cornell astronomy professor who headsMars mission's science team, said "It's causeconcern, certainly, but it's not causealarm. I've beenthis businessalmost 25 years now,I've been involvedoverdozen different planetary missions. I don't know ofsingle one that hasn't hadproblem like this somewhere alongline,I includethat list missions like VoyagerMagellan that were spectacular successes. This kindthingpart ofbusinessoperating complicated spacecraft far from Earth." He continued stating that "This vehicle knows howprotect itself when something goes wrong,can do solong periodstime." He concluded saying "I'm very optimistic that we'll get this straightened out,get back tobusinessexploring Gusev crater."
  • The NASA team plansinstructcraftsend back engineering data from Spirit's onboard memory (for diagnostic purposes)possibly send commandsrestore normal communication at around 6 a.m. EST tommorow.
  • On NASA Television, JPL Director Charles Elachi said "Wecautiously encouraged,"added "It ispretty smart machine that we have up there andkeythat wegoingdo next iscommunicate withtomorrow morningask itsend us some data down so we can dodiagnosticwhat'sproblem"
• January 23
  • NASA's Spirit rover communicatedEarth insignal 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 duringcommunication window about 90 minutes after Spirit woke up formorning on Mars. The signal lasted10 minutes atdata rate10 bits per second. Mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., plansend commandsSpirit seeking additional data fromspacecraft duringsubsequent few hours. [1]
  • The flight teamNASA's Spirit received actual data fromroveranother communication session that began at 13:26 Universal Time (5:26 a.m. PST)lasted 20 minutes atdata rate120 bits per second. [1]
  • Shortly before noon, controllers were surprisedreceiverelaydata from Spirit viaMars Odyssey orbiter. Spirit sent 73 megabits atrate128 kilobits per second.
  • Atnews briefing, Pete Theisinger said, "The softwarein X-band fault mode. We surmisegot there becausesome problem withhigh-gain antenna pointing,thatwhysecond high-gain antenna pass on Wednesday did not work. It gives uslittle bit oftale-tellwhatgoing on withprocessor now. But as I pointed outyou,flight softwarenot functioning normally. The two times we have gonecommunicated withsystem, we have gotten different flight software behaviors. Therefore we do not have assurancenext time we goaskit we will get either onethose two behaviors or perhapsthird behavior. " Later Theisinger said thatSpiritin "critical condition"stated that "We do not knowwhat extent we can restore functionality tosystem because we don't know what's broke. We don't know what started this chainevents. I think, personally, that issequencethings. And we don't know, therefore,consequencesthat. I think itdifficult, at this very preliminary stage,assume that we did not have some typehardware event that caused thisstart. Therefore, we don't knowwhat extent we can work around that hardware event andwhat extent we can getsoftwareignore that hardware event, if thatwhat we eventually havedo. "
  • An anomaly team has been formed, completely separate fromOpportunity team. They will be workingschedule that will look like 0500 Mars Timeabout 1500 Mars Time.
  • Atpress conference, Theisinger said that Spirit "has been inprocessor reset loopsome type, mostly since Wednesday, we believe, whereprocessor wakes up, loadsflight software, uncoverscondition that would cause itreset. Butprocessor doesn't do that immediately. It waits forperiodtime - atbeginning ofdaywaits15 minutes twicethen forrest ofdaywaitsan hour -thenresetscomes back up." He added that Spirit's central computer has rebooted itself more than 60 times overpast two days. Theisinger also noted that "The indications we have on two occasionsthatthing that causesresetnot always perceivedbesame."
  • Atpress conference, two computer animationsSpirit's landing were released.[1], [1] Also released was an imageSpirit's landing site taken byMars Orbiter Camera onMars Global Surveyor. [1] [1]

• January 24
  • Atpress conference which started at 3:00 EST, Theisinger says thatthere isproblemSpirit's flash memory andsoftware that writesit. The Spiritin crippled modecan operate using RAM insteadflash. In this mode,rover has obeyed commands about communicatinggoing into sleep mode. Spirit communicated successfully at 120 bits per secondnearly an hour.
  • "The rover has been upgraded from criticalserious," said Mars Exploration Rover Project Manager Peter Theisinger
• January 25
  • Atpress conference, Theisinger says thatNASA team been ablesuccessfully runfirst master sequence sinceanomoly preventedcompletition oftask on Wednesday. He adds thatteammoving towards regardingsituation as"guarded condition" as opposed tocurrent "serious condition." He says thatflash hardwarein fact believedbe working correctly butfile management module insoftware"not robust enough" foroperationsSpirit was engagedwhenproblem occurred, indicatingsoftware bug, as opposedfaulty hardware.
• January 27
  • At today's 12:00 EST press conference, Jennifer Trosper explainscurrent situtation regarding Spirit: "First comm window ofdayhappening as we speak. Notlotnew data yet. Subsystems all nominal. Batteriesin good shape. No degradation from dischargecouple nights ago. Thermal working. Today our intent wastrygettrace oftask causingproblem. We don't have that data yet. Maybe atlater comm today. We've done some analysisdata we already had on ground plus some testingtestbed. One data isposition ofHGA based on potentiometers. Rover doesn't rely on that, justmeasurements. HGA was active when we startedget problems. We got info that inmooringsol 18 our comm dropped out 10 minutes early. Asresult we attemptedcommandHGA session. We saw nothing. It hadcalibration where we movehardstopthen track earth. Position now indicates thatonly moved through calibration half way. Important because activity that startedreset was not inHGA becausemoved fully tocorrect position afterreset problem. That's good news. The other information we got wasresultrunning testsour avionics test environment. Loading upbunchfiles. Couldn't reproducefully. Got some key aspects ofproblem. Looking forwardgetting more data down. Continuingdump outflash memory, get that data down. Yesterday only about 18.5 megabits. Expectget 80 megabits today."

Related articles

• ExplorationMars
• Space exploration
• Unmanned space missions
• Autonomous robot

External links

• SpaceFlightNow Status Page
• Mission Status updates from NASA JPL
• Marsbase.net,site that tracks time on Mars.
• Planetary Photojournal (Mars), NASA JPL's Planetary PhotojournalMars.
• JPL's Mars Exploration Rover home page
• NASA TV Special Events ScheduleMER News Briefings at JPL
• MAESTRO - public versionrover simulation software
• FAQMaestrolinksother amateur sites
• Cornell's rover site: Athena
• Finding Spirit: high resolution imageslanding site (Mars Global Surveyor - Mars Orbiter Camera)
• Finding Spirit: interactive Mars atlas based on Viking images: you can zoom in/outpan images,find your preferred site. "Spirit" approximate position14.82°S (= -14.82°N) , 184.85°W (= 5.15°E)