張燕

Since 1960， humankind has launched dozens of missions to Mars in an effort to get to know our planetary neighbor better. Some of the missions were flybys， gathering information in brief bursts. Others were long-standing orbiters that lasted years as they traveled around the Red Planet.

1960s—early 1970s： Flybys & photographs

The first attempts to reach Mars happened near the dawn of space exploration. Considering that the first satellite， the Soviet Unions Sputnik， launched in 1957， it is extraordinary that only three years later the Soviet Union space program looked to extend its reach to Mars. The Soviet Union made multiple attempts in the 1960s to reach the Red Planet， and NASA soon followed with its Mariner 3 spacecraft. These first few missions failed to make it even close to Mars.

While those first several missions didnt reach their target， NASAs Mariner 4 finally did. The spacecraft launched on Nov. 28， 1964， and was the first to fly by Mars on July 14， 1965. It sent 21 photos of the Red Planet back to Earth.

Two days after Mariner 4 launched， the Soviet Union tried again with Zond 2. The spacecraft passed by Mars but the radio failed and it did not return any planetary data.

NASA also sent Mariners 6 and 7 in 1969， both of which reached Mars and sent back a few dozen photos. Coincidentally， all of these spacecraft flew over areas of Mars that were cratered. This gave astronomers the false first impression that Mars looked like the moon.

In 1971， the Soviet Union finally met with success after several attempts to reach the Red Planet. Its Mars 2 orbiter， which launched on May 19， 1971， arrived on Nov. 2. However， the Mars 2 lander crashed on the surface and was no longer operable. Mars 3， a lander and orbiter mission， launched on May 28， 1971， and arrived on Dec. 3. The lander worked for only a few seconds on the surface before failing， but the orbiter worked successfully.

The image of Mars changed with the arrival of NASAs Mariner 9 in November 1971. The spacecraft， which launched on May 30， 1971， arrived at Mars when the entire planet was engulfed in a dust storm. Whats more， something mysterious was poking above the plumes of dust. When the debris settled to the surface， scientists discovered those unusual features were the tops of dormant volcanoes. Mariner 9 also discovered a huge rift across the surface of Mars， later called Valles Marineris—after the spacecraft that discovered it. Mariner 9 spent nearly a year orbiting the Red Planet， and returned 7，329 photos.

1970s—1980s： Landings on Mars， and attempts to reach Phobos

As the Soviet Union continued its Mars series of spacecraft， it garnered partial success; out of four spacecraft aimed for the Red Planet， only one orbiter and one lander briefly returned data in 1974.

Meanwhile， NASA sent two pairs of orbiters and landers toward Mars in 1975. Viking 1 and Viking 2 both arrived at the Red Planet in 1976， and sent their lander to the surface while the orbiter remained working above. The Viking program represented the first extended exploration of Mars， as each spacecraft lasted years and transmitted reams of information back to Earth.

Hopes of finding life on the Red Planet， however， were dashed when the probes could not definitively prove the existence of microbes on the surface.

The Viking missions also revealed that the composition of Mars was almost identical to certain meteorites found on Earth. This suggested that some meteorites found on Earth were originally from Mars.

The Soviet Union also made two attempts to reach one of the moons of Mars， Phobos， in the 1980s， but both missions failed.

1990s： Faster， better， cheaper

NASAs next attempt to reach the Red Planet came in the 1990s， when Mars Observer launched to the planet on Sept. 25， 1992. The spacecraft was lost just before it was supposed to achieve Mars orbit on Aug. 21， 1993. While the loss of communication was never fully explained， the most likely cause was a fuel tank rupture that caused the spacecraft to spin and lose contact with Earth.

The loss was especially painful because the spacecraft had cost so much; an estimated $813 million， which was nearly four times the original budget for the project， according to NASAs Jet Propulsion Lab. The exorbitant cost and the spacecrafts failure sparked a new move within NASA to create better， faster and cheaper missions that would take advantage of advanced computer electronics and new team management techniques. NASA called it the Faster， Better， Cheaper， or FBC program.

In the meantime， NASAs Mars Global Surveyor （MGS） left Earth on Nov. 7， 1996， and arrived at Mars on Sept. 12， 1997. Its mission was extended several times until NASA lost contact with it in 2006. MGS mapped the Red Planet from pole to pole， revealing many ancient signs of water， such as gullies and hematite （a mineral that forms in water）. Data from MGS helped NASA decide where to land its future Mars rovers. MGS also took pictures of public interest， including re-imaging the famous “face on Mars”1.

In 1991， the Soviet Union was dismantled and the Soviet space program was inherited by Russia and Ukraine. The Russian space agency continued their quest for Mars with their Mars 96 mission， which launched on Nov. 16， 1996. However， the orbiter， two landers and two penetrators were lost after the rocket failed.

On the other side of Earth， the FBC programs first mission was a great success. The Pathfinder lander and Sojourner rover arrived at Mars in July 1997. The lander was the first to use a set of airbags to cushion the landing， and Sojourner was the first rover to trundle around on Mars.

Japan was next to enter the mission-to-Mars arena with Nozomi， which launched on July 4， 1998. The spacecraft made it to Mars but failed to enter orbit.

2000s to present： Rovers and orbiters galore2

The discovery of ancient water evidence on Mars sparked a renaissance in Mars exploration.

NASAs Mars Odyssey launched March 7， 2001 and arrived at the Red Planet on Oct. 24， 2001. The orbiter is still conducting its extended science mission. It broke the record for the longest-serving spacecraft at Mars on Dec. 15， 2010. The spacecraft has returned about 350，000 images， mapped global distributions of several elements， and relayed more than 95 percent of all data from the Spirit and Opportunity rovers.

The European Space Agency launched its lander-orbiter called Mars Express/Beagle 2 on June 2， 2003. The lander was lost on arrival on Dec. 25， 2003， but the orbiter completed its prime mission in November 2005 and is currently on an extended mission.

NASAs two rovers， Spirit and Opportunity， were sent to the surface of Mars in 2004. Each discovered ample evidence that water once flowed on the Red Planet. Spirit died in a sand dune in March 2010， while Opportunity continued work for nearly another decade. Opportunity fell silent during a sandstorm in summer 2018 and NASA declared the mission over in early 2019.

Another NASA orbiter， the Mars Reconnaissance Orbiter， launched on Aug. 12， 2005. It began orbiting the planet on March 12， 2006. The mission has returned more data than all previous Mars missions combined.

On Aug. 4， 2007， NASA launched a stationary lander called Mars Phoenix， which arrived at Mars on May 25， 2008， and found water ice beneath the surface. Phoenixs solar panels suffered severe damage from the harsh Martian winter， and communication with the $475 million lander was lost in November 2008. After repeated attempts to re-establish contact， NASA declared Phoenix broken and dead in May 2010. The damage was confirmed in orbital photos taken at the Red Planet.

The Russian space agency， Roscosmos， made another attempt to reach Phobos with the Phobos-Grunt mission， which launched in 2011 and crashed on Jan. 15， 2012， after failing to leave Earth orbit. Phobos-Grunt was also carrying Chinas first attempt at a Mars orbiter， along with an experiment run by the U.S.-based Planetary Society designed to study how a long journey through deep space affects microorganisms.

NASAs more powerful rover， called Curiosity， arrived at Gale Crater in 2012 to search for signs of ancient habitable environments. Its major findings include finding previously water-soaked areas， detecting methane on the surface and finding organic compounds. Opportunitys design has inspired another rover， temporarily called Mars 2020， which will continue with more advanced investigations when it arrives on the Red Planet.

NASAs MAVEN （Mars Atmosphere and Volatile Evolution）， launched in November 2013， achieved orbit on Sept. 21， 2014， and continues to observe changes in the Martian atmosphere to better understand why it thinned over billions of years.

NASA sent the Mars InSight to the Red Planet in 2018， and the spacecraft safely landed that November. As of early 2019， the lander is setting up its instruments to examine the interior of Mars.

India successfully arrived at Mars in 2014， when MOM （Mars Orbiter Mission） successfully arrived in orbit. The spacecraft is far enough from Mars to image the entire planet， and it has already transmitted many images back to Earth.

For its part， the European Space Agency plans to return to Mars with two missions later this decade. The ExoMars program， which is a collaboration with Russia， launched an orbiter called the Trace Gas Orbit （TGO） and a demonstration lander called Schiaparelli in 2016. Although Schiaparelli crashed on the Martian surface， TGO is still operational. The next tranche of ExoMars is the Rosalind Franklin rover and its companion lander， which are scheduled to leave Earth in 2020.3

自1960年以來(lái)，人類(lèi)為了更好地了解我們的行星近鄰，對(duì)火星進(jìn)行了數(shù)十次探測(cè)。其中一部分僅僅是飛越火星，在短暫掠過(guò)時(shí)收集信息;另外一些則是長(zhǎng)期繞軌飛行器，圍繞火星飛行了數(shù)年。

1960年代至1970年代初：飛越及拍照

在太空探索的萌芽時(shí)期，人類(lèi)就已開(kāi)始嘗試去往火星?？紤]到蘇聯(lián)在1957年發(fā)射人類(lèi)第一顆人造衛(wèi)星伴侶號(hào)后僅僅三年就將太空探索范圍擴(kuò)展到了火星，這實(shí)在是非同凡響。蘇聯(lián)在1960年代曾多次嘗試到達(dá)火星，而美國(guó)國(guó)家航空航天局（NASA）也迅速跟進(jìn)發(fā)射了探測(cè)器水手3號(hào)。然而最初的這些嘗試甚至都沒(méi)能靠近火星。

最初的嘗試屢屢失敗之后，NASA的水手4號(hào)終于取得成功。這架探測(cè)器于1964年11月28日發(fā)射，1965年7月14日飛越火星，成為完成此舉的首個(gè)探測(cè)器。它將21張火星照片發(fā)回了地球。

水手4號(hào)發(fā)射兩日后，蘇聯(lián)再次嘗試，發(fā)射了探測(cè)器2號(hào)。這架探測(cè)器雖然也經(jīng)過(guò)了火星，但因無(wú)線電系統(tǒng)故障，未能傳回任何與行星相關(guān)的資料。

1969年，NASA又先后發(fā)射了水手6號(hào)和水手7號(hào)，它們先后抵達(dá)火星并分別傳回幾十張照片。巧合的是，這些探測(cè)器飛越的都是火星的環(huán)形山區(qū)域，這讓天文學(xué)家產(chǎn)生了錯(cuò)誤的第一印象，即火星表面與月球相似。

1971年，數(shù)次嘗試后，蘇聯(lián)抵達(dá)火星的努力終獲成功。1971年5月19日發(fā)射的火星2號(hào)軌道器于11月2日抵達(dá)火星。然而，火星2號(hào)著陸器在星球表面撞毀，無(wú)法繼續(xù)運(yùn)行。1971年5月28日發(fā)射的火星3號(hào)著陸器及軌道器于12月3日抵達(dá)火星。著陸器在火星表面僅僅工作數(shù)秒就壞了，而軌道器則成功運(yùn)行。

NASA的水手9號(hào)于1971年11月抵達(dá)火星，扭轉(zhuǎn)了人們對(duì)這個(gè)星球的印象。這架探測(cè)器發(fā)射于1971年5月30日，到達(dá)火星時(shí)正值沙塵暴籠罩整個(gè)星球。除此之外，還可以看到團(tuán)團(tuán)塵霧中探出些神秘的東西。當(dāng)塵埃落定，科學(xué)家發(fā)現(xiàn)那些不尋常的東西原來(lái)是休眠火山的頂部。水手9號(hào)在火星表面還發(fā)現(xiàn)了一道巨大的裂縫，這道裂縫后來(lái)被命名為“水手號(hào)峽谷”，以此紀(jì)念發(fā)現(xiàn)它的探測(cè)器。水手9號(hào)環(huán)繞火星飛行了近1年，并發(fā)回了7329張照片。

1970年代至1980年代：火星登陸及嘗試抵達(dá)火衛(wèi)一

蘇聯(lián)繼續(xù)向火星發(fā)射探測(cè)器，其不懈努力僅獲得部分成功：在向火星發(fā)射的四架探測(cè)器中，只有一架軌道器和一架著陸器于1974年短暫發(fā)回了一些數(shù)據(jù)。

與此同時(shí)，1975年，NASA向火星發(fā)射了兩對(duì)軌道器和著陸器。海盜1號(hào)和海盜2號(hào)于1976年抵達(dá)火星，并將它們的著陸器送至火星表面，而軌道器則繼續(xù)在空中工作。海盜計(jì)劃代表了對(duì)火星的首次長(zhǎng)時(shí)間探測(cè)，每一架探測(cè)器均工作數(shù)年，并向地球傳回大量數(shù)據(jù)。

然而，數(shù)次探索都未能在火星表面找到微生物存在的確切證據(jù)，在火星上發(fā)現(xiàn)生命的希望就此落空。

海盜計(jì)劃還發(fā)現(xiàn)，火星的成分與在地球發(fā)現(xiàn)的某些隕石幾乎完全一致。這表明，地球上發(fā)現(xiàn)的部分隕石源自火星。

蘇聯(lián)在1980年代還兩次嘗試抵達(dá)火星的衛(wèi)星之一——火衛(wèi)一，但均告失敗。

1990年代：更快、更好、更經(jīng)濟(jì)

NASA于1990年代再次嘗試抵達(dá)火星：1992年9月25日發(fā)射了火星觀察者號(hào)。該探測(cè)器本應(yīng)在1993年8月21日到達(dá)火星軌道，卻在預(yù)計(jì)抵達(dá)的前一刻失去聯(lián)絡(luò)。失聯(lián)問(wèn)題始終未得到充分解釋?zhuān)钣锌赡艿脑蚴怯拖淦屏褜?dǎo)致探測(cè)器急速旋轉(zhuǎn)，從而失去與地球的聯(lián)系。

由于該探測(cè)器成本高昂，這次損失尤其慘重：NASA噴氣推進(jìn)實(shí)驗(yàn)室的數(shù)據(jù)顯示，總成本估約8.13億美元，將近該計(jì)劃最初預(yù)算的4倍。過(guò)高的成本和探測(cè)器的失靈在NASA內(nèi)部引發(fā)了新舉措：利用先進(jìn)的計(jì)算機(jī)電子設(shè)備和新的團(tuán)隊(duì)管理技巧，來(lái)策劃更好、更快且成本更低的探測(cè)行動(dòng)。NASA稱(chēng)之為“更快（Faster）、更好（Better）、更經(jīng)濟(jì)（Cheaper）”計(jì)劃，即FBC計(jì)劃。

與此同時(shí)，NASA在1996年11月7日發(fā)射的火星全球探勘者號(hào)（MGS）于1997年9月12日抵達(dá)火星。其探測(cè)任務(wù)時(shí)間多次延長(zhǎng)，直到2006年NASA與之失去聯(lián)系。MGS繪制了火星從北極到南極的詳細(xì)地圖，發(fā)現(xiàn)了許多可以證明曾經(jīng)有水存在的古老痕跡，例如沖溝和赤鐵礦（一種在水中形成的礦物質(zhì)）。MGS提供的數(shù)據(jù)有助于NASA決定其日后火星車(chē)的著陸點(diǎn)。MGS也拍攝了一些大眾感興趣的照片，包括重新拍攝了著名的“火星臉”。

1991年，蘇聯(lián)解體，俄羅斯和烏克蘭繼承了其航天計(jì)劃。1996年11月16日，俄羅斯聯(lián)邦航天局發(fā)射了火星96探測(cè)器，繼續(xù)對(duì)火星的探索。然而，發(fā)射火箭出現(xiàn)故障，軌道器、兩個(gè)著陸器及兩個(gè)鉆探器均毀于一旦。

在地球另一端，F(xiàn)BC計(jì)劃的首次探測(cè)任務(wù)取得巨大成功。探路者號(hào)著陸器和旅居者號(hào)火星車(chē)在1997年7月抵達(dá)火星。該著陸器首次使用一組氣囊為著陸提供緩沖，而旅居者號(hào)則首次漫游火星各地。

日本于1998年7月4日發(fā)射希望號(hào)，從此加入火星探索行列。該探測(cè)器抵達(dá)了火星但未能進(jìn)入火星軌道。

21世紀(jì)初至今：火星漫游和軌道飛行發(fā)展迅速

在火星上發(fā)現(xiàn)曾經(jīng)有水的古老證據(jù)再次激發(fā)了火星探索的熱潮。

NASA的火星奧德賽號(hào)2001年3月7日升空，并于2001年10月24日抵達(dá)火星。這一軌道器至今仍在執(zhí)行經(jīng)過(guò)延期的科考任務(wù)，并于2010年12月15日打破了火星探測(cè)器服役時(shí)長(zhǎng)紀(jì)錄。該探測(cè)器已傳回約35萬(wàn)張圖像，繪制了多種元素在整個(gè)火星的分布圖，勇氣號(hào)和機(jī)遇號(hào)火星車(chē)所獲資料中超過(guò)95%也由它作為通信中繼傳回地球。

2003年6月2日，歐洲航天局發(fā)射了火星快車(chē)/小獵犬2號(hào)（又譯獵兔犬2號(hào)）著陸器-軌道器。著陸器于2003年12月25日抵達(dá)火星時(shí)失聯(lián)，但軌道器于2005年11月完成主要任務(wù)，至今仍在延長(zhǎng)服役中。

NASA的兩架火星車(chē)——勇氣號(hào)和機(jī)遇號(hào)——于2004年抵達(dá)火星表面。它們都發(fā)現(xiàn)了火星曾經(jīng)存在水流的大量證據(jù)。勇氣號(hào)在2010年3月葬身一處沙丘，而機(jī)遇號(hào)繼續(xù)工作了將近十年。機(jī)遇號(hào)在2018年夏的一次沙暴中銷(xiāo)聲匿跡，NASA最終于2019年初宣布此次任務(wù)結(jié)束。

NASA的另一架軌道器——火星勘測(cè)軌道飛行器——于2005年8月12日發(fā)射升空。它于2006年3月12日開(kāi)始環(huán)繞火星飛行。這一次傳回的數(shù)據(jù)比之前所有火星探測(cè)任務(wù)的總和還多。

2007年8月4日，NASA發(fā)射了火星鳳凰號(hào)靜止著陸器。它于2008年5月25日到達(dá)火星，并發(fā)現(xiàn)了火星地表下的水冰。鳳凰號(hào)的太陽(yáng)能板在火星的嚴(yán)冬中遭受?chē)?yán)重?fù)p傷，這一耗資4.75億美元的著陸器在2008年11月失聯(lián)。反復(fù)嘗試重建聯(lián)系未果后，NASA于2010年5月宣布鳳凰號(hào)損毀。火星軌道器拍攝的照片證實(shí)了鳳凰號(hào)的損傷。

俄羅斯聯(lián)邦航天局2011年發(fā)射了火衛(wèi)一—土壤號(hào)，再次嘗試探測(cè)火衛(wèi)一，但該探測(cè)器因脫離地球軌道失敗，于2012年1月15日墜毀。火衛(wèi)一—土壤號(hào)還搭載了中國(guó)的第一架火星探測(cè)器，美國(guó)行星學(xué)會(huì)則打算借用它開(kāi)展實(shí)驗(yàn)，研究長(zhǎng)途宇宙飛行對(duì)微生物的影響。

NASA另一架更強(qiáng)大的火星車(chē)好奇號(hào)于2012年抵達(dá)蓋爾環(huán)形山，探索火星古老宜居環(huán)境留下的痕跡。它的主要發(fā)現(xiàn)包括：找到曾經(jīng)有豐富水源的區(qū)域，探測(cè)到火星表面的沼氣，以及找到有機(jī)化合物。機(jī)遇號(hào)的設(shè)計(jì)為新的火星車(chē)設(shè)計(jì)帶來(lái)了靈感，該火星車(chē)暫時(shí)命名為火星2020號(hào)，將在抵達(dá)火星后采用先進(jìn)技術(shù)繼續(xù)展開(kāi)一系列勘探。

2013年11月，NASA發(fā)射了馬文號(hào)（火星大氣與揮發(fā)物演化探測(cè)器），它于2014年9月21日抵達(dá)火星軌道，將持續(xù)觀察火星大氣變化，以更好了解為何火星大氣在數(shù)十億年中日漸稀薄。

2018年，NASA發(fā)射了火星洞察號(hào)，該探測(cè)器于當(dāng)年11月安全著陸。截至2019年年初，該著陸器正在安置各種儀器，以探測(cè)火星內(nèi)部。

2014年，印度發(fā)射的莫姆號(hào)（火星軌道器）成功入軌，標(biāo)志其成功到達(dá)火星。該探測(cè)器距離火星的距離足以令其拍攝到整個(gè)星球的圖片，它已將多張照片傳送回地球。

歐洲航天局計(jì)劃于2010年代末執(zhí)行兩次探測(cè)任務(wù)重返火星。一個(gè)是與俄羅斯合作的“火星太空生物”項(xiàng)目（ExoMars），于2016年發(fā)射了微量氣體軌道器（TGO）及示范性著陸器斯基亞帕雷利號(hào)。雖然斯基亞帕雷利號(hào)著陸時(shí)墜毀了，但TGO仍能正常運(yùn)行。ExoMars項(xiàng)目的下一步計(jì)劃是于2020年發(fā)射羅莎琳德·富蘭克林號(hào)火星車(chē)及配套著陸器。? ? ? ? ? ?□