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Mars craft lands in search of ice

May 26, 2008
Courtesy NASA
and World Science staff
Photos updated

A del­i­cate touch-down ope­ra­t­ion for NASA’s Mars Phoe­nix lan­der has con­clud­ed suc­cess­ful­ly, agen­cy of­fi­cials say. That marks the be­gin­ning of what they hope will be the first in-depth robotic ex­plora­t­ion of fro­zen wa­ter, and per­haps life, on the Red Plan­et.

Artist's illustration of the touchdown. (NASA/JPL-Caltech/University of Arizona)

Cheers burst through the mission control room as suc­cess be­came ap­par­ent fol­low­ing an in­tri­cate­ly cho­reo­graphed descent that en­gi­neers called “se­ven mi­nutes of ter­ror.” Raising the ten­sion was the know­ledge that six of 11 past at­tempts to land crafts on Mars have ended in fail­ure.

Launched Aug. 4, Phoenix is de­signed to ex­plore Mars’ north­ern po­lar re­gion to study ice lurk­ing just un­der­ground, us­ing a robotic arm to dig through the top soil. The ob­jec­tive is to br­ing both soil and ice to the lan­der plat­form for soph­is­t­icated sci­en­tif­ic anal­y­sis.

Mars is a cold des­ert plan­et with lit­tle or no liq­uid wa­ter on its sur­face, but find­ings by the Mars Od­ys­sey Or­biter in 2002 showed abun­dant subsur­face wa­ter ice in the north­ern arc­tic plain. 

This grainy, aer­i­al view of Phoe­nix ar­riv­ing with its par­a­chute was snapped by a cam­era or­bit­ing Mars on NA­SA's Mars Re­con­nais­sance Or­biter. (Cre­d­it: NA­SA/JPL-Calech/University of Ar­i­zo­na)

Re­search­ers hope that might con­tain evi­dence of mi­cro­bial life forms, at least from a warm­er past if not from to­day.

As Phoe­nix sped to­ward its ar­ri­val, Mars’ gravita­t­ional pull sped up the craft, said mis­sion lead­ers based at NASA’s Je­t Pro­pul­sion Lab­o­r­a­to­ry in Pas­a­de­na, Ca­lif. 

“Mars is lit­er­ally pulling on our space­craft,” said Phoe­nix Prin­ci­pal In­ves­ti­ga­tor Pe­ter Smith, of the Uni­ver­s­ity of Ar­i­zo­na, Tuc­son, on Sun­day morn­ing in Pas­a­de­na. “We are ex­cit­ed at how close we are … Mar­tian wa­ter ice will be with­in our reach, af­ter all these years of prepara­t­ions.” 

Gra­vity about dou­bled the craft’s speed rel­a­tive to Mars to around 20,000 km (13,000 miles) per hour, as it ap­proached the top of the Red Plan­et’s at­mos­phere. 

One of the first im­ages cap­tured by the Phoe­nix lan­der shows the vast plains of Mars' Arctic zone, a flat, pebble-strewn land­scape with po­lyg­o­nal crack­ing—a pat­tern seen wide­ly in Mar­tian high lat­i­tudes and al­so in Earth's per­ma­frost. (Cre­d­it: NA­SA/JPL-Calech/University of Ar­i­zo­na)

Con­firma­t­ion of the craft’s ar­ri­val came more than 15 min­utes af­ter touch­down due to the time needed for ra­dio sig­nals to reach Earth. 

Mis­sion con­trollers de­cid­ed over the week­end to for­go two fi­nal op­por­tun­i­ties for ad­just­ing the space­craft’s trajecto­ry. “We are so well on course that those ad­just­ments were not nec­es­sary,” said Phoe­nix Proj­ect Man­ag­er Bar­ry Gold­stein of the Je­t Pro­pul­sion Lab­o­r­a­to­ry.

Phoe­nix will be the first mis­sion to re­turn da­ta from ei­ther po­lar re­gion, NASA of­fi­cials said, pro­vid­ing a ma­jor con­tri­bu­tion to the agen­cy’s Mars re­search strat­e­gy, dubbed “Fol­low the Wa­ter.” 

Its over­all goals are to de­ter­mine wheth­er life ev­er arose on Mars, un­der­stand its cli­mate and ge­ol­o­gy, and pre­pare for hu­man ex­plora­t­ion.

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A delicate touch-down operation for NASA’s Mars Phoenix lander has concluded successfully, agency officials say—marking the beginning of what they hope will be an in-depth robotic exploration of water ice, and perhaps life, on the Red Planet. Launched Aug. 4, the craft is designed to explore Mars’ Northern polar region to study water ice lurking just underground, using a robotic arm to dig through the top soil. The objective is to bring both soil and ice to the lander platform for sophisticated scientific analysis. Mars is a cold desert planet with little or no liquid water on its surface, but findings by the Mars Odyssey Orbiter in 2002 showed abundant subsurface water ice in the northern arctic plain. But landing the craft was a hair-raising challenge, as only five of 11attempts to land a spacecraft on Mars have ever succeeded. As Phoenix sped toward its arrival, Mars’ gravitational pull sped up the craft, said mission leaders based at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Mars is literally pulling on our spacecraft,” said Phoenix Principal Investigator Peter Smith, of the University of Arizona, Tucson, on Sunday morning in Pasadena. “We are excited at how close we are … Martian water ice will be within our reach, after all these years of preparations.” Gravity roughly doubled the craft’s speed relative to Mars, to over 12,000 miles (19,000 km) per hour, as it approached the top of the Red Planet’s atmosphere. Confirmation of the craft’s arrival was to come at least 15 minutes after its arrival due to the time needed for radio signals to reach Earth. Mission had controllers decided over the weekend to forgo two final opportunities for adjusting the spacecraft’s trajectory. “We are so well on course that those adjustments were not necessary,” said Phoenix Project Manager Barry Goldstein of the Jet Propulsion Laboratory. The most challenging part of the entire mission, getting from the top of the atmosphere to a safe landing on three legs, still lies ahead. Phoenix will be the first mission to return data from either polar region, NASA officials said, providing a major contribution to the agency’s Mars research strategy, dubbed “Follow the Water.” The agency hopes overall to determine whether life ever arose on Mars, understand its climate and geology, and prepare for human exploration.