NASA to launch tele­scope, most pow­er­ful ever

The China Post - - ARTS - BY JEAN-LOUIS SAN­TINI

As the Hub­ble Space Tele­scope cel­e­brates 25 years in space this week, NASA and its in­ter­na­tional part­ners are build­ing an even more pow­er­ful tool to look deeper into the uni­verse than ever be­fore.

The James Webb Space Tele­scope will be 100 times more po­tent than Hub­ble, and will launch in 2018 on a mission to give as­tronomers an un­prece­dented glimpse at the first gal­ax­ies that formed in the early uni­verse.

“JWST will be able to see back to about 200 mil­lion years af­ter the Big Bang,” NASA said on its web­site.

It de­scribed the tele­scope as a “pow­er­ful time ma­chine with infrared vi­sion that will peer back over 13.5 bil­lion years to see the first stars and gal­ax­ies form­ing out of the dark­ness of the early uni­verse.”

The project has drawn scru­tiny from law­mak­ers for its bal­loon­ing costs — now at about US$8.8 bil­lion, far higher than the ini­tial es­ti­mate of US$3.5 bil­lion (NT$108.58 bil­lion).

But NASA has promised to keep the next-gen­er­a­tion tele­scope on track for its Oc­to­ber 2018 launch.

“What the Webb will re­ally be do­ing is look­ing at the first gal­ax­ies of the uni­verse,” Webb tele­scope ob­ser­va­tory project sci­en­tist Mark Clampin told AFP at NASA’s God­dard Space Flight Cen­ter in Green­belt, Mary­land.

“We will also be able, with th­ese ca­pa­bil­i­ties, to look in very dark parts of the uni­verse where stars are be­ing born.”

In­side a mas­sive room that is par­tially closed off from view, in clean room where no dust can harm the tele­scope, a team of en­gi­neers dressed in white, re­sem­bling sur­geons, work on build­ing the JWST.

The space tele­scope will weigh 6.4 tons. JWST’s main mir­ror will be 6.5 me­ters (yards) in di­am­e­ter, three times as large as Hub­ble’s.

A joint project of NASA, the Euro­pean and Canadian space agen­cies, JWST will carry four in­stru­ments, in­clud­ing cam­eras and spec­trom­e­ters that can cap­ture ex­tremely faint sig­nals.

Infrared ca­pa­bil­ity will help it ob­serve dis­tant ce­les­tial bod­ies, and its cam­era shut­ter will be able to re­main open for long pe­ri­ods, ex­plained Matt Green­house, JWST project sci­en­tist for the science in­stru­ment pay­load.

“The Webb will have 70 times the light- gath­er­ing ca­pac­ity of Hub­ble. So the com­bi­na­tion of the large size and the infrared ca­pa­bil­i­ties will al­low us to ob­serve this epic of the uni­verse past,” he said in an in­ter­view.

Hunt for Life

Even more, the tele­scope should fur­ther the search for life else­where in the uni­verse by open­ing a new win­dow on plan­ets out­side the so­lar sys­tem — known as ex­o­plan­ets — that might have wa­ter and or­bit their stars at a suit­able dis­tance to pre­vent freez­ing or boil­ing.

Al­ready, NASA’s Ke­pler Space tele­scope, launched in 2009, has helped as­tronomers iden­tify thou­sands of ex­o­plan­ets. JWST is ex­pected to pro­pel that re­search even fur­ther.

“Webb is quite big enough to have a high prob­a­bil­ity of find­ing bio signatures in the at­mos­phere of ex­o­plan­ets, ev­i­dence of life,” Green­house said.

“We have sen­sors on board, equip­ment on board that will en­able us to study the at­mos­phere of ex­o­plan­ets spec­tro­scop­i­cally. So we will be able to un­der­stand the com­po­si­tion of those at­mos­pheres,” he added.

“We can make big progress in the search for life.”

Un­like the Hub­ble Space Tele­scope, which cir­cles the Earth, the JWST will go even fur­ther, to a place called L2, for La­Grange Point, 1.5 mil­lion kilo­me­ters away in space.

That dis­tance will keep the tele­scope cold, pre­vent it from be­ing blinded by its own in­fra-red light and shel­ter it from ra­di­a­tion.

“It will fol­low the Earth around the sun over the course of the year. So it’s in a sun cen­ter or­bit in­stead of an Earth cen­ter or­bit,” said Green­house.

The heavy tele­scope is sched­uled to launch atop an Ariane 5 rocket, made by the Euro­pean Space Agency, from French Guiana in Oc­to­ber 2018.

“Just as Hub­ble rewrote all the text­books, Webb will re­write it again,” said Green­house.

AFP

The James Webb Space Tele­scopes In­te­grated Science In­stru­ment Mod­ule (ISIM) is seen mounted on a test frame in a clean room at the NASA God­dard Space Flight Cen­ter in Green­belt, Mary­land on April 2.

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