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Mis­sions to Venus: Hell’s call­ing again

Much vis­ited in an ear­lier era of space ex­plo­ration, the planet has been over­looked in re­cent decades

- SHAN­NON STIRONE Space Research · Space Technology · Space · Spacecraft · Space Travel · Interplanetary Space Flights · Solar System · Science · Planets · Space Flights · Milky Way Galaxy · North Carolina State University · North Carolina · Soviet Union · Japan · India · New Zealand · Earth · Carl Sagan · European Space Agency · Rocket Lab · Soviet space program

Carl Sa­gan once said that Venus is the planet in our so­lar sys­tem most like hell. So when are we go­ing back? Astronomer­s last week re­ported the de­tec­tion of a chem­i­cal in the acidic Venu­sian clouds, phos­phine, which may be a pos­si­ble sign of life. That has some plan­e­tary sci­en­tists itch­ing to re­turn to the sun’s sec­ond planet, es­pe­cially those who feel Venus has long been over­looked in favour of Mars and other des­ti­na­tions.

“If this planet is ac­tive and is pro­duc­ing phos­phine, and there is some­thing that’s mak­ing it in the Venus at­mos­phere, then by God almighty, for­get this Mars non­sense,” said Paul Byrne, a plan­e­tary sci­en­tist at North Carolina State Univer­sity. “We need a lan­der, an or­biter, we need a pro­gramme.”

Venus is not easy to visit. Its car­bon-diox­iderich at­mos­phere is 90 times as dense as ours, and sur­face tem­per­a­tures av­er­age 427 de­grees Cel­sius. Its sur­face pres­sure is in­tense enough to crush some sub­marines.

But that hasn’t stopped hu­man space pro­grammes from try­ing. About 40 ro­botic space­craft launched by gov­ern­ments on Earth have tried to visit Venus in one way or an­other. Here are high­lights from past jour­neys to Venus, as well as the prospects for a speedy re­turn to the planet to find out what’s go­ing on in those clouds.

SOVIET VIS­I­TORS TO VENUS

In 1961, the Soviet space pro­gramme be­gan try­ing to ex­plore Venus. In the decades that fol­lowed, it shot dozens of space­craft to­ward the world some­times known as Earth’s twin. While Soviet ex­plo­ration of Venus started with many mis­fires, the coun­try be­came the first to land a space­craft on an­other world, and not long af­ter, the first to take pho­tos from the sur­face of an­other planet. Their en­gi­neer­ing achieve­ments were sig­nif­i­cant even by mod­ern stan­dards.

Af­ter see­ing their first round of space­craft sent into the at­mos­phere squashed like tin cans, the Sovi­ets re­alised just how ex­treme the pres­sure on Venus was. This trial and er­ror led to the con­struc­tion of a 5-tonne metal space­craft built to with­stand, even if for just an hour, the im­mense sur­face pres­sures.

Ven­era 4 in 1967 be­came the first space­craft to mea­sure the at­mos­phere of an­other planet, de­tect­ing large amounts of car­bon diox­ide that cause the cease­less Venu­sian green­house ef­fect.

Then in 1975, the coun­try’s Ven­era 9 probe be­came the first to take im­ages from the sur­face of an­other planet.

The world of­fi­cially met Venus. The im­ages it and later mis­sions sent back re­vealed a planet that was truly like no other: cracked ter­rain be­neath hazy, di­luted neon green light. The planet we thought might have been covered in oceans and akin to our own was in­stead an alien world with poi­son rain.

Later mis­sions in the Ven­era se­ries into the 1980s gave sci­en­tists a bet­ter un­der­stand­ing of the planet’s ge­o­log­i­cal pro­cesses. Ven­era 11 and 12 both de­tected large amounts of light­ning and thun­der as they trav­elled to the sur­face. Ven­era 13 and 14 were both equipped with mi­cro­phones that doc­u­mented the sounds of their de­scent to the sur­face, mak­ing them the first space­craft to record au­dio from an­other planet.

In 1985 the Soviet Union con­cluded its Venus en­coun­ters with the twin Vega space­craft, which each re­leased large bal­loons loaded with sci­en­tific in­stru­ments, demon­strat­ing the po­ten­tial for probes that could float in the planet’s clouds.

The slowed pace of the Soviet space pro­gramme to­ward the end of the Cold War halted launches to Venus. While the Rus­sian space pro­gramme has dis­cussed fu­ture ex­plo­ration of Venus, its con­cepts have not moved off the draw­ing board.

NASA KEPT AN EYE ON VENUS, TOO

While Mars has al­ways seemed like the ap­ple of the eyes of Amer­i­can space plan­ners, the Mariner and Pioneer pro­grammes of the 1960s and ’70s made time for Venus.

Mariner 2 was the first Amer­i­can space­craft to make it to Venus, in 1962. It de­ter­mined that tem­per­a­tures were cooler higher in the clouds, but ex­tremely hot on the sur­face. In 1978, the Pioneer mis­sions gave Amer­i­can re­searchers a closer look. The first of the pair or­bited the planet for nearly 14 years, re­veal­ing much about the mys­te­ri­ous Venu­sian at­mos­phere.

It also ob­served the sur­face was smoother than Earth’s, and that Venus had very lit­tle or per­haps no mag­netic field. A sec­ond Pioneer mis­sion sent a num­ber of probes into Venus’ at­mos­phere, re­turn­ing in­for­ma­tion on the struc­ture of the clouds and radar read­ings of the sur­face.

Nasa’s Mag­el­lan en­tered into or­bit in 1990 and spent four years map­ping the sur­face and look­ing for ev­i­dence of plate tec­ton­ics.

It dis­cov­ered that nearly 85% of the sur­face was covered in old lava flows, hint­ing at sig­nif­i­cant past and pos­si­ble present vol­canic ac­tiv­ity. It was also the last of the Amer­i­can vis­i­tors, although a num­ber of Nasa space­craft have used Venus as a sling­shot as they set course for other des­ti­na­tions.

OTHER VIS­I­TORS TO VENUS

Venus Ex­press was launched by the Euro­pean Space Agency in 2005. It or­bited the planet for eight years and ob­served that it still may have been ge­o­log­i­cally ac­tive.

The planet’s only guest from Earth right now is Akat­suki, which was launched by Ja­pan in 2010. The probe missed its meet­ing with Venus when its en­gine failed to fire as it headed into or­bit. By 2015, the mis­sion’s man­agers had man­aged to steer it on a course to or­bit and study the planet. It has since trans­formed how sci­en­tists view our clouded twin. In its study of the physics of the dense cloud lay­ers of Venus, the mis­sion has re­vealed dis­tur­bances in the planet’s winds known as grav­ity waves, as well as equa­to­rial jet streams in its at­mos­phere.

WHO’S NEXT?

Many mis­sions back to Venus have been pro­posed, and some space agen­cies have de­clared am­bi­tions of vis­it­ing the planet. But it’s hard to say whether any will make the trip.

In­dia’s space agency has pro­posed a mis­sion called Shukrayaan-1, which will or­bit the planet and pri­mar­ily fo­cus on the chem­istry of the at­mos­phere. Peter Beck, the founder of Rocket Lab, a pri­vate com­pany started in New Zealand that has launched about a dozen rock­ets to space, has spo­ken of send­ing a small satel­lite to the planet.

Nasa has con­sid­ered a num­ber of Venus pro­pos­als in the past decade, in­clud­ing two in 2017 that were fi­nal­ists of Nasa’s Dis­cov­ery pro­gramme, which has pre­vi­ously sent ex­plor­ers to the moon, Mars, Mer­cury and other des­ti­na­tions. But the agency in­stead se­lected a pair of as­ter­oid mis­sions.

Also in 2017, for the larger, more ex­pen­sive New Fron­tiers com­pe­ti­tion, Nasa con­sid­ered a Venus mis­sion called Venus In situ Com­po­si­tion In­ves­ti­ga­tions, or VICI, which sought to put two lan­ders on the planet’s sur­face. It was passed over for Drag­on­fly, which will send a plu­to­nium-pow­ered drone to fly on Ti­tan, the largest moon of Saturn.

Nasa, how­ever, did pro­vide money for some of the tech­nolo­gies that VICI would need. And Venus pro­po­nents may have a new ad­vo­cate in­side Nasa. Lori S Glaze, the prin­ci­pal in­ves­ti­ga­tor of VICI, is now the plan­e­tary sci­ence di­vi­sion di­rec­tor at Nasa.

The agency will have an­other chance to pick a Venus mis­sion for fund­ing in the next round of its Dis­cov­ery pro­gramme. Two Venus space­craft, named DAVINCI+ and VER­I­TAS, are com­pet­ing against pro­posed mis­sions to Nep­tune’s moon Tri­ton or Jupiter’s vol­canic moon Io. Nasa may se­lect two of the four fi­nal­ists. And there could be other pos­si­bil­i­ties for vis­i­tors to Venus.

“Venus is a plan­e­tary des­ti­na­tion we can reach with smaller mis­sions as well,” said Thomas Zur­buchen, the head of Nasa’s sci­ence mis­sion direc­torate.

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 ?? PHOTO: NASA/JPL/THE NEW YORK TIMES ?? A global view of the sur­face of Venus made mostly from data cap­tured by the Mag­el­lan space­craft in 1991.
PHOTO: NASA/JPL/THE NEW YORK TIMES A global view of the sur­face of Venus made mostly from data cap­tured by the Mag­el­lan space­craft in 1991.
 ?? PHOTO: PAUL HUD­SON/NASA/THE NEW YORK TIMES ?? ABOVE RIGHT An artist’s ren­der­ing of Nasa’s Pioneer Venus 2 space­craft and four at­mo­spheric probes, for a 1978 mis­sion to learn more about the planet’s at­mos­phere.
PHOTO: PAUL HUD­SON/NASA/THE NEW YORK TIMES ABOVE RIGHT An artist’s ren­der­ing of Nasa’s Pioneer Venus 2 space­craft and four at­mo­spheric probes, for a 1978 mis­sion to learn more about the planet’s at­mos­phere.
 ?? PHOTO: RUS­SIAN ACADEMY OF SCI­ENCES/TED STRYK/THE NEW YORK TIMES ?? RIGHT A view of the sur­face of Venus cap­tured by the Soviet Union’s Ven­era 14 lan­der in 1982.
PHOTO: RUS­SIAN ACADEMY OF SCI­ENCES/TED STRYK/THE NEW YORK TIMES RIGHT A view of the sur­face of Venus cap­tured by the Soviet Union’s Ven­era 14 lan­der in 1982.
 ??  ?? ABOVE A false-colour im­age of Venus’ night side, taken by the Akat­suki space­craft in 2016.
ABOVE A false-colour im­age of Venus’ night side, taken by the Akat­suki space­craft in 2016.

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