{"id":14898,"date":"2017-02-02T21:26:07","date_gmt":"2017-02-02T13:26:07","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/juno-dives-over-jupiters-cloud-tops-with-main-engine-still-offline\/"},"modified":"2017-02-02T21:26:07","modified_gmt":"2017-02-02T13:26:07","slug":"juno-dives-over-jupiters-cloud-tops-with-main-engine-still-offline","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/juno-dives-over-jupiters-cloud-tops-with-main-engine-still-offline\/","title":{"rendered":"Juno dives over Jupiter\u2019s cloud tops with main engine still offline"},"content":{"rendered":"

Updated at 3:30 p.m. EST with additional comments from Scott Bolton.<\/strong><\/em><\/p>\n

\"\"
This amateur-processed image was taken on Dec. 11, 2016, at 9:27 a.m. PST (12:27 p.m. EST), as NASA\u2019s Juno spacecraft performed its third close flyby of Jupiter. Credits: NASA\/JPL-Caltech\/SwRI\/MSSS\/Eric Jorgensen<\/figcaption><\/figure>\n

NASA\u2019s Juno spacecraft made a high-speed pass less than 3,000 miles over Jupiter\u2019s turbulent clouds Thursday, taking dozens of pictures, measuring radiation and plasma waves, and peering deep inside the planet\u2019s atmosphere, but officials still have not cleared the orbiter\u2019s main engine for a planned maneuver to position the probe in its intended science orbit.<\/p>\n

As Juno prepared for Thursday\u2019s encounter, managers weighed whether to cancel an engine burn originally scheduled for October to reshape the craft\u2019s orbit.<\/p>\n

The solar-powered spacecraft made its closest approach about 2,670 miles (4,300 kilometers) over Jupiter\u2019s cloud tops at 1257 GMT (7:57 a.m. EST) Thursday. NASA said all of Juno\u2019s science instruments and its JunoCam color camera were operating during the flyby, and the data is being returned to Earth.<\/p>\n

Juno zipped by Jupiter at a relative velocity of about 129,000 mph (57.8 kilometers per second), approaching the planet over its north pole and departing over the south pole, according to NASA.<\/p>\n

For the first time, the Juno team solicited votes from the public to select all the pictures the JunoCam camera would take during the flyby.<\/p>\n

Participants on the mission\u2019s web site will be able to vote on which points of interest on Jupiter they want imaged by JunoCam on each future encounter. Once the raw images are back on Earth, the data will be posted online for interested members of the public to do their own processing.<\/p>\n

Thursday\u2019s close flyby, called a perijove, was the fourth time Juno has come so close to Jupiter since the probe arrived in orbit July 4. Two of the previous perijove encounters \u2014 on Aug. 27 and Dec. 11 \u2014 have yielded science data, giving researchers a taste of the harsh environment surrounding the planet.<\/p>\n

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Artist\u2019s concept of the Juno spacecraft. Credit: NASA\/JPL-Caltech<\/figcaption><\/figure>\n

The data haul from the $1.1 billion mission so far shows that Jupiter\u2019s magnetic field and auroras are bigger than expected, and the belts and zones seen at the top of the planet\u2019s clouds extend deep into the atmosphere, according to NASA.<\/p>\n

A pair of problems thwarted manager\u2019s plans during Juno\u2019s Oct. 19 close approach.<\/p>\n

The original flight plan called for Juno to fire its main engine Oct. 19 to send the spacecraft into a tighter 14-day orbit around Jupiter. Juno currently takes about 53 days to complete one orbit.<\/p>\n

But ground controllers discovered a potential problem with two check valves in the spacecraft\u2019s propulsion system less than a week before the scheduled engine burn. The valves are part of the spacecraft\u2019s helium pressurization system, and they took several minutes to open after receiving commands, when they should have taken only a few seconds.<\/p>\n

The behavior of the valves led managers to postpone the Oct. 19 engine burn to study the problem, and researchers hoped to use the flyby to collect science data from Juno\u2019s nine instruments, comprising 29 individual sensors.<\/p>\n

An unexpected computer reboot just before the perijove shut down Juno\u2019s science instruments. The spacecraft safely made the passage by Jupiter, but it gathered no data.<\/p>\n

Scott Bolton, Juno\u2019s principal investigator, said in October that the mission can still obtain its intended measurements from the 53-day orbit. The prime time for Juno\u2019s observations of Jupiter come when the spacecraft is closest to the planet, and the probe will still pass through that region on each orbit.<\/p>\n

But the science opportunities will come less frequently, just once every 53 days instead of once every two weeks.<\/p>\n

\u201cWe can obtain all of the science goals of Juno even if we stay in a 53-day orbit,\u201d said Bolton, a scientist based at the Southwest Research Institute in San Antonio. \u201cEach pass has the same value that a 14-day orbit would have had. We were changing to 14 days primarily because we wanted the science faster, but there was no requirement to do that.\u201d<\/p>\n

\u201cShortening the orbit gets the science faster but it is not improved,\u201d Bolton wrote in an email to Spaceflight Now on Friday. \u201cThe larger orbit is better science. \u201c<\/p>\n

One factor limiting Juno\u2019s lifetime around Jupiter is the spacecraft\u2019s radiation exposure. The spacecraft only flies through Jupiter\u2019s intense radiation belts just before and after each perijove, and Bolton said in October that keeping Juno in its current orbit will not affect the radiation dose on each flyby, but it will spread out the overall exposure over a longer period of time.<\/p>\n

Juno\u2019s original flight plan called for the mission to complete 32 of the 14-day science orbits before the spacecraft was to be intentionally crashed in Jupiter\u2019s thick atmosphere in February 2018. That outline is now being re-evaluated with the delay in Juno\u2019s orbital adjustment.<\/p>\n

Juno\u2019s next low-altitude flyby of Jupiter will come March 27.<\/p>\n

Email the author.<\/i><\/b><\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Updated at 3:30 p.m. EST with additional comments from Scott Bolton. This amateur-processed image was taken on Dec. 11, 2016, at 9:27 a.m. PST (12:27 p.m. EST), as NASA\u2019s Juno spacecraft performed its third close flyby of Jupiter. Credits: NASA\/JPL-Caltech\/SwRI\/MSSS\/Eric Jorgensen NASA\u2019s Juno spacecraft made a high-speed pass less than 3,000 miles over Jupiter\u2019s turbulent […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[1929,1606,472,2020,1561,2612],"class_list":["post-14898","post","type-post","status-publish","format-standard","hentry","category-news","tag-juno","tag-jupiter","tag-lockheed-martin","tag-new-frontiers","tag-planetary-science","tag-swri"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/14898"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=14898"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/14898\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=14898"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=14898"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=14898"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}