{"id":15376,"date":"2016-07-15T17:53:40","date_gmt":"2016-07-15T09:53:40","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/researchers-eager-for-junos-first-chance-for-jupiter-science\/"},"modified":"2016-07-15T17:53:40","modified_gmt":"2016-07-15T09:53:40","slug":"researchers-eager-for-junos-first-chance-for-jupiter-science","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/researchers-eager-for-junos-first-chance-for-jupiter-science\/","title":{"rendered":"Researchers eager for Juno\u2019s first chance for Jupiter science"},"content":{"rendered":"
\"Animation
Animation of Juno 14-day Orbits Starting in late 2016. Juno is currently in an even larger 53-day orbit. Credit: NASA\/JPL-Caltech<\/figcaption><\/figure>\n

NASA\u2019s Juno spacecraft fine-tuned its orbit around Jupiter this week, helping steer the spinning space probe on a course to dip beneath the giant planet\u2019s radiation belts in late August for the first time with all its science instruments activated.<\/p>\n

The orbit correction maneuver Wednesday began around 2:45 p.m. EDT (1845 GMT; 11:45 a.m. PDT) and lasted about one hour, using Juno\u2019s 12 reaction control system thrusters to change the orbiter\u2019s speed by about 11 mph, or 4.9 meters per second, according to Rick Nybakken, Juno\u2019s project manager at NASA\u2019s Jet Propulsion Laboratory in Pasadena, California.<\/p>\n

The rocket burn Wednesday did not use Juno\u2019s main engine, a more powerful thruster which fired when the spacecraft slipped into orbit around Jupiter on July 4.<\/p>\n

Up to two more orbit trim maneuvers are planned before Juno completes its first elongated, egg-shaped orbit around the solar system\u2019s biggest planet Aug. 27, when the craft will dive within 3,000 miles (about 5,000 kilometers) of Jupiter\u2019s swirling, banded cloud tops.<\/p>\n

The Aug. 27 flyby \u2014 called a \u201cperijove\u201d by orbit dynamicists \u2014 will be the second time Juno approaches so close to Jupiter. But the July 4 encounter occurred during Juno\u2019s make-or-break orbit insertion burn, and mission managers elected to turn off the spacecraft\u2019s science instruments to focus all of the probe\u2019s energy and computing power on executing the engine firing.<\/p>\n

Next time, Juno will have its eyes, ears and nose ready.<\/p>\n

Scott Bolton, Juno\u2019s principal investigator from the Southwest Research Institute in San Antonio, said scientists plan to release the initial findings from the late August perijove around Sept. 1.<\/p>\n

According to Nybakken, Juno will turn itself into an orientation to allow its microwave radiometer to make measurements of Jupiter\u2019s deep atmosphere when it swings back close to the planet next month. That scenario also allows Juno\u2019s visible camera, called JunoCam, to take the best pictures of the mission, officials said.<\/p>\n

Juno\u2019s flight plan calls for the solar-powered spacecraft to complete 37 orbits of Jupiter, and other close-up encounters will have the probe in a different pointing position favoring measurements of the gas giant\u2019s strong gravity field, an area of study that will help researchers learn whether the planet has a solid core at its center.<\/p>\n

Juno\u2019s mission is aimed at peering inside Jupiter with a suite of cameras, spectrometers and particle detectors to track the distribution of high-energy electrons around the planet, measure the water inside Jupiter\u2019s atmosphere, search for the trigger of the gas giant\u2019s brilliant auroras, and probe the source of its expansive, teardrop-shaped magnetosphere, a bubble that blocks the solar wind from reaching Jupiter.<\/p>\n

Data from Juno will help scientists learn about the origin of Jupiter, which experts believe was the first planet to form from a ring of dust and gas surrounding the adolescent sun. Understanding how and where Jupiter formed could help explain how the rest of the solar system evolved, including Earth.<\/p>\n

In an interview with Spaceflight Now this week, Nybakken said the Lockheed Martin-built Juno spacecraft is healthy after completing its 1.7 billion-mile (2.8 billion-kilometer) journey to Jupiter.<\/p>\n

Ground controllers have turned on most of Juno\u2019s nine science instruments, comprising 29 total sensors, since July 4, Nybakken said.<\/p>\n

\u201cMost of them are on and working just fine,\u201d he said.<\/p>\n

Two more science instruments are due to start returning data in the coming days. Juno\u2019s atmosphere and aurora-mapping ultraviolet spectrograph and a special Ka-band radio system to track the spacecraft\u2019s position, and help derive the strength of Jupiter\u2019s gravity field, will be turned on this weekend.<\/p>\n

Engineers finished testing of Juno\u2019s scientific payload before it reached Jupiter, but Nybakken said a handful of calibrations are planned later this month.<\/p>\n

\u201cEverything is working well,\u201d Nybakken said. \u201cThe instruments that are on are taking data and performing nominally, and they\u2019re really getting excited about their first perijove pass on Aug. 27.\u201d<\/p>\n

\"This
This color view from NASA\u2019s Juno spacecraft is made from some of the first images taken by JunoCam after the spacecraft entered orbit around Jupiter. Credit: NASA\/JPL-Caltech\/SwRI\/MSSS<\/figcaption><\/figure>\n

JunoCam is taking pictures of Jupiter and its moons every day through its 53-day circuit around the planet. Juno is the first mission to orbit over Jupiter\u2019s poles, giving the imager a unique perspective.<\/p>\n

\u201cWe\u2019re working on something we call a marvel movie, because when we start the movie now Jupiter is pretty small, but we\u2019ll go all the way around and create a full orbit movie, which will be pretty cool when we go over the poles for the first time and zip by the planet,\u201d Nybakken said.<\/p>\n

Earlier this week, NASA released one of the first images from JunoCam since the mission reached Jupiter.<\/p>\n

Taken July 10, the picture shows Jupiter and three of its large Galilean moons \u2014 Io, Europa and Ganymede \u2014 from a distance of 2.7 billion miles (4.3 billion kilometers). The wide-angle camera, based on technology originally developed for NASA\u2019s Curiosity Mars rover, resolved the planet\u2019s colorful cloud bands and Jupiter\u2019s iconic Great Red Spot.<\/p>\n

The views will only get better as Jupiter pulls Juno toward its Aug. 27 close-up.<\/p>\n

\u201cThis scene from JunoCam indicates it survived its first pass through Jupiter\u2019s extreme radiation environment without any degradation and is ready to take on Jupiter,\u201d Bolton said in a statement. \u201cWe can\u2019t wait to see the first view of Jupiter\u2019s poles.\u201d<\/p>\n

Officials are pleased with the outcome of Juno\u2019s July 4 arrival burn, the third of four firings by the craft\u2019s British-made main engine planned of the course of the nearly seven-year mission.<\/p>\n

\u201cWe were aiming for a 53.4-day orbit, and we ended up in a 53.4-day orbit,\u201d Nybakken said. \u201cI think it was well within a 1-sigma performance. That\u2019s the third time we\u2019ve fired the main engine. We\u2019re getting consistent, predictable performance out of it, which helps because we don\u2019t have auto restart on the fourth one.\u201d<\/p>\n

Engineers programmed Juno\u2019s flight computer to immediately resume the July 4 engine burn if it ran into trouble or suffered a computer reset triggered by Jupiter\u2019s intense radiation belts. That feature, called auto restart, will not be installed on Juno for the next main engine maneuver set for Oct. 19 to steer the probe into a tighter, 14-day orbit for regular science observations.<\/p>\n

The down side of employing the automatic engine restart software logic is that engineers on Earth would not have a chance to correct any underlying problem that triggered a computer fault in the first place.<\/p>\n

Engineers were willing to take the risk July 4 because Juno had only one shot to enter orbit around Jupiter and complete its $1.1 billion mission.<\/p>\n

One key unanswered question before Juno\u2019s arrival at Jupiter was the exact location and intensity of the inner limit of the planet\u2019s radiation belts, doughnut-shaped clouds of high-energy electrons surrounding the equator.<\/p>\n

The radiation is a concern for Juno\u2019s health because particles can penetrate the spacecraft, jeopardizing computing functions and degrading electronic components. Planners designed Juno\u2019s orbit to stay away from the worst of the radiation, but doses will increase before the end of the mission in February 2018, and will likely determine when Juno\u2019s campaign of exploration must conclude.<\/p>\n

Nybakken said Juno did not gather any detailed information on the radiation environment July 4, but telemetry radioed to Earth after the arrival burn showed signs the spacecraft\u2019s computer saw some particle hits as the probe passed in and out of the radiation belts.<\/p>\n

\u201cWith the instruments off, we don\u2019t get a lot of data,\u201d Nybakken said. \u201cWe did see an increase, for a very short amount of time near the beginning of the burn and the end of the burn, kind of as expected, in the single bit errors that showed up on our spacecraft flight computer. They were all corrected.\u201d<\/p>\n

Juno\u2019s most sensitive electronics are housed inside a titanium box on the spacecraft\u2019s main body to protect systems from Jupiter\u2019s radiation. Juno\u2019s three large solar panels, each extending nearly 30 feet (about 9 meters) long, are covered in an extra-thick layer of glass to shield the craft\u2019s power-generating solar cells from the energetic electrons lurking around Jupiter.<\/p>\n

Managers want to learn about the radiation around Jupiter, both for scientific research and for practical, engineering purposes to help plan Juno\u2019s mission.<\/p>\n

\u201cThat\u2019s part of what we\u2019re going to be looking at,\u201d Nybakken said. \u201cModels are just that. They don\u2019t give you highly accurate predictions, and, of course, the data we will be obtaining will help us refine environmental models as we go through the mission.\u201d<\/p>\n

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

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

Animation of Juno 14-day Orbits Starting in late 2016. Juno is currently in an even larger 53-day orbit. Credit: NASA\/JPL-Caltech NASA\u2019s Juno spacecraft fine-tuned its orbit around Jupiter this week, helping steer the spinning space probe on a course to dip beneath the giant planet\u2019s radiation belts in late August for the first time with […]<\/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":[1183,1929,2522,1606,472,1561,2612],"class_list":["post-15376","post","type-post","status-publish","format-standard","hentry","category-news","tag-jet-propulsion-laboratory","tag-juno","tag-junocam","tag-jupiter","tag-lockheed-martin","tag-planetary-science","tag-swri"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/15376"}],"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=15376"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/15376\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=15376"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=15376"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=15376"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}