تصویری خیالی از فضاپیمای جونو بر فراز سیاره مشتری
مؤسسه تحقیقات جنوب غربی|
کاوشگر فضایی به مقصد منظومه شمسی|
اتلس ۵ ۵۵۱|
بیش از ۱۰ سال|
جونو (به انگلیسی: Juno) نام فضاپیمای روباتیکِ بدونِ سرنشینِ ناسا است که در چهارم ژوئیهٔ ۲۰۱۶ در مدار قطبی سیاره مشتری قرار گرفت. این کاوشگر فضایی در پنجم اوت ۲۰۱۱ از فلوریدا به فضا پرتاب شده و شرکت لاکهید مارتین و مؤسسه تحقیقات جنوب غربی سازنده و پیمانکار هدایت آن هستند.
نیروی این قمر با انرژی خورشیدی تأمین میشود.
این فضاپیما در مدار قطبی این سیاره قرار گرفته تا ترکیب، میدان گرانشی، میدان مغناطیسی، و مَگنِتوسفِرِ مشتری را بررسی کند. جونو همچنین تلاشهایی برای یافتن سرنخهایی در مورد چگونگی تشکیل شدن این سیاره، از جمله احتمالِ داشتنِ یک هستهٔ سنگی، مقدار آب موجود در ژرفای جوّ آن، توزیع انبوه جِرمی، و بادهای عمیق آن؛ که سرعت آن میتواند تا ۶۱۸ کیلومتر (۳۸۴ مایل) در ساعت برسد، خواهد داشت.
جونو دومین فضاپیمایی است که مدار مشتری را دور میزند؛ پس از فضاپیمای گالیله که از ۱۹۹۵ تا ۲۰۰۳ این سیاره را دور زد.
فضاپیمای جونو نیروی مورد نیاز خود را از آرایههای خورشیدی میگیرد، روشی که معمولاً توسط ماهوارههای مستقر و مشغول به کار در مدار زمین یا در منظومهٔ شمسی درونی استفاده شده، در حالی که مولد گرما-الکتریک رادیوایزوتوپی معمولاً برای مأموریت به بخش بیرونیِ منظومهٔ شمسی و فراتر از آن استفاده میشود، با این حال، برای جونو، سه بال خورشیدی، که بزرگترین پانلی است که تا کنون بر روی کاوشگرهای سیارهای مستقر شده، نقشی اساسی در ایجاد ثبات در فضاپیما و تولید قدرت بازی کنند.
نام این فضاپیما از اساطیر یونانی-رومی بر گرفته شده: ژوپیتر حجابی از ابرها برای پنهان کردن فساد خود، در اطراف خود جذب میکرد اما همسر او، الهه یونو، توانست به درون ابر بنگرد و ماهیت واقعی ژوپیتر را ببیند.
پیمودن مسیر زمین تا مدار مشتری که برای جونو پنج سال به درازا کشید در ۴ ژوئیه، ۲۰۱۶ به پایان رسید. این فضاپیما یک فاصلهٔ تقریبی بیشتر از ۲٫۸ میلیارد کیلومتر (۱۸٫۷ واحد نجومی؛ ۱۷۴۰۰۰۰۰۰۰ مایل) را برای رسیدن به مشتری پیمود. این فضاپیما، در نقش یک مدارگرد، مدار مشتری را ۳۷ بار در دورهٔ از پیش برنامهریزی شدهٔ ۲۰ ماه دُور خواهد زد. تلاش جونو برای استفاده از دریافتِ کمک گرانشی از زمین برای افزایش سرعت خود، دو سال پس از راه اندازیِ ۵ اوت ۲۰۱۱، در اکتبر ۲۰۱۳ به نتیجه رسید. در تاریخ ۵ ژوئیه ۲۰۱۶، فضاپیمای جونوبه انجام یک مانور برای کُند کردن سرعت خود به منظورِ ایجادِ امکانِ قرار گرفتن در مدار مشتری پرداخت. جونو دو بار این مدار ۵۳ روزه را؛ پیش از انجام مانور دیگری در تاریخ ۱۹ اکتبر که آن را به یک مدار قطبی ۱۴ روزه خواهد افکند، دُور خواهد زد.
- ↑ "Juno Mission to Jupiter—NASA Facts" (PDF). NASA. April 2009. p. 1. Retrieved April 5, 2011.
- ↑ "Juno Spacecraft Information – Power Distribution". Spaceflight 101. 2011. Retrieved August 6, 2011.
- ↑ ۳٫۰ ۳٫۱ Greicius, Tony (September 21, 2015). "Juno – Mission Overview". NASA.gov. Retrieved October 2, 2015.
- ↑ http://www.nasa.gov/mission_pages/juno/main/index.html
- ↑ http://www.usatoday.com/tech/science/space/2011-08-01-jupiter-mission_n.htm
- ↑ http://www.nasa.gov/centers/goddard/news/topstory/2008/jupiter_lrs.html Winds in Jupiter's Little Red Spot almost twice as fast as strongest hurricane
- ↑ http://www.nasa.gov/mission_pages/juno/launch/Juno_solarpower.html "NASA – Juno's Solar Cells Ready to Light Up Jupiter Mission". www.nasa.gov. Retrieved October 4, 2015.
- ↑ http://www.nasa.gov/mission_pages/juno/news/juno20110805.html ^ "NASA – Juno's Solar Cells Ready to Light Up Jupiter Mission". www.nasa.gov. Retrieved October 4, 2015.
- ↑ http://usatoday30.usatoday.com/tech/science/space/2011-08-01-jupiter-mission_n.htm Dunn, Marcia (August 1, 2011). "NASA going green with solar-powered Jupiter probe". USA Today.
- ↑ Dunn, Marcia (August 1, 2011). "NASA going green with solar-powered Jupiter probe". USA Today. Jump up to: a b c d Greicius, Tony (September 21, 2015). "Juno – Mission Overview". NASA. Retrieved October 2, 2015.
- ↑ http://www.nasa.gov/launchschedule/ "NASA's Shuttle and Rocket Launch Schedule". NASA. Retrieved February 17, 2011.
پیوند به بیرون[ویرایش]
Artist's rendering of the Juno spacecraft
||NASA / JPL
||Planned: 7 years
Elapsed: 6 years, 9 months, 15 days
Cruise: 4 years, 10 months, 29 days
Science phase: 2 years
||3,625 kg (7,992 lb)
||1,593 kg (3,512 lb)
||20.1 × 4.6 m (66 × 15 ft)
||14 kW at Earth, 435 W at Jupiter
2 × 55-ampere-hour lithium-ion batteries
|Start of mission
||August 5, 2011, 16:25UTC
||Atlas V 551 (AV-029)
||Cape Canaveral SLC-41
||United Launch Alliance
|Flyby of Earth
||October 9, 2013
||559 km (347 mi)
||July 5, 2016, 03:53 UTC
1 year, 10 months, 16 days ago
||4,200 km (2,600 mi) altitude
75,600 km (47,000 mi) radius
||8.1 million km (5.0 million mi)
||90 degrees (polar orbit)
Juno mission insignia
Juno is a NASA space probe orbiting the planet Jupiter. It was built by Lockheed Martin and is operated by NASA's Jet Propulsion Laboratory. The spacecraft was launched from Cape Canaveral Air Force Station on August 5, 2011 (UTC), as part of the New Frontiers program, and entered a polar orbit of Jupiter on July 5, 2016 (UTC), to begin a scientific investigation of the planet. After completing its mission, Juno will be intentionally deorbited into Jupiter's atmosphere.
Juno's mission is to measure Jupiter's composition, gravity field, magnetic field, and polar magnetosphere. It will also search for clues about how the planet formed, including whether it has a rocky core, the amount of water present within the deep atmosphere, mass distribution, and its deep winds, which can reach speeds up to 618 kilometers per hour (384 mph).
Juno is the second spacecraft to orbit Jupiter, after the nuclear powered Galileo orbiter, which orbited from 1995 to 2003. Unlike all earlier spacecraft sent to the outer planets, Juno is powered by solar arrays, commonly used by satellites orbiting Earth and working in the inner Solar System, whereas radioisotope thermoelectric generators are commonly used for missions to the outer Solar System and beyond. For Juno, however, the three largest solar array wings ever deployed on a planetary probe play an integral role in stabilizing the spacecraft as well as generating power.
Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.
The mission had previously been referred to by the backronym Jupiter Near-polar Orbiter. Juno is sometimes called New Frontiers 2 as the second mission in the New Frontiers program, but is not to be confused with New Horizons 2, a proposed but unselected New Frontiers mission.
Juno's interplanetary trajectory; tick marks at 30-day intervals.
Juno spacecraft trajectory animation
Juno was selected in 2005 as the next New Frontiers mission after New Horizons. The desire for a Jupiter probe was strong in the years prior to this, but there had not been any approved missions. The Discovery Program had passed over the somewhat similar but more limited Interior Structure and Internal Dynamical Evolution of Jupiter (INSIDE Jupiter) proposal, and the turn-of-the-century era Europa Orbiter was cancelled in 2002. The flagship-level Europa Jupiter System Mission was in the works in the early 2000s, but funding issues resulted in it evolving into ESA's Jupiter Icy Moons Explorer.
Juno completed a five-year cruise to Jupiter, arriving on July 5, 2016. The spacecraft traveled a total distance of roughly 2.8 billion kilometers (18.7 astronomical units; 1.74 billion miles) to reach Jupiter. The spacecraft was designed to orbit Jupiter 37 times over the course of its mission. This was originally planned to take 20 months. Juno's trajectory used a gravity assist speed boost from Earth, accomplished by an Earth flyby in October 2013, two years after its launch on August 5, 2011. The spacecraft performed an orbit insertion burn to slow it enough to allow capture. It was expected to make three 53-day orbits before performing another burn on December 11 that would bring it into a 14-day polar orbit called the Science Orbit. Because of a suspected problem in Juno's main engine, the burn of December 11 was canceled, and Juno will remain in its 53-day orbit for its remaining orbits of Jupiter.
During the science mission, infrared and microwave instruments will measure the thermal radiation emanating from deep within Jupiter's atmosphere. These observations will complement previous studies of its composition by assessing the abundance and distribution of water, and therefore oxygen. This data will provide insight into Jupiter's origins. Juno will also investigate the convection that drives natural circulation patterns in Jupiter's atmosphere. Other instruments aboard Juno will gather data about its gravitational field and polar magnetosphere. The Juno mission was planned to conclude in February 2018, after completing 37 orbits of Jupiter. The probe was then intended to be de-orbited and burn up in Jupiter's outer atmosphere, to avoid any possibility of impact and biological contamination of one of its moons.
Juno was launched atop the Atlas V at Cape Canaveral Air Force Station, Florida. The Atlas V (AV-029) used a Russian-built RD-180 main engine, powered by kerosene and liquid oxygen. At ignition it underwent checkout 3.8 seconds prior to the ignition of five strap-on solid rocket boosters (SRBs). Following the SRB burnout, about 93 seconds into the flight, two of the spent boosters fell away from the vehicle, followed 1.5 seconds later by the remaining three. When heating levels had dropped below predetermined limits, the payload fairing that protected Juno during launch and transit through the thickest part of the atmosphere separated, about 3 minutes 24 seconds into the flight. The Atlas V main engine cut off 4 minutes 26 seconds after liftoff. Sixteen seconds later, the Centaur second stage ignited, and it burned for about 6 minutes, putting the satellite into an initial parking orbit. The vehicle coasted for about 30 minutes, and then the Centaur was reignited for a second firing of 9 minutes, placing the spacecraft on an Earth escape trajectory in a heliocentric orbit.
Prior to separation, the Centaur stage used onboard reaction engines to spin Juno up to 1.4 r.p.m.. About 54 minutes after launch, the spacecraft separated from the Centaur and began to extend its solar panels. Following the full deployment and locking of the solar panels, Juno's batteries began to recharge. Deployment of the solar panels reduced Juno's spin rate by two-thirds. The probe is spun to ensure stability during the voyage and so that all instruments on the probe are able to observe Jupiter.
The voyage to Jupiter took five years, and included a flyby of the Earth on October 10, 2013. When it reached the Jovian system, Juno had traveled approximately 19 AU, almost two billion miles.
Flyby of the Earth
as seen by JunoCam
on its October 2013 Earth flyby
Video of Earth and Moon taken by the Juno spacecraft
After traveling for two years in an elliptical heliocentric orbit, Juno returned to pass by the Earth in October 2013. It used Earth's gravity to help slingshot itself toward the Jovian system in a maneuver called a gravity assist. The spacecraft received a boost in speed of more than 3.9 km/s (8,800 mph), and it was set on a course to Jupiter. The flyby was also used as a rehearsal for the Juno science team to test some instruments and practice certain procedures before the arrival at Jupiter.
Insertion into jovian orbit
Jupiter's gravity accelerated the approaching spacecraft to around 210,000 km/h (130,000 mph). On July 5, 2016, between 03:18 and 03:53 UTC Earth-received time, an insertion burn lasting 2,102 seconds decelerated Juno by 542 m/s (1,780 ft/s) and changed its trajectory from a hyperbolic flyby to an elliptical, polar orbit with a period of about 53.5 days. The spacecraft successfully entered Jupiter orbit on July 5 at 03:53 UTC.
Orbit and environment
elliptical orbit and the Jovian radiation belts
Juno's highly elliptical initial polar orbit takes it within 4,200 kilometers (2,600 mi) of the planet and out to 8.1 million km (5.0 million mi), far beyond Callisto's orbit. An eccentricity-reducing burn, called the Period Reduction Maneuver, was planned that would drop the probe into a much shorter 14 day science orbit. Originally, Juno was expected to complete 37 orbits over 20 months before the end of its mission. Due to problems with helium valves that are important during main engine burns, mission managers announced on February 17, 2017, that Juno would remain in its original 53-day orbit, since the chance of an engine misfire putting the spacecraft into a bad orbit was too high. Juno will now complete only 12 science orbits before the end of its budgeted mission plan, ending July 2018.
The orbits were carefully planned in order to minimize contact with Jupiter's dense radiation belts, which can damage spacecraft electronics and solar panels, by exploiting a gap in the radiation envelope near the planet, passing through a region of minimal radiation. The "Juno Radiation Vault", with 1-centimeter-thick titanium walls, also aids in protecting Juno's electronics. Despite the intense radiation, JunoCam and the Jovian Infrared Auroral Mapper (JIRAM) are expected to endure at least eight orbits, while the Microwave Radiometer (MWR) should endure at least eleven orbits. Juno will receive much lower levels of radiation in its polar orbit than the Galileo orbiter received in its equatorial orbit. Galileo was damaged by radiation during its mission, including an LED in its data recording system.
The spacecraft completed its first flyby of Jupiter (perijove 1) on August 27, 2016, and captured the first images of the planet's north pole.
On October 14, days prior to perijove 2 and the planned Period Reduction Maneuver, telemetry showed that some of Juno's helium valves were not opening properly. On October 18, 13 hours before its second close approach to Jupiter, Juno entered into safe mode, an operational mode engaged when its onboard computer encounters unexpected conditions. The spacecraft powered down all non-critical systems and reoriented itself to face the Sun to gather the most power. Due to this, no science operations were conducted during perijove 2.
On December 11, the spacecraft completed perijove 3, with all but one instrument operating and returning data. One instrument, JIRAM, was off pending a flight software update. Perijove 4 occurred on February 2, with all instruments operating. Perijove 5 occurred on March 27, 2017. Perijove 6 took place on May 19, 2017.
Although the mission's lifetime is limited by radiation exposure, almost all of this dose is acquired during the perijoves. The current 53.4 day orbit will be maintained through July 2018 for a total of twelve science-gathering perijoves. At the end of this prime mission, the project will go through a science review process by NASA's Planetary Science Division to determine if it will receive funding for an extended mission.
Planned deorbit and disintegration
When Juno reaches the end of the mission, it will perform a controlled deorbit and disintegrate into Jupiter's atmosphere. During the mission, the spacecraft will be exposed to high levels of radiation from Jupiter's magnetosphere, which may cause future failure of certain instruments and risk collision with Jupiter's moons. The controlled deorbit will eliminate space debris and risks of contamination in accordance with NASA's Planetary Protection Guidelines. In its current 53-day orbit, this is planned to occur at the end of its 12th science orbit (perijove 14) in July 2018. However, NASA may choose to extend the mission if there are no technical issues aboard the spacecraft and there is merit to continuing science operations.
Scott Bolton of the Southwest Research Institute in San Antonio, Texas is the principal investigator and is responsible for all aspects of the mission. The Jet Propulsion Laboratory in California manages the mission and the Lockheed Martin Corporation was responsible for the spacecraft development and construction. The mission is being carried out with the participation of several institutional partners. Coinvestigators include Toby Owen of the University of Hawaii, Andrew Ingersoll of California Institute of Technology, Frances Bagenal of the University of Colorado at Boulder, and Candy Hansen of the Planetary Science Institute. Jack Connerney of the Goddard Space Flight Center served as instrument lead.
Juno was originally proposed at a cost of approximately US$700 million (fiscal year 2003) for a launch in June 2009. NASA budgetary restrictions resulted in postponement until August 2011, and a launch on board an Atlas V rocket in the 551 configuration. As of June 2011 , the mission was projected to cost US$1.1 billion over its life.
Jupiter imaged using the VISIR instrument on the VLT
. These observations will inform the work to be undertaken by Juno
The Juno spacecraft's suite of science instruments will:
- Determine the ratio of oxygen to hydrogen, effectively measuring the abundance of water in Jupiter, which will help distinguish among prevailing theories linking Jupiter's formation to the Solar System.
- Obtain a better estimate of Jupiter's core mass, which will also help distinguish among prevailing theories linking Jupiter's formation to the Solar System.
- Precisely map Jupiter's gravitational field to assess the distribution of mass in Jupiter's interior, including properties of its structure and dynamics.
- Precisely map Jupiter's magnetic field to assess the origin and structure of the field and how deep in Jupiter the magnetic field is created. This experiment will also help scientists understand the fundamental physics of dynamo theory.
- Map the variation in atmospheric composition, temperature, structure, cloud opacity and dynamics to pressures far greater than 100 bars (10 MPa; 1,450 psi) at all latitudes.
- Characterize and explore the three-dimensional structure of Jupiter's polar magnetosphere and auroras.
- Measure the orbital frame-dragging, known also as Lense–Thirring precession caused by the angular momentum of Jupiter, and possibly a new test of general relativity effects connected with the Jovian rotation.
The Juno mission's scientific objectives will be achieved with a payload of nine instruments on board the spacecraft:
||Description and scientific objective
||The microwave radiometer comprises six antennas mounted on two of the sides of the body of the probe. They will perform measurements of electromagnetic waves on frequencies in the microwave range: 600 MHz, 1.2, 2.4, 4.8, 9.6 and 22 GHz, the only microwave frequencies which are able to pass through the thick Jovian atmosphere. The radiometer will measure the abundance of water and ammonia in the deep layers of the atmosphere up to 200-bar (20 MPa; 2,900 psi) pressure or 500–600 km (310–370 mi) deep. The combination of different wavelengths and the emission angle should make it possible to obtain a temperature profile at various levels of the atmosphere. The data collected will determine how deep the atmospheric circulation is. The MWR is designed to function through orbit 11 of Jupiter.
(Principal investigator: Mike Janssen, Jet Propulsion Laboratory)
||Jovian Infrared Auroral Mapper
||The spectrometer mapper JIRAM, operating in the near infrared (between 2 and 5 μm), conducts surveys in the upper layers of the atmosphere to a depth of between 50 and 70 km (31 and 43 mi) where the pressure reaches 5 to 7 bar (73 to 102 psi). JIRAM will provide images of the aurora in the wavelength of 3.4 μm in regions with abundant H3+ ions. By measuring the heat radiated by the atmosphere of Jupiter, JIRAM can determine how clouds with water are flowing beneath the surface. It can also detect methane, water vapor, ammonia and phosphine. It was not required that this device meets the radiation resistance requirements. The JIRAM instrument is expected to operate through the eighth orbit of Jupiter.
(Principal investigator: Alberto Adriani, Italian National Institute for Astrophysics)
||The magnetic field investigation has three goals: mapping of the magnetic field, determining the dynamics of Jupiter's interior, and determination of the three-dimensional structure of the polar magnetosphere. The magnetometer experiment consists of the Flux Gate Magnetometer (FGM), which will measure the strength and direction of the magnetic field lines, and the Advanced Stellar Compass (ASC), which will monitor the orientation of the magnetometer sensors.
(Principal investigator: Jack Connerney, NASA's Goddard Space Flight Center)
||The purpose of measuring gravity by radio waves is to establish a map of the distribution of mass inside Jupiter. The uneven distribution of mass in Jupiter induces small variations in gravity all along the orbit followed by the probe when it runs closer to the surface of the planet. These gravity variations drive small probe velocity changes. The purpose of radio science is to detect the Doppler effect on radio broadcasts issued by Juno toward Earth in Ka band and X band, which are frequency ranges that can conduct the study with fewer disruptions related to the solar wind or Jupiter's ionosphere.
(Principal investigator: John Anderson, Jet Propulsion Laboratory; Principal investigator (Juno's Ka-band Translator): Luciano Iess, Sapienza University of Rome)
||Jovian Auroral Distributions Experiment
||The energetic particle detector JADE will measure the angular distribution, energy, and the velocity vector of ions and electrons at low energy (ions between 13 eV and 20 KeV, electrons of 200 eV to 40 KeV) present in the aurora of Jupiter. On JADE, like JEDI, the electron analyzers are installed on three sides of the upper plate which allows a measure of frequency three times higher.
(Principal investigator: David McComas, Southwest Research Institute)
||Jovian Energetic Particle Detector Instrument
||The energetic particle detector JEDI will measure the angular distribution and the velocity vector of ions and electrons at high energy (ions between 20 keV and 1 MeV, electrons from 40 to 500 keV) present in the polar magnetosphere of Jupiter. JEDI has three identical sensors dedicated to the study of particular ions of hydrogen, helium, oxygen and sulfur.
(Principal investigator: Barry Mauk, Applied Physics Laboratory)
||Radio and Plasma Wave Sensor
||This instrument will identify the regions of auroral currents that define Jovian radio emissions and acceleration of the auroral particles by measuring the radio and plasma spectra in the auroral region.
(Principal investigator: William Kurth, University of Iowa)
Ultraviolet imaging spectrometer
||UVS will record the wavelength, position and arrival time of detected ultraviolet photons during the time when the spectrograph slit views Jupiter during each turn of the spacecraft. Using a 1024 × 256 micro channel plate detector, it will provide spectral images of the UV auroral emissions in the polar magnetosphere.
(Principal investigator: G. Randall Gladstone, Southwest Research Institute)
||A visible light camera/telescope, included in the payload to facilitate education and public outreach. It was anticipated that it would operate through only eight orbits of Jupiter due to the planet's damaging radiation and magnetic field, but as of February 2018 (Perijove 11), JunoCam remains operational.
(Principal investigator: Michael C. Malin, Malin Space Science Systems)
Locations of Juno's
Illumination test on one of Juno's
Juno is the first mission to Jupiter to use solar panels instead of the radioisotope thermoelectric generators (RTG) used by Pioneer 10, Pioneer 11, the Voyager program, Ulysses, Cassini–Huygens, New Horizons, and the Galileo orbiter. It is also the farthest solar-powered trip in the history of space exploration. Once in orbit around Jupiter, Juno receives only 4% as much sunlight as it would on Earth, but the global shortage of plutonium-238, as well as advances made in solar cell technology over the past several decades, makes it economically preferable to use solar panels of practical size to provide power at a distance of 5 AU from the Sun.
The Juno spacecraft uses three solar panels symmetrically arranged around the spacecraft. Shortly after it cleared Earth's atmosphere, the panels were deployed. Two of the panels have four hinged segments each, and the third panel has three segments and a magnetometer. Each panel is 2.7 by 8.9 meters (8.9 by 29.2 ft) long, the biggest on any NASA deep-space probe.
The combined mass of the three panels is nearly 340 kg (750 lb). If the panels were optimized to operate at Earth, they would produce 12 to 14 kilowatts of power. Only about 486 W was generated when Juno arrived at Jupiter, projected to decline to near 420 W as radiation degrades the cells. The solar panels will remain in sunlight continuously from launch through the end of the mission, except for short periods during the operation of the main engine and eclipses by Jupiter. A central power distribution and drive unit monitors the power that is generated by the solar panels and distributes it to instruments, heaters, and experiment sensors, as well as to batteries that are charged when excess power is available. Two 55-amp-hour lithium-ion batteries that are able to withstand the radiation environment of Jupiter provide power when Juno passes through eclipse.
high-gain antenna dish being installed
Juno uses in-band signaling ("tones") for several critical operations as well as status reporting during cruise mode, but it is expected to be used infrequently. Communications are via the 34-metre (112 ft) and 70-metre (230 ft) antennas of the NASA Deep Space Network (DSN) utilizing an X band direct link. The command and data processing of the Juno spacecraft includes a flight computer capable of providing about 50 Mbit/s of instrument throughput. Gravity science subsystems use the X-band and Ka-band Doppler tracking and autoranging.
Due to telecommunications constraints, Juno will only be able to return about 40 megabytes of JunoCam data during each 11-day orbital period, limiting the number of images that are captured and transmitted during each orbit to somewhere between 10 and 100 depending on the compression level used. The overall amount of data downlinked on each orbit is significantly higher and used for the mission's scientific instruments; JunoCam is intended for public outreach and is thus secondary to the science data. This is comparable to the previous Galileo mission that orbited Jupiter, which captured thousands of images despite its slow data rate of 1000 bit/s (at maximum compression level) due to the failure of its high-gain antenna.
The communication system is also used as part of the Gravity Science experiment.
Juno uses a LEROS 1b main engine with hypergolic propellant, manufactured by Moog Inc in Westcott, Buckinghamshire, England. It uses hydrazine and nitrogen tetroxide for propulsion and provides a thrust of 645 newtons. The engine bell is enclosed in a debris shield fixed to the spacecraft body, and is used for major burns. For control of the vehicle's orientation (attitude control) and to perform trajectory correction maneuvers, Juno utilizes a monopropellant reaction control system (RCS) consisting of twelve small thrusters that are mounted on four engine modules.
Galileo plaque and minifigures
Juno carries a plaque to Jupiter, dedicated to Galileo Galilei. The plaque was provided by the Italian Space Agency and measures 7.1 by 5.1 centimeters (2.8 by 2.0 in). It is made of flight-grade aluminum and weighs 6 grams (0.21 oz). The plaque depicts a portrait of Galileo and a text in Galileo's own hand, penned in January 1610, while observing what would later be known to be the Galilean moons. The text translates as:
On the 11th it was in this formation - and the star closest to Jupiter was half the size than the other and very close to the other so that during the previous nights all of the three observed stars looked of the same dimension and among them equally afar; so that it is evident that around Jupiter there are three moving stars invisible till this time to everyone.
The spacecraft also carries three Lego minifigures representing Galileo, the Roman god Jupiter, and his sister and wife, the goddess Juno. In Roman mythology, Jupiter drew a veil of clouds around himself to hide his mischief. Juno was able to peer through the clouds and reveal Jupiter's true nature. The Juno minifigure holds a magnifying glass as a sign of searching for the truth, and Jupiter holds a lightning bolt. The third Lego crew member, Galileo Galilei, has his telescope with him on the journey. The figurines were produced in partnership between NASA and Lego as part of an outreach program to inspire children's interest in science, technology, engineering, and mathematics (STEM). Although most Lego toys are made of plastic, Lego specially made these minifigures of aluminum to endure the extreme conditions of space flight.
||Earth flyby for speed boost (from 126,000 to 150,000 km/h (78,000 to 93,000 mph))
|July 5, 2016, 02:50
||Arrival at Jupiter and polar orbit insertion (1st orbit)
|August 27, 2016, 13:44
|October 19, 2016
||Perijove 2: Planned Period Reduction Maneuver, but the main engine's fuel pressurisation system did not operate as expected.
|December 11, 2016, 17:04
|February 2, 2017, 12:57
|March 27, 2017, 08:52
|May 19, 2017, ≈06:00
|July 11, 2017
||Perijove 7: Fly-over of the Great Red Spot
|September 1, 2017
|October 24, 2017
|December 16, 2017
|February 7, 2018
|April 1, 2018
|May 24, 2018
|July 16, 2018
||Perijove 14, end of primary mission. Future observations will depend on possible mission extension after review.
Gallery of Jupiter images
Perijove 6 pass of Jupiter (May 19, 2017)
Image from about 94,500 km (58,700 mi) of Jupiter's southern polar region (August 27, 2016)
Jupiter growing and shrinking in apparent size before and after the spacecraft made its closest approach (August 27, 2016)
Infrared view of the southern aurora of Jupiter (August 27, 2016)
Southern storms of Jupiter
Area of Jupiter where multiple atmospheric conditions appear to collide (March 27, 2017)
Retreating from Jupiter, about 46,900 km (29,100 mi) above the cloud tops (May 19, 2017)
Closeup of the Great Red Spot taken from about 8,000 km (5,000 mi) above it (July 11, 2017)
Image taken from 16,535 km (10,274 mi) above the atmosphere at a latitude of -36.9 degrees (July 10, 2017)
Low resolution view of Io captured by JunoCam (September 2017)
- ^ a b "Juno Mission to Jupiter" (PDF). NASA FACTS. NASA. April 2009. p. 1. Retrieved April 5, 2011.
- ^ a b c d "Jupiter Orbit Insertion Press Kit" (PDF). NASA. 2016. Retrieved July 7, 2016.
- ^ a b Foust, Jeff (July 5, 2016). "Juno enters orbit around Jupiter". Space News. Retrieved August 25, 2016.
- ^ a b c d e Chang, Kenneth (July 5, 2016). "NASA's Juno Spacecraft Enters Jupiter's Orbit". The New York Times. Retrieved July 5, 2016.
- ^ a b c d Greicius, Tony (September 21, 2015). "Juno – Mission Overview". NASA. Retrieved October 2, 2015.
- ^ Dunn, Marcia (August 5, 2011). "NASA probe blasts off for Jupiter after launch-pad snags". MSN. Retrieved August 31, 2011.
- ^ a b Chang, Kenneth (June 28, 2016). "NASA's Juno Spacecraft Will Soon Be in Jupiter's Grip". The New York Times. Retrieved June 30, 2016.
- ^ a b c d e Riskin, Dan (July 4, 2016). Mission Jupiter (Television documentary). Science Channel.
- ^ Cheng, Andrew; Buckley, Mike; Steigerwald, Bill (May 21, 2008). "Winds in Jupiter's Little Red Spot Almost Twice as Fast as Strongest Hurricane". NASA. Retrieved August 9, 2017.
- ^ "Juno's Solar Cells Ready to Light Up Jupiter Mission". NASA. July 15, 2011. Retrieved October 4, 2015.
- ^ "NASA's Juno Spacecraft Launches to Jupiter". NASA. August 5, 2011. Retrieved August 5, 2011.
- ^ "Mission Acronyms & Definitions" (PDF). NASA. Retrieved April 30, 2016.
- ^ Leone, Dan (February 23, 2015). "NASA Sets Next $1 Billion New Frontiers Competition for 2016". SpaceNews. Retrieved January 2, 2017.
- ^ Hillger, Don; Toth, Garry (September 20, 2016). "New Frontiers-series satellites". Colorado State University. Retrieved January 2, 2017.
- ^ "Juno Mission to Jupiter". Astrobiology Magazine. June 9, 2005. Retrieved December 7, 2016.
- ^ a b Ludwinski, Jan M.; Guman, Mark D.; Johannesen, Jennie R.; Mitchell, Robert T.; Staehle, Robert L. (1998). The Europa Orbiter Mission Design. 49th International Astronautical Congress. September 28 – October 2, 1998. Melbourne, Australia. hdl:2014/20516.
- ^ a b Zeller, Martin (January 2001). "NASA Announces New Discovery Program Awards". NASA / University of Southern California. Archived from the original on March 5, 2017. Retrieved December 25, 2016.
- ^ Dougherty, M. K.; Grasset, O.; Bunce, E.; Coustenis, A.; Titov, D. V.; et al. (2011). JUICE (JUpiter ICy moon Explorer): a European-led mission to the Jupiter system (PDF). EPSC-DPS Joint Meeting 2011. October 2–7, 2011. Nantes, France. Bibcode:2011epsc.conf.1343D.
- ^ Dunn, Marcia (August 1, 2011). "NASA going green with solar-powered Jupiter probe". USA Today.
- ^ "NASA's Shuttle and Rocket Launch Schedule". NASA. Retrieved February 17, 2011.
- ^ a b c d e f Brown, Dwayne; Cantillo, Laurie; Agle, D. C. (February 17, 2017). "NASA's Juno Mission to Remain in Current Orbit at Jupiter" (Press release). NASA. Retrieved March 13, 2017.
- ^ a b Juno Mission Profile & Timeline Archived November 25, 2011, at the Wayback Machine.
- ^ "Atlas/Juno launch timeline". July 28, 2011. Retrieved August 8, 2011.
- ^ Administrator, NASA (June 27, 2016). "Juno's Solar Cells Ready to Light Up Jupiter Mission". Retrieved July 5, 2016.
- ^ Juno Spacecraft Overview Juno – NASA's Second New Frontiers Mission to Jupiter. Archive copy from September 2, 2011
- ^ "Atlas/Juno launch timeline". Spaceflight Now. July 28, 2011.
- ^ "NASA's Juno is Halfway to Jupiter". NASA. August 12, 2013. Retrieved August 12, 2013.
- ^ Greicius, Tony, ed. (March 25, 2014). "Earth Triptych from NASA's Juno Spacecraft". NASA.
- ^ a b c "Earth Flyby - Mission Juno". Mission Juno. Retrieved October 2, 2015.
- ^ "NASA's Juno Gives Starship-Like View of Earth Flyby". Retrieved October 2, 2015.
- ^ Greicius, Tony. "Juno Earth Flyby". NASA. Retrieved October 8, 2015.
- ^ Greicius, Tony (February 13, 2015). "NASA's Juno Gives Starship-Like View of Earth Flyby". Retrieved July 5, 2016.
- ^ Chang, Kenneth (July 5, 2016). "NASA's Juno Spacecraft Enters Jupiter's Orbit". The New York Times. Retrieved July 5, 2016.
- ^ "NASA's Juno Spacecraft in Orbit Around Mighty Jupiter". NASA. July 4, 2016. Retrieved July 5, 2016.
- ^ Clark, Stephen (July 4, 2016). "Live coverage: NASA's Juno spacecraft arrives at Jupiter". Spaceflight Now. Retrieved July 5, 2016.
- ^ Gebhardt, Chris (September 3, 2016). "Juno provides new data on Jupiter; readies for primary science mission". NASA Spaceflight. Retrieved October 23, 2016.
- ^ Clark, Stephen (February 21, 2017). "NASA's Juno spacecraft to remain in current orbit around Jupiter". Spaceflight Now. Retrieved April 26, 2017.
- ^ Moomaw, Bruce (March 11, 2007). "Juno Gets A Little Bigger With One More Payload For Jovian Delivery". Space Daily. Retrieved August 31, 2011.
- ^ "Juno Armored Up to Go to Jupiter". NASA. July 12, 2010. Retrieved July 11, 2016.
- ^ "Understanding Juno's Orbit: An Interview with NASA's Scott Bolton". Universe Today. Retrieved February 6, 2016.
- ^ Webster, Guy (December 17, 2002). "Galileo Millennium Mission Status". NASA / Jet Propulsion Laboratory. Retrieved February 22, 2017.
- ^ Firth, Niall (September 5, 2016). "NASA's Juno probe snaps first images of Jupiter's north pole". New Scientist. Retrieved September 5, 2016.
- ^ Agle, D. C.; Brown, Dwayne; Cantillo, Laurie (October 15, 2016). "Mission Prepares for Next Jupiter Pass". NASA. Retrieved October 19, 2016.
- ^ Grush, Loren (October 19, 2016). "NASA's Juno spacecraft went into safe mode last night". The Verge. Retrieved October 23, 2016.
- ^ "NASA Juno Mission Completes Latest Jupiter Flyby". NASA / Jet Propulsion Laboratory. December 9, 2016. Retrieved February 4, 2017.
- ^ a b c Agle, D. C.; Brown, Dwayne; Cantillo, Laurie (March 27, 2017). "NASA's Juno Spacecraft Completes Fifth Jupiter Flyby". NASA. Retrieved March 31, 2017.
- ^ a b Anderson, Natali (May 20, 2017). "NASA's Juno Spacecraft Completes Sixth Jupiter Flyby". Sci-News. Retrieved June 4, 2017.
- ^ Bartels, Meghan (July 5, 2016). "To protect potential alien life, NASA will destroy its $1 billion Jupiter spacecraft on purpose". Business Insider. Retrieved January 7, 2018.
- ^ Dickinson, David (February 21, 2017). "Juno Will Stay in Current Orbit Around Jupiter". Sky & Telescope. Retrieved January 7, 2018.
- ^ a b "NASA Juno Spacecraft to remain in Elongated Capture Orbit around Jupiter". Spaceflight101.com. February 18, 2017. Retrieved January 7, 2018.
- ^ "Juno Institutional Partners". NASA. 2008. Archived from the original on November 15, 2009. Retrieved August 8, 2009.
- ^ "NASA Sets Launch Coverage Events For Mission To Jupiter". NASA Press Release. July 27, 2011.
- ^ Cureton, Emily Jo (June 9, 2011). "Scientist with area ties to study Jupiter up close and personal". Big Bend Now. Retrieved July 17, 2011.
- ^ "Jupiter Awaits Arrival of Juno". Retrieved June 28, 2016.
- ^ a b "Juno Science Objectives". University of Wisconsin-Madison. Archived from the original on September 19, 2015. Retrieved October 13, 2008.
- ^ Iorio, L. (August 2010). "Juno, the angular momentum of Jupiter and the Lense–Thirring effect". New Astronomy. 15 (6): 554–560. arXiv:0812.1485 . Bibcode:2010NewA...15..554I. doi:10.1016/j.newast.2010.01.004.
- ^ Helled, R.; Anderson, J.D.; Schubert, G.; Stevenson, D.J. (December 2011). "Jupiter's moment of inertia: A possible determination by Juno". Icarus. 216 (2): 440–448. arXiv:1109.1627 . Bibcode:2011Icar..216..440H. doi:10.1016/j.icarus.2011.09.016.
- ^ Iorio, L. (2013). "A possible new test of general relativity with Juno". Classical and Quantum Gravity. 30 (18): 195011. arXiv:1302.6920 . Bibcode:2013CQGra..30s5011I. doi:10.1088/0264-9381/30/19/195011.
- ^ "Instrument overview". Wisconsin University-Madison. Archived from the original on October 16, 2008. Retrieved October 13, 2008.
- ^ a b c d Dodge, R.; Boyles, M. A.; Rasbach, C. E. (September 2007). "Key and driving requirements for the Juno payload suite of instruments" (PDF). NASA. GS, p. 8; JADE and JEDI, p. 9. Archived from the original (PDF) on July 21, 2011. Retrieved December 5, 2010.
- ^ "Juno Spacecraft: Instruments". Southwest Research Institute. Archived from the original on April 26, 2012. Retrieved December 20, 2011.
- ^ "Juno launch: press kit August 2011" (PDF). NASA. pp. 16–20. Retrieved December 20, 2011.
- ^ "More and Juno Ka-band transponder design, performance, qualification and in-flight validation" (PDF). Laboratorio di Radio Scienza del Dipartimento di Ingegneria Meccanica e Aerospaziale, università "Sapienza". 2013.
- ^ Owen, T.; Limaye, S. (October 23, 2008). "Instruments : microwave radiometer". University of Wisconsin. Archived from the original on March 28, 2014.
- ^ "Juno spacecraft MWR". University of Wisconsin. Retrieved October 19, 2015.
- ^ a b c "After Five Years in Space, a Moment of Truth". Mission Juno. Southwest Research Institute. Retrieved October 18, 2016.
- ^ "About JIRAM". IAPS (Institute for Space Astrophysics and Planetology of the Italian INAF). Retrieved June 27, 2016.
- ^ Owen, T.; Limaye, S. (October 23, 2008). "Instruments : the Jupiter Infrared Aural Mapper". University of Wisconsin. Archived from the original on March 3, 2016.
- ^ "Juno spacecraft JIRAM". University of Wisconsin. Retrieved October 19, 2015.
- ^ Anderson, John; Mittskus, Anthony (October 23, 2008). "Instruments : Gravity Science Experiment". University of Wisconsin. Archived from the original on February 4, 2016.
- ^ "Juno spacecraft GS". University of Wisconsin. Retrieved December 31, 2015.
- ^ "Juno spacecraft JADE". University of Wisconsin. Retrieved December 31, 2015.
- ^ "Juno spacecraft JEDI". University of Wisconsin. Retrieved October 19, 2015.
- ^ a b Boyle, Alan (February 9, 2018). "Fresh raw imagery from NASA's Juno orbiter puts Jupiter's fans in 11th heaven". Geekwire. Retrieved February 12, 2018.
- ^ "NASA's Juno Mission to Jupiter to Be Farthest Solar-Powered Trip". Retrieved October 2, 2015.
- ^ David Dickinson (March 21, 2013). "US to restart plutonium production for deep space exploration". Universe Today. Retrieved February 15, 2015.
- ^ Greenfieldboyce, Nell. "Plutonium Shortage Could Stall Space Exploration". NPR. Retrieved December 10, 2013.
- ^ Greenfieldboyce, Nell. "The Plutonium Problem: Who Pays For Space Fuel?". NPR. Retrieved December 10, 2013.
- ^ Wall, Mike. "Plutonium Production May Avert Spacecraft Fuel Shortage". Retrieved December 10, 2013.
- ^ Administrator, NASA (June 24, 2016). "Juno Solar Panels Complete Testing". Retrieved July 5, 2016.
- ^ NASA's Juno Spacecraft Launches to Jupiter "... and that its massive solar arrays, the biggest on any NASA deep-space probe, have deployed and are generating power."
- ^ "Juno's Solar Cells Ready to Light Up Jupiter Mission". Retrieved June 19, 2014.
- ^ "Juno prepares for mission to Jupiter". Machine Design. Archived from the original on October 31, 2010. Retrieved November 2, 2010.
- ^ a b c "Juno Spacecraft Information – Power Distribution". Spaceflight 101. 2011. Retrieved August 6, 2011.
- ^ "Key Terms". Mission Juno. Southwest Research Institute. Section TONES. Archived from the original on May 5, 2016.
- ^ "Junocam will get us great global shots down onto Jupiter's poles".
- ^ "Images".
- ^ Amos, Jonathan (September 4, 2012). "Juno Jupiter probe gets British boost". BBC News. Retrieved September 4, 2012.
- ^ a b "Juno Jupiter Mission to Carry Plaque Dedicated to Galileo". NASA. August 3, 2011. Retrieved August 5, 2011.
- ^ "Juno Spacecraft to Carry Three Lego minifigures to Jupiter Orbit". NASA. August 3, 2011. Retrieved August 5, 2011.
- ^ "Juno Spacecraft to Carry Three Figurines to Jupiter Orbit". NASA. August 3, 2011. Retrieved December 25, 2016.
- ^ Pachal, Peter (August 5, 2011). "Jupiter Probe Successfully Launches With Lego On Board". PC Magazine.
- ^ "Juno's Two Deep Space Maneuvers are 'Back-To-Back Home Runs'". NASA. September 17, 2012. Retrieved October 12, 2015.
- ^ "Juno Earth Flyby - Oct. 9, 2013". NASA. Retrieved July 4, 2016.
- ^ Agle, D. C.; Brown, Dwayne; Cantillo, Laurie (August 27, 2016). "NASA's Juno Successfully Completes Jupiter Flyby". NASA. Retrieved October 1, 2016.
- ^ "Mission Prepares for Next Jupiter Pass". Mission Juno. Southwest Research Institute. October 14, 2016. Retrieved October 15, 2016.
- ^ Agle, D. C.; Brown, Dwayne; Cantillo, Laurie (December 12, 2016). "NASA Juno Mission Completes Latest Jupiter Flyby". NASA / Jet Propulsion Laboratory. Retrieved December 12, 2016.
- ^ a b Thompson, Amy (December 10, 2016). "NASA's Juno Spacecraft Preps for Third Science Orbit". Inverse. Retrieved December 12, 2016.
- ^ "It's Never 'Groundhog Day' at Jupiter". NASA / Jet Propulsion Laboratory. February 1, 2017. Retrieved February 4, 2017.
- ^ Witze, Alexandra (May 25, 2017). "Jupiter's secrets revealed by NASA probe". Nature. doi:10.1038/nature.2017.22027. Retrieved June 14, 2017.
- ^ Lakdawalla, Emily (November 3, 2016). "Juno update: 53.5-day orbits for the foreseeable future, more Marble Movie". The Planetary Society. Retrieved June 14, 2017.
- ^ "Photos from Juno's Seventh Science Flyby of Jupiter". Spaceflight101.com. September 8, 2017. Retrieved February 12, 2018.
- ^ Mosher, Dave (November 7, 2017). "NASA's $1 billion Jupiter probe just sent back stunning new photos of the gas giant". Business Insider. Retrieved March 4, 2018.
- ^ "Juno's Perijove-10 Jupiter Flyby, Reconstructed in 125-Fold Time-Lapse". NASA / JPL / SwRI / MSSS / SPICE / Gerald Eichstädt. December 25, 2017. Retrieved February 12, 2018.
- ^ "Overview of Juno's Perijove 10". The Planetary Society. December 16, 2017. Retrieved February 12, 2018.
||Wikimedia Commons has media related to Juno.
- Official website
- Juno mission at Southwest Research Institute
- Juno Mission at NASA's Solar System Exploration
- Why With Nye playlist on YouTube, Bill Nye discussing the science behind NASA's Juno mission to Jupiter
- JunoCam image processing web site
- Animation of Perijove 5 flyby by Gerald Eichstädt (see channel for more)
- Animation of Perijove 6 flyby by Seán Doran (see albums 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 for more)