Tag: Jupiter

Because Juno entered safe mode prior to its close approach of Jupiter today, no science data was gathered.

NASA’s Juno spacecraft entered safe mode Tuesday, Oct. 18 at about 10:47 p.m. PDT (Oct. 19 at 1:47 a.m. EDT). Early indications are a software performance monitor induced a reboot of the spacecraft’s onboard computer. The spacecraft acted as expected during the transition into safe mode, restarted successfully and is healthy. High-rate data has been restored, and the spacecraft is conducting flight software diagnostics. All instruments are off, and the planned science data collection for today’s close flyby of Jupiter (perijove 2), did not occur. “At the time safe mode was entered, the spacecraft was more than 13 hours from its closest approach to Jupiter,” said Rick Nybakken, Juno project manager from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We were still quite a ways from the planet’s more intense radiation belts and magnetic fields. The spacecraft is healthy and we are working our standard recovery procedure.”

This problem, combined with the thruster valve problem that prevented engineers from putting the spacecraft into its proper 14-day science orbit today, is significantly delaying science operations. They will not be able to adjust the orbit again until its next close approach December 11 (assuming the thruster problem has been solved by then), and until then it will also not be able to do much science.

Valve problems detected during Juno’s orbital insert around Jupiter has caused engineers to delay the October 19 engine burn that would have lowered the probe’s orbit around Jupiter.

Mission managers for NASA’s Juno mission to Jupiter have decided to postpone the upcoming burn of its main rocket motor originally scheduled for Oct. 19. This burn, called the period reduction maneuver (PRM), was to reduce Juno’s orbital period around Jupiter from 53.4 to 14 days. The decision was made in order to further study the performance of a set of valves that are part of the spacecraft’s fuel pressurization system. The period reduction maneuver was the final scheduled burn of Juno’s main engine. “Telemetry indicates that two helium check valves that play an important role in the firing of the spacecraft’s main engine did not operate as expected during a command sequence that was initiated yesterday,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. “The valves should have opened in a few seconds, but it took several minutes. We need to better understand this issue before moving forward with a burn of the main engine.”

Because of this, they will instead use this next close approach to Jupiter to do pure science, something that they would not have done during the engine burn. Though this is a good example of turning lemons into lemonade, it will not be a good thing if Juno can never reduce its orbit to 14 days. A 53 day orbit will mean that they can only do good research every two months, and will seriously limit what they can learn over the long run.

The Juno science team today released the mission’s first science results gathered during its first close fly-by of Jupiter.

I have cropped on the right one of their full images to focus in on two of the strangely shaped storms Juno imaged during its pass. This image is of the northern pole. They also have some fascinating images of the south pole storms as well. Unlike the equatorial regions, which on gas giants have what appear to be parallel coherent bands of weather, the poles appear very chaotic, with the storms forming shapes that have not been seen in any other atmosphere in the solar system. They also found a hexagon-shaped weather feature in the pole.

The first link above also included data from the spacecraft’s other instruments, showing the gas giant’s complex atmosphere in a variety of other wavelengths.

Juno today successfully completed its first and closest fly-by of Jupiter during its primary mission, zipping only 2,600 miles above the gas giant’s cloud tops.

We are getting some intriguing early data returns as we speak,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “It will take days for all the science data collected during the flyby to be downlinked and even more to begin to comprehend what Juno and Jupiter are trying to tell us.”

While results from the spacecraft’s suite of instruments will be released down the road, a handful of images from Juno’s visible light imager — JunoCam — are expected to be released the next couple of weeks. Those images will include the highest-resolution views of the Jovian atmosphere and the first glimpse of Jupiter’s north and south poles. “We are in an orbit nobody has ever been in before, and these images give us a whole new perspective on this gas-giant world,” said Bolton.

The image to the right, cropped and reduced in resolution to show here, was taken today when the spacecraft was still 437,000 miles away.

Juno has now passed the farther point from Jupiter in its first orbit and has started dropping back down to the gas giant.

Juno arrived at Jupiter on July 4, firing its main rocket engine as planned for 35 minutes. The flawless maneuver allowed Jupiter’s gravity to capture the solar powered spacecraft into the first of two 53.4-day-long orbits, referred to as capture orbits. Following the capture orbits, Juno will fire its engine once more to shorten its orbital period to 14 days and begin its science mission.

But before that happens, on Aug. 27, Juno must finish its first lap around Jupiter, with a finish line that represents the mission’s closest pass over the gas giant. During the encounter, Juno will skim past Jupiter at a mere 2,600 miles (4,200 kilometers) above the cloud tops.

The Juno science team have released the first image since the spacecraft entered orbit around Jupiter. I have posted a cropped version on the right, showing only the moon Io. The full image shows Europa and Ganymede as well.

The image was taken from almost 3 million miles away, which accounts for its fuzziness. Expect much better pictures when the spacecraft dips down close in late August.

The Juno engineering team has begun turning the spacecraft’s instruments back on following its Jupiter orbital insertion.

Everything looks fine. The next important engine burn on October 19 will shrink the orbit from 53 days to 14 days. In the meantime the present orbit will dip down close to Jupiter on August 27. Expect some news on September 1.

After five years of travel, Juno last Friday entered Jupiter’s gigantic and very powerful magnetic field in its approach for its July 4 orbital insertion.

Meanwhile, they have uploaded to the spacecraft its final software commands for that orbital insertion.

At about 12:15 pm PDT today (3:15 p.m. EDT), mission controllers will transmit command product “ji4040” into deep space, to transition the solar-powered Juno spacecraft into autopilot. It will take nearly 48 minutes for the signal to cover the 534-million-mile (860-million-kilometer) distance between the Deep Space Network Antenna in Goldstone, California, to the Juno spacecraft. While sequence ji4040 is only one of four command products sent up to the spacecraft that day, it holds a special place in the hearts of the Juno mission team. “Ji4040 contains the command that starts the Jupiter Orbit insertion sequence,” said Ed Hirst, mission manager of Juno from NASA’s Jet Propulsion Laboratory in Pasadena, California. “As soon as it initiates — which should be in less than a second — Juno will send us data that the command sequence has started.”

After a five year journey the Jupiter science probe Juno today entered the gas giant’s gravity well.

It will fire its engines on July 4 to enter orbit.

The Juno spacecraft, heading for a July 4 rendezvous with Jupiter, when it will go into orbit around the giant planet, successfully completed a mid-course correction engine burn on Wednesday.

In preparation for its arrival in orbit around Jupiter in about a year, engineers for the unmanned probe Juno have revised their planned orbital maneuvers.

Following a detailed analysis by the Juno team, NASA recently approved changes to the mission’s flight plan at Jupiter. Instead of taking 11 days to orbit the planet, Juno will now complete one revolution every 14 days. The difference in orbit period will be accomplished by having Juno execute a slightly shorter engine burn than originally planned.

The revised cadence will allow Juno to build maps of the planet’s magnetic and gravity fields in a way that will provide a global look at the planet earlier in the mission than the original plan. Over successive orbits, Juno will build a virtual web around Jupiter, making its gravity and magnetic field maps as it passes over different longitudes from north to south. The original plan would have required 15 orbits to map these forces globally, with 15 more orbits filling in gaps to make the map complete. In the revised plan, Juno will get very basic mapping coverage in just eight orbits. A new level of detail will be added with each successive doubling of the number, at 16 and 32 orbits.

The change will extend the official mission from 15 to 20 months, though I expect that even this will be extended if the spacecraft’s fuel holds out.