Juno and Jupiter

Earlier in the week the Juno spacecraft manoeuvred itself into orbit around Jupiter, nearly five years  after blasting off from Earth. It will spend the next few months running a range of tests that amongst other things will substantially aid understanding of how planets and our solar system formed.

From NASA: Juno Spacecraft in Orbit Around Mighty Jupiter


After an almost five-year journey to the solar system’s largest planet, NASA’s Juno spacecraft successfully entered Jupiter’s orbit during a 35-minute engine burn. Confirmation that the burn had completed was received on Earth at 8:53 p.m. PDT (11:53 p.m. EDT) Monday, July 4.

Confirmation of a successful orbit insertion was received from Juno tracking data monitored at the navigation facility at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, as well as at the Lockheed Martin Juno operations center in Littleton, Colorado. The telemetry and tracking data were received by NASA’s Deep Space Network antennas in Goldstone, California, and Canberra, Australia.

“This is the one time I don’t mind being stuck in a windowless room on the night of the 4th of July,” said Scott Bolton, principal investigator of Juno from Southwest Research Institute in San Antonio. “The mission team did great. The spacecraft did great. We are looking great. It’s a great day.”

Preplanned events leading up to the orbital insertion engine burn included changing the spacecraft’s attitude to point the main engine in the desired direction and then increasing the spacecraft’s rotation rate from 2 to 5 revolutions per minute (RPM) to help stabilize it..

The burn of Juno’s 645-Newton Leros-1b main engine began on time at 8:18 p.m. PDT (11:18 p.m. EDT), decreasing the spacecraft’s velocity by 1,212 miles per hour (542 meters per second) and allowing Juno to be captured in orbit around Jupiter. Soon after the burn was completed, Juno turned so that the sun’s rays could once again reach the 18,698 individual solar cells that give Juno its energy.

“The spacecraft worked perfectly, which is always nice when you’re driving a vehicle with 1.7 billion miles on the odometer,” said Rick Nybakken, Juno project manager from JPL. “Jupiter orbit insertion was a big step and the most challenging remaining in our mission plan, but there are others that have to occur before we can give the science team the mission they are looking for.”

Over the next few months, Juno’s mission and science teams will perform final testing on the spacecraft’s subsystems, final calibration of science instruments and some science collection.

“Our official science collection phase begins in October, but we’ve figured out a way to collect data a lot earlier than that,” said Bolton. “Which when you’re talking about the single biggest planetary body in the solar system is a really good thing. There is a lot to see and do here.”

Juno’s principal goal is to understand the origin and evolution of Jupiter. With its suite of nine science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter’s intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet’s auroras. The mission also will let us take a giant step forward in our understanding of how giant planets form and the role these titans played in putting together the rest of the solar system. As our primary example of a giant planet, Jupiter also can provide critical knowledge for understanding the planetary systems being discovered around other stars.

The Juno spacecraft launched on Aug. 5, 2011 from Cape Canaveral Air Force Station in Florida. JPL manages the Juno mission for NASA. Juno is part of NASA’s New Frontiers Program, managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space Systems in Denver built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.

jupiter_and_its_shrunken_great_red_spot

From Juno’s mission page a mission status report:

The engineers and scientists working on NASA’s Juno mission have been busying themselves, getting their newly arrived Jupiter orbiter ready for operations around the largest planetary inhabitant in the solar system. Juno successfully entered Jupiter’s orbit during a 35-minute engine burn on Monday, July 4. Confirmation that the burn had completed was received on Earth at 8:53 pm. PDT (11:53 p.m. EDT) that evening.

As planned, the spacecraft returned to high-rate communications on July 5 and powered up five of its science instruments on July 6. Per the mission plan, the remaining science instruments will be powered up before the end of the month. Juno’s science instruments had been turned off in the days leading up to Jupiter orbit insertion.

The Juno team has scheduled a short trajectory correction maneuver on July 13 to refine the orbit around Jupiter.

“Prior to launch five years ago we planned a date and time for the Jupiter orbit insertion burn and the team nailed it,” said Rick Nybakken, project manager for Juno from NASA’s Jet Propulsion Laboratory in Pasadena, California. “We are in our planned 53.4 day orbit. Now we are focusing on preparing for our fourth and final main engine burn, which will put us in our 14-day science orbit on October 19.”

The next time Juno’s orbit carries it close by the planet will be on Aug. 27. The flyby is expected to provide some preliminary science data.

“We had to turn all our beautiful instruments off to help ensure a successful Jupiter orbit insertion on July 4,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “But next time around we will have our eyes and ears open. You can expect us to release some information about our findings around September 1.”

juno_current_position_7_04_2016

Juno on 4 July (5 July NZ time)

Leave a comment

5 Comments

  1. Gezza

     /  8th July 2016

    Cheers PG. Of great interest to me at least.

    Reply
  2. The picture of Jupiter is extraordinary. It reminds me of layers of sand in a glass jar or test tube, and of the background to a Michaelangelo painting …

    Beautiful. Thanks for the topic PG.

    Reply
  3. Brown

     /  8th July 2016

    Yep, great stuff that inspires while still putting us in our place in the scheme of things. This is what NASA should be doing – not weather forecasting.

    Reply

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