Juno Mission Update 9/26/13

 

 

Elapsed Mission Time:

02 Years 53 days (1.75 months) 06 Hours 43 Minutes

To Earth Flyby:

12 Days 20 Hours 13 Minutes

To Jupiter Arrival:

02 Years 283 Days (9.93 months) 03 Hours 20 Minutes

 

NASA's Juno spacecraft successfully executed a second Deep Space Maneuver, called DSM-2 on Friday, Sept. 14. The 30 minute firing of its main engine refined the Jupiter-bound spacecraft's trajectory, setting the stage for a gravity assist from a flyby of Earth on Oct 9, 2013. Juno will arrive at Jupiter on July 4, 2016.The maneuver began at 3:30 p.m. PDT (6:30 p.m. EDT), when the Leros-1b main engine began to fire. The burn ended at 4 p.m. PDT (7 p.m. EDT). Based on telemetry, the Juno project team believes the burn was accurate, changing the spacecraft's velocity by about 867 mph (388 meters a second) while consuming about 829 pounds (376 kilograms) of fuel. The burn occurred when Juno was more than 298 million miles (480 million kilometers) from Earth.

Juno's Current Position

As of Sept. 16, Juno was approximately 13 million miles (21 million kilometers) from Earth. The one-way radio signal travel time between Earth and Juno is currently about 71 seconds. Juno is currently traveling at a velocity of about 23 miles (37 kilometers) per second relative to the sun. Velocity relative to Earth is about 7 miles (11 kilometers) per second. Juno has now traveled 951 million miles (1.53 billion kilometers, or 10.1 AU) since launch.  The Juno spacecraft is in excellent health and is operating nominally. All science instruments are powered off except for the magnetometer experiment, which continues to operate in low-power mode.

 

Artist’s rendering of the Juno spacecraft approaching Earth on Oct. 9, 2013.

NASA’s Jupiter-bound Juno spacecraft will perform a close flyby of Earth on Oct. 9, 2013. The time of closest approach is approximately 19:21 UTC (3:21 pm U.S. Eastern time). During the flyby Juno will come to within 347 miles (559 kilometers) of Earth.  Juno will receive a huge boost from Earth’s gravity equivalent to about 70 percent of the total change in velocity, or delta-v, provided by the Atlas V 551 rocket. The boost from the flyby is almost as powerful as a second rocket launch. The spacecraft passes over South Africa at the point of closest approach. Shortly after this point, Juno will pass into Earth’s shadow for about 20 minutes. Juno emerges from the planet’s shadow when it is about 5,400 miles (8,700 kilometers) above Earth at approximately 19:39 UTC when it is over the east coast of India.

 

Map showing Juno’s ground track during the Earth flyby.

• Plans for the close flyby:
  The close flyby provides the opportunity for a trial run of science operations at Jupiter. The Juno team will use this occasion to exercise Juno’s science instruments and sample a planetary magnetosphere to get a preview of what to expect from the spacecraft once it arrives at the giant planet. Most of Juno’s science instruments have observations planned for the encounter, except for the exquisitely sensitive Microwave Radiometer, which will remain powered off as a protective measure. 
  
• Juno’s imaging camera for public engagement, called JunoCam, will take a series of color images of our home planet beginning near the time of closest approach.
  
• The radio and plasma wave instrument, called Waves, will listen to the transmissions of Earth’s magnetosphere – possibly detecting signals of human origin as well.
  
• Once processing of these data products is completed, these visuals will be published.