Catching Jupiter

Ignition…and…liftoff of the Atlas V with Juno on a trek to Jupiter, a planetary piece of the puzzle on the beginning of our Solar System.

– George Diller, NASA Launch Commentator

On 3pm on August 5, 2011, I was awakened by a cacophony of alarms.  Groggily opening my eyes, I reached beside my bed, and switched off my alarm clock.  Next, I picked up my phone, silenced its alarm as well, and immediately opened a browser window.  Navigating to, I saw a headline with a photo of a large rocket lifting off from a launchpad in Florida.  That was all I needed to see: Juno was on its way, and it was time for me to get ready to go to work.


Juno lifts off, beginning its long journey to Jupiter.  Photo courtesy of NASA.

I had a close relationship with the Juno spacecraft during my time as an interplanetary flight controller.  Having begun work in the Lockheed Martin Mission Support Area in January 2011, I was originally assigned to work on the Pointing Control Subsystem of the Spitzer Space Telescope.  However, controllers in the MSA typically “wear a variety of hats.” So, after receiving my Spitzer PCS console certification in March, I began training as an ACE: an operator that sends commands to the spacecraft (I discussed some of my ACE training in a previous post).  Being a newly-minted ACE, Juno launch and initial operations provided me with my first experience in a mission-critical operation. My role was to work the night shifts.  As the spacecraft was freshly off the pad and still being brought up to normal configuration, much of the automation that normally runs the spacecraft had yet to be turned on.  I was responsible for manually handing the spacecraft over between DSN stations, and keeping the spacecraft healthy between daytime “prime” shifts, where most of the actual configuration took place.

Juno and I would cross paths again a couple of years later, on October 9, 2013.  As far as interplanetary space probes go, Juno is one of the largest.  So large, in fact, that even the mighty Atlas V 551 – a massive rocket, with five solid rocket boosters strapped on for even more power – couldn’t provide enough speed to push it all the way out to Jupiter.  As a result, after flying out a bit past the orbit of Mars, Juno came speeding back to Earth for a gravity assist maneuver.  Like a giant slingshot, Juno used Earth’s gravity to catapult itself toward Jupiter. The effect was so powerful that it was equivalent to a second rocket launch.  After gaining confidence and experience as an ACE in the years since launch, it was my turn to be on the prime shift: I got the nod to be the ACE for the big event, and was at the control console as Juno sped by Earth at over 33,000 miles per hour, passing a mere 347 miles above the southern tip of Africa.


Juno on the spin table, shortly before being shipped to Cape Canaveral to be readied for launch. My wife, Christy, is also a flight controller in the MSA; she’s a Systems engineer for MRO.  Photo courtesy of Lockheed Martin.

Perhaps it’s fitting that Juno gave me my last opportunity to be on console for a mission-critical operation before I left the MSA to begin my journey to sMars.  About a year or so prior, a computer glitch had caused Juno to autonomously switch over from its primary “A-side” computer to its backup “B-side”.  To prepare for Jupiter arrival, still several months away at the time, the Juno team decided to switch back over to the A-side to ensure that the computer was still healthy.  In the meanwhile, I had continued to advance in my role as as ACE and had become a mentor for new controllers-in-training.  As I sent the commands to carefully reboot the spacecraft – as you might imagine, rebooting a spacecraft’s computers while it’s in flight is a rather delicate manner – I was observed by three new ACE trainees.  I had the opportunity to pass on my knowledge to the next generation of ACEs, the controllers who would take my place after I was gone.  Life had come full circle.

Looking back, a lot has happened in five years.  And, when I was sitting in the ACE chair during that first night shift, five years seemed like a long stretch ahead.  I wondered where I’d be when Juno finally arrived at Jupiter.  Would I still be flying spacecraft from the MSA, or would I have moved on to something else?  It definitely didn’t cross my mind that I’d be sitting here, writing to you all from the surface of simulated Mars!

The five years have passed, and the big day is almost here.  To the Juno team, from simulated Mars, I wish you guys the best of luck on Monday, and excitement for the great science waiting just around the corner.  Go Juno!



2 thoughts on “Catching Jupiter

  1. I watched the NASA online broadcast for orbit insertion last night. (Played with the Eyes simulator, too.) Seemed to go flawlessly–all “tones” on time. Amazing to be sending a spacecraft 5AU out with solar power. I wonder why we risked bringing her so close to earth’s surface for that gravity assist? Good to get your “inside look” at the work!


    • I’m glad you enjoyed the article Jeff! I’m happy to share the experience – there’s a lot that goes on behind the scenes to get a spacecraft out there, and not all of it makes the news. I got the video sent to me by mission support last night, and have been watching it in my spare time. I’m enjoying watching my friends have a successful night!

      The distance Juno passed from Earth was determined by the laws of physics: the closer you are when you fly by, the bigger a boost you get. And Juno needed a big boost! Fortunately, the JPL navigation guys working our missions are top notch – they routinely hit windows a few kilometers wide at planets millions of miles away. So, we were pretty sure we weren’t going to hit Earth…but there actually was some concern that we might hit another spacecraft as we blasted through the low-Earth orbit zone! We had a couple of commands in our back pocket that we could send on a moment’s notice – brief, 1-second burns forward and backward – in case the Collision Avoidance folks made a sudden determination that we were at risk of running into something. Fortunately, we were clear the whole way through, and didn’t have to use any of them.


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