Enceladus Approach Maneuver Cancelled — We're Good to Go!

Todd BargerTodd Barber, Cassini Lead Propulsion Engineer (bio)

Monday greetings from the engineering side of the Cassini flight team!  I’m very happy to report via this blog that we just decided to cancel the final Enceladus approach Orbit Trim Maneuver (OTM), OTM-148, and its back-up maneuver labeled JTM-148.  Since these burns were scheduled after midnight local time in California last night and tonight, respectively, I don’t think many of us will mourn their cancellation.  These final targeting maneuvers for Wednesday’s thrilling close flyby of Saturn’s icy companion were deemed unnecessary, largely due to excellent performance at OTM-147 four days ago.  In fact, we were able to save a little bit of propellant for the mission overall by canceling these maneuvers!
We took an engineering image of Enceladus yesterday evening, a so-called “optical navigation” or “op-nav” image.  Rather than being used for science, we actually used this image to measure the position of Enceladus very accurately with respect to known background stars.  This helped us improve our knowledge of Enceladus’ location, and the result of this latest op-nav is that Cassini remains on target for its historic rendezvous with Enceladus and its icy south polar plumes in two short days.  We in engineering wish our science colleagues on the mission a very fruitful and eye-opening close encounter with one of Saturn’s most intriguing moons. 

21 thoughts on “Enceladus Approach Maneuver Cancelled — We're Good to Go!”

  1. This stuff is awesome! Do you ever feel like Christopher Columbus? You are seeing these amazing things for the first time and sharing them with the world. Thanks for the great pictures and science!

  2. what do engineering pictures look like?
    i would assume it’d be mostly technical data
    what else is involved in an op-nav? it’s incredible to thing about the immense amount of calculations required for navigation at such distances no?

    is there a page which exists which summarizes the spacecraft’s vital functions? i am curious about this propellant, when I was young, i always assumed spacecraft would not require consumable materials due to solar energy. how naive I was 🙂

  3. Anytime you can save propellant, it is a bonus that will pay for itself later down the mission timeline.

    March 12th being my birthday, will be very special for me with this mission to the phenomenal moon of Enceladus!

    I wish you all good luck, and thank you for continuing this great journey into the realm of the Lord of the Rings!

  4. Good luck with this new flyby that, if it goes well, will be another exploit of that legendary explorer that’s Cassini and all the people behind her.
    The most awesome thing is the precision needed to fly at 14 km/sec at just 52 kilometers of the moon’s surface -it’s a distance Cassini will transverse in just a bit more than three seconds-.

  5. Congratulation to the Cassini navigation team. For they always get their target with great accuracy to permit us enjoying all those stunning swarms of data gathering from such a distant worlds.

  6. Looking fordward to Cassini encounter with Enceladus Plume I am very excited to study the science findings and see the images of the Northern Region of the moon.

    Good look with the close encounter and congratulations on the success of the Cassini Mission to Saturn and its moons

    Bill Reddin Rep of IRE….

  7. I look very much forward to reading (and hearing) your observations accrued from the Enceladus fly-by tomorrow, March 12th. Also, it would be fascinating to peruse two items of interest: 1. whether the geysers at Enceladus’ south pole are primarily the result of the gravitational tidal forces of Saturn and its larger moons, entirely enceladological internal forces peculiar to the moon, or a combination of both; and 2. the chemistry of the geysers, i.e. whether the geysers aerosols had their origins in such water-related fluids as the ammonia spewed from Titan’s cryovolcanoes. Hopefully, you will mention something about these two concerns.

    Thank you.

    David Bookbinder

  8. Todd Barber is the most awesome engineer – Rocket Man Extraordinaire!What an amazing journey – always intriging – always mind-boggling!

  9. Congrats to all, I know it’s been a long haul. I am glad the “charitable singer” from Wichita was able to get some extra sleep! We up here in Connecticut are looking forward to any/all news and images.

    Again, kudos to all and keep up the good work!

  10. Thanks so much for starting this blog.

    “We took an engineering image of Enceladus yesterday evening, a so-called “optical navigation” or “op-nav” image. Rather than being used for science, we actually used this image to measure the position of Enceladus very accurately with respect to known background stars.”

    On what scale of accuracy, meters? kilometers? Egads! hehe

  11. Over 15 years ago, I sent an op-ed letter in to my local newspaper (San Diego Union Tribune) regarding the failure of the Mars Observer to make orbit. They had published another op-ed piece that was highly critical of Nasa as a result of what this guy loosely referred to as their many failures. His diatribe was driven by the failure of the Mars Observer.

    That pissed me off, and I wrote a letter correcting his many errors of logic, and, I championed the many successes that NASA had posted to that date. One thing I mentioned was a great achievement was Voyager 2 sending back data that indicated the possibility of a water ocean under the tiny moon Enceladus! I wrote, “suspected water ocean” in my letter. The newspaper editor removed that line, but published the letter otherwise intact, and with a byline…which made me very happy. But I was always disappointed that they refused to acknowledge the possible existence of water on Enceladus. I believe I got a call from them before publishing that said they couldn’t publish speculation!

    And now, here we are…a day away from flying through the water/ice plumes of Enceladus! I’ve been waiting a long time for this, but actually, I was already vindicate quite awhile ago when they first imaged the plumes. That said, I only was an avid reader and follower of planetary science, so all I was doing originally was passing on the good news that NASA, and JPL had provided through their works of genius!

    Thanks JPL and NASA for making this long time fan so happy! This is an amazing time to be alive…truly a renaissance in planetary science. Hope I live long enough to see all the current missions come to frution, and to see what you all come up with for the extended mission at Saturn…you’ve got a vote here for a return to Iapetus, but that said, I realize it requires quite a bit of delta-V to get out to it, so I suspect I’ll probably have to be satisfied with the brilliant dataset that Cassini (and the masters in the team) has/have provided!

    Thanks so much…I’ll be tuning in tomorrow and in the following days!

    Matt Gibbons
    Bellingham, WA

  12. Seriously, you guys are amazing.
    I’m a big Cassini fan so, I love to get on the website everyday and learn not only about science discoveries but, operations as well. And, every day I learn something new.
    Your ability to navigate the Saturnian system has captured my imagination and motivated me to take math and science classes at my local community college, at 47 years old.
    Your perfect execution will forever benefit all mankind.
    I can’t wait for tomorrow!!
    Thank you.

    I do hope you’re having fun along the way:)

  13. Incredible Jobs, an one very accuratte navigation.
    Congratulations for the Cassini Team.!!!!!

  14. Congratulatios, your happy face tell us how good the things go. It’ll be a madness to bet against you in a dart-match.

    I’m thinking..it would possible, during flyby, to mark anyway a big ammount of particles in order to follow the trayectories?


    Excuse my english

  15. Congratulations to the Cassini Team. IF he is still there – give my best to Bob Springfield – an old team member of mine during the DMSP days.. Best regards from an old Galileo MCT member from the late 80’s… Charlie Barber

  16. Go, Cassini! Go! Please, Cassini, send us the most amazing high-resolution images of the “Yellowstone-like” geysers of Enceladus the most active ice world of Saturn. I hope you will find and analyze the possible water on Enceladus…. and possible life, too.

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