Todd Barber, Cassini Lead Propulsion Engineer
Greetings again from Cassini engineering, as we are literally a day away from our date with destiny and a super-close Enceladus flyby. Another engineering event, critical for the health and safety of the spacecraft, has gone off without a hitch. Earlier this morning, around 4 am Pacific Daylight Time (PDT), we closed (or deployed, in our nomenclature) the main-engine cover. As we planned to head in closer to Saturn and Enceladus, we recognized the potential for a slight dust hazard, not uncommon during our multi-year orbital tour of the ringed planet. Even with minute dust grains, our delicate main-engine columbium coating could be damaged with hypervelocity impacts, so occasionally we have to deploy our “baby-carriage” cover to protect our twin main engines.
Our thermal control and devices team reports to me yet another successful deployment of the main-engine cover, an event that has taken place roughly three dozen times since launch over ten years ago. I can usually tell when this happens as a propulsion engineer because the closing of the cover helps to warm up the area around the engines, causing the temperature readings I monitor to increase. After the dust hazard is behind us, we’ll again open (or stow) the main-engine cover, although this will occur around 7 pm PDT on Wednesday. In other words, this event will occur after the thrilling E3 flyby, an important engineering event to be sure, but likely one that will be buried in the excitement of the prospect of new Enceladus science results mere hours away.
Looking forward to tomorrows images. Maybe some surprises in the analysis of the materials picked up.
Cassini Getting Cozy with Enceladus, eh?
Looking forward to the photos and data. We love you NASA!
Oh to be born 100 years from now…where we could Actually be there…
when will the flyby be?
wednesday?
This blog is great for all of us “NASA Engineer wanabees”. Thanks for making me feel like an insider.
Should you run into trouble during the fly by, how long before you find out and make changes in, say, the flight path to avoid the problem. I would think the time/distance would be too great to effect a “hard right” turn…
When did you send commands to have the craft make a closer path to the moon and how is it powered? Does the fuel for the engines have a life time limit?
Thank you,
John Maasch
Todd,
Thanks for taking the time to explain what is happening. You mention the thermal controls. What is the ambient temperature of the electronics on the spacecraft? When the cover is deployed, does it raise the temperature just a few degrees or does the radiant barrier create a larger thermal cycle? Is there another “burn” scheduled for immediately after the flyby? I would have thought that the flyby data would have been downloaded prior to potentially disrupting the stability of the spacecraft (by stowing the cover again). Please take good care of Cassini. Thank you again for your efforts. I am sure there are many more exciting discoveries to come.
It is just screeming to be said how happy the science and astronomical communities are about your fly through idea. In many ways your Cassini mission is as by-the-book as it can get however; your daring science manuevers are writing new chapters in the art of pacecraft navigation combined with ability and guts.
We all extend you the sincerest “yooraw”
Fingers crossed for Cassini.
Thanks for rolling the dice on an exciting encounter like this!