Which of Cassini's engines have been used?

[willpittenger]

I know that Cassini has two engines. I remember noting that one was intended only as a backup for the first and that both would not be used at the same time. The question is: Does the probe alternate engines to spread out the wear and tear? <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[vogon13]

No.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[3488]

There is the 'primary engine' & the secondary one which is a twin.<br /><br />Given the liklehood of failure during Saturn Orbital insertion, it was decided that two would<br />be [ut on the spacecraft, if the primary one failed, the secondary one was there <br />to pick up the batton so to speak.<br /><br />It was never needed & has never been used. It would make sense for the two to be used <br />alternately, but they never have. One engine was always the requirement for the mission.<br /><br />However having the second engine does increase the chance of the success of an <br />extended mission, if the primary one does show signs of wear & tear, <br />the secondary one is still available. <br /><br />AFAIK, the engines are not used much, as the smaller thrusters can be used for minor <br />course corrections & changes.<br /><br />The secondary engine was insurance, rather than a real requirement.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>