OSC's History with Cassini's Saturn Rendezvous

    Date Posted: 
    Thursday, May 25, 2017

    On April 21, the New York Times ran an article entitled Cassini's Grand Finale: A Dive Between Saturn and Its Rings. As the Cassini spacecraft plunges toward Saturn, where no human artifact has ever gone, we look back on the relationship between Cassini and the College of Optical Sciences.

    In the early 1990s the UA's Dimensional Stability Lab at OSC worked with NASA's Jet Propulsion Laboratory (JPL) to develop a metal that was ultrastable with time and temperature. Cassini's optical systems required long-term stability with time and temperature, under wide-ranging conditions. JPL developed an improved Invar metal using ultrapure carbon, and OSC's Dimensional Stability Lab — with Professor Emeritus Stephen F. Jacobs — measured the time and temperature stability to a precision of 1ppb/year and 1ppb/K respectively. Jacobs reported this to be two orders of magnitude better than ordinary Invar.

    Until 2009, Jacobs' OSC laboratory was effectively a National Bureau of Standards for dimensional stability of materials for optical engineering. 

    Cassini will penetrate between Saturn and its innermost ring not once, but 22 times, about once per week until Sept. 15, when it will crash into Saturn and be incinerated. 

    For more on Cassini's last mission, see the New York Times article and the NASA Cassini website. For more on Stephen F. Jacobs, see his website and Reflections article.

    Photo provided by NASA.