Monday Assignment Diederik Beker (10190848) - matthijsbos/swe2013team5 GitHub Wiki

Mars Climate Orbiter failure November 10, 1999

Diederik Beker University of Amsterdam 13-01-2013

I decided to study the Mars Climate Orbiter failure from November 10th 1999. I chose this particular project because of the type of mistake that was made. One that was so easily fixed, but yet cost millions of dollars. The problem could have so easily been helped, if it had been checked instead of assumed. What I teach my students when I teach scuba diving: “When you assume, people die”. Which is true in the case of being deep underwater, if you make a mistake because you assume that someone knows something, or has done something, you could die. While dying was not part of this project, a lot of money was lost and a lot of valuable data was not collected because people assumed the guidelines had been followed.

“The MCO MIB has determined that the root cause for the loss of the MCO spacecraft was the failure to use metric units in the coding of a ground software file, “Small Forces,” used in trajectory models.” The guidelines had stated that metric units were to be used, but the people coding the ground software failed to do so. Apparently this was not checked with other personnel and it was assumed it would be correct. “The Board recognizes that mistakes occur on spacecraft projects. However, sufficient processes are usually in place on projects to catch these mistakes before they becomecritical to mission success. Unfortunately for MCO, the root cause was not caught by the processes in-place in the MCO project.” A seemingly small error can thus cause major effects, since the trajectory of the Mars Climate Orbiter was faultily entered on multiple occasions due to this error.

Another reason I chose this project is because of the relevance to what we have talked about in the past lecture. This project was written up in guidelines and planned the entire way before any execution was done. As we have learned in the past this can be solved by using scrum. If this had been done using scrum the software, that now malfunctioned, would have had regular feedback and this small problem could have been avoided. Of course it is not a guarantee that this problem would not have occurred, but the value of using scrum and regular feedback is highlighted by this project’s mistake, or as they like to say “mishap”.

I suppose, just like in scuba diving, almost all mistakes are human errors. Obviously we cannot make humans perfect, making sure they do not make mistakes, but we can put certain checks in place to make sure these errors are not overlooked. A good lesson for me, and something to take with me and discuss with my fellow students during this and future projects.

References [1] ftp://ftp.hq.nasa.gov/pub/pao/reports/1999/MCO_report.pdf