Columbia Investigation

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Java Radar Analysis Tool (JRAT) Success Story

On February 1st of 2003, the STS-107 Columbia space shuttle and her crew were lost while returning back from a very successful science mission. Immediately following this catastrophic event NASA initiated an accident investigation team to determine the cause of the breakup. In addition to searching the primary debris sites in Texas and Louisiana, the search teams also focused on orbiter shedding events documented in videos while the orbiter was still flying over the west coast of the United States. These shedding events were of particular interest because the items shed at this time may provide the biggest clue as to the cause of the breakup.

With the help of the United States Air Force (USAF), National Transportation and Safety Board (NTSB) and the Federal Aviation Administration (FAA), NASA gathered all air traffic control radar data from the available radars across the nation in order to search for the impact locations of early shedding debris. More than 2 million individual radar returns, beyond private/commercial aircraft returns, were available from 1330 GMT to 1500 GMT on February 1, 2003. The radar search team, with the help of several software packages provided by the USAF, NTSB and FAA, began the pain-staking task of searching for possible debris tracks in the 2 million returns.

Figure 1. click to enlarge

The available programs were all limited to a 2D view of the radar return so a new program was developed by the Flight Design and Dynamics Division at NASA Johnson Space Center to provide a 3D view. This program, called the Java Radar Analysis Tool (JRAT), was written in Java and Java3D. The 2D component of the tool provides scatter plots of the radar returns from various perspectives, while the 3D component displays the radar returns as spheres suspended in the air over a planar map of the earth. The user can select and highlight a point in both the 2D scatter plots and in the 3D world with the corresponding selection highlighted in both representations. Additionally, data can be filtered for easier visualization and can also be animated to show the timeline of radar return appearance. A 3D shuttle orbiter model can be displayed in the animation to show the relative position of the orbiter with respect to the appearance of the individual radar returns. The 3D environment can be rotated, panned and zoomed for optimal viewing to better track possible debris tracks.

Figure 2. click to enlarge

The ease of development in Java and Java3D allowed this tool to be completed in a relatively short period of time so that the JSC Radar Assessment Team could better search the extremely large data set of radar returns. JRAT helped in finding several potential debris tracks that in turn defined search boxes used by the ground search teams.