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9 Conjunction Assessment Risk Analysis and Launch Collision Avoidance
Pages 65-71

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From page 65...
... /conjunction assessment (CA; at JSC for the ISS and the space shuttle) is the process performed for mitigating the risk of an operational satellite colliding with a cata loged object, and launch collision avoidance (COLA)
From page 66...
... Between Febru ary 2009 and February 2011, Iridium made 41 collision mitigation maneuvers based on 46 close approach warnings;6 however, all of these actions were integrated into normal constellation maintenance actions and so had little impact on Iridium operations. 1 NASA Orbital Debris Program Office, "Orbital Debris Frequently Asked Questions," available at http://orbitaldebris.
From page 67...
... FIGURE 9.1.2 Screen shot from AGI Viewer 9 file of current Iridium constellation and collision debris clouds. SOURCE: Courtesy of T.S.
From page 68...
... Also, although SP data do include covariance information, it is generally agreed that the amount is too small (meaning that the uncertainty is large) as a result of the way the SSN sensor observations are collected and sent to the JSpOC for 1 C
From page 69...
... Currently, the JSpOC looks out 5 to 7 days ahead, but reports only close approaches within 1 km total and 200 m radial for LEO objects and 5 km total for GEO objects 3 days ahead. The 3-day time horizon leaves little time for an operator to attempt to get better tracking data, make the necessary decision regarding collision avoidance measures, and then plan and conduct a maneuver if necessary.
From page 70...
... Range safety COLA applies to crewed or crewable space objects, and mission assurance COLA applies to uncrewed objects. COLA is performed by the Launch Services Program (LSP)
From page 71...
... 5 B Beaver, "Launch Collision Avoidance for MASA ELV Missions," presentation to the Committee for the Assessment of NASA's Orbital Debris Programs, January 19, 2011, National Research Council, Washington, D.C.


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