Suggested Searches

CARA Research and Development

Conjunction Risk Assessment

Conjunction Risk Assessment

Overview of R&D efforts

CARA directs R&D efforts in all CA-related areas, but the principal focus is on collision risk assessment (RA), meaning determination of which events are truly risky and thus require mitigation. Recently in this area, CARA has established a number of important findings:

  • Two Line Elements (TLEs) are not sufficient for CA mitigation decisions (CATAC statement, 2016)
  • Maximum Probability of Collision (Pc) not sufficient as a stand-alone RA parameter (Hejduk, 2016)
  • Calculated Pc is a durable RA parameter (Hejduk and Snow, 2019)
  • Determined tests for proper use of 2-D Pc calculation approach (Hall, 2019a)
  • Developed fast, appropriate Monte Carlo techniques for situations in which 2-D Pc calculation is not reliable (Hall et al., 2018)
  • Evaluated approaches for eliminating correlated error between primary and secondary object covariances (Casali, 2018)
  • Developed approaches to establishing Pc confidence intervals through covariance error histories (Hejduk and Johnson 2016; Elrod 2019)
    • Established collision consequence as an important and useful component of CA risk (Hejduk et al. 2017, Lechtenberg 2019)
  • Other research areas are adjusted to fluctuate with this rapidly evolving field of study, but include such topics as:
    • Orbit Determination (OD) product adequacy (e.g., Degenerate and unrealistic covariances; commercial data)
    • CA screenings (e.g., Proper screening volume sizing; screening filtering techniques; autonomous spacecraft CA)
    • Pc calculation (e.g., 2-D Pc Limitations; non-Gaussian error volumes; Monte Carlo techniques)
    • Special studies (e.g., Effects of SF radar, mega-constellation deployments)

Archived Technical Papers

The CARA program has published numerous conference papers. These technical papers summarize the analysis and research and development work done by the CARA team in the technical subjects surrounding CA and operations. Access to the archived technical papers, organized by year of publication, is found here: .