Target NEO: Open Global Community NEO Workshop Report

DRAFT: RELEASED FOR PUBLIC COMMENT≈ 2-5 times more observation time.• Observing from the first or second Sun-Earth libration points is an effective option forDiscovery-class cost.• Observing from a Venus-like heliocentric (≈ 0.7 AU) orbit is the most effective option, but ismore expensive than observing from one of the aforementioned Sun-Earth libration points.• Visible systems are less expensive than thermal infrared (IR), but the latter may enable bettercharacterization of target size.Table 5: NEO Survey Simulation ResultsConcept % Completion Duration Comments80% complete after 1010-year nominal LSST 2-year extension to existingyears; 90% after 12LSSTmission with 2-year extensionoptimization for NEO scienceLSST design would includeyears for all NEOs, diameter> 140 mNEOCam≈ 70% for PHOs, diameter> 140 m4 yearsPHOs are Potentially HazardousObjects, a subset ofthe NEO populationNEST40% for full NEO population,diameter > 140m2 yearsThe L 2 “sweet spot” surveyis more efficient for larger objects(> 140 m), the 0.7 AUopposition survey is more efficientfor smaller (> 50 m) objectsNEO Survey≈ 70% for NEO populationsubset of interestfor HSF (diameter> 60 m); 90% completionfor full NEO population,diameter > 140m, in 7 years2.5 yearsIn 2.5 years this concept willdiscover > 50 objects withdiameter > 60 m; Statisticsonly considered targets withprobable one-way rendezvous∆v < 5 km/s; Additionalcost required to satisfy GeorgeE. Brown goal, primarily inlonger operational costsThe details of the individual survey concept presentations highlight the fact that completion metricsfor the concepts are not identical, and that capabilities and costs have had minimal inter-comparisonto date. It would be prudent to conduct some form of inter-comparison, preferably sanctionedby NASA, of effectiveness and cost among available concepts using a predefined, common set ofassumptions on undiscovered target population parameters and completion metrics to objectivelyassess the range of survey options. It is also essential that the requirements for an HSF targetDRAFT: RELEASED FOR PUBLIC COMMENT 27