A SYSTEMATIC EXAMINATION OF GROUND-BASED AND SPACE-BASED APPROACHES TO OPTICAL DETECTION AND TRACKING OF SATELLITES

Transcription

1 31 st Space Symposium - Technical Track April 14 th, 2015 A SYSTEMATIC EXAMINATION OF GROUND-BASED AND SPACE-BASED APPROACHES TO OPTICAL DETECTION AND TRACKING OF SATELLITES Mark R. Ackermann, Sandia Labs Col Rex R. Kiziah, USAF Academy Peter C. Zimmer, John T. McGraw, David D. Cox, Sandia Labs 1

2 Overview Current systems Characteristics and performance Cost and value Limitations Proposed future architecture Characteristics and performance Cost and value estimation 2

3 Current SSA Systems Ground-Based Radar GEODSS Ground-based Electro-Optical Deep Space Surveillance SST Space Surveillance Telescope SBSS Space Based Space Surveillance Sapphire Canada ORS-5 ( in development) In development GSSAP GEO SSA Program 3

4 Ground-Based Radar Systems Dedicated Space Surveillance Radars Missile Defense Radars Other Contributing Radar Facilities Large, Fixed Sites Expensive Mostly used for LEO Not the subject of this presentation 4

5 GEODSS 9 active telescopes at 3 sites 1-m aperture, 2.15-m focal length 2 deg field of view magnitude sensitivity hours typical latency 30% sky coverage efficiency Observation Latency (hours) GEODSS Coverage and Latency GEO Satellite Orbital Slot (east longitude of satellite) Minimum Average Maximum 2m Aluminum Sphere 5

6 SST (with GEODSS) Single prototype telescope GEODSS + SST Coverage and Latency 3.5-m aperture, 3.5-m focal length 3.5 deg field of view 19.5 visual magnitude sensitivity hours typical latency Observation Latency (hours) Minimum Average Maximum 35% sky coverage efficiency GEO Satellite Orbital Slot (east longitude of satellite) 2m Aluminum Sphere 6

7 Single pathfinder system 30-cm aperture, est. 2x4 deg FOV Sun synchronous orbit Estimated 16.5 mag sensitivity 6-8 hours typical latency 49% sky coverage efficiency 2m Aluminum Sphere SBSS 7

8 Single operational system 15-cm aperture, 1.4 x 1.4 deg FOV Sun synchronous orbit 15 visual magnitude sensitivity 6 hours typical latency 49% sky coverage efficiency 2m Aluminum Sphere Sapphire (Canada) 8

9 Single system in development Estimated 10cm aperture Equatorial Low Earth Orbit Estimated 16.5 mag sensitivity 2-4 hour typical latency ORS-5 / GeOST 2m Aluminum Sphere MIT Lincoln Laboratory SensorSat Concept 9

10 Two on orbit, two ready to launch GSSAP Near GEO orbits - above/below GSSAP? Characterization of GEO objects Few details available Probably not used for search as search of GEO, from GEO is difficult Frames for Each GEO Location Fields Required by Observer Altitude Frames Required per Degree Frames to Scan Entire GEO Belt Location of GEO Satellite (Observer at 0 deg) Altitude of Observer Satellite 10

11 Cost / Performance / Value Cost per Observations Average Maximum Inherent Sensitivity System Observation per Day Availability Latency Latency Sensitivity in Use Single GEODSS $ , GEODSS Network $ , SST $ , SBSS $ , Sapphire 360 Tracks $ , Sapphire 400 Tracks $ , GeOST/ORS 5 $ , Ground-based systems High sensitivity, significant latency, low cost Space-based systems Moderate sensitivity, lower latency, high cost SBSS and Sapphire cost about the same per observation SBSS is about 10X more expensive but 10X more productive ORS/5 is an exceptional value with lower latency 11

12 Problem Areas Sensitivity Ground-based systems perform better Latency Space-based systems perform better Cost/Value Ground-based systems are the cheapest ORS-5 appears to be an exceptional value Survivability and Resiliency Ground-based systems have the edge Looking close to the sun Solar exclusion remains a problem 12

13 Proposed Architecture Ground-based 1-m aperture - 16 telescopes at 8 sites 2-m aperture - 10 telescopes at 5 sites Search and tasked observations Space-based LEO - 2x ORS-5 type systems sweeping search - combines search and tasked obs Low GEO - 3x Sapphire type systems tasked observation to close solar exclusion gap can be used for other tasked observations 13

14 Proposed Ground-Based Network 2 telescopes/site for redundancy Geographically diverse sites 18 th magnitude for 1-m systems 19.5 magnitude for 2-m systems 10-hour typical network latency 57% sky coverage efficiency Observation Latency (hours) Proposed Large + Small Aperture Sites Coverage and Latency GEO Satellite Orbital Slot (east longitude of satellite) Minimum Average Maximum 2m Aluminum Sphere 14

15 Proposed Space-Based LEO 2x systems in equatorial LEO >10-cm aperture, >5 deg FOV Minimum 16.5 mag sensitivity 2-4 hour maximum latency 45 minute typical latency 2m Aluminum Sphere Remaining Problem 2-4 hour solar exclusion 15

16 Proposed Space-Based Low GEO 3x systems in low GEO orbit ~10-20-cm aperture, ~2 deg FOV Minimum 16.5 mag sensitivity Tasked observations to close solar exclusion gap of LEO birds Additional observations possible 2m Aluminum Sphere Remaining Problems None Ground-based for sensitivity LEO for frequency and latency Low GEO to close solar gap 16

17 Performance Summary Ground-based 19.5 visual magnitude search Routine 18 th visual magnitude observations hour max latency, excluding weather Space-based 16.5 visual magnitude search Typical 45 minute latency for observations Tasked observations from low-geo birds to eliminate solar exclusion gap 17

18 Cost of Proposed Architecture Per Unit Total Life Cost Observations Overall Observations Total Cost per Cost Number Cost Expectancy per Year per unit System per unit Observations Observation ($M) of Units ($M) (years) ($M) per Day Availability per Year per Year ($) 1 m Telescope $4 16 $ , ,314,000 21,024,000 1 m Site Development $5 8 $40 1 m Site Ops & Maint $3 8 $24 1 m Telescope Network Amortized Annual Cost $26.60 $ m Telescope $25 10 $ , ,314,000 13,140,000 2 m Site Development $5 5 $25 2 m Site Ops & Maint $3 5 $15 2 m Telescope Network Amortized Annual Cost $21.88 $1.66 GeOST Satellite $100 2 $ , ,653,750 9,307,500 GeOST Launch $50 1 $50 GeOST Operations $5 2 $10 GeOST Constellation Amortized Annual Cost $45.71 $4.91 LGSSA Satellite $100 3 $ , ,551,250 4,653,750 LGSSA Launch $150 1 $150 LGSSA Operations $5 3 $15 LGSSA Constellation Amortized Annual Cost $60.00 $12.89 Initial Cost - $1.08B Annual operations and maintenance - $64M Reuse of GEODSS telescopes can reduce cost Building upon ORS-5 investment can reduce cost 18

19 Summary Current SSA architecture performs well but leaves gaps Gaps in coverage Gaps due to sun Significant latency Proposed architecture Closes all gaps Provides high sensitivity with low latency Affordable and maintainable 19