Commercial Space Operations STM Conference January 2018 Responsible Behavior for Constellations and Clusters   Darren McKnight Integrity Applications, Inc., USA, dmcknight@integrity-apps.com Jonathan Rosenblatt Spire Global, USA, jonathan.rosenblatt@spire.com Darren Garber NXTRAC, USA, darren.garber@nxtrac.com Commercial Space Operations STM Conference January 2018

STM as part of Space Operations Assurance… Input to NSpC and AIAA on STM

Examine Three Constellations Iridium 72 560kg spacecraft @ ~776km OneWeb 720 150kg spacecraft @1125- 1275km Spire 175 cubesats @ 400-600km

Constellation Specifications   Number of Objects Ave cross-section (m2) / mass (kg) Total Area (m2) Total Mass (kg) Altitude Span (km) Annual Inter-Cluster Collision Rate Cataloged (LNT) Fragments from Collision Event Constellation Iridium 72 4/560 300 ~40,000 6 N/A ~1,600 (~16,000) OneWeb 720 3.5/150 2,500 ~108,000 150 ~450 (~4,500) Spire 175 0.09/5 16 875 200 ~14 (~140)

Perspective: Clusters vs Constellations   Number of Objects Ave cross-section (m2) / mass (kg) Total Area (m2) Total Mass (kg) Altitude Span (km) Annual Inter-Cluster Collision Rate Cataloged (LNT) Fragments from Collision Event Cluster C775 89 (45RB & 44PL) RB: 14/1434 PL: 6/800 900 ~100,000 60 ~1/500 ~4,500 (~45,000) C850 36 (18RB & 18PL) RB: 44/8300 PL: 8/3250 936 ~208,000 45 ~1/1200 ~16,000 (~160,000) C975 286 (144RB & 142PL) 3,000 ~560,000 85 ~1/120 Constellation Iridium 72 4/560 300 ~40,000 6 N/A ~1,600 (~16,000) OneWeb 720 3.5/150 2,500 ~108,000 150 ~450 (~4,500) Spire 175 0.09/5 16 875 200 ~14 (~140)

Perspective: Constellations Around Clusters

Variable Risk Primary risk to each constellation is different OneWeb Collision risk during transit is greater by 2x per unit time than operations Non-adherence risk during retirement may be minimal (time will tell) Iridium Collision risk from background population and fratricide are significant Located on edge of C775 and just below C850 Spire Lower functionality (elegant simplicity) creates lower risk profile across the board Picking three constellations belies the diversity and heterogeneity of likely range of constellations and satellites to be deployed

A Little Reality… Misconception 1: All close approaches are the same. Misconception 2: Information on close approaches is fairly accurate. Misconception 3: Maneuvers can be executed perfectly and in a timely fashion and, thereby, reduce the risk of collision.

Non-Adherence Risk Three forms (i) permitted non-adherence, (ii) technical non-adherence, and (iii) willful non-adherence. Compliance actually improves when considering CubeSats – despite rhetoric

Get Off The Stage… Constellation management and space flight safety requires as much “soft science” than “hard science” Communicate  Cooperate  Collaborate  Success Existing abandoned hardware in LEO may pose a greater short-term and long-term collision risk than constellations Do not focus on issues that you feel that you have the greatest control Focus on issues that make the greatest difference… Debris mitigation and debris remediation must be taken seriously by all operators if LEO is to remain a safe place to operate Do not let “infrastructure” crumble under “robustly managed space traffic”