1. Commercial Space Operations STM Conference January 2018
Responsible Behavior for Constellations and Clusters   Darren McKnight Integrity Applications, Inc., USA, Jonathan Rosenblatt Spire Global, USA, Darren Garber NXTRAC, USA,
Commercial Space Operations STM Conference
January 2018

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

3. Examine Three Constellations
Iridium
72 560kg spacecraft @ ~776km
OneWeb
kg 1275km
Spire km

4. 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)

5. 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)

6. Perspective: Constellations Around Clusters

7. 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

8. 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.

9. 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

10. 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”