Operational Collision Avoidance by ESA's Space … UNCLASSIFIED - For Official Use Klaus Merz |...
Transcript of Operational Collision Avoidance by ESA's Space … UNCLASSIFIED - For Official Use Klaus Merz |...
ESA UNCLASSIFIED - For Official Use
Operational Collision Avoidance by ESA's Space Debris Office
Klaus Merz
03/11/2016
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 2
Outline
• Introduction • Space Debris Office • Collision avoidance at ESA
• Reaction threshold with CDMs • ESA’s DRAMA/ARES tool
• Current process • Drivers • Back-end database and tools • Front-end • Process control
• Statistics • Summary
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 3
ESA’s Space Debris Office
OPS-GR Space Debris System SCARAB
DISCOS Database 50 users
Space Debris Tools 400 users
Collision Avoidance System Debris Evolution Model
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 4
Covered missions Since 2002: Operational collision avoidance activities at SDO for ESA missions in LEO • Conjunction event detection • Collision risk assessment • Chaser orbit determination and orbit and
covariance propagation Current focus on ESA’s/Copernicus EO (LEO) Third party customer • Planet (RapidEye: constellation of 5
satellites) • EUMETSAT (Sentinel 3) Upcoming missions (selection) Sentinels, Earth Explorers, LEOPs, CHEOPS
Satellite Comment
ERS-2 Manoeuvre/TLE screening, CDM processing including de-orbiting phase in 2011
Envisat Manoeuvre/TLE screening, CDM processing until failure in 2012
Cryosat-2 Manoeuvre/MC screening, CDM processing since launch
Swarm-A, B, C Manoeuvre/MC screening, CDM processing since launch
Sentinel-1A/B, 2A, 3A Manoeuvre/MC screening, CDM processing since launch
Proba 1, V Only review of JSpOC alerts, automated CDM processing
Proba 2 MC screening, CDM processing, support of thruster experiments
RapidEye 1-5 Manoeuvre/MC screening, CDM processing, since 2012
Cluster-II 1-4 Manoeuvre/TLE/MC screening, during GEO passages
XMM Manoeuvre/TLE screening, during GEO passages and LEO passages
Galileo/Giove/MetOp-A/B/MSG-3/4 JSpOC alerts received for a limited period of time (LEOP)
Artemis CSM/JSpOC alert received until operations handed over, now case-by-case support
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 5
ESA’s MASTER-2009: Spatial Density > 10cm
Swarm A,C
Swarm B
Sentinel-1A/B Cryosat-2
Sentinel-2A
RapidEye 1-5
Sentinel-3A
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 6
Outline
• Introduction • Space Debris Office • Collision avoidance at ESA
• Reaction threshold with CDMs • ESA’s DRAMA/ARES tool
• Current process • Drivers • Back-end database and tools • Front-end • Process control
• Statistics • Summary
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 7
Recommended reaction threshold
What is a good reaction threshold? • Requires a management decision • Trade ignored/accepted risk vs. risk reduction • Estimate cost i.e. manoeuvre frequency for the selected reaction threshold
• Depends on orbit uncertainties of the secondary (chasing) objects • TLE vs CDM: collision avoidance manoeuvres reduced by roughly one
order of magnitude for same threshold • Uncertainties of TLEs for collision risk assessment? See detailed studies • CDM/CSM: improvement of uncertainties by one order of magnitude
• Typical managerial target function: • avoid 90% of the accumulated collision probability (CDM era) • avoid 50% of the accumulated collision probability (TLE era)
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 8
ESA’s DRAMA SW Tool Suite “The aim of DRAMA is to support the objectives of the ESA Space Debris Mitigation Requirements by enabling satellite programs in Europe to assess their compliance with the recommendations contained in that document.”
ARES Assessment of Risk Event Statistics: Analyze requirements for collision avoidance manoeuvres expected for a mission.
MIDAS MASTER (-based) Impact Flux and Damage Assessment Software: Modeling of the collision flux and damage statistics for a mission.
OSCAR Orbital Spacecraft Active Removal: Analyze disposal manoeuvres of spacecraft and compliance with ESA’s mitigation requirements.
CROC Compute projected cross-sectional areas of complex bodies
SARA Spacecraft Entry Survival Analysis Module (SESAM): Modeling the re-entry of a spacecraft. Spacecraft Entry Risk Analysis Module (SERAM): Assessing the on-ground risks of objects surviving re-entry.
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 9
DRAMA/ARES
• Providing statistics related to the collision risks for a mission.
• Determines required CAM fuel mass
• Flux based on MASTER-2009
• Results statistical, based on “average encounters”
• Four functionalities:
• Annual collision probability
• Manoeuvre rate, false alarm rates, risks as a function of accepted collision probability level (ACPL)
• Estimate DV to perform CAMs
• Estimate propellant mass for CAMs
Risk reduction: risk actually removed by manoeuvres Residual risk: risk not intended to be reduced (although it would be possible) Remaining risk: risk which cannot be reduced (caused by undetectable objects) + Residual risk
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 10
ARES example
Envisat-like: 780 km altitude polar, 26 m diameter, chaser limit size 10 cm
Catalogue covariance as per CDM Catalogue covariance as per TLE
Higher risk reduction for same ACPL, in particular for 10-4 almost all risk reduced with CDM accuracy, only half the risk with TLE accuracy
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 11
ARES example - manoeuvres
With TLE accuracies: Much higher number of manoeuvres for same ACPL. Risk reduction 50 % at ACPL of 10-4 at cost of approx. 30 manoeuvres!
Catalogue covariance as per CDM Catalogue covariance as per TLE
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 12
Outline
• Introduction • Space Debris Office • Collision avoidance at ESA
• Reaction threshold with CDMs • ESA’s DRAMA/ARES tool
• Current process • Drivers • Back-end database and tools • Front-end • Process control
• Statistics • Summary
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 13
Operational process - drivers
• CDM information for enlarged screening volumes used as baseline • CDM superior to TLE in accuracy and its knowledge
• Automation of CDM processing due large number of CDMs • Including combined/mixed processing using OO information on target and
JSpOC CDM information on chaser (“MiniCatalog”) • Interface to mission control teams streamlined
• Simplifying data provision and interpretation • Providing concise status display to missions
• Internal coordination within collision avoidance support team simplified with help of a conjunction management tool and manoeuvre monitoring system
• Overall driver: support of task automation thereby reducing process risk
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 14
Database of conjunction events
• Central DB for all automatic and manual processing • Grouping by conjunction event ID: unambiguous description by 2 conjunction partners and
TCA • DB content
• CDM data obtained from JSpOC • Augmented by collision risk and other analyses results/sources • Automated insertion and standard analysis
• “Mini-catalogue” screening results against operational ephemeris/cov. • Same data model as CDM (but different originator) • Automated insertion and standard analysis after each update
• Scenario results for collision avoidance • Same data model as CDM (but different originator, multiple eph.)
• Fed manually by analyst
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 15
automated Target
properties
Flight Dynamics
Debris Analyst
Flight Dynamics SC Operators
CRASS/ CORAM
Solar & geomag. activity data
Chaser orbits and covariance data
ODIN
Orbit tracks
JSpOC Automated retrieval CDMs
Target orbits Covariance
Event characteristics
„Minicat“ pool of chaser ephemeris and covariances
Propagation
Target properties
DISCOS
SCARF/PREEMPT Visualisation
Extended operational collision avoidance process at ESA/ESOC with CDMs
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 16
Risk assessment and avoidance manoeuvres
Collection of Algorithms for collision risk assessment among two objects (CORCOS): • Alfriend Akella • Maximum Probability • Covariance scaling • Algorithms for low delta-v approaches • Non-spherical objects • Monte-Carlo
Support of manoeuvre planning (CAMOS) • Minimising risk or maximising (radial)
separation at TCA • Varying size, direction, epoch • Constraints (bounds, fixed, free) • Parametric or evaluation mode • Trajectory parameters (latitude/longitude,
eclipses, SAA crossing)
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 17
SCARF - Spacecraft Conjunction Assessment and Risk Frontend Web-frontend to CDM/Event database • Mission
“dashboard” view • Event view • Analyst view • Link to 3D
visualisation
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 18
Manoeuvre Monitoring System
• Process control and tasks allocation system • “ticket” per manoeuvre • Assignee management • Status transitions
• Views: • Status filter • Gantt • Calendar • Wiki (procedures)
• Redmine-based
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 19
Outline
• Introduction • Space Debris Office • Collision avoidance at ESA
• Reaction threshold with CDMs • ESA’s DRAMA/ARES tool
• Current process • Drivers • Back-end database and tools • Front-end • Process control
• Statistics • Summary
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 20
Event Statistics from ESA/ESOC (end 2015)
0
10
20
30
40
50
60
70
80
90
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
CRASS warnings JSPOC warnings Tracking campaigns Avoidance Manoeuvres
ESA Space Debris Office
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 21
O/O vs. TLE orbits (in 10 km x 25 km x 10 km ellipsoid) CDM events as per screening volume
0%
20%
40%
60%
80%
100%
S/C R/B MRO
Fragments FengYun 1C Cosmos/Iridium
0
2000
4000
6000
8000
10000
12000
cosmos2251 iridium33 fengyun1c other
Classes of close approach objects – sampling of the LEO environment
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 22
Fly-by Statistics
0
5
10
15
20
25
30
35
40
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8Miss distance [km]
Frequency of conjunction events by miss distance CRY-2 (2010-013A)
SW-A (2013-067B)
SW-B (2013-067A)
SW-C (2013-067C)
S-1A (2014-016A)
S-2A (2015-028A)
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 23
Frequency of events per risk level
• Highest risk of all CDMs for a given conjunction
• CDMs received from JSpOC (SP vs SP)
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 24
Latency of CDMs
0
5
10
15
20
25
30
35
40
45
50
0 1 2 3 4 5 6 7
[%]
of a
ll ev
ents
Time between first notification and TCA [d]
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 25
Summary • For more than a decade, ESA has a well-established collision avoidance process
• supporting several own and third party missions • ESA’s system and processes look back on a history of highly dynamic adaptation and innovation.
• Excellent collaboration with USSTRATCOM/JSpOC for years! • DRAMA/ARES ready to support mission / operations concept design phase
(https://sdup.esoc.esa.int) • to estimate collision avoidance needs • Use of CDMs as baseline, allowing lower manoeuvre thresholds, but reducing more overall risk than TLE-based
• Operational toolchain evolved significantly to meet growing needs • Approach centred around database of processed CDMs • “minicat”: flexibility, manoeuvre support with short turn-around times for small delta-v (changes) • Automation of CDM mixed CDM/OO processing (needed due to large number of CDMs) • Web-based interfaces for visualisation and coordination (Space Debris experts and FCT/FDT) • Support tools for specific analysis in back-end
• Improved/expanded risk assessment and avoidance manoeuvre planning • Maintain capability to acquire dedicated tracking
• The presented statistics show that the challenges differ over time and for each orbit type
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 26
Questions?
Thank you for your attention!
Abstracts due 22 Nov 2016
https://conference.sdo.esoc.esa.int/
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 27
Extra slides
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 28
Method Threshold to trigger…
Threshold to trigger manoeuvre
Manoeuvre screening Manoeuvre target Time
TLE screening Meeting: Pc > 10-4
D < 300m
Pc > 1-5*10-3
D < 300m TLE screening None 2003-2011
TLE screening + Tracking
Tracking: Pc > 10-4
D < 300m
Distance based (no mano for low risks)
Screen against precise chaser orbit only
None 2006-2011
JSpOC alerts Meeting: alert
Dradial < 3σchaser+3σtarget+cross-section radii
Request to JSpOC for a new alert message
Dradial > 3σchaser+3σtarget+cross-section radii
2010
CSM/CDM Meeting: Pc > 10-4
Pc > 10-4 Request to JSpOC (Pc < 10-6)
2010-2013
CSM/CDM full volume
Meeting: Pc > 10-4
Pc > 10-4 MINICAT and JSpOC (Pc < 10-6)
2013-
Typical thresholds used to trigger avoidance manoeuvres
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 29
SCARF - Dashboard Dashboard view - presentation of most relevant information for a mission: • Highest probability, smallest miss
distance, smallest radial miss distance; also “top 10” list for these criteria
• Highlighting escalated events, i.e. those for which control teams have been informed
• Some charts: Evolution of maximum collision probability, cumulative risk, number of events (total and above threshold), scatter plots showing collision probability and miss distance of upcoming events over time
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 30
SCARF - Event view Event view - presentation of all information related to a single event: • Reached via clicking on event in
dashboard view or event ID search • Interface to manage the status
(ownership, escalation level) • Lists core event data (objects,
TCA, CDMs) • Trend plots for relevant data • or all related CDM data in tabular
view
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 31
SCARF - Event view Event view - presentation of all information related to a single event: • Objects Info • Single CDMs can be displayed,
commented, get status changed • Log sub-view • E-mails can be triggered via templates • Single CDMs can be displayed,
commented, get status changed
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 32
SCARF – Analyst view
Analyst view - presentation of CDM information as one-liners • Selection of CDMs via filtering, options include
• Event, target, chaser, TCA interval, owner, assignee, collision risk, miss distance (components), uncertainties, originator, relative spread, approach azimuth/elevation, etc.
• Sorting data by any column • Optional grouping of CDMs by event
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 33
Conjunction visualisation
• 3D dynamic visualisation of close approaches: Earth, trajectories, covariance ellipsoids, CDM data, …
• Interactive control of camera position, view angle, time, zoom, …
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 34
Conjunction visualisation
• Zooming in showing conjunction details and object positions (boxes)
ESA UNCLASSIFIED - For Official Use Klaus Merz | 03/11/2016 | Slide 35
Conjunction visualisation
• Zooming in showing conjunction details and object positions and covariance ellipsoids (here 3 sigma)