Space Situational Awareness Forum Following another very successful conference in London in November 2014, Space Situational Awareness 2015 took place in Hyattsville, Maryland in May 2015, with over 60 SSA experts from all over the globe coming together to discuss the most pressing SSA challenges. With increasing dependence on space-based services, the ability to protect space infrastructure has become essential to our society. Any shutdown of even a part of space infrastructures could have significant consequences for the well-functioning of economic activities and our citizens’ safety, and would impair the provision of emergency services. However, space infrastructures are increasingly threatened by the risk of collision between spacecraft and more importantly, between spacecraft and space debris. As a matter of fact, space debris has become the most serious threat to the sustainability of certain space activities. In order to mitigate the risk of collision it is necessary to identify and monitor satellites and space debris, catalogue their positions, and track their movements (trajectory) when a potential risk of collision has been identified, so that satellite operators can be alerted to move their satellites. This activity is known as space surveillance and tracking (SST), and is today mostly based on ground-based sensors such as telescopes and radars. With a focus on solving the political issues but not ignoring the technical, Space Situational Awareness 2015 the leading gathering of dedicated SSA experts from the USA, Europe and beyond, to discuss and debate the business, political and technical challenges that lie ahead. Take a look at our previous Space Situation Awareness event… Who should attend Space Situational Awareness? Space Situational Awareness 2015 is a community of experts from Government, Space Agencies, Satellite/Spacecraft Operators, Space Lawyers, Space Insurance providers and Defense who are looking to understand and predict the physical location of natural and manmade objects in orbit around the Earth, with the objective of avoiding collisions. How can you get involved in Space Situational Awareness? If you feel that you could add to the debate and discussion at Space Situational Awareness, we’d be delighted to hear from you. Please drop us a line on +44(0)7769157787 or email me at adam.plom@coriniumintelligence.com.

1. Operational Flight Dynamics
CNES Toulouse, France
Monique MOURY
Monique.moury@cnes.fr
Hyattsville, SSA 2015
May 12, 2015
CNES role in
French Space Surveillance

2. SUMMARY
SSA 2015 – French SSA2
 MITIGATION
 OPERATIONAL ACTIVITIES
 FOCUS on COLLISION AVOIDANCE

3. SSA 2015- French SSA3
SPACE DEBRIS MITIGATION
French Space Act – JUNE 2008
Objective:
 To authorize and to monitor space activities when
France bears international responsibility
Shall obtain an authorization since DEC 10:
 Any operator launching or controlling a space object from French territory or French
facilities
 Any French operator launching a space object from anywhere
 Any French operator controlling a space object in orbit
Authorizations are granted by the Ministry in charge of space
based on:
 Administrative review of the main characteristics of the company
 Technical review: compliance to the Technical Regulations is checked by CNES on
behalf of the Ministry in charge of space

4. SSA 2015- French SSA4
Objective => protection of:
People
Public health
Properties
Environment on Earth, in Atmosphere or in Orbit
Directly derived from ISO 24113
Compliant with IADC and UN-COPUOS Mitigation Guidelines
A 10-year transition period is foreseen (2010 – 2020)
During this period, some of the requirements may be not fulfilled: the operator
shall demonstrate that best efforts have been accomplished taking in account
the existing design
After the transition period all the requirements will be mandatory
SPACE DEBRIS MITIGATION
Technical Regulations

5. SSA 2015- French SSA5
SPACE SURVEILLANCE
French Organization
Overall responsibility belongs to Defense
CIE: « Commandement Interarmées de l’Espace », Joint Space Command
Air Force
Operational organization is shared between Air Force and CNES
Air Force and Procurement Agency (Defense)
Overall coordination
Operation of the surveillance system (GRAVES)
Operation of the tracking radars
CNES (Research and Defense)
Station keeping of civilian and military satellites
In-orbit collision risk monitoring
Launch collision risk monitoring
Prediction of atmospheric reentries
Flight dynamics support to Air Force
Implementation of French Space Act

6. SSA 2015- French SSA6
OPERATIONAL ACTIVITIES
at CNES
Maintenance of a catalog of orbits of LEO objects using GRAVES data
Altitude < 1000 km
35° < inclination < 145°
Launch collision avoidance
French Space Act requires to take into account human space flights
In-orbit collision avoidance
Service delivered to all satellites controlled at CNES and open to external satellites
Middle Man between Conjunction Message provider and operators
End of life operations
Transition phase for French Space Act requirements
Atmospheric re-entry predictions

7. SSA 2015- French SSA7
OPERATIONAL ACTIVITIES
Launch Collision Avoidance
Input data :
 Launched objects trajectory and dispersion (primary objects)
 manned vehicles trajectory and dispersion (secondary objects)
 Closing window criteria
Output data : Closed instants in the launch window to avoid the collision
risk
Launch window0 3600 s
Closed instants

8. SSA 2015- French SSA8
OPERATIONAL ACTIVITIES
End of life operations
30 years of improvements for end of life operations at CNES
GEOSTATIONARY SATELLITES (since 1975)
Symphonie : get out of the GEO ring
Telecom 1 : complete reorbitation
TDF : fluidic passivation
Telecom 2 : reliability
 REMOTE SENSING SATELLITES (since 1985)
Spot 1, 2 : lowering perigee
Helios 1, SPOT 4 : fluidic passivation
Spot 5, Helios 2, Pleiades : preparing the future
 MINI & MICRO SATELLITES (since 2000)
Essaim : multiple disposal
Demeter : fluidic passivation
Parasol & Jason 1 : get out of operational orbit

9. SSA 2015- French SSA9
OPERATIONAL ACTIVITIES
End of life operations : synthesis
CNES has controlled 39 satellites since 40 years
… and has performed EOL operations for more than half of them
 Many improvements, mainly concerning passivation and automation
Still a lot to be done…
17 : nominal operations,
1 : anticipated operations due to a payload component failure
2 : removed from operational orbit before end of life, to reduce risk towards
other satellites in case of failure : it proved a wise decision for one of them.
2 : emergency situation, successfully handled
2 : lost with no possible disposal operations
Through end of life operations and collision risk management, satellite
operators contribute to prevent significant causes of space debris generation

10. SSA 2015- French SSA10
OPERATIONAL ACTIVITIES
Atmospheric re-entry predictions
Objectives of the monitoring process:
Detect objects representing a risk to French territory
Detect French registered objects representing a risk to foreign
countries
Main steps:
Long term:
» Automatic screening of the catalogue, filtering based on perigee altitude
» Ballistic coefficient estimation and lifetime determination
Middle term (<2 months)
» Orbit monitoring with dedicated CNES tool OPERA
» Object characteristics and, when possible, fragmentation analysis
» Risk computation
Short term (< 3 days)
» Tracking measurements, reentry prediction with uncertainties
» On-ground track
» Risk update

11. SSA 2015- French SSA11
ORERATIONAL ACTIVITIES
In-orbit Collision Avoidance is essential
2007 January 11th : Old Fengyun 1C satellite is deliberately destroyed by a
missile (ASAT)
=> Debris cloud of 2 000 cataloged objects
2009 February 10th : Operational Iridium 33 satellite collides with Cosmos
2251 satellite (not operational since 1995)
=> 2 debris clouds of respectively 600 and 1 600 cataloged objects
Impact of those 2 “events” => ~50% of the detected close approaches in LEO
involve a debris from one of those 3 clouds
The Iridium – Cosmos collision
could have been avoided...

12. SSA 2015- French SSA12
Conjunction Assessment
Conjunction Messages: a real satellite protection …
Since 2009, JSpOC distributes conjunction messages
to all satellite owners/operators (O/O)
As a positive
reaction to this
situation …
O/O O/O O/O O/O O/O O/O …
JSpOC

13. SSA 2015- French SSA13
Orbit Determination
characteristics
Conjunction message, an information message
=
Conjunction Summary Message since July 2010
Position/Velocity
Position dispersion
Time of the Closest Approach
Conjunction Assessment
CSM: what is it ?

14. SSA 2015- French SSA14
Conjunction message, an information message
=
Conjunction Data Message since April 2014
Conjunction Assessment
CDM: what is it ?

15. SSA 2015- French SSA15
O/O must put in place an
Acquisition, Evaluation, Alert and
Recommendation process:
 Automatic acquisition : 24/7
Risk Evaluation:
Alert FD team of the Control Center
Recommendation for avoidance
Only very few CMs lead to an
avoidance action, but those messages
(HIE) mustn’t be missed.
 This process is not so easy …
Middle Man Concept
Conjunction Assessment is a two-step process
Space Surveillance Network
JSpOC
Precise complete catalog
Screening – Information Messages generation
Avoid… the avoidable

16. SSA 2015- French SSA16
O/O
JSpOC
Ephem.
CAESAR
Conjunction Analysis and Evaluation Service : Alerts and Recommendations
Flight Dynamics
System
(SPADOC)
Flight Dynamics
System (X)
ΔV
ΔV
CASR
JWD = CAESAR
WARN ALERT
Flight Dynamics
System (JOCC)
On Call analyst
On Call analyst
JWD = Analyst
On Call O/O
JWD = O/O
CDMs-JSPOC
CDMs-ALM
CDMs-GNOSE
GO
TC
ΔV
ΔV
Screening
additional
measurement (when
available)
Almanac
Improved OD
ΔV

17. SSA 2015- French SSA17
Java for Assessment of Conjunctions
JAC contributes to the collaborative work environment for CAESAR.
 JAC addresses the needs of teams responsible for managing in-orbit collision
risks for one or many satellites.
 JAC helps to retrieve and analyze close approach alerts by providing a synthetic
vision of each close approach described by CDMs. It helps the user to evaluate
the level of risk according to its own criteria and to take and validate a decision.
 JAC is a modular software :
 JAC Basic Module: to be aware of the situation.
 JAC Expert Module: to take and validate a decision.
JAC is distributed by CNES after signature of a license

18. SSA 2015- French SSA18
In-orbit Collision Avoidance
Synthesis
 JSpOC’s CDMs combined with O/O data thanks to Middle Man entities are the best available
data to avoid collision in space:
All the O/O should take into account JSpOC’s CDMs: but it is not an easy process;
The Middle Men can help O/O and improve the reliability of the process;
Reliability of the process protects space environment for the benefit of all, but does not guarantee
individual satellite protection => public role (for ex European Commission decision for EU service)
CAESAR (the French Middle Man) relies on JAC software for its essential collaborative work
environment.
 Some of the difficulties of CA:
 Take into account maneuvers => LARGE CRITERIA
 Deal with huge amount of CDMs => BURDEN-SHARING BETWEEN JSpOC & Middle Man
 Risk level sensitivity to small variations of input data => EXPANDED PoC
 JAC, distributed by CNES in 2 levels, can help:
Basic (“to be aware of the situation”) for free;
Expert (“to take and validate a decision”) for an annual fee.
https://spod.cnes.fr
jac@cnes.fr