The document proposes using modified upper rocket stages to perform active debris removal missions in low Earth orbit. Upper stages would be modified to include subsystems for rendezvousing with and capturing space debris objects. This could allow one large debris object to be removed per launch, helping stabilize the debris environment, at a potentially lower cost than current active debris removal concepts. A case study found that various medium and heavy launch vehicles could deliver the necessary payload to capture debris in high-inclination low Earth orbits, with some requiring electric deorbit tugs. Removing space debris in this way could support the United Nations' goals for space sustainability.

1. ACTIVE DEBRIS REMOVAL USING
MODIFIED UPPER STAGES
IN SUPPORT OF THE UNITED NATIONS
PROGRAMME ON SPACE APPLICATIONS
Matteo Emanuelli
S. Ali Nasseri
Siddharth Raval
Andrea Turconi
SGAC Space Safety and Sustainability Project Group

2. SGAC: BEYOND A NETWORK
• ADR: Where?
• System concept
• System components
• Feasibility study
• Conclusion
• Future work
Outline
5/23/2014
2IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

3. SGAC: BEYOND A NETWORK
• Space debris density could reach a critical level.
• Continuous increase in the number of debris
objects, primarily driven by debris-debris collision
activity.
• Mitigation guidelines don’t apply to existing debris.
• Existing debris risk is higher in low-Earth orbit
(LEO) due to a combination of high debris
concentration, large number of crossings and high
relative velocities.
• NASA studies: To stabilize the LEO debris
environment, 5-15 large objects have to be
removed per year
Space Debris Situation
5/23/2014
3IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

4. SGAC: BEYOND A NETWORK
• The critical region of interest for a future
Active Debris Removal (ADR) missions
• Altitude between 800km and 1000km, with an
inclination ranging from 60° to 110°
• The larger space debris were identified as
suitable ADR targets
• Higher total mass
• Higher risk of cascade collisions
• Easy to track
• Well defined in size, mass and shape
• Focusing on rocket bodies
Suitable ADR targets
5/23/2014
4IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

5. SGAC: BEYOND A NETWORK
• In the selected region of interest, 141 rocket
bodies are being tracked
• The majority of which are at an inclination of
around 80°.
Suitable ADR targets
5/23/2014
5IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
157
33
14
19
11
10
8 27
Komos
Soyuz
Tsyklon-3
Zenit
Dnepr
Thor Burner 2A
Scout
Other
5/23/2014
Kosmos
ADR USING MODIFIED UPPER STAGES

6. SGAC: BEYOND A NETWORK
• Kosmos-3 M debris used as case study. (SL-8 R/B
32053)
• Orbital altitude of 959 km, inclination of about 83° and
mass of 1435 kg
• Does not decay automatically within the 25 years
guideline  ADR mission necessary for timely
disposal
• Many studies on ADR conducted by various entities
currently focus on the Kosmos 3M
Target Debris for Test Studies
5/23/2014
6IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

7. SGAC: BEYOND A NETWORK
Target Debris for Test Studies
5/23/2014
7IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

8. SGAC: BEYOND A NETWORK
• An Active Debris Removal System (ADRS) is capable
of approaching the debris object through a close-range
rendezvous, establishing physical contact, stabilizing
its attitude and finally de-orbiting the debris object.
• Frequent missions
• Cost-effective
• Initial solution: A piggyback payload with two
propulsion systems
• However, upper stages are used during the launch
and they do have many subsystems which we need
• Why not use them?
System Concept
5/23/2014
8IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

9. SGAC: BEYOND A NETWORK
• Modify launch vehicle upper stage
• All de-orbiting subsystems integrated onto the
upper stage (as packages) and work in concert
with upper stage subsystems during mission.
• Merits:
• No new debris due to space launch. (average 70
launches per year)
• One large space debris can be de-orbited per launch,
stabilizing the debris environment
• Reduced cost and complexity by using upper stage
subsystems
System Concept
5/23/2014
9IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

10. SGAC: BEYOND A NETWORK
Concept of Operation
5/23/2014
10IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
Phase 5
Reduce inclination using chemical propulsion Deploy EDT Reduce orbital altitude to 200 km
Phase 4
Estimate motion of debris Grab object Control attitude
Phase 3
Approach debris object Identify object
Phase 2
Deliver primary payload Initiate debris removal mission
Phase 1
Launch
5/23/2014ADR USING MODIFIED UPPER STAGES

11. SGAC: BEYOND A NETWORK
• Case study performed using these estimations
System Components
5/23/2014
11IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
Subsystems Mass (kg)
EDT mass [8] 80
Grabbing Mechanism 100
Motion Estimation 5
Power System 5
Misc. 10
Total 200
5/23/2014ADR USING MODIFIED UPPER STAGES

12. SGAC: BEYOND A NETWORK
System Components: Grabbing Mechanism
5/23/2014
12IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014
Method Pros Cons
Docking through propulsive nozzle
Application for a wide range
of rocket bodies.
Usable also if the target is
spinning.
Very precise close approach
required.
Not applicable to tumbling
targets.
Harpoon
Projectile designed to anchor
safely into a wide range of
materials.
Possible creation of new
debris during the impact,
risk of explosion, attitude
modification.
Net Indifferent to target attitude.
Net’s material to be flexible
and resistant.
Net deployment required
specialized manoeuvres.
Robotic arm
Applicable to different type
of space debris.
Provides the most control on
the space debris.
De-tumbling procedure
required.
Accurate pre-inspection of
the debris to chose the
grabbing point.
Most complex.
ADR USING MODIFIED UPPER STAGES

13. SGAC: BEYOND A NETWORK
• Analyzed as a possible option
• Propellant-less and fully reusable
• Low thrust
• Collision avoidance is critical due to their length
• Current model (Bombardelli, 2010)
System Components: EDT
13IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

14. SGAC: BEYOND A NETWORK
• Criteria
• Reach the target orbit with enough payload.
• Restartable due to the number of maneuvers required.
• Enough propellant for the mission.
• Following launchers analyzed
• Soyuz 2 with the Fregat upper stage launched from the
Plesetsk and Kourou spaceports.
• Proton M with the Breeze-M upper stage launched from the
Plesetsk spaceport.
• DELTA 4M launched from Vandenberg air force base.
• Atlas 5 401 launched from Vandenberg air force base.
• Vega launched from Kourou spaceport.
• Small, medium and heavy launch systems are all
represented.
Mission Analysis: Launch
5/23/2014
14IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

15. SGAC: BEYOND A NETWORK
• Simulation in AGI STK
• Several manoeuvres, during which the primary payload is
released, the upper stage reaches the target orbit at an altitude of
920 km and an inclination of 83°
• The upper stage should approach and grab the debris (not
modelled)
• Reduce inclination, if necessary
Mission Analysis: ΔV Required
5/23/2014
15IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014
Manoeuvre Δ V (km/s)
Launch Vehicle Soyuz 2 Plesetsk Soyuz 2 Kourou Proton M Vega Delta 4 ATLAS 5
Altitude increase 0.105 0.164 0.105 0.181 0.177 0.186
Hohmann transfer 0.056 0.143 0.056 0.196 0.046 0.046
Combined change 0.849 2.200 0.849 2.139 0.331 0.331
Inclination change 1 (83 to 74 deg) 1.710 1.101 1.71 1.101 1.100 1.100
Inclination change 2 (74 to 66 deg) 1.101 0.600 1.101 0.501 0.501 0.501
Inclination change 3 (66 to 53 deg) 1.809 1.908 1.809 - 2.093 2.107
Inclination change 4 (53 to 43 deg) 1.402 1.300 1.402 - 1.204 1.221
Inclination change 5 (43 to 29 deg) 1.576 1.900 1.576 - 1.901 1.901
Inclination change 6 (29 to 18 deg) 2.808 1.700 2.808 - 1.829 1.731
ADR USING MODIFIED UPPER STAGES

16. SGAC: BEYOND A NETWORK
Mission Analysis: Propellant Available
5/23/2014
16IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014
ATLAS V DELTA IV M
ADR USING MODIFIED UPPER STAGES

17. SGAC: BEYOND A NETWORK
Mission Analysis: Propellant Available
5/23/2014
17IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
Soyuz from Plesetsk Soyuz from Korou
ADR USING MODIFIED UPPER STAGES

18. SGAC: BEYOND A NETWORK
Mission Analysis: Propellant Available
5/23/2014
18IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
Proton M Vega
ADR USING MODIFIED UPPER STAGES

19. SGAC: BEYOND A NETWORK
• At least a velocity increment of 0.5 km/s is needed
• Propellant used in grabbing manoeuvre not included
Mission Analysis: Direct De-orbit
5/23/2014
19IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014
Inclination
ΔV (km/s)
ATLAS V DELTA IV M Proton
Soyuz
from Kourou
Soyuz
from Plesetsk
83 7.618 7.672 4.043 0 1.820
74 6.518 6.572 2.333 0 0.110
66 6.016 6.071 1.232 0 0
53 3.909 3.978 0 0 0
43 2.689 2.774 0 0 0
29 0.787 0.873 0 0 0
18 0 0 0 0 0
ADR USING MODIFIED UPPER STAGES

20. SGAC: BEYOND A NETWORK
Mission Analysis: Time to De-orbit with EDT
5/23/2014
20IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014
Reduce
altitude to
200 km
ADR USING MODIFIED UPPER STAGES

21. SGAC: BEYOND A NETWORK
• The launch cost for the system ranges from $390
k to $1689 k, averaging at $848k.
• As the upper stage removes itself and a rocket
body, it seems reasonable that the removal cost
per kg of debris will be lower than costs per kg
using this concept, which is important in choosing
ADR methods [9].
• May be implemented as a service provided by the
launch service provider.
Costs and Implementation
5/23/2014
21IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
ADR USING MODIFIED UPPER STAGES

22. SGAC: BEYOND A NETWORK
• The proposed solution can remove large space
debris from high altitude high inclination LEO
orbits in a timely manner using medium to heavy
launchers.
• Heavy launchers could carry out the mission
without an EDT or on several objects, but medium
upper stages require an EDT system.
Conclusions
22IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

23. SGAC: BEYOND A NETWORK
• Finalize choice of grabbing mechanism
• Model the close approach, grabbing and
stabilization of the space debris
• Re-entry safety analysis
• Cost estimation
• Simulate mission for more launchers and several
target debris for comparison
Future Work
23IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
5/23/2014ADR USING MODIFIED UPPER STAGES

24. SGAC: BEYOND A NETWORK
Acknowledgement
24IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
1. Analytical Graphics, Inc. (AGI)
2. International Association for the Advancement of
Space Safety
5/23/2014ADR USING MODIFIED UPPER STAGES

25. SGAC: BEYOND A NETWORK
Space Safety and Sustainability Project Group
Sustaining space activities for future generations
Email: ali.nasseri@spacegeneration.org
Website: www.spacegeneration.org/sss
Thank you!
5/23/2014
25IN SUPPORT OF THE UNITED NATIONS PROGRAMME ON SPACE APPLICATIONS
ADR USING MODIFIED UPPER STAGES