1. RUAG Reusable Payload Fairing
32nd National Space Symposium
Colorado Springs, US
April 11-14, 2016
Andreas Wiesendanger
Program Manager
RUAG Space 1
│RUAG Space

2. Overview Introduction PLF Analyses PLF Recovery System Concept Outlook
CFD Simulation
Fluid-Structure Interaction
PLF Recovery System Concept
Mid-Air Recovery
In-Water Recovery
Outlook
Build-up of demonstrator
In-flight demonstration 2
│RUAG Space

3. Reusable Payload Fairing
Introduction
Increased competitive environment is driving to drastic cost reductions.
Recovery and reusability of PLF could support reduction of recurring costs.
PLF retrieval system is also a pathfinder for extended recovery and reusability of high value LV elements.
Advantages of Parachute Recovery System: relatively low-mass and passive operation.
Demonstrate feasibility
In-flight demonstration 3
│RUAG Space

4. Reusable Payload Fairing
Introduction
Recovery system compartment
Drogue / Stabilizing
parachute
Recovery system
Mid-Air Recovery
In-Water Recovery
Payload Fairing
Approx 1 ton per half-shell
Flexible structure
Composite sandwich
Extraction device / Mortar system
Main parachute
Floating device compartment 4
│RUAG Space

5. Reusable Payload Fairing Introduction
Separation altitude: ~110km
Separation velocity: ’300m/s
Flight path angle: ˚ (horizontal)
Total PLF mass: ~2.0t
Main topics investigated
Aerodynamic stability of the PLF during re-entry (CFD analyses)
Re-entry loads on the PLF and structural integrity
Recovery concept / systems
Mid-air recovery
In water recovery
300-1’000 km
Stabilized fall
Thermal loads
Low-speed fall
Recovery:
MAR
On-Water
Ballistic phase
PLF flight trajectory
│RUAG Space

6. PLF Analyses Results CFD Simulation
Trajectory Simulation and CFD Analyses
Fully coupled with CFD solver to take into account aerodynamic damping.
Covering sub- and supersonic flight conditions and different PLF attitudes.
Subsonic regime
Non-streamlined geometrical shapes in low-speed regime present a special challenge for CFD numerical simulation.
‘Lattice Boltzmann Method’ (LBM) selected as best approach in terms of CFD simulation for low-speed.
Supersonic regime
Supersonic load cases calculated with normal ‘Reynolds Averaged Navier-Stokes’ (RANS) method.
Normal ‘Reynolds Averaged Navier-Stokes’ (RANS) calculations tend to be unreliable if large areas of detached flow exist. This also holds true for unsteady RANS using standard turbulence models. Alternatively, unsteady RANS together with Large Eddy Simulation (LES) can provide good results, but are computationally expensive.
Therefore, for low-speed the best approach in terms of CFD simulation is based on ‘Lattice Boltzmann Method’ (LBM). 6
│RUAG Space

7. PLF Analyses Results CFD Simulation: Sensitivity study
Ideal PLF (homogeneous mass distribution) is aerodynamically stable whereas a Real PLF is not
Ideal PLF
Real PLF 7
│RUAG Space

8. PLF Analyses Results CFD Simulation: Supersonic Case 3 Case 2 Case 1
Reynolds Averaged Navier-Stokes (RANS)
Pressure
Low Ambient High 8
│RUAG Space

9. PLF Analyses Results CFD Simulation: Subsonic Case 1 Case 2
Lattice Boltzmann Method (LBM) 9
│RUAG Space

10. PLF Analyses Results CFD Simulation: Subsonic Case 3 Case 3
Lattice Boltzmann Method (LBM) 10
│RUAG Space

11. PLF Analyses Results Fluid-Structure Interaction
Case 3 - Outer pressure
Pressure distributions from CFD analyses implemented in FE model.
Predicted max. dynamic pressure case around 56 km altitude.
Different load cases and PLF attitudes analyzed.
Case 2 - Outer pressure
Case 2 - Inner pressure
Case 3 - Inner pressure
Case 2 - Delta pressure
* Represents qmax condition 11
│RUAG Space

12. PLF Recovery System Concept
Baseline
Reference architecture per PLF half-shell:
Ballistic drogue parachute
Main parachute
MAR or in-water recovery
Floating device
Drogue system:
stabilization purposes
Avoid critical PLF attitudes in air stream
Facilitate deployment of main parachute
Main parachute: provides the necessary aerodynamic drag in order to slow the PLF to acceptable descent rates
Floating devices: may be incorporated to allow landing in water and subsequent recovery 12
│RUAG Space

13. (model reference only)
PLF Recovery System Concept
Mid-Air Recovery
Drogue Parachute
Assembly
Parachute only: approx 4.5kg (10lbs)
Canopy
9.85ft Do Conical Ribbon
Primary materials: Nylon, Kevlar structure
12 gores and 22 ribbons
Suspension lines and riser
Primary materials: Kevlar
Suspension line length ratio: 1.15
Deployment Bag
Primary materials: Gentex, Kevlar structure
Protects from hot gases and allows for controlled deployment
Mortar Assembly
Provides energy to deploy package (expose canopy skirt)
Pyrotechnic .vs. pneumatic operation options
Estimated weight: 4.5kg (10lbs)
Derived from Shuttle program: 100+ operations within 7.4” mortar class and similar pack weights
Threaded components with dual locking features
Eroding orifice technology to reduce reaction loads: 35.5kN kN (8-10 kip)
Drogue Canopy & Lines
(model reference only)
Drogue
Deployment Bag
Mortar
Assembly 13
│RUAG Space

14. PLF Recovery System Concept
Mid-Air Recovery
MAR Parafoil Requirements
Low descent-rate to maximize time for Helicopter/Parafoil interception and MAR.
Forward-speed above helicopter translation and aero-grapple maneuvering speed.
High altitude deployment capability (~11km).
Effective reefing system for reduced mass.
High density packing. High reliability.
Parafoil Sizing
Descent-rate
Low descent-rate: increases time for Helicopter to intercept Parafoil.
Wing loading: in excess of 2:1 results in high descent-rate and steering sensitivity.
Forward-speed
Wing loading: of less than 1:1 reduces Parafoil forward-speed below helicopter translation and aero-grapple maneuvering speed.
Preliminary Parafoil Design (Estimates)
Description
Recovery Weight
Wing Loading
Parafoil Area
Average Descent Rate
Parafoil Weight
Pack Density
Pack Volume at 30 lb/ft3
Span
Chord
Aspect Ratio kg
lb/ft2
ft2
fps lb
lb/ft3
ft3 ft
Mass T- half shell
1000
1.6
1587 20 85 38 30
2.82
50.40
18.33
2.75:1 14
│RUAG Space

15. PLF Recovery System Concept
Mid-Air Recovery
Drogue to Parafoil Hand-off
High altitude Parafoil opening desired to increase time available for MAR operations.
PLF flight stability required for reliable Parafoil deployment.
Parafoil deployment options: via Pilot chute, Drogue or deployment line attached to the stabilization drogue.
Standard slider reefing system for deployment.
PLF strength capability defines max allowed Parafoil opening force.
High drag payload under Parafoil reduces glide-path performance.
Controlled payload orientation for high speed ferry may be required.
PLF Tracking
Range Tracking
VHF aircraft band radio communications with helicopter
Visual acquisition (crew members)
ADS-B Out Transmitter on the payload 15
│RUAG Space

16. PLF Recovery System Concept
Mid-Air Recovery
Capture line
3G MAR with efficient load transfer
Capture line routed over front (nose) of Parafoil.
Helicopter positioned over Parafoil/payload.
Load transfer releases Parafoil from capture line, followed by Parafoil jettison (radio control from helicopter).
Aero-grapple traps capture line during Helicopter fly over.
Reduce helicopter sink-rate creating vertical separation until stop contacts grapple
Continued vertical separation pulls-up slider, collapsing Parafoil
Allows high-speed long-distance ferry (may require payload drogue). Simplifies payload set-down.
Does not require wrangling the Parafoil after payload set-down 16
│RUAG Space

17. PLF Recovery System Concept
Mid-Air Recovery
Stern Integral Heli-Pad
Bow Mount Heli-Pad Installation 17
│RUAG Space

18. PLF Recovery System Concept
In-Water Recovery
Alternative Recovery Option
1. PLF half-shells separated from Launch Vehicle at 110 km.
2. Drogue mortar deployed at certain altitude inflates and stabilizes PLF half.
3. Drogue separated from PLF with sequence cutter; releases and extracts Main Parachute assembly via static line attachment at specific altitude.
4. Main parachute inflates and controls PLF final descent.
5. Floating devices inflated/released prior to landing in-water.
6. Beacon initiated for recovery operations.
110 km
361 kft
83 km
271 kft
28 km
90 kft
55 km
180 kft 2 5
3-4 6 1 18
│RUAG Space

19. PLF Recovery System Concept
Outlook
Phase 1 ( )
Concept study
Feasibility studies: aerodynamic, technologies identification, concept definition
Sub-system identification and preliminary definition
Phase 2 (2016)
PLF Impact study
Detailed impact study on PLF (mechanical, dynamic, kinematics, …)
Mass-breakdown and CoG
Performance of sub-systems development tests
Phase 3 ( )
In-flight demonstration
Selection of demonstration objectives/mission
Definition of test article
Procurements
Realization of in-flight demonstration
Evaluation of test data 19
│RUAG Space