Venus is one of the important planetary destinations for scientific exploration, but: The combination of extreme entry environment coupled with extreme surface conditions have made mission planning and proposal efforts very challenging. We present an alternate, game-changing approach (ADEPT) where a novel entry system architecture enables more benign entry conditions and this allows for greater flexibility and lower risk in mission desig

Arnold, James O.

Chinnapongse, Ronald I.

Gage, Peter J.

Makino, alberto

Peterson, Keith Hoppe

Prabhu, Dinesh K.

Smith, Brandon

Venkatapathy, Ethiraj

Wercinski, Paul F.

Yount, Bryan C.

NASA Technical Reports Server

GAME CHANGING DEVELOPMENT DACC Project Enabling Venus In-Situ Science – 
Deployable Entry System Technology, 
Adaptive Deployable Entry and 
Placement Technology (ADEPT): 
A Technology Development Project  
funded by Game Changing Development 
Program of the Space Technology Program 
P. Wercinski, E. Venkatapathy, P. Gage, B. 
Yount, D. Prabhu, B. Smith, J. Arnold, A. 
Makino, K. Peterson, R. Chinnapongse 
https://ntrs.nasa.gov/search.jsp?R=20130001711 2019-08-30T23:46:03+00:00Z
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What is this talk about? 
•  Venus is one of the important planetary destinations for scientific 
exploration, but… 
–  The combination of extreme entry environment coupled with extreme surface 
conditions have made mission planning and proposal efforts very challenging 
•  We present an alternate, game-changing approach (ADEPT) where a 
novel entry system architecture enables more benign entry 
conditions and this allows for greater flexibility and lower risk in 
mission design  
Outline 
•  Background: The challenge of entry at Venus 
•  Venus Mission 
–  VITaL: Example Venus Lander mission to meet NRC Decadal Survey Science 
Recommendations 
•  ADEPT – Mechanically Deployable Aeroshell Integrated Approach and 
Results of application to VITaL mission design 
•  Concluding Remarks 
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ACKNOWLEDGEMENT 
–  This work is currently supported by the Game Changing Development 
Program of the Space Technology Program , NASA HQ.   
–  NASA Ames Research Center is leading this effort and is supported 
by NASA Langley Research Center, NASA Johnson Flight Center, 
NASA Goddard Flight Center and Jet Propulsion Laboratory. 
–  Content of this presentation was previously given at the IPPW-9 
(June 2012) in two presentations by (Venkatapathy, Glaze et al) 
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m/CdA(β) = 208 kg/m2 ( 3.5m diam, 45º sphere-cone, 2100 kg entry mass) 
Ventry = 11.25 km/s 
Trajectories terminated at Mach 0.8 
Traditional Venus Entry:  
Rigid 45º sphere-cone, Steep entry (-23.4º) 
•  Peak g-load 200-300 g’s 
•  Peak Heat Rate (Total) ~4000 W/cm2 
•  Peak Stagnation Pessure ~10 atm 
•  Total Heat Load ~16,000 J/cm2 
•  Payload Mass Fraction ~0.5 
What happens if we enter at a shallow flight path angle 
near skip-out (-8.5º) with the same architecture? 
•  Peak g-load ~20-30 g’s 
•  Peak Heat Rate (Total) ~800 W/cm2 
•  Peak Stagnation Pressure ~1 atm 
•  Total Heat Load ~28,000 J/cm2 
•  Payload Mass Fraction ~0.2 
Decreasing G-load 
Improved science capability 
Reduced heat shield carrier structure mass 
Increasing Heat Load 
Increased carbon phenolic thickness 
Increasing TPS Mass Fraction! 
Decreasing Payload Mass Fraction! 
Net Effect: 
High-Speed Atmospheric Entry at Venus : 
The Challenge 
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High-Speed Atmospheric Entry at Venus : 
The Challenge 
•  For rigid aeroshell entry: 
–  Ballistic coefficient 200-250 kg/m2 
–  Size constrained by launch shroud 
–  Entry mass constrained by launch 
vehicle throw capability 
•  For Carbon-Phenolic TPS: 
–  Balance between TPS and 
Payload mass fraction leads 
to extreme heatflux, pressure 
and G’load 
•  Alternate option: 
–  Design entry architecture that 
can operate at shallower entry 
flight path angle (lower g-
loads) and a lower ballistic 
coefficient (lower heat load) 
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Game Changing Approach to Venus Direct Entry with 
a Low Ballistic Aeroshell Concept 
•  Assume ballistic 
coefficient can be 
lowered 10 x  
• A material that can 
sustain  250 W/cm2  is 
now feasible 
• Corresponding heatload 
and pressure are 
considerably lower as 
well 
• Peak deceleration can be 
reduced by an order of 
magnitude 
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Project Deliverables 
•  Characterize thermal and mechanical 
performance of 3D woven carbon fiber 
fabric 
•  Produce flight like woven fabric skin for ground test 
article and integrate with breadboard structural/
mechanical system 
•  Capable to 250W/cm2 
•  Perform mission feasibility study to 
understand operational requirements/
parameters and sizing calculations  
•  Design, Fabricate and Test sub-scale 
ground test article (~2m diameter) 
•  Fabricate rib/strut/ring/nose structures using COTS 
type extruded shapes for breadboard structural 
support system 
•  Design and procure COTS hinge/joint/deployment 
mechanisms to simulate behavior of ADEPT for 
ground testing 
•  Conduct Mission Concept Assessment for 
potential flight demonstration 
ADEPT (Adaptable, Deployable, Entry and Placement Technology) is a low ballistic 
coefficient entry architecture (m/CdA < 50 kg/m2) that consists of a series of deployable ribs 
and struts, connected with flexible 3D woven carbon fabric skin, which when deployed, 
functions as a semi-rigid aeroshell system to perform entry descent landing (EDL) functions. 
ADEPT:  STP GCD Project (2yr) started in FY12 
 => Achieve TRL 5 at end of FY13 
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Applying ADEPT to a VISE-like Surface Mission: 
Venus Intrepid Tessera Lander (VITaL) 
•  1 hour descent science 
–  Evolution of the atmosphere 
–  Interaction of surface and atmosphere 
–  Atmospheric dynamics 
•  2 hours of surface and near-surface science 
–  Physics and chemistry of the crust 
8 
Chop  
Molded C-P 
Tape 
Wrapped 
C-P 
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VITaL Strawman Science   
Instrument Complement 
9 
Entry flight System Camera/Raman/LIBS Fields of View Stable Landing 
Optimistic with conventional aeroshell: steep entry 
angle = high g-loads 
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50
 
75
 
10
0 
12
5 
15
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17
5 
20
0 
0 2 4 6 8 10 12 
A
lti
tu
de
, k
m
 
Velocity, km/s 
Entry Interface 
29 September 2024 
V = 10.8 km/s 
γ  = -8.25º 
Ballistic trajectory 
Peak Total Heating 
Entry + 100 sec 
qtotal = 203 W/cm2 
Pstag = 0.16 atm 
19.2 G 
Targeting maneuver 
Deploy ADEPT  
Spin up 
Release ADEPT for EDL 
Cruise stage divert +1 day 
Launch 
Atlas V 551 
29 May 2023 
Peak Deceleration 
Entry + 110s 
qtotal 122 W/cm2 
Pstag = 0.24 atm  
29.8 G 
Mach 2 
16 Month Trajectory 
Alpha 
Region Landing 
Uncertainty 
Mach 0.8: Separation Event Begins 
•  Mortar-deployed pilot parachute 
•  Aft cover release 
•  Pilot-deployed main parachute 
•  VITaL separation from ADEPT 
•  Cut main parachute / VITaL release 
ADEPT-VITaL Mission Quick-Look 
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ADEPT-VITaL  Design Details 
•  ADEPT- VITaL Design Results: 
–  Margined mass estimates for ADEPT-VITaL entry 
configuration are lower than baseline VITaL  
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•  Study Objective: assess the feasibility of the ADEPT concept by quantifying potential 
benefits for the NRC Decadal Survey’s Venus In-Situ Explorer (VISE) Mission and checking 
for potential adverse interactions with other mission elements, such as launch and cruise. 
•  The ADEPT project chose to study the Venus Intrepid Tessera Lander (VITaL) design, a 
VISE lander developed by NASA GSFC for the Decadal Survey’s Inner Planets Panel. 
Results are documented in the ADEPT-VITaL Mission Feasibility Report, dated 13 July 
2012. 
•  Mission Design Elements: 
–  Launch vehicle 
–  Interplanetary trajectory design / launch date 
–  Cruise CONOPS / time of ADEPT deployment 
–  Carrier spacecraft mods. / mass and power impacts 
–  VITaL lander modifications and mass savings 
•  ADEPT-VITaL Vehicle Subcomponent Design: 
–  Structures 
–  Mechanisms 
–  Materials 
•  Payload Separation Event 
•  Key Trade Studies: 
–  Entry shape / trajectory 
–  Structures and mechanisms trades 
•  Operating environments: stowed configuration 
–  Launch vibro-acoustic 
–  Cruise cold soak 
•  Operating environments: deployed configuration 
–  Aerothermodynamic loads 
–  Structural and aeroelastic loads 
–  Aerodynamic stability and flight dynamics 
The ADEPT-VITaL Study Addresses: 
The ADEPT Team used Venus robotic as most challenging class for low 
ballistic coefficient decelerator applications 
 - Fully addressed mission feasibility 
 - Technology development risks identified 
 - Close collaboration with Venus Mission Stakeholder (GSFC: Glaze) 
ADEPT-VITaL Mission Feasibility Report 
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Oct 30, 2012 DACC/NASA Distribution Only 13 
ADEPT Project Element Vision and Challenges 
The ADEPT concept consists of a series of deployable ribs and struts, connected 
with flexible 3D woven carbon fabric skin, which when deployed, functions as a 
semi-rigid aeroshell entry system to perform entry descent landing (EDL) functions.  
Carbon fabric material withstands 
thermal and mechanical loads 
Fluid structure interaction of fabric at 
supersonic/subsonic conditions 
Manufacture of carbon fabric as system (seams 
and attachment) 
Aero stability of ADEPT entry system 
Stowage in launch configuration and deployment 
•  ADEPT Year 1 – Budget ($3.3 M) 
•  Characterize thermal and mechanical performance of 3D woven carbon fiber fabric 
- Arcjet Testing in relevant enviornments 
•  Develop ADEPT flight system requirements/capabilities 
- Establish end-to-end mission feasibility to support MOT 
•  Start design process for Sub-scale demonstration ground test article 
•  ADEPT Year 2 – Budget ($3.5M) 
•  Continue 3D woven material of Thermal and Mechanical characteristics development 
•  Design, Fabricate and Test sub-scale ground test article (~2m diameter) 
•  Initiate Flight Test Planning and Development 
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ADEPT Year-1 Major Accomplishment:  
Carbon Fabric Capability Demonstration 
•  Bi-axial Loaded Aerothermal Mechanical (BLAM) Test 
Objectives: 
–  Evaluate the carbon fabric’s structural integrity under combined 
aerothermal and biaxial loading. Intended to be a unit test for the acreage 
of the ADEPT vehicle (far away from the ribs)  
–  Evaluate the rate of layer loss as a function of different combined 
loads. 
•  Test Results: 
–  Data shows that the carbon fabric is able to maintain load at 
temperature. 
–  Biaxial load in the cloth from 188 lbs/in to 750 lbs/in has little to no 
impact on the rate of layer loss of the carbon fabric. 
–  Flipping the warp/weft direction had little effect on the rate of layer loss 
of the carbon fabric. 
–  Fabric tested easily withstood a heat load of 15.7 kJ/cm2. This is well 
above the 11 kJ/cm2 expected for a Venus mission. 
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ADEPT Year-2 Technical Plan Highlights 
FY 13 Oct  Nov  Dec Jan Feb Mar Apr May Jun Jul Aug Sep 
G
TA
 
R
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Te
st
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g 
C
om
po
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nt
 T
es
tin
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Fl
ig
ht
 
Te
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SRR PDR CDR *Deployment 
Testing 
*Load 
Testing 
*GTA tests could occur earlier by accelerating procurement of long lead items 
ADEPT/VITaL 
Test Plan Kick-off 
Ground Test Article 
Deployment & Load Tests 
Radiant Testing 
Thermal Tests 
BLAM-2  
C-Fabric Seam Tests 
ADEPT/VITaL  
Flight Test Planning 
PDR CDR 
MCR SRR SDR 
C-Cloth 
Materials 
Database 
C-Cloth 
Load 
Tests 
Radiant 
Test-1 
BLAM-2 
Seam Tests 
CDR 
BLAM-2 
PDR 
BLAM-2 
ADEPT/VITaL ADEPT/VITaL Final Report 
CDR C-Cloth/ 
Procurement
s 
Oct 30, 2012 15 DACC/NASA Distribution Only 
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ADEPT Technology Maturation and 
Mission Applications Timeline 
Human/ Heavy 
Mass Mars Mission 
and Design Studies                        
FY’11 
ADEPT Project             
TRL Maturation 
OCT Project     
FY’12 – FY’14 
Sounding Rocket 
Flight Test               
FY’2015 
ADEPT 
Ballistic for 
Robotic Mars
(~2020) 
ADEPT Lifting -TRL 
Maturation Project     
(FY’14 – FY’17) 
Lifting Concept  
Flight Demos            
( > FY’2022) 
Human 
Mars 
(~2035)  
Robotic 
Science 
Venus, Saturn 
New Frontier & 
Flagship Class 
(~2020) 
MER/MSL class 
High altitude access 
Non-Lifting, Subsonic 
Parachute 
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Concluding Remarks 
•  ADEPT, a Low Ballistic Coefficient, Mechanically Deployable Entry 
System Architecture is a Game Changer: 
–  Dramatically decreases severity of the entry environment conditions due to high 
altitude deceleration 
–  Enables use of delicate and sensitive instrumentation  
–  Use of flight qualified instrumentation for lower g-load at Mars and elsewhere 
–  Entry mass and the launch mass are considerably reduced 
–  Mission Risk and Cost, once the technology is matured and demonstrated, will be 
reduced considerably  -  
•  GCD investment in ADEPT, mechanically deployable aeroshell 
technology, has broad payoff for Solar System Exploration and Science 
including Venus 
•  Continued Technology Maturation of ADEPT concept by 2015/2016 will  
–  Enable Venus Missions with more comprehensive science to be a top 
contenders for the next round of New Frontier AO 
–  Continue Deployable Entry Concept development for Mars robotic and 
eventual human exploration missions   
GAME CHANGING DEVELOPMENT DACC Project 
Backup 
Oct 24, 2012 18 
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Design/Analysis Accomplishments 
Flight Aerodynamics 
Key Points: 
•  Static aerodynamics and dynamic stability of open-back configurations 
•  Flow-structure interaction and determination of “flutter” boundary (if any) at 
supersonic speeds 
Accomplishments: 
•  Static aerodynamic database completed up to Mach 2 using 3D CFD code DPLR 
•  Wake and vehicle dynamics computations with 3D CFD code US3D (pitch damping 
characteristics) 
•  Model developed for flow-structure interaction and incorporated into 3D CFD code 
US3D 
Oct 30, 2012 19 DACC/NASA Distribution Only 
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Game changing Approach to  
Venus Direct Entry with a Low Ballistic Aeroshell Concept 
•  Assume ballistic 
coefficient can be 
lowered 10 x  
• A material that can 
sustain  250 W/cm2  is 
now feasible 
• Corresponding heatload 
and pressure are 
considerably lower as 
well 
• Peak deceleration can be 
reduced by  an order of 
magnitude 
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ADEPT-VITaL  Design Details and MEL 
Item 
ADEPT-
VITaL 
CBE 
(kg) 
ADEPT-
VITaL 
Margined 
(kg) 
VITaL 
Baseline 
Margined 
(kg) 
Probe 1,621** 2,100** 2,758 
Spacecraft 797 970 846 
Satellite Dry 
Mass (Probe + 
Spacecraft) 
2,418 3,070 3,858 
Propellant Mass 1,111 1,122*** 356 
Satellite Wet 
Mass 3,529 4,192 4,214 
Atlas V 551 
Throw Mass 
Available to Lift 
Wet 
5,140 kg 
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Deployable (Low-β ), Shallow-γ Sweet Spot 
May 15, 2012 22 
•  Low-β entry, results in high 
altitude deceleration where the 
resulting entry aerothermal 
environment is benign  
–  Well within the capability of 
carbon cloth 
•  Furthermore, the low-β 
architecture allows entry with a 
very shallow flight path angle,  
dramatically reducing entry G-
load 
•  ADEPT key benefits: 
1.  No need for carbon phenolic 
2.  Benign entry G-load 
  Simplifies qualification of 
scientific instruments 
  Reduced structural mass of 
payload 
  Opens doors for improved 
science return using more 
delicate instruments 
Peak 
deceleration (n) 
Peak 
heat flux (q) 
Total heat 
load (Q) 
Direction of 
increasing pressure 
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ADEPT-VITaL Master Equipment List and 
Comparison with VITaL 
May 15, 2012 
23 


Enabling Venus In-Situ Science - Deployable Entry System Technology, Adaptive Deployable Entry and Placement Technology (ADEPT): A Technology Development Project funded by Game Changing Development Program of the Space Technology Program

Enabling Venus In-Situ Science - Deployable Entry System Technology, Adaptive Deployable Entry and Placement Technology (ADEPT): A Technology Development Project funded by Game Changing Development Program of the Space Technology Program

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