mission analysis - International Planetary Probe Workshop

T AND 

LA ANDI ING MISS 

SION 

AN NALYS SIS 

CENT 

EXO OMAR RS ENTR 

RY, DESC 

OF THE 

EVOLUTION OF THE EXOMARS 

ENTRY DESCENT AND LANDING 

MISSION ANALYSIS 

Session 3 

Rodrigo Haya Ramos, Juan Luis Cano, Davide Bonetti, 

Cristina Parigini, Francesco Cacciatore 

DEIMOS Space, Spain 

Stefano Portigliotti, Alberto Anselmi - 

Thales Alenia Space, Italy 

Olivier Bayle 

ESA/ESTEC, The Netherlands 

ION 

EVOLUTI 

© 2010 DEIMOS Space S.L.U. – www.deimos-space.com 

7th International Planetary Probe Workshop 

- 1 - Barcelona, 14-1818 th June 2010


RY, DESC 

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SION 

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THE 

ION OF T 

EVOLUTI 

• Motivation and Objective 

• ExoMars Missioni 

• Evolution of Mission Scenario 

• Interplanetary Mission 

• Arrival Conditions 

• EDL Requirements 

• Global Entry Corridor 

• Mission Performances 

• Conclusions 

Agenda 





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Motivation and Objective 

• Project Motivations 

– ExoMars is ESA’s current mission to planet Mars aimed for two 

launches: 2016 2018 

– ExoMars is the first Aurora Flagship mission under assessment 

– Project is currently undergoing Phase B2 studies under ESA 

management and Thales Alenia Space Italia project leadership 

– DEIMOS Space provides support to TAS-I on interplanetary and 

in-orbit Mission Analysis and Design 

– DEIMOS Space is responsible for the Mission Analysis and Design 

for the Entry, Descent and Landing (EDL) activities. i i Within this 

contract, Tessella is responsible for the support to sizing and 

analysis of the Descent and Landing System 

• Presentation Objectives 

– The Mission requirements have evolved since the beginning g of 

Phase B leading to significant changes in the Mission & System 

Design 

– An overview of the evolution of the Mission from an EDL Mission 

Design and Analysis standpoint is presented 




OF THE EXO OMAR RS ENTR 

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EVO LUTI ION 

• Technological objectives 

– Entry, Descent and Landing (EDL) of a payload 

on the surface of Mars; 

– Surface mobility with a Rover, 

– Access to the sub-surface surface to acquire samples; 

– Sample preparation p and distribution for analyses 

by scientific instruments. 

• Scientific Objectives 

– To search for signs of past and present life on 

Mars; 

– To investigate the water/geochemical 

environment as a function of depth in the 

shallow subsurface; 

– To investigate Martian atmospheric trace gases 

and their sources. 

• The ExoMars Mission will deploy two elements: 

– EDL Demonstrator with a Surface Platform (SP) 

– a high-mobility Rover 

Exomars Mission 




ING MISS 

SION 

AN NALYS SIS 

ION OF THE EXO OMAR RS ENTR 

RY, DESC 

CENT 

AND 

LA ANDI 

• 

Credits: LMCo 

Atlas V (421) 

Actual Mission Scenario 

EVOLUTI 

Credits: ESA 





RY, DESC 

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SION 

AN NALYS SIS 

OF THE 

EVOLUTI ION 

Evolution 

• The mission Design has evolved during the Phase B as 

a result of 

– Updated Mission Requirements 

– Mission options trade-offs 

– Budget restrictions 

ti 

– Cooperation with NASA 

• The Mission Design during Phase B has developed 

several Mission Baselines 

Phase Frame Final Review 

B1 October 2005 – March 2007 SRR 

B1X April 2007 – December 2007 BCR 

B2 January 2008 – March 2009 I‐PDR 

B2X April 2009 ‐ Mach 2010 B2XR 

B2X2 April 2010 ‐ Mach 2011 PDR 




N AN NALYS SIS 

SION MISS ING M 

ANDI D LA 

T AND 

CENT DESC 

RY, D 


THE OF T 

LUTI ION 

EVO 

• Launcher 

• Carrier (CM) / Data Relay Carrier (DRC) 

• Orbiter Module (OM) 

• Carrier Science Relay Module (CSRM) 

• Descent Module Composite (DMC) 

EDL Demonstrator t Module (EDM) 

Enhanced Descent Module (EDM) 

• Lander 

Exomars Elements along Phase B 

• Rover 

Credits: ESA, NASA, TASI 

Images are illustrative, not corresponding to actual designs 





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Descent Module (DM) Elements along Phase B 

Single and 2 stage 

parachute system 

BackShell & 

(drogue and Main) 

Structuret 

Liquid/Solid 

retrorockets 

Surface Platform (SP) 

with crushable structure 

Vented / non- 

vented Airbag 

Rover Stowed in 

Lander 

Crushable Structure 

FrontShield 

Images are illustrative, not corresponding to actual designs 

Credits: TASI 





RY, DESC 

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SION 

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OF THE 

EVO LUTI ION 

• Mission Scenario 

Mission Scenario & EDL: Nominal 

Phase B1 Phase B1X Phase B2 Phase B2X Phase B2X / B2X2 

Option Baseline Baseline Baseline Baseline 

Baseline 

Spacecraft 

CM + DM 

Rover (ESA) 

CM + DM CM + DM (CM possibly as OM + Enh.DM OM + EDM Carrier, EDL, 

Orbiter) 

Rover (NASA) 

Opportunity 

2011 / 2013 2013 / 2016 2013 / 2016 2016 

2016 2018 

Launcher Soyuz 2-1b Ai Ariane 5 Ai Ariane 5 Atlas V 551 Atlas V 421 Atlas V 531 

Escape type 

From HEO with 4 

Direct Direct Direct Direct Direct 

escape burns 

Transfer type 

T3 with DSM T2 with DSM T2 with DSM T2 with DSM T2 with DSM T2 with DSM 

Release type 

Elliptic from 4-sol 



Hyperbolic 

Hyperbolic Elliptic 

orbit 

orbit 

orbit 

• EDL Architecture 

DM 70º/47º aeroshell 70º/47º aeroshell 70º/47º aeroshell 70º/47º aeroshell 70º/47º aeroshell 

3.4 m Diameter 3.4 m Diameter 3.4 m Diameter 3.4 m Diameter 2.4 m Diameter 

1 Ton 1.2 Ton 1.2 Ton 1.2 Ton 600 kg 

Descent System Single / 2 Stage 

2StageSystem System 2StageSystem System 

2 Stage System 

Single Stage 

System (DGB, 

(DGB, ringslot) (DGB, ringslot) (DGB, ringslot) System (DGB) 

ringslot) 

MSL derived 

Powered Descent Throttleable / 

Throttleable Throttleable Throttleable Modulated 

Solid 

Retrorockets Retrorockets Retrorockets Retrorockets 

Retrorockets 

Landing 

Vented / non- 

Crushable 

Vented airbag Vented airbag Vented airbag 

ventedairbag 

Structure 




NALYS SIS 

N AN SION 

MISS ING M ANDI D LA T AND CENT DESC RY, D ENTR RS E OMAR 

THE EXO 

ION OF T 

LUTI 

EVO 

Credits: TASI 

EDL Sequence 

Enhanced DM 

EDL Demonstrator 





RY, DESC 

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OF THE 

EVO LUTI ION 

• Mission Scenario 

Mission Scenario & EDL: Trade-offs 

Phase B1 

Phase B1X Phase B2 Phase B2X 

Option Option 1 Option 2 Option 1 Option 1 Option 1 

Spacecraft 

CM + DM 

CM + DM 

As nominal + 

Orbiter + DM CM + DM (CM possibly as (CM possibly as 

Orbiter alone 

Orbiter) 

Orbiter) 

Opportunity 2011 / 2013 

2011 / 2013 / 2015 

(backup) (backup) 

2013 / 2016 2013 / 2016 2016 

Launcher Soyuz 2-1b Ai Ariane 5 Proton M Proton M Proton M 

Escape type 

Direct 

(Launch 3 

Direct Direct Direct Direct 

Transfer type 

th b f 

Direct with DSM 

T3 with DSM 

T3 & T4 with DSM 

T2 with DSM T2 with DSM T2 with DSM 

Release type 

N/A 

Elliptic & Elliptic from 4-sol Elliptic from 4-sol Elliptic from 4-sol 

SSO of 500 km hyperbolic orbit orbit orbit 

• EDL Architecture 

Phase B1 

Phase B2 

Phase B2X 

Phase B2X / B2X2 

Option Option 1 Option 1 Option 1 Option 1 

DM 

3.2 m Diameter 

3 m Diameter 

1.3 Tons 

1 Ton / 1.2 Tons 400 / 800 Kg 

Descent System 

Powered Descent 

Landing 

ringsail 

Solid retrorockets 

Non-Vented 

airbag 

Huygens DGB / 

Viking DGB 





RY, DESC 

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Interplanetary Mission Scenario 

• The interplanetary Transfer design has evolved as a result 

of the 

– The hyperbolic -Elliptic -Hyperbolic release evolution 

– Constrained arrival / release date – unconstrained arrival date 

– Direct / staged escape 

– Use of T1/T2 transfers - T3/T4 transfers 

– Arrival or not under MGDS 

PhB1: Soyuz, 2011 B2: A5, 2013 

Actual: A421, 2016 

Departure from Earth 

(December 2013) 

Departure from Earth 

(January 2016) 

OF THE 

EVO LUTI ION 

2.9 km/s 

DSM 

(May 2014) 

Arrival to Mars 

(October 2014) 

DSM 

(May 2016) 

Arrival to Mars 

(October 2016) 




EVOLUTI ION OF THE EXO OMAR RS ENTR 

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Navigation 

• Navigation 

– Driven by Mars – Earth – GS Geometry (distance, angles) 

– Dedicated campaigns for each scenario 

– Delta DOR measurements as 

compulsory 

– Navigation assumptions have 

evolved towards reducing 

conservatism 

s 

– Drives EIP dispersion in case of 

hyperbolic release 

– Low impact for elliptic release 





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Arrival Conditions 

• Arrival epoch 

– Driven by release strategy, visibility, surface operation constraints 

– Actually landing is foreseen in the middle of the EGDS 

• Arrival Conditions 

– Landing constrained to morning / early morning 

– Retrograde entry for Elliptic release for daylight landing 





RY, DESC 

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SION 

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OF THE 

LUTI ION 

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EDL Mission Requirements 

• The main evolution of the EDL constraints For Mission 

Design concerns the change from the Enhanced 

Mission to the EDL demonstrator 

• System constraints t removed from M&SRD 

Phase B1 

Subject 

Requirement 

… 

Phase B2X2 

Landing Latitude 15ºS S, 45ºN Subject 

Requirement 

Nominal Surface Mission 180 sols outside MGDS 

Landing accuracy 25 km 3 (15 km goal) 

Landing time 

Daylight 

Landing altitude 

< 0 m MOLA 

Oscillations (parachute) < 10º 

Descent & Landing Loads < 40 g 

Entry Control concept ballistic 

Terrain Slopes 


RY, DESC 

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• lsPlot.fig 

EDL Entry Conditions 

Phase B1 B1X B2 

B2X B2X / B2X2 

Type Of Entry Hyperbolic 

Elliptic 

Elliptic 

Elliptic Hyperbolic 

Launch Opp. 2011 2013 2011 2013 2013 2016 2016 2016 

V [km/s] 2.89 2.78 N/A N/A N/A N/A N/A 3.25 : 3.46 

Inertial Velocity [m/s] 5719 5667 4851 4851 4851 4851 4851 5910 : 6030 

Heading [deg] 86 : 116 73 : 100 230 : 245 240 236 244 240 : 244 117 : 125 

Velocity [m/s] 5474 : 5563 5424 : 5511 5063 5063 5023 5089 5063 : 5068 5474 : 5563 

LT Min 10.8 : 13:1 10.9 : 13.2 8:3 : 9.5 9.5 9.2 9.9 10.9 : 11.3 13.4 : 13:7 

Design Site 15S : 45N 

15S : 45N 

4Sites 

Meridiani Meridiani 

*4 BCR Sites *MC 

EIP 





RY, DESC 

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OF THE 

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Entry Corridors 

• All the EDL Mission Constraints (thermomechanical, 

parachutes, RDA, landing accuracy… ) are collapsed in a 

single figure of merit: the Entry Corridor 

– Go / no-go for a particular landing site 

– Identification of Mission/DM i design issues 

– Support the DM sizing selection, landing windows, sizing cases 

– Foster the review of specifications and designs 

– Mission-trade offs 

• Actual Corridors for Meridiani pending of consolidation 

nation n (kW/m m2) 

Flux at stag 

Heat 

440 

420 

400 

380 

360 

340 

320 

300 

Elliptic, Meridiani v Ls 

Latitude (deg) = -2.0 

mass = 1079 kg 

mass = 1200 kg 

constraint 

280 

50 55 60 65 70 75 80 85 

Solar Longitude (deg) 

Hyperbolic, Meridiani vs V ∞ 





RY, DESC 

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Global Entry Corridors 

• Extension to a Planetary level of the Entry Corridors (LEC) 

• Powerful tool to: 

– identify landing Site candidates Extensively used and validated 

against Monte Carlo along Phase B (see Poster about it…) 

– Fast Evaluation of Mission i Performances in sites and epochs 

different from the design one (s) 

PhB2, Peak Heat Flux Map 




D LA ANDI ING MISS 

SION 

AN NALYS SIS 

T AND CENT 

DESC RY, D ENTR RS E OMAR 

THE EXO 

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Mission Performances 1/3 

• 3DOF/6DOF/Multibody Monte Carlo campaigns have been run 

for verification of predicted EC performances 

• End-2-End analysis with continuous interplanetary and EDL 

phases (ex: trajectory t and dispersion i analyses) 

Ph B2, Elliptic Release 

Ph B2X/B2X2 Hyperbolic 





RY, DESC 

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• Performances in previous scenarios cross- 

validated with NASA 

• In the EDM scenario, the landing during Dust 

storm season increases dispersions significantly 

• Single Stage requires opening at higher altitudes 

(verticalisation) 

• Campaign for B2X2 ongoing 






RY, DESC 

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• The gap between hyperbolic and elliptic release is 

removed due to separation errors improvement 

• The +/50 km ellipse size constraint was respected 

either in the Enhanced Exomars mission or in the EDM. 

Elliptic, large 

Hyperbolic, 

Sep Errors 

reduced d Sep Errors 





RY, DESC 

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OF THE 

LUTI ION 

EVO 

Conclusions 

• Since the beginning of Phase B, the Exomars Mission has evolved as a result of internal and 

external factors leading to a large number of scenarios and elements analyzed and traded- 

off. 

• A comprehensive set of End-to-End Mission Analysis results from launch to landing, including 

surface mission phases, has been delivered to the Prime (TASI) to support this Mission 

evolution 

• The End-2-End EDL Mission Analysis and Design Tools and methods developed in early 

Phase B1 has been matured and widely used to support this Mission i evolution providing 

quick feasibility feedback. 

• Key elements in this EDL MA support are: the reliability of the predicted mission 

performances avoiding large MC campaigns, validation, high fidelity of models and close 

integration with interplanetary Mission analysis 

• Actual 2016 Mission Baseline is under design and analysis from and EDL Mission Analysis 

perspective. Consolidate results expected by the PDR, hopefully to be presented by IPPW-8

mission analysis - International Planetary Probe Workshop

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