83230913-doc-tas-en-002 altec auditorium - torino - italy december 9-10, 2014 bruno musetti eswt#7...

ALTEC Auditorium - Torino - Italy December 9-10, 2014

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ESWT#7–

THE EXOMARS 2018 MISSION & SYSTEMS

This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space - 2012, Thales Alenia Space


EXOMARS 2018 Mission: Introduction

The ExoMars Program is pursued as part of a joint cooperation between ESA and Roscosmos, with an important contribution from NASA, to explore Mars and prepare for the Mars Sample Return and for future planetary exploration mission.

In particular, it features two missions, one to be launched in January 2016 and one in May 2018.

The 2018 mission is devoted to develop a Spacecraft Composite (SCC), consisting of a Carrier Module (CM) and a 2 ton Descent Module (DM), capable to land on Mars and allow for the deployment and egress of the European Rover Module (RM) and the operations of an instrumented Russian Surface Platform (SP).

The 2018 mission will be launched with a Proton M/Breeze-M rocket and is expected to arrive on Mars on January 2019.


EXOMARS 2018: System Elements Tree


Space Segment

Spacecraft Composite (SCC)

Ground Segment & Operations

Launcher &Launch Services

ExoMars Programme 2018 Mission - System Elements Tree

Carrier Module (CM) Descent Module (DM)

Ground Stations & Communication

Subnet (ESTRACK)

Mission Operations Centre (MOC)ExoMars 2016

Mission TGO

Ground Stations Support

Roscosmos Contribution

ESA Contribution

Scientific Payload

Parachute System

Scientific Instruments

Lander Operations Centre

Rover Operations Control Centre

(ROCC)

RM Science Data Archiving (ESAC) (*)

Lander Science Data Archiving (TBD) (*)

RHUs

CM-DM Separation System

IR Spectrometer & Neutron Detector

OBC - 2

OBC- 1

UHF System (Transceiver and LP

antennas)

(*) Mirror Archiving Sites will exist under the other International Partner

Rover Module(RM)

GNC (IMU & Radar)

This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space - 2012, Thales Alenia SpaceALTEC Auditorium - Torino - Italy December 9-10, 2014

2018 Mission within ESA-ROS international cooperation

Roscosmos RNS

ESA ESTRACK DSN

Trace Gas Orbiter (TGO)

2018 Mission

Spacecraft Composite (Carrier Module + Descent Module + Rover Module)

ROCC (incl SOC- Altec)

Proton M /

Breeze MMOCC @ ESOC, DarmstadtSpacecraft Operations

Rover and Landing Platform

Archiving (ESAC)Archiving (ROS)

EXOMARS 2018 International Cooperation

NASA DSN

Lander Op. Center (ROS)


Mission Objectives (1/2)

The ExoMars Programme will demonstrate key flight and in situ enabling technologies in support of the European ambitions for future exploration missions, as outlined in the Aurora Declaration pursuing fundamental scientific investigations. In particular:

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

To characterize the surface environment



Mission Objectives (2/2)

In support of the objectives of the Aurora Program, the development, in flight and in situ demonstration of the following technologies shall be achieved:

Entry, Descent and Landing (EDL) of a payload on the surface of Mars

Surface mobility with a Rover

Access to the sub-surface to acquire samples

Sample preparation and distribution for analyses by scientific instruments

Qualification of Russian ground-based means for deep-space communication in cooperation with ESA’s ESTRACK

Adaptation of Russian on-board computer for deep space missions and ExoMars landed operations

Development and qualification of throttleable braking engines for prospective planetary landing missions

Another important objective of the ExoMars Programme is to provide data relay services for landed assets on the surface of Mars until the end of 2022

Note: this objective will be achieved as part of the ExoMars 2016 Mission.




EXOMARS 2018 Reference Mission Main Requirements

Spacecraft Composite housekeeping data return of 20 Mb/day during CruiseSpacecraft Composite Telecommand data rates ranging from 8 bps to 4 kbps, according to the ECSS standardMission to be designed to allow visibility from Earth of the EDL eventEssential telemetry transmitted at 8 kbps by the DM during the Coast and EDL phases to allow real time transmission to the 2016 TGO (or other compatible and available Data RelaysAverage Data return of 0.150 Gb/sol for each asset on Mars (RM and SP)Mass 2900 Kg at Launcher separation, including all maturity and system margins (w/o Launcher Adapter)Note: DMC Mass shall be bounded to 2000 Kg NTE (including 345

Kg Rover Module)Power 350 W to DM during Cruise (up to 1600 W supplied to the whole System by the Carrier Module 15 m2 Solar Arrays during CRUISE to Mars)Single Failure Tolerance (where applicable)


EXOMARS 2018 Reference Mission Main Elements

The ExoMars 2018 Mission System consists of:

The Space Segment, as a single Spacecraft Composite (SCC), which is composed by:

The Carrier Module (CM) which carries the whole system close to Mars atmospheric borders.

The Descent Module (DM) which separates from the CM, heading the Descent Module into its entry, descent and landing trajectory. It performs the entry, descent and landing on the Martian surface of a Landing Platform (LP) and its payloads for static science research.

The DM consists of Landing Platform, Front shield and Rear Jacket (or Backshell) and a Parachute system.

Note 1: The Landing Platform (LP) ensures the landing on Mars Surface and consists of Propulsion system, Landing devices, systems ensuring operation on Martian surface and scientific instruments.

The CM-DM separation is implemented through a CM-DM Separation Assembly, which is composed by the Separation mechanism and the mechanical Adapter.

The Rover Module (RM) which, egressing from inside the DM, allows a Rover Vehicle (RV) and its boarded experiments to perform science exploration onto the Mars Planet



EXOMARS 2018 Reference Mission

The transfer for the ExoMars 2018 mission is a short transfer, where the trajectory roughly resembles a half-ellipse. The obtained transfer for the 2018 opportunity departs Earth in May 2018 and arrives at Mars on 2019/1/15, fulfilling the constraint on the arrival Ls that states that it arrival shall not be in the global dust storm season.

All trajectory design is subject to the following assumptions, which also implicitly apply to all applicable Launch opportunities:

Consistency with a Proton M / Breeze M launch Application of a launch period that spans 21 consecutive days (with Launcher Programmes

currently limited to 6) Absence of Deep Space Manoeuvres (DSM)

Note: Currently, a ΔV allocation of 25m/s for the Launcher Injection Correction (LIC) and 25 m/s for the transfer navigation has been assumed as a reliable figure

No constraints on the Mars hyperbolic arrival velocity

The ExoMars 2018 mission comprises : a Launch and Cruise phase carried out by the ExoMars Composite Spacecraft an atmospheric Entry Descent and Landing (EDL) phase carried out by the Descent Module two well-separated Mars Surface Science Missions, one implemented by the DM Static Landing

Platform and one be the Rover Module that will egress the Surface Platform (SP) after completion of its Check-out after landing.



EXOMARS 2018 Reference Mission

Event Date

Launch window 7-27 May 2018

CM-DM separation 15 January 2019

DM landing 15 January 2019 (Ls = 324°)

Rover Egress < 25 January 2019

Nominal end of mission31 August 2019 (RM)15 January 2021 (SP)

Nominal sequence of events



EXOMARS 2018 Reference Mission: CRUISE


The escape sequences is 4.5 hours, counted from lift-off to separation of the payload from the Breeze M stage, when the Mission Operations control is handed-over to ESOC

TCM1 ((Launch +7 days) First Trajectory Correction TCM2 (Launch +30 days) is to clean up the TCM1 error TCM3 (EIP -30 days) TCM4 (EIP -8 days) TCM5 (EIP -2 days)

The Spacecraft Composite (SCC) will perform the whole Cruise spinning at 2.5 rpm, controlled by the Carrier Module (CM) GNC. For the first 50 days, the SCC will keep a sun pointing attitude, guaranteeing the communication with the CM Low Gain antenna’s. After that and up to the preparation for CM-DM separation, the SCC will be Earth Pointing, except for Safe mode, to allow communication with Ground by means of the CM Medium Gain Antenna.

Shortly before atmospheric entry the DM is separated from the CM by means of a linear Separation mechanism part of the DM.

After being separated, the CM is not foreseen to operate and break/burn up during its uncontrolled entry in Mars atmosphere while the DM starts its EDL mission for landing onto the Mars surface.


EXOMARS 2018 Reference Mission: EDL


The DM is separated from the CM 0.5 hours before crossing the Entry Interface Point (EIP). Prior to separation, the Spacecraft Composite is reoriented to the attitude that the DM requires at atmospheric entry, assumed parallel to the relative velocity at the EIP.

In the current reference mission, the EIP is taken to be at 120 km altitude above a spherical planet radius of 3397.5 km; the reference entry flight path angle is -13.00°.

The separation mechanism imparts relative linear velocity of at least 35 cm/s between DM and CM while the DM spinning rate, ranging between 2.25 and 2.75 rpm, is guaranteed by the SCC dynamics condition at release. For the DM, neither orbit nor attitude trim manoeuvres are possible after separation.

After separation, the DM coasts autonomously to the Entry Interface Point followed by hyperbolic entry, descent and landing at its landing site (still to be selected at any latitude in the range 5 degrees South to 25 degrees North of the Martian surface).

The DM will hit the top of the Martian atmosphere at approximately 20,000 km/h. A thermal shield at the bottom of the capsule will be used to decelerate to roughly twice the speed of sound. Thereafter, the parachute system will take over. However, even after the main parachute has reached its terminal velocity, the DM will be still traveling at more than 300 km/h. The last stage will involve the use of throttled liquid engines. A multi-beam radar will measure the distance to ground and the horizontal speed over the terrain. The DM’s computer will receive this information and combine it with its knowledge of the DM’s attitude to decide how to exercise the engines and achieve a controlled landing. Legs will be used for the final touchdown.

Landing of the EDM occurs about 6.5 min after EIP.


EXOMARS 2018 Reference Mission: EDL



Spacecraft Composite Configuration (1/2)


SCC with deployed Solar Arrays SCC with stowed Solar Arrays



Spacecraft Composite Configuration (2/2)



Descent Module Configuration

CM-DM Separation Adapter



SCC Avionics Block Diagram

BC

RT

RT

RS422-SBDL

RM

CTU

LPCDU

CPCDU

CRTU

CPCDU

CRTURT

CM

IMU-1

IMU-2

RDA

UHF-1

UHF-2

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-155

3B DM

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UHF

PCDEPCDE

OBCOBC

UHF

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-155

3BTCS TCS

RT

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RT

STR-1

STR-2

XDST-1

XDST-2

TCS

SS1SS2

CMPropulsion

RFDN

LGA1

LGA2&3

MGA

CTUROSOBC

DMPropulsion

CU

RFDN

BSHAnt.

LPAnt.

ESAOBC

Payloads

SA BAT

SABAT

LPCDU

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