Combined antenna & solar arrays for space exploration · antenna surface. Being thinner than 0.5...

1J. Mosig, EPFL Space Day.Dec.8, 2006

Combined antenna & solar arrays Combined antenna & solar arrays for space explorationfor space exploration

[email protected]://itopwww.epfl.ch/LEMA

Prof. Juan Mosig LEMA-STI, EPFLDr.Stefano Vaccaro, JAST Switzerland


Two finished ESA-Projects (TRP/GSTP):

From concept development (1999) to in-flight demonstration (2005)

One ESA-Project under negotiation:

Application to ExoMars(2007-2010)


The leading idea

•Antennas and solar cells compete for limited available surface in satellite spacecrafts.

•An appropriate combination of the two can save valuable “real estate”.


Different waves, different directions

The same surface could sharethe antenna and the solar cell functions

Sunlight waves for the solar cells: cosine square angular dependance;Radio waves for the antenna: flexible angular dependance


Epoxy

Solar cell (55 μm with PI film)

Foam

Ultralam 2000

6.86

mm

(686

0 μ m

)Antennas and Solar cells: Two different world scales

1 µm Aluminium

50 µm Polyimide

1.5 µm ZnO

1.5 µm ZnO0.7 µm Ag

0.02 µm <p> a-Si:H0.35 µm <i> a-Si:H0.02 µm <n> a-Si:H

Solar cell thickness: comparable tocopper printed antenna thickness

The overall antenna thicknessmust be around 0.1 wavelenghts

Planar antenna technology,

speciality at LEMA-EPFL


Two types have been investigated:

1) Well known, high efficiency, space-qualified GaAs cells (CESI, Italy, efficiency >20%)

2) Innovative amorphous Silicon (a-Si:H) cells (UniNE, Switzerland).

1 µm Aluminium

50 µm Polyimide

1.5 µm ZnO

1.5 µm ZnO0.7 µm Ag

0.02 µm <p> a-Si:H0.35 µm <i> a-Si:H0.02 µm <n> a-Si:H

Despite a much lower efficiency (<10%),Silicon cells could be grown directly on the antenna surface.Being thinner than 0.5 mm, the cells’ weight with 50 µm Polyimide substrate is 70 gr/m2and Power efficiency is more than 1 watt/gram!

The solar cells


Integration of two worlds

ANT

SC

PATCH ANTENNA

SC & ANT

CELL ANTENNA

ANT

SCSC

SLOT ANTENNA

Three differentantenna

strategies

SOLar ANTenna:SOLANT

AdvancedSOLar ANTenna:

ASOLANT

The future?


The ASOLANT G3 prototype (2002)

Folded slots Circ. Pol.

GaAs cellsspace qualified design

4.3 w solar power

The SOLANT 4 prototype (1999)

Patch antennaLinear Pol a-Si cells

Beamforming0.1 w solar power

Two prototypes

Joint project with IMT Uni Neuchâtel, CH


SOLANT atSalon du Bourget,

Paris, 2001


ASOLANT back to Earth

« Solant » tile for roofs, containers, highway posts

GROUND APPLICATIONS: low cost devices,

flexible technologies (antennas cut on

solar cell foil)

Integrated design: the solar antenna is also

the ground plane


ASOLANT Technology Projects

SOLANT Project

Goals:

•Feasibility study

•Concept development

•A-Si:H solar cells

Goals:

• Application of the concept to a real space mission (MITA)

• GaAs solar cells applications

SOLANT prototypes

ASOLANT Project

Goals:

•Demonstration flight.

Highly successful under unfavorable conditions…

ASOLANT In-Flight Experiment


ESA-ESTEC founded project

Partners:

LEMA-EPFL Lausanne CHPRIME CONTRACTOR

OHB-System AG Bremen,D

Sub-contractor

HTS AG, now RUAG, CH, Sub-Contractor

Payload design & Launch

Antenna design & RF testing

Solar Antenna manufacturing & Mechanical testing

ASOLANT In-flight Experiment: Project Team

PROJECT SUPPORT


Experiment Schematics

Attached payload on Cosmos launch vehicle upper stage

L-Band Antenna tests with GPS Receiver

S-Band Antenna test with HAM Radio Beacon

Mission control via Orbcomm satellite network and Internet


S-Band Antenna

Debris ImpactDetector

RUBIN-5Bus

Container

Two Orbcomm Antennas (on the back-side)

Cosmos-3M Payload Adapter

Experiment Accommodation

ASOLANT#1

GPS-Band Antenna

ASOLANT#2


One single solar panel design for two antennasA limited number of solar cells has been used, but enough to ensure a safe mission power budget“Safe design“ approach for the solar panel and antenna designA modular solar panel design has been used being compatible with different antenna design

ASOLANT Antennas design approach

Limited budget has required a low cost solar antenna design approach:

ASOLANT Antennas


First ASOLANT launch: Launcher: Kosmos (OHB)Launch site: Plesetsk, RussiaLaunch date: October 27, 2005

All the space

qualifying tests

successful!

Space Qualification tests

Use of OrbComm Network + Rubin sat + Cosmos launcher:OHB-Teledata Bremen, D

Tests atRUAG/HTS

Wallisellen, CH


Launch Vehicle Overview (Kosmos)

System Integration and Launch


ASOLANT Experiment together with small satellites on payload adapter

before SSETIEXPRESSintegration Complete Payload

System Integration and Launch -1

Integration at Launch Site (Plesetsk, Russia)


SSETIEXPRESS

MOZHAETS

ASOLANT#1GPS

ASOLANT#2S-Band

ASOLANT Antennas and Solar Generators on payload adapter

Integration at Launch Site (Plesetsk, Russia)

System Integration and Launch - 2


Launch vehicle erection October 26th Launch October 27th

Launch (Plesetsk, Russia)

System Integration and Launch- 3


Experiment Results - 1

Mission Start

• Switch on afterLift Off + 4 minutes at firing separation event

• First telemetry received after Lift Off + 20 minutes

• Nominal flight confirmation, temperature and power level nominal telemetry data received

1 [email protected] [REPORT] 27 Oct 2005 07:11:08 +0000 20 1 6 0 90 117 23 23 44 2 [email protected] [REPORT] 27 Oct 2005 07:11:27 +0000 20 1 6 101 98 119 7 11 18 3 [email protected] [REPORT] 27 Oct 2005 07:13:03 +0000 20 1 6 102 98 119 7 11 36 4 [email protected] [REPORT] 27 Oct 2005 07:13:23 +0000 20 1 6 103 98 118 7 13 11 5 [email protected] [REPORT] 27 Oct 2005 07:13:43 +0000 20 1 6 104 94 117 7 13 30 6 [email protected] [REPORT] 27 Oct 2005 07:14:03 +0000 20 1 6 105 94 118 7 13 567 [email protected] [REPORT] 27 Oct 2005 07:14:33 +0000 20 1 6 106 98 118 7 14 148 [email protected] [REPORT] 27 Oct 2005 07:14:57 +0000 20 1 6 107 98 117 7 14 41

Remark:

[email protected] is the email address of ASOLANT In-Flight experiment.To avoid possible spam the part of the real address was removed and replaced by xxx.


The S-Band beacon canonly be swiched on for short periods due to power limitations

Several Amateur radio ground station have tracked the ASOLANT passes

Beacon signal has been received by DF4PV in Ingelheim (Germany) the21.11.2005 at 0:57 GMT

HB9THGHB9THG

DG6BCEDG6BCE

DF4PVDF4PV

Amateur radio receiving stations


S-Band Beacon


Received GPS signal confirmation by transmittedGPS receiver onboard timeupdate

No GPS navigation solution possible due to the limittedsky view and high rotation rate of the upper stage


GPS Signals

ASOLANT#1GPS

Mozhaets still on payload adapter…

One of the companion satellites didn‘t separate from the payload adapter where ASOLANT was installed !!


Compact power and telecommunication system

GPS navigation

Data monitoring

Low cost, low resolution on-board camera (60x80 pixels!)



A S O L A N TA S O L A N TF o r F o r E x o M a r sE x o M a r s

A S O L A N TA S O L A N TF o r F o r E x o M a r sE x o M a r s


•Mars Rovers are powered by solar cells

•Antennas and solar cells compete for limited available surface.

•An appropriate combination of the two can save valuable volume, mass and costs.

•ASOLANT technology has proven its technical feasibility.

•ASOLANT technology has been successfully applied to a satellite spacecraft

Some good reasons for using ASOLANT in ExoMars

ESA ExoMars Rover

NASA-JPL Rover

ASOLANT Flight models


Extend the rover capabilities for the same system size, weight and complexity

Improvement of the available rover power

Longer mission time

More power available for science

Larger space available for the antenna

More reliable data transmission

Higher bit rate telecommunications

Complexity reduction of the complete system

No need of deployment systems for the antenna

Safer operations

ASOLANT Enabling advantages

Mars landers deployable antennas (Spirit & Beagle 2)

ASOLANT planar antenna array


SOLAR ANTENNAS for ExoMars: 1) Some starting ideas

Hypothesis: available surface for antennas not bigger than a square wavelenght

60 x 60 cm at 500 MHz

Use "solar" antennasAvoid "shadow and mechanical problems of other antenna types

The Solant concept can be explorated in several topologiesIn all of these, a lot of room and weight can be saved

This would allow more flexibility for the antenna system (Tx/Rx)

Red: RF radiating surface

Yellow: solar cells

Patch Slot Full integration


SOLAR ANTENNAS for ExoMars. 2 : A roadmap

Start a project looking for a specific design meeting ExoMars specification.Frequency, transmission system, link distance and geometries

X-pol levels, radiation pattern, realized gain, bandwidth, bit rate...

Explore existing and new topologies of "solar" antennas: model them!Patches, slots, wire antennas on solar cells, RF-radiating solar cells

Don't forget the harsh environmentExperience with previous SOLANT satellite flight very useful here

Consider specific problems like martian dustAntenna sensitivity

Project goal: a full mathematical/numerical model, a selected design and a working prototype tested on a rover mock-up


ESA ExoMars Rover

Spirit rover antenna& experiment arm (NASA-JPL)

Actual rover concepts


Actual rover concepts


ASOLANT rover concept

Same rover conceptSame weight and volumeExtended rover capabilities

More solar powerLarger antenna Less deployment system


ASOLANT's future in Space

SPACE APPLICATIONS: Deep space missions,

planetary rovers, ExoMars...


http://itopwww.epfl.ch/LEMA/Asolant/

Combined antenna & solar arrays for space exploration · antenna surface. Being thinner than 0.5...

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