1 corot science week, marseille, 3-6 june 2003 corot mission agenda ðsystem progress report...
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1COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Agenda System progress report
Scenario of observations Satellite engineering
Confirmation of the flight domain System engineering
Satellite-to-ground link
Telemetry budget Launch of COROT
Picture of SOYUZ in Kourou
2COROT Science Week, Marseille, 3-6 June 2003
Instrument progress reportInstrument progress report
COROTCASE
COROTEL
COROTLOG
COROTCAM
PROTEUS
3COROT Science Week, Marseille, 3-6 June 2003
System progress reportSystem progress report
Satellite engineering overview Many activities
Spacecraft mathematical modelfor coupled load analysis with the launcher
SED-16 star tracker accommodation AOCS specific command & control Mechanical and electrical interfaces
AOCS performances To be estimated after coupled simulation with payload ecartometry Results available for the next Corotweek (Marseille, spring 2003)
Spacecraft roll domain Power budget improved by Li-Ion battery Beginning of life : simulations show that the ± 20° requirement will be met End of Life (low electrical efficiency, broken cells) : performance TBC
Last step of the contract negotiation with Alcatel Contract to be signed in the first quarter of 2003
4COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Orbit parameters The orbit will not be kept phased after commissioning
risk of sun glare in case of semi-major axis correction maneuver semi-major axis drift over 5 years : - 7 km (atmospheric drag) orbit period stability over 6 months : better than 1 s
Eclipse
Xs+
Thruster along Xs
Sun direction
5COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Orientation of the satellite - flight domain
South
North
Orbit plane
Perpendicular to the orbit plane
boresightRoll angle
Sun
6COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
The sky observed by COROT
0°
30°
60°
90°
120°
150°
180°
210°
240°
270°
300°
330°
0h2h4h6h8h10h12h14h16h18h20h22h
SummerZone of observationcentered at 18h50
WinterZone of observationcentered at 6h50
Galaxy
7COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Satellite design / axes
Zs+
Xs+
Ys+
Equipment bayUpper compartment with sensitive equipmentFine thermal regulation subsystem
8COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Platform design “PROTEUS Evolution” family
series of 5 platforms upgraded electrical and AOCS chains
Li-Ion battery higher capacity (80 A h)
no more problem of power supply in Safe Hold Mode lower thermal dissipation
the battery sidewall can withstand any solar incidenceno need to rotate on the boresight axis after 5 months
New Magneto Torquer Bars higher capacity (180 A m2)
better convergence of the Safe Hold Mode equipment driven by a proportional control law
no more pointing disturbances due to MTB activations
Other features : new star trackers (SODERN), 2-antenna GPS
9COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
New mission schedule Thermal constraints shrunk to payload constraints
the Ys+ satellite wall (focal unit radiator) must be in the shadeas much as possible
No more 180° rotation on Xs between CP and EP No more EP2 critical thermal configuration for payload design Several possibilities for the scheduling
Exploratory Programs can be carried out either at the beginningor at the end of a 6-month period
an alternate schedule CP1, EP1, CP2, EP2 is operationally recommended
Focal unit radiator temperature worst cases in 1b and 2b 1b and 2b zones crossed by the Line of Equinoxes temperature depending on direction of observation and roll angle
10COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Straylight Thermal constraints
polar caps lightened under small angles see the Corotweek n°3 (Liège) - presentation by Annie Baglin « scattered light from Earth »
the maximum is reached when the satellite flies over the day part of the Earth
11COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Eclipses (over the year) max : 0.34 Torb
Eclipses à 826 km
0
500
1000
1500
2000
2500
0 1000 2000 3000 4000 5000 6000
numéro d'orbite
du
rée
to
tale
(s
ec
)
19/01 19/06 22/07 19/12
Favorable period of timeLow-level perturbations
12COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Previous schedule“Peace and Love”
Line of nodes
Summer
Winter
Autumn
Solar declinationup to +23°
Ys+
Solar declinationdown to –23°
Central Program 2
Exploratory Programs 1 & 2
180° rotation on Zs
180° rotation on Xs
180° rotation on Xs
180° rotation on Zs
Satellite axesin a fixed orbital reference frame ROF
XJ2000
YJ2000
XOF
ZOF
Equatorial plane
12.5°
Earth orbit
Central Program 1
Line of Equinoxes
Spring
S
Xs+
Zs-
Xs+
Zs-
Ys+
Xs+
Zs-
Ys+
Zs-
Xs+ Ys+
Anticenter (6h50)Center (18h50)
13COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Updated schedule“Piece of cake”
Line of nodes
Summer
Winter
Autumn
Solar declinationup to +23°
Solar declinationdown to –23°
Central Program 2
Exploratory Programs 1 & 2
180° rotation on Zs
180° rotation on Zs
Satellite axesin a fixed orbital reference frame ROF
XJ2000
YJ2000
XOF
ZOF
Equatorial plane
12.5°
Earth orbit
Central Program 1
Line of Equinoxes
Spring
S
Xs+
Zs-
Ys+
Zs-
Xs+ Ys+
1b
1a 2b
2a
Center (18h50) Anticenter (6h50)
14COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Line of nodes
Summer
Autumn
Solar declinationup to +23°
EP 1
180° rotation on Zs
180° rotation on Zs
Satellite axesin a fixed orbital reference frame ROF
XJ2000
YJ2000
Equatorial plane
12.5°
Earth orbit
CP 1
Line of Equinoxes
Spring
Zs-
Xs+ Ys+
1b
1a
18h50
Favorable directionin the observation cone
RA +
S
15COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Line of nodes
Winter
Autumn
Solar declinationdown to –23°
CP 2EP 2
180° rotation on Zs
180° rotation on Zs
Satellite axesin a fixed orbital reference frame ROF
XJ2000
YJ2000
Equatorial plane
12.5°
Earth orbit
Line of Equinoxes
Spring
Xs+
Zs-
Ys+
2b
2a
6h50
Favorable directionin the observation cone
RA +
S
16COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Straylight maximum level (on the orbit) as a function of time
case of winter
-12° RA +12° RA
-12° dec
+12° dec
17COROT Science Week, Marseille, 3-6 June 2003
COROT missionCOROT mission
Performance management Performance management consists in choosing the most favorable edge for
each observing run a slight drop in periodic performances (compatible with the requirements) can be tolerated
for the EP observing runs white noise bphot = f(1/ Tobs) in Fourier space
spectrum analysis less sensitive to periodicperturbations (hidden lines) in EP runs
i 2 Ai / ( bphot (T)) 1 / Qi < 100 Hz
To define a scenario, the users shall have a series of criteria direction of observation roll angle to optimize the projection of the targets onto the CCD criticity of the thermal regulation (level, variability) function of the roll angle criticity of the straylight intensity if any
18COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Spacecraft overview (-Zs sidewall)
Antenne patch GPS -Xs
Antenne patch GPS -Zs
Proteus Corotcase Corotel
19COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Spacecraft overview (+Zs sidewall)
Corotel Corotcase Proteus
20COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Spacecraft overview (+Zs sidewall)
21COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Ys+
Xs+Zs+
S
RSF cover
dec < 0
Sidewall in the shade
WINTER - Sun in the back of the satellite
22COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Ys+
Xs+Zs+
SRSF cover dec < 0
Sidewall lightened if roll < 0
WINTER - First days
roll < 0
23COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Ys+
Xs+
Zs+S
RSF cover
dec > 0
Sidewall lightened even if roll = 0increasing flux when roll > 0
WINTER - Last days (round J91)
roll > 0
24COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Spacecraft overview (+Zs sidewall)
25COROT Science Week, Marseille, 3-6 June 2003
Spacecraft overviewSpacecraft overview
Equipment bay (COROTCASE) scientific data processing electronics
BCC camera controlBEX extraction units DPU processor
instrument housekeeping electronicsBCV power distribution BS1 analogical payload telemetry BS2 synchronization and thermal regulation
On-board software (COROTLOG) aperture photometry algorithms angle error measurements for AOCS satellite-to-ground link : 900 Mbits/jour
26COROT Science Week, Marseille, 3-6 June 2003
System progress reportSystem progress report
Spacecraft roll domainwinter
Ys+
Zs+
S E
CP and EP n°2
Objective : ± 20°
angle for optimum power budget : = arctan (-tan sin) = 5.25°
Confirmed
for
Beginning of Life
27COROT Science Week, Marseille, 3-6 June 2003
Spacecraft roll domain summer
Ys+
Zs+
CP and EP n°1
E S
Objective : ± 20°
angle for optimum power budget : = arctan (-tan sin) = 5.25°
System progress reportSystem progress report
Confirmed
for
Beginning of Life
28COROT Science Week, Marseille, 3-6 June 2003
System progress reportSystem progress report
System engineering overview System engineering activity currently focused on
instrument modes and in-flight operations all command & control interfaces ground segment architecture use of ground stations system tools for Corotsky light curve corrections level 0/1 products
CCC
PLTMHKTM
Network
CMC
TC
TTCET
TTCET
CDC
29COROT Science Week, Marseille, 3-6 June 2003
System progress reportSystem progress report
Instrument modes
VEILLE
SAFEOFF
VALIDATION ECARTOMETRIE GROSSIERE
VALIDATIONECARTOMETRIE FINE
VALIDATION IMAGE EXOPLANETES
VALIDATION IMAGE ASTERO
VALIDATIONPLAN DE MASQUES
OBSERVATION
Phase de Mise en station
CALIBRATION PERIODIQUE
Modes dédiés aux CALIBRATIONS DEBUT DE VIE
30COROT Science Week, Marseille, 3-6 June 2003
System progress reportSystem progress report
Satellite-to-ground link capacity Station Acquisition Phase Preparation of an observing run
(7 days) VFA + NTL + KRN for many TC/TM operations useful scientific telemetry up to 2.2 Gbits / day
31COROT Science Week, Marseille, 3-6 June 2003
System progress reportSystem progress report
Satellite-to-ground link capacity Observation Phase Observing run (20, 150 days)
VFA + NTL useful scientific telemetry up to 1.4 Gbits / day
32COROT Science Week, Marseille, 3-6 June 2003
Satellite-to-ground link capacity The nominal scientific mission is performed with VFA station
Seismology 12 windows by CCD– 5 star windows, with 2 mask images (over 32 s)
– 5 background windows
– 2 offset windows
Exoplanets 6000 windows by CCD– 4 964 chromatic star windows
– 36 oversampled chromatic star windows
– 949 monochromatic star windows
– 42 oversampled monochromatic windows (including offset)
– 9 imagettes
Total for 2 photometric chains : 958 300 kbits / day
System progress reportSystem progress report
33COROT Science Week, Marseille, 3-6 June 2003
System progress reportSystem progress report
Satellite-to-ground link capacity How the additional telemetry with NTL station can be used ?
More seismology mask images
1 mask image over 32 s --> 45.6 Mbits / day1 mask image over 16 s --> 91.6 Mbits / day1 mask image over 8 s --> 182.4 Mbits / day (mask size = 25 x 25)
More exoplanet imagettes
1 imagette over 32 s --> 6.5 Mbits / day
Examples of scenario Spreadsheet program 5 seismology mask images (over 32 s) + 25 exoplanet imagettes x 2 3 seismology mask images (over 16 s) + 15 exoplanet imagettes x 2 2 seimology mask images (over 8 s) + 20 exoplanet imagettes
+ 2 seismology mask images (over 32 s) + 20 exoplanet imagettes
Total for 2 photometric chains : < 1 400 000 kbits / day
34COROT Science Week, Marseille, 3-6 June 2003
Project statusProject status
Launch of COROT in June 2006 Launch of COROT by SOYUZ/ST from the Guiana Space Center
Choice made by CNES headquartersin July 2002
Maiden flight from Kourou Contract to be signed with Arianespace
before end of 2003, after next ESA Council Civil engineering in Malmanury River
expected before July 2003
If any inacceptable delayon the launch pad work,back-up by ROCKOT from Plesetsk