Free fall payload test environment and mission simulationgram.oca.eu › Ressources_doc › EP_Colloquium_2011 › 9 H Selig.pdf · Free fall payload test environment and mission

ONERA Palaiseau - 19.9.2011 H. Selig / M. List funded by DLR-Agency

Free fall payload test environment and mission simulation


• Drop Tower Bremen

• Free flyer concept

µg-quality

• Catapult system

µg-quality

• MICROSCOPE test configuration baseline

• Mission simulation


Drop Tower Bremen

1g 0g 45g


)()( tFmgtma drag )()( tFmgtma drag

mg

FdragAir drag - air friction

22 )(2

)()( tvcAtvtF wNewton

Centrifugal acceleration2 rac

0 .00 0 .05 0 .1 0 0 .1 5 0 .2010 -10

1 0 -9

1 0 -8

1 0 -7

1 0 -6

d is tance to sp inaxis

0 .01m 0 .05m 0 .10m 0 .20m 0 .30m

a z [ms-2

] (=

2 r)

S p in ra te [°/s ]

Vibrationpayload (fans, harddisks, etc.),transition 1g-0g

vibration damping, no vibrating payload components!




µg-quality

• Catapult system

µg-quality




Power supply

Computer

Accelerometer ONERA

Accelerometer

ZARM

Radio link

Power supply

Computer

Drop capsule

Free-Flyer

Radio link


1 10 100 10001E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

drop 2011-03-17_1blocked freeflyer, blocked damping system, capsule computer fan off 1s before drop

AccX (vert.) AccY AccZ

ms-2

Hz-1

/2

Hz

1 10 100 10001E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

drop 2011-03-18_1unblocked freeflyer, blocked lower damping system, unblocked upper damping system, capsule computer fan off 15s before drop

AccX (vert.) AccY AccZ

ms-2

Hz-1

/2

Hz

Free flyer+ vibration damping

Standard Capsule




µg-quality

• Catapult system

µg-quality




The ZARM Catapult system

-1 0 1 2 3 4 5 6 7 8 9 10-0,0005

-0,0004

-0,0003

-0,0002

-0,0001

0,0000

0,0001

0,0002

0,0003

0,0004

0,0005

AccX measured AccX simulated

22.01.2008 Vp=40V

AccY

,Z,X

/ms-2

Time/s

22 )(2

)()( tvcAtvtF wNewton

Acce

lera

tion

/ms-

2

10 100 100010-9

10-8

10-7

10-6

10-5

10-4

10-3

Acc (horizontal) Free-Flyer Acc (horizontal) Katapult

Hz

ms-2

Hz-1

/2


Stanard drop Free-flyer

Standard drop Catapult shot

µg duration 2-3 s 4 s 7-8 s

present µg-level 10-7 - 10-8g 10-5 - 10-6g 10-5 - 10-6g (10-7 g around apex)

advantage

disadvantage

best µg-level

short experiment time

low spin rates

lower µg-level

long experiment time

lower µg-levelhigher spin rates

better for High-Resolution-ModeHRM

better for Full-Range-ModeFRM




µg-quality

• Catapult system

µg-quality




• Pre qualification tests SU QM2 : 2011Several drops in order adjust the parameters

• Qualification tests SU QM2 : 2011Qualification purpose: drop before and after environmental tests

• Functionnal tests SU FM : 2011/2012control the PM for all axis

• Test SU FM : 2011/2012Flight configuration

Test configuration baseline




µg-quality

• Catapult system

µg-quality



19.09.2011 | Paris

1

Testing the Equivalence Principle from a Basis of General Relativity to a Key to Quantum Gravity

Center of Applied Space Technology and Microgravity

• Processing of MICROSCOPE data – data reduction methods

High performance satellite dynamics simulation tool

• Comprehensive simulation of the real system including the science signal and error sources

• By means of mission simulations data is generated to test the reduction and processing methods

19.09.2011 | Paris

2



19.09.2011 | Paris

3



19.09.2011 | Paris

4



• Models of Earth Gravity Field: Simple Gravity Model (spherical potential including zonal

harmonic coefficients Jn up to degree n is approximated)

Higher order Gravity Model: Spherical harmonic model of

the Earth's gravitational potential (complete to degree and

order 360, based on GRACE data: EGM2008, EIGEN-5C,GGM03)

all effects of the Earth's non-symmetric mass

distribution can be described

Higher order Gravity Model: Method of Pines (based on

Grace data, zero-tide system: includes permanent tidal

deformation due to external bodies)

19.09.2011 | Paris

5



• Earth Magnetic Field: The International Geomagnetic Reference Field (IGRF-11)

External magnetic field: Tsyganenko Model• Internal magnetic field (IGRF-11)• Distortion of the internal magnetic field in high altitudes

because of the solar wind

• Ephemerides: Sun, the planets and Pluto

Based on the algorithm of Montenbruck & Pfleger

better: JPL ephemeris (based on n-body-calculations of approx.

300 solar system objects including the PPN of GR)

19.09.2011 | Paris

6



• Atmospheric Density: Empirical model for the atmosphere extending from the

ground to the exosphere (NRLMSISE-00):

• associated with the NRLMSIS data base

• models the temperatures and densities of the atmosphere's

components

HWM93 atmospheric wind Models

Model of Harries-Priester

• based on the properties

of the upper atmosphere

as determined from the

solution of the heat

conduction equation

under quasi hydrostatic

conditions

19.09.2011 | Paris

7



• Eclipse Model

• Solar Pressure Model: Point-like source

Finite disk source

• Albedo Irradiance Model: Reflectivity data taken from

• Total Ozone Mapping Spectrometer (TOMS):

22. July 1996 – 14. December 2005• Aura Mission: 1. January 2005 - 30. June 2009• Monthly mean data sets can be used (generated from TOMS

data)

19.09.2011 | Paris

8



• Transformations

19.09.2011 | Paris

9



• Transformations

19.09.2011 | Paris

10



• Surface Forces:Calculation of surface forces and resulting torques by means of

Finite Elements

Dependence of the disturbance force on the geometry of

satellite

• Space Debris:Under Construction!!!

Uses data obtained with the help of ESA-tool MASTER

(Meteoroid and Space Debris Terrestrial Environment

Reference)

19.09.2011 | Paris

11



• Test mass and satellite dynamics

• Noise Model of MICROSCOPE instrument

Noise model and filter estimation with simulated noise sampled at 1000 Hz for 100s


“Simulation” team at ZARM

Stefanie BremerMeike ListBenny RieversHanns Selig

Free fall test team at ZARM

Manfred BehrensHanns SeligMarcus Stadtlander

Students

Patrick NtsanaSebastian Hinck

Project Leader

Claus Lämmerzahl

Documents

Free fall payload test environment and mission simulationgram.oca.eu › Ressources_doc › EP_Colloquium_2011 › 9 H Selig.pdf · Free fall payload test environment and mission