MIST Team 11 Final Presentation

19th May 2020. Stockholm

MIST Team 11Final Presentation

19/05/2020 KTH, Stockholm, Sweden 2

Table Of Contents

Time Duration Topic Speakers Page

13:00

5 min 1. Major Events & Student workforce Sven 3

15 min 2. System Engineering Anna 8

15 min 3. Mechanical Filippo, Topias 32

15 min 4. Thermal Engineering Mikael, Filipp 48

15 min 5. ADCS Leonardo, Hasan 61

25 min 6. OBSW John, William, Elias, Sonal, Erik, Ojasvi 74

14:30

10 min 10 minutes break

15 min 7. Ground Station Joan 117

25 min 8. Functional Testing and Electrical Design Andrii, Citlali, Xiyao, Theodor, Alejandro 129

15 min 9. Master Thesis - Nanoprop Victor 160

Questions

1. Project managementSven Grahn

19/05/2020 Sven Grahn - KTH, Stockholm, Sweden

MAJOR EVENTS 2019-2020

Final satellite subsystem hardware deliveries• ISIS Generic Interface System, 27 May 2019• OBC daughter board, 27 May 2019• Solar panels, 11 September 2019• Solar panel release mechanism, 11 September 2019.Ground station• Main design features frozen.• Key subsystems ordered.Fly Your Satellite competition• ESTEC 9-13 December 2019, technically highly very

useful, KTH withdrew for several reasons.Additional funding• The KTH SCI-school added 1 MSEK in December 2019.

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Solar panels arrive from ISISpace , Sept 2019

Sven Grahn - KTH, Stockholm, Sweden

STUDENT WORKFORCE

Fall 201918 students worked on the project. 15 of which continued from the spring of 2019. Spring 2020An almost new student team of 16 started in January 2020, including one M.Sc. thesis student and three B.Sc. thesis students.

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PROJECT WORK DURING COVID-19


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• KTH closed its premises to students on 18 March. • Students took out some hardware & computers to their lodgings the previous

evening.• Some limited work in the MIST lab is possible under a special protocol. • 9 project meetings with up to 20+ participants held on Zoom since 18 March.

PROJECT WORK DURING COVID-19


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The place from whichthe project is managed!

2. System Engineering

19/05/2020 Anna Larsson - KTH, Stockholm, Sweden

Anna Larsson

What is system engineering about?

• Keeping track of system budgets➢ Power budget➢ System budget➢Mass budget➢…

• Keeping data up to date➢Valispace

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Overview

Been working outside schedule this semester to finish up some work:

• Finish power losses in simulations

• Include the camera in simulations


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Goals of the semester

Overview

MIST Experiments


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Overview

MIST Experiments and power groups


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INGGroup 1 Group 2 Group 3 Group 4

SEUD SEUD SEUD SEUD

SiC SiC SiC SiC

CUBES_1 Piezo Legs Piezo Legs

CUBES_2 Nanoprop


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Power losses


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Power losses

• Implemented by previous student, used as input to current simulations


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Power losses

• Implemented by previous student, used as input to current simulations• Battery efficiency: 85%


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Power losses

• Implemented by previous student, used as input to current simulations• Battery efficiency: 85%• Regulator affects switched line. Total efficiency: 90%. Implemented as increase

in experiment usage.


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Power losses



• Cables and connectors losses


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Power losses



• Cables and connectors losses

ImplementedPotentially future work


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Power losses

• Limiting factor for power usage

• MIST limit: 80%


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State of Charge


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Simulation Results: Group 1


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9 h37 min

• Result in comparison to the goal


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• Implemented new case for Nanoprop➢ Based on thesis, but might need to be updated again

• Power losses implemented

• Nanoprop helper board implemented

• All groups except CUBES are fine → further discussions needed➢Was expected


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Results

• Nanoprop according to thesis

• Nanoprop Helper board details➢ Mass

• Housekeeping➢ Subsystems in data budget

• Power losses between solar panels and battery due to cables

• Updates as experiment finishes

• Camera➢ Not yet ready for implementation, but code is ready for it


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Additional work

Thank you for the time in MIST!


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Additional work

3. MechanicalFilippo Pozzi & Topias Tyystjärvi

19/05/2020 Filippo Pozzi & Topias Tyystjärvi - KTH, Stockholm, Sweden

• Finalise mechanical design• Update mechanical status documentation• Choose and order fasteners• Assembly procedure• Mechanical testing procedure

19/05/2020 Filippo Pozzi & Topias Tyystjärvi - KTH, Stockholm, Sweden 33

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• CAD model checked and completed• Inaccuracies solved or documented

• Drawings of components are updated


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Completed work

• Stack height finalised and drawings created for assembly


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Completed work

• Design and fit checks of the coverplates (-Z still to be confirmed)


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Completed work

DRAWN

CHECKED

ENG APPR

MGR APPR

UNLESS OTHERWISE SPECIFIEDDIMENSIONS ARE IN MILLIMETERS

ANGLES ±X.X°2 PL ±X.XX 3 PL ±X.XXX

NAME

D. Mainwaring

DATE

2019-09-03 Solid EdgeTITLE

PosZ_Coverplate

SIZEA2

DWG NO REV1

FILE NAME: M110_022_PosZ_Coverplate_v1.dft

SCALE: WEIGHT: SHEET 1 OF 1

REVISION HISTORY

REV DESCRIPTION DATE APPROVED

B. Bernus 2019-09-28

1,5

80,4

98,4

O2,6

10,7

5

80,4

98,4

O20

9

9

+X

+Y

+X

+Z

24,45

3,4

5,2

5

20 R1

-Z -X +Z

• Two Solar panel mock-ups manufactured and fit checked• Mock-up hinge for solar panel in deploy position, manufactured• Holding mechanism for the thermal chamber, manufactured


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Completed work

DOCUMENTS CREATED/UPDATED:• Harnessing road map (= Information of electrical cabling) updated and better organized


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Completed work


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Completed work

DOCUMENTS CREATED/UPDATED:• Checklist before start of the

final assembly


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Completed work

DOCUMENTS CREATED/UPDATED:• Assembly manual

• Step by step procedure for the whole satellite• Pictures from mock-up and subsystem documents• Torque requirement and Harnessing designated

number


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Completed work


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Completed work

DOCUMENTS CREATED/UPDATED:• Vibration testing

• Test plan: accelerometer and lasermeasurements, satellite orientation

• Testing specification reviewed• Sine sweep and random

vibration • Planned with KTH vibration facility

DOCUMENTS CREATED/UPDATED:• Vibration testing

• List of equipment – no new orders needed• Step by step testing procedure• Template for reporting during test


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Completed work

Orders of components• Main considerations: extra-low magnetic (due to magnetorquer), thermal properties,

resistance to wear• A4l steel and titanium preferred• Titanium has low thermal conductivity – work with thermal team to confirm viability

• ISIS APF screws• ISIS new hex nuts • Bumax M3 stainless steel screws• Titane services titanium screws-nuts-washers• Screws and more titanium screws-nuts-washers• Farnell Torque screwdriver and screwdriver bits• Galindberg epoxy glue


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Completed work

Other Work• Piezo meeting for update on drawing version• Piezo mounting board in aluminium, ready to be manufactured• Torque requirement for larger screws• Screws to be glued before the testing• Harnessing check, length and specification document review• Kill switch connection specified• Mock-up is completed, only the camera itself is missing• Countersunk holes fabricated in custom ribs


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Completed work

CONSIDERING THE CORONA SITUATION• Solar panel fit check and Assembly procedure rehearsal not performed - Needs two people in the lab • Some in-house parts have not been completed (cutting rods and spacers)

NOT PRIORITIZED ON THE PAST SEMESTER• Flight hardware coverplate manufacture in standby, thermal team will confirm the coating• Document for the complete list of all materials used not yet started but information has been gathered


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Future work

• Complete the assembly check-list with more detailed information• Rehearse the assembly procedure on the mock-up considering everything as flight hardware, with the

necessary precautions• Fit check of the solar panels on a “cleaned” mock-up• Conduct a simplified rehearsal before the vibration test• Manufacturing of the flight hardware cover plates• Receive and check all Harnessing• Receive and check all the screws, nuts, and washers• Cut the titanium rods as defined• Manufacture new Aluminium spacers


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Future work

4. Thermal TeamFilipp Byström , Mikael Lyth

19/05/2020 Filipp Byström, Mikael Lyth - KTH, Stockholm, Sweden

• Simulating the thermal tests• Preparing the thermal tests

19/05/2020 Filipp Byström, Mikael Lyth - KTH, Stockholm, Sweden 49

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Model

•Create a model of the satellite•Software implementations

Simulations

•Space environment•Test environment•Material decisions

Testing

•Thermal balance •Thermal cycling

Finish

•Update the simulations with results from testing•Thermal bake-out


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Introduction to MIST Thermal Analysis

• Simulations• Thermal balance test• Thermal cycling test• Material changes• Model changes

• Testing plans• Thermal balance test• Thermal cycling test

• Thermal bake-out


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Work


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Results – Thermal Balance Simulations


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Results – Thermal Cycling Simulations

Reference

5 h 12 h 5 h

OBC

5 h 12 h 5 h


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Testing - Procedure

1. Start2. Thermal Balance Test3. Thermal Cycling Test

1. Maximum and minimum temperatures2. Functional testing3. Temperature changes

4. End

5 h 12 h 5 h

Systems check


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Testing - Procedure


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Testing - Equipment

Vacuum chamber

Mounting rack

• 4 Minco HK6908 (or Omega) heaters in two heater groups• 6-7 T Thermocouples (Type B10)• AWG 26 wire, 8-10 m• Non-degassing conductive tape & Non-degassing non-conductive tape• Electrical feedthrough

• Finish the test simulations (Output expected temperatures)• Finish the test plans (Communication and control important!)• Restart work on getting acceptable flight temperatures (flight sim + thermal analysis)• Obtain all test equipment (Hooks to hang MIST)• Prepare post test analysis• Perform the thermal testing*• Evaluate the test results*• Update the flight simulations*

* Might be affected by Covid-19


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Additional Work

5. Attitude Determination and

Control SystemLeonardo Ricci, Hasan Basaran

19/05/2020 Leonardo Ricci, Hasan Basaran - KTH, Stockholm, Sweden

• Make the S-I-L simulation for the ADCS SW run properly; [completed]

• Explore the performance of the “ISIS ADCS Next Gen Library” used in the ADCS SW; [WIP]- Robustness (develop orbital disturbances and phenomena)- Capability (tune controller gains and estimator covariances)

• Find ways of testing sensor/actuator interfaces to the ADCS SW; [WIP]

• Explore further tests of the ADCS SW approaching H-I-L fashion; [completed]

19/05/2020 Leonardo Ricci, Hasan Basaran - KTH, Stockholm, Sweden 62

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Make the S-I-L simulation for the ADCS SW run properly

Attending to a workshop at ISIS in Delft made the team realize:• Former ADCS SW simulation layout had some major conceptual errors• The software port to run the library in MATLAB® environment made the process too slow (2-3hrs)• The current windows version of the “ISIS ADCS Next Gen Library” is working

The decision was to move the whole ADCS SW simulation in C environment :• Create functions to cope with the whole simulation tasks• Integrate the controller • Develop a dynamic equations integrator

Improvements have been carried out during the rest of the semester.


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Current ADCS SW simulation layout.


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Explore the performance of the “ISIS ADCS Next Gen Library” used in the ADCS SW

• Albedo model developed:Every time the controller is called the cone of view below the satellite is subdivided into 99 surfaces1 of equal area identified by unit vectors in Body frame.Then an intensity is assigned to each of the radiations coming from thesurfaces and their contributions to the photodiodes output current is obtained

• Disturbance Torques model developed:- Aerodynamic torque (attitude dependant based on atmospheric density)- Residual magnetic dipole torque - Gravity gradient torque (classic linearized formulation)- Pressure radiation torque (Solar radiation pressure, Earth albedo and Earth radiation)

1. MIST_M132_001_version_1_20170601_Power_System_Modelling_for_Nanosatellites

Integration sanity checks


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Results

Simplified model, ω0=[0.5,0,0]rad/s β0=[1,0,0,0]


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Results

Simplified model, ω0=[0,0,1]rad/s β0=[1,0,0,0]


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Results

Simplified model, ω0=[0.3,0,0.2]rad/s β0=[1,0,0,0]


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Results

Find ways of testing sensor/actuator interfaces to the ADCS SW

Work closely with FT team running weekly meetings:

- Shared repositories on GitLab

- Added communications from the ADCS SW to Sun Sensor Simulator (UART)

Voltages output (then turned into total photodiodes currents) →

- Added communications from the ADCS SW to and from iMTQ Simulator (UART)

Output simulated magnetometer data →

→ Calculated command dipole


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Explore further tests of the ADCS SW approaching H-I-L fashion

Work closely with FT team running weekly meetings:

- Shared repositories on GitLab

- Common toolbox and code to generate initial data

- “In parallel” running capability of the Power Simulation and the Dynamics Propagator:

The test environment is controlled via a test manager able to activate and run the different codes

(cf. Functional Testing diagram on the next page).

- Preliminary set of commands to interact with the ADCS SW via the test manager


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Results

We had separate data sources that made the architecture complex and complicated to use.

The current architecture is more user and test-manager friendly:it eases out the test procedure.

• Complete last semester WIP tasks:• Explore the performance of the “ISIS ADCS Next Gen Library” used in the ADCS SW;

- Capability (tune controller gains and estimator covariances) → Run Test Cases. - Introduce noise and biases models for the measurements

• Find ways of testing sensor/actuator interfaces to the ADCS SW;

• Introduce new goals:• Provide active support in developing the ADCS SW inside the OBC;• Study ways of implementing H-I-L test procedure on the assembled s/c to test responses of the final system

to different scenarios (include orbital phenomena mock ups);• Obtain a set of parameters to configure the “ISIS ADCS Next Gen Library” on the flight hardware;


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Additional work

6. OBC TeamJohn Wikman, William Stackenäs, Elias Johansson, Sonal Shrivastava, Erik Flink,

Ojasvi Singh

19/05/2020 KTH, Stockholm, Sweden

1. Overview of major changes since last semester (John Wikman)2. Experiment module (William Stackenäs)3. Experiment communication (Elias Johansson)4. MIST Macro Telecommand Protocol (Sonal Shrivastava)5. Telemetry Fragmentation (Erik Flink)6. FDIR and Initialization Phase (Ojasvi Singh)

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Agenda

OBC TeamJohn Wikman

Overview of major changes since last semester


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1. Identified flaws in existing on-board software2. Changed the development philosophy3. Restarted with a new code base for the main on-board software4. Developed additional tools to aid the on-board software


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In short…

• OBC from ISIS• Drivers/API for hardware and procured subsystems• Development environment from ISIS• Timed C for real-time programming• MSP and I2C for on-board communication• AX.25 and CCSDS PUS for radio communication

• (Elveti as the MCS)• (Arduino Dues to simulate subsystems and experiments)


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Recap of the OBC platform

• The result of a master thesis• A real-time framework design• Modular tasks for experiments and subsystems• Customizable through a small set of callbacks• The framework is portable to different platforms


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The previous on-board software

• Fundamental design did not comply with many requirements of MIST• (Real-time aspects, TM transmission, etc…)

• Underdeveloped and difficult to work with• Most of the existing code was temporary

• Difficult to change the foundations with this in place!

• Many important functionalities were missing• (FDIR, TC acks, init phase, flight param DB, etc…)

• Most code was platform dependent, eliminating the benefit of multi-platform support

• and more... To keep developing this on MIST was not viable


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What was wrong with the old framework?

• Start with a brand-new code base• Should be easier for students to maintain• No restrictive framework, allow customizable real-time behavior

• (New requirements are still coming in for experiments!)

• Change in philosophy: Focus on the core foundation• (TC handling, TM handling, Param DB, ...)• Initially implement only what we need to test the foundation

• Do not rely on unfinished interfaces, rely on the requirements• Created fictional XTest experiment• Made up interface, but reflects actual experiment requirements


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What did we change? (1/2)

• Unified the radio link data interface• Created the mission-information-base• Single point of data interface specification• Generates code both for Elveti and the OBC• Version controlled

• Develop as if using the actual subsystems• No made up simulator interfaces• Simulators must work with existing drivers/API• Constructed MCS ↔ OBC communication simulator


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What did we change? (2/2)


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Current state of on-board software(Simplified, not including initialization or modes)

OBC

gettc

sendtm

TCqueue

handletc

hk

xtestTRXVU(Radio)

TMqueues

FlightParam DB

XTest(Ard. sim.)

MSPI2C

Elveti &Ground Station

Internal data flow (TC, TM)

Internal API calls

External communication

AX.25 &CCSDS PUS


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Test/development bench setup

The OBC Team “Corona” Lab

ElvetiComputer(MCS / GS)

OBC Development Computer


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Test/development bench setup

The OBC Team “Corona” Lab

Debugger

OBC EMTRXVU

Simulator

XTestSimulator

(only used to power the Arduino)

Demo Video


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Communication Demo

• Initialization phase• FDIR functionality• EPS handling • Needs to be integrated:

• Macro TC• TM Fragmentation• ADCS software

• The actual experiment callbacks

• (Possibly TC auth. and Radio Beacon mode, needs further investigation)


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Future (implementation) work

OBC TeamWilliam Stackenäs

Experiment module

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Payloads• Measurement mode

• Image payload (8096 bytes)• Width (1 byte)• Height (1 byte)• Pixel data (8094 bytes)

• Idle mode• Bluetooth payload (8 bytes)• Verification payload (8 bytes)

Housekeeping• ID (4 bytes)• Timestamp (4 bytes)• Mode (1 byte)• Temperature (2 bytes)• Error count (2 bytes)


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XTest Experiment


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The Module Window

Displays telemetryreceived from XTest in measurement mode.

Displays telemetryreceived from XTest in idle mode.

Used to select archivedtelemetry and housekeeping to be displayed

Displays housekeepingreceived from XTest.

Shows error messages.

• Automated build scripts• Send telecommands to XTest• Variable length housekeeping parameter


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Planned Features

OBC TeamElias Johansson

Experiment communication

19/05/2020 Elias Johansson. KTH, Stockholm, Sweden 92

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• Different modes (currently Idle, Measurement)• Expandable data structure• Continuous update loop• OBC Request Callback


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XTest Simulator

Xtest Data Structure

- Update Interval

- Mode of operation

- Data Flag

- Data

- Size of data

Loop through data structures

If time to update and mode:

Update data

OBC Request

If has data:

Send data, set size

Else

Respond size zero

• Telecommand to telemetry


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OBC - XTest

Examine TC then:

Request Data

Data Passthrough

Telemetry

Insert into queue

TC specific function

OBC TeamSonal Shrivastava

MIST Macro Telecommand Protocol (M2TP)

19/05/2020 Sonal Shrivastava. KTH, Stockholm, Sweden 95

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• Define and design M2TP framework (as a common module among OBC and Ground station)• Test if it works!


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BACKGROUND• What is M2TP and why is it needed?

• M2TP stands for MIST Macro Telecommand protocol.• Module defined, designed and responsible for handling macro telecommands on Ground station and OBC

sides.

• What is a macro telecommand?• A custom defined telecommand constituted by other desired telecommands

• Why do we need this?• Limited Uplink bandwidth available – 1200bits/s only• Maximum Uplink payload size restricted to 200 bytes• Trigger actions on OBC which require repetition• Examples – OBC requesting payload data from experiments, managing operation of experiments and so on…


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Work


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Concept

OBC

M2TP LIBRARY

MACRO TELECOMMAND

Send Telecommand

M2TP MODULE

TC1 TC2 TCn. . . . .

Packing

Receive Telecommand

M2TP MODULE

TC1 TC2 TCn. . . . .

Unpacking

GROUND STATION

M2TP LIBRARY

• Required implementation in three repositories – Mission Information Base, OBC andTMTC-API

• Constituent telecommands’ data is packed into an array of bytes

• Max 200 bytes allowed in one transaction (limitation by TRXVU)

• One entry of telecommand = 13 bytes

• Maximum number of telecommands that can fit ≈ 14

Highlights:

• Number of repetitions range = [1 – 254] (‘0’ means no repetition)

• Maximum repetition time interval = 65535 seconds (around ~18 hours)

• Extensible framework


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Implementation

Structure Attributes - Target APID- ACK type- Service Type- Service Subtype- Execution time- Number of Repetitions- Repetition Interval- Application Data

Macro Telecommand

N . . . . . . . . .TC1 TC2 TC3 TCn


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Results

Goals accomplished so far...

✓Define M2TP ✓Design modifiable M2TP framework

Test if it works!

FUTURE WORK• Separate handling of acknowledgements of Macro telecommands and its constituent telecommands to

be sent back to Ground Station• Proper sequence counting for the same• Handle erroneous and other left out scenarios on OBC and GS• Further optimizations


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Additional work

OBC TeamErik Flink

Telemetry Fragmentation

19/05/2020 Erik Flink. KTH, Stockholm, Sweden 102

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Enable fragmentation of messages sent between the OBC and the ground station.Fragmentation is needed since the experiments on board will need to send telemetry that won't fit in one TRXVU frame.1. Identifying limitations and requirements.2. Looking at existing protocols and solutions.3. Selecting/developing a solution.4. Implementing the solution in both the OBC and the ground station.5. Testing the solution.


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1. Identifying limitations and requirements.• CUBES generates 8 kB of data every minute when it is active.• Maximum telemetry size: 214 B.• Fragment loss rate 55% with a BER of 10^-5, but only 0.08% after 2 minutes.• No dynamic memory allocation and minimal stack usage in OBC software.

2. Looking at existing protocols and solutions.3. Selecting/developing a solution.4. Implementing the solution in both the OBC and the ground station.5. Testing the solution.


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Work

1. Identifying limitations and requirements. 2. Looking at existing protocols and solutions.

• IP, TCP, RDP & CSP/SFP were examined• SFP similar to what we want, but not optimal (32-bit length and byte offset)

3. Selecting/developing a solution.4. Implementing the solution in both the OBC and the ground station.5. Testing the solution.


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Work

1. Identifying limitations and requirements. 2. Looking at existing protocols and solutions.3. Selecting/developing a solution.

• 3-byte header• Maximum block size: 54016 B• Fragmentation is simple• Defragmentation based on IP reassembly algorithm (RFC 815)

4. Implementing the solution in both the OBC and the ground station.5. Testing the solution.


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Work

1. Identifying limitations and requirements. 2. Looking at existing protocols and solutions.3. Selecting/developing a solution.4. Implementing the solution in both the OBC and the ground station.

• OBC: C library. • Uses statically assigned variables.• Initialize, get fragments, put in telemetry queue

• Elveti: C# class and processing module• Processes telemetry with given ST & SST• Generates Custom Reporting Data to be processed by other modules

5. Testing the solution.


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Work

1. Identifying limitations and requirements. 2. Looking at existing protocols and solutions.3. Selecting/developing a solution.4. Implementing the solution in both the OBC and the ground station.5. Testing the solution.

• Unit testing has been done• Simple integration test with 3 fragments• Further integration tests have not been possible to perform

• Issue with the Elveti computer (timeout after 6 telemetry packets)


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Work

• Working fragmentation protocol and implementation• Asymptotic time complexity is linear, both for fragmentation and defragmentation• Theoretical net data rate has been calculated

• 7.9 kb/s for 8 kB data blocks with TRXVU @ 9.6 kb/s• CUBES data from 24-hour active period will take 3 h 18 min to download


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Results

• Further integration tests• Serialization/Deserialization of Custom Reporting Data• Storage and retrieval of Custom Reporting Data• Integration with experiments and subsystems


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Additional work

OBC TeamOjasvi Singh

FDIR and Initialization Phase

19/05/2020 Ojasvi Singh. KTH, Stockholm, Sweden 111

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• Design skeleton for the initialization phase of the onboard software.• Identify checkpoints in the initialization phase, so that steps are not repeated in case of a reset and the

OBC does not get stuck at any one step.• Implementation of Fault Detection, Isolation and Recovery within this task.


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• Currently at the Design Stage of the project.• Referred to documentation on the Initialization Phase to gather requirements.• Designed flow charts for macro steps within the initialization phase.


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Fig: Pseudo Code for the Initialization Phase.


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Results

Fig: Flow Chart for Detumbling Procedure.Fig: Flow Chart for Solar Panel Deployment Leading

into UHF and VHF Antenna Deployment Stages.

To implement and test the different aspects of the initialization phase. These include:1. Keep track of Initialization phase, using timers and a flag.2. Checking AntS deployment status.3. Development of a simulator to prototype HDRM interface to the OBC.


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Ska vi fika? (10 min)

7. Ground Station (GS)

11/05/2020 Joan Mitjans - KTH, Stockholm, Sweden

Joan Mitjans

• Orders• ISIS Transceiver• M2 Antennas• Rotator & Rotator controller• Lattice tower

• GS Placement• Lightning protection

• Frontend Design, Procurements & Test• Rotator Controller / Satellite Tracking• ISIS Transceiver – Mission Control interaction

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Goals of the Semester


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Overview

M2 2MCP14M2 436CP42UG

AlfaSpid RAS

Antennas-Amplifiers Low Loss

BPF

PGA-103+

EME2/3-144 BPF, LNA and

T/R Relay

LGS (ISIS)

Elveti (Solenix)

Alfa ROT2Prog Controller

GS-Rotator

LP175TBD

SDR SW (ISIS)ISIS

Transceiver

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GS Location

• No grounding point on TK 31/33 • All GS equipment together and close to the antennas (accessibility)

Uplink Command Budget:

Parameter: Value: Units:

Ground Station:

Ground Station Transmitter Power Output: 100,0 watts

In dBW: 20,00 dBW

In dBm: 50,00 dBm

Ground Stn. Total Transmission Line Losses: 0,70 dB

Antenna Gain: 12,34 dBi

Ground Station EIRP: 31,64 dBW

Uplink Path:

Ground Station Antenna Pointing Loss: 0,04 dB

Gnd-to-S/C Antenna Polarization Losses: 3,00 dB

Path Loss: 143,58 dB

Atmospheric Losses: 2,10 dB

Ionospheric Losses: 0,70 dB

Rain Losses: 0,00 dB

Isotropic Signal Level at Spacecraft: -117,78 dBW

Spacecraft (Eb/No Method):

Spacecraft Antenna Pointing Loss: 0,00 dB

Spacecraft Antenna Gain: 0,00 dBi

Spacecraft Total Transmission Line Losses: 0,67 dB

Spacecraft Effective Noise Temperature: 2897,50 K

Spacecraft Figure of Merrit (G/T): -35,29 dB/K

S/C Signal-to-Noise Power Density (S/No): 75,53 dBHz

System Desired Data Rate: 1200 bps

In dBHz: 30,79 dBHz

Command System Eb/No: 44,74 dB

Demodulation Method Seleted: AFSK/FM

Forward Error Correction Coding Used: None

System Allowed or Specified Bit-Error-Rate: 1,0E-05

Demodulator Implementation Loss: 1 dB

Telemetry System Required Eb/No: 19,00 dB

Eb/No Threshold: 20,00 dB

System Link Margin: 24,74 dB11/05/2020 Joan Mitjans - KTH, Stockholm, Sweden 121

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Link Budget Uplink

• Spacecraft rx sensitivity: -104 dBm• Rx signal at spacecraft: -88.45 dBm• The link margin is limited by the ISIS satellite transceiver to

15.55 dB.


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Link Budget Downlink

Elevation L Free Space dB L atm dB Margin dB

2.5º 153.9 4.6 1.1

5º 153.1 2.1 4.4

10º 151.6 1.1 6.9

30º 146.6 0.4 12.6

45º 144.2 0.3 15.1

90º 141.7 0 17.9

Downlink Telemetry Budget:

Parameter: Value: Units:

Spacecraft:

Spacecraft Transmitter Power Output: 0,5 watts

In dBW: -3,01 dBW

In dBm: 26,99 dBm

Spacecraft Total Transmission Line Losses: 0,70 dB

Spacecraft Antenna Gain: 0,00 dBi

Spacecraft EIRP: -3,71 dBW

Downlink Path:

Spacecraft Antenna Pointing Loss: 0,00 dB

S/C-to-Ground Antenna Polarization Loss: 3,00 dB

Path Loss: 153,12 dB

Atmospheric Loss: 2,10 dB

Ionospheric Loss: 0,40 dB

Rain Loss: 0,00 dB

Isotropic Signal Level at Ground Station: -162,33 dBW

Ground Station (EbNo Method):

Ground Station Antenna Pointing Loss: 0,23 dB

Ground Station Antenna Gain: 18,90 dBi

Ground Station Total Transmission Line Losses: 0,81 dB

Ground Station Effective Noise Temperature: 517,94 K

Ground Station Figure of Merrit (G/T): -9,05 dB/K

G.S. Signal-to-Noise Power Density (S/No): 56,99 dBHz

System Desired Data Rate: 9600 bps

In dBHz: 39,82 dBHz

Telemetry System Eb/No for the Downlink: 17,17 dB

Demodulation Method Seleted: D-BPSK

Forward Error Correction Coding Used: None

System Allowed or Specified Bit-Error-Rate: 1,0E-05

Demodulator Implementation Loss: 2 dB

Telemetry System Required Eb/No: 10,80 dB

Eb/No Threshold: 12,80 dB

System Link Margin: 4,37 dB

Simulated Coupling at 145 MHz= -68.9 dB

• 3rd harmonic frequency= 3·145.86 MHz = 437.58 MHz (175 KHz away from the downlink carrier at 437.405 MHz)

• Power coupled (between tx – rx) = -55.4 dBm

• Power 2nd harmonic generated at LNA = -173.73 dBm (far from -92 dBm of expected satellite signal)


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Study of Tx Coupling & IMP3

3rd order intermodulation products• In-band interferences should be lower

than -31.1 dBm

3rd harmonic at the LNA output

Source: RF Microelectronics, Behzad Razavi

LNA (PGA-103+) Tests

Noise Figure → Hot/Cold Test

3rd Harmonic

• Datasheet NF = 0.5 dB

• Measured NF = 0.8~0.9 dB (both LNA)


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• Failed with Rigol R3131 Spectrum Analyzer

• Done theoretically & checked with IMP3 tests

Parameters• Noise figure

• Decrease the ൗ𝐶 𝑁0

• 3rd Harmonic• In-band interference

• 3rd order intermodulation products (IMP3)• Co-channel interference

3rd order IMP3


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LNA (PGA-103+) Tests

Maximum in-band interference = -33.1 dBm

Close to the -31.1 dBm computed theoretically

Source: RF Microelectronics, Behzad Razavi

• The highest interference (around 434.9 MHz): -49 dBm.

• MIST antenna is 7.4 dB more directive than SEAM one, so it will receive -41.6 dBm (worst case).

• Far from the -33.1 dBm threshold


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Interference Scan


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Rotator Software

• Allow simultaneous tracking till 24 satellites• Tracking Priority• TLE auto update through Celestrak• Compatible with 23 rotators (trough Hamlib)• Allow remote antenna tracking with external

software (through Hamlib)


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Additional work

• Measurements• Noise measurements must be repeated with BPF• Antennas S parameters• G/T Measurements

• Procurements• LPF (and VHF Rx BPF ?)• Lightning box and fuses• Elveti computer

• Assembly / installation• Write mounting plan/schedule• Antenna assembly• Find grounding point

• Software• GUI to control/view the rotator status & test, test, test…• Build a GNU Radio code for MIST beacon decoding

• Downlink test with FlatSat

8. Functional Testing and Electrical Design

Andrii Berezovskyi, Citlali Bruce Rosete, Xiyao Song, Theodor-Adrian Stana, Alejandro Vicario Espinosa

19/05/2020 KTH, Stockholm, Sweden

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Andrii Berezovskyi, Citlali Bruce Rosete, Xiyao Song, Theodor-Adrian Stana, Alejandro Vicario Espinosa. KTH, Stockholm, Sweden19/05/2020

Goals for spring 2020

• Complete and document sub-systems to be used for ADCS HIL flight simulations

o Get Sun Sensor Simulator (SSS) up and running

o Connect SSS to IOBC through the daughterboard

o Write IOBC software for reading sun sensor measurements and logging them

o Implement and test communication interface between SSS and Simulink orbital model

o Implement IMTQ simulator and test it dubs as the IMTQ on the I2C bus

o Implement and test communication interface between Simulink orbital model and IMTQ

simulator

• Outline flight simulation methodologies

o Establish how the flight simulations will be run

o Establish how correct or erroneous functioning will be checked

o Establish how to run scripted error checks

o Create a document outlining the data that needs to be communicated by the IOBC and checked

by the scripts to check for correct or erroneous functioning

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FlatSat Diagram


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A familiar picture


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Hardware-in-the-loop test concept


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ADCS HIL Flight simulations (1)










simulator







❖ SSS not working at beginning of semester

• Checked output voltages: no voltage

• Checked schematics: coincided with circuit

• Checked continuity: correct

• Checked resistance: correct resistors

• Checked Arduino code: register was receiving the input command and sending back the correct

information, but no output voltage

• Checked all channels: communication seemed correct with all channels

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Get Sun Sensor Simulator (SSS) up and running


❖ Solved: error in documentation• Input voltage of 5 [V] instead of 3.3 [V]

❖ SSS code was cleaned, but still need to implement new commands.

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Get Sun Sensor Simulator (SSS) up and running


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Connect SSS to IOBC through the DB


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Connect SSS to IOBC through the DB

Measured current from the Multimeter (uA)

Output Voltage read from the

iOBC (mV)

Circuit gain

𝐕

𝐈𝐕 𝐀−𝟏

2.28 2500 1096.971.36 1625 1196.610.94 1124 1197.020.68 808 1191.740.65 772 1195.050.56 662 1191.930.47 554 1187.570.38 449 1185.010.29 342 1185.440.20 237 1172.690.11 129 1167.420.03 29 1137.25

Average gain = 1177.4 ≈ 1.2k

Amplification factor of thecircuitry in the DB


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Connecting SSS to DB Document

• M631-035• Released• Describes steps to connect the SSS to DB, and how to test the correct communication.


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Moving SSS home

• Moved some lab equipment home• Connected SSS to Arduino to obtain analog readings from it


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simulator







• Moved to Arduino Due as a substitute, and wrote analog test program• Implemented command to send photodiode data from ADCS to SSS

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IOBC software to read and log SSS data


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Interface between SSS and C orbital model


StartDummy commandto jump start

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simulator







• Arduino as iMTQ simulator• Another Arduino as dummy master playing the roll of iOBC• Implemented I2C commands between iMTQ simulator and dummy master• Implemented command to send magnetometer (MTM) data from ADCS to iMTQ sim

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IMTQ


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IMTQ


iMTQ simulator

Dummy master

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Flight Simulation Methodologies (1)









simulator








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How does one test a complex system’s functionality?


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The answer: Use a test manager!


• Professional-grade test manager• Could come in handy in your future careers, students!

• Allows for creating, editing, running and debugging test sequences• Works with a large variety different programming languages (NI’s LabView, C/C++, C#, Python)• Test sequences are programming language-agnostic• Creates test reports during test runs

• Test report format can be configured to one’s liking (even for automatic processing)• Test reports can be in XML, HTML, text file formats• Graphs can also be generated as part of test reports!

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National Instruments’ TestStand


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Testing the SSS using TestStand

Test Algorithm:

for chan in range(1,7):set_output_channel(chan)for val in range(1024, 16384, 2048):

set_output_voltage(val)set_expected_voltage(exp[chan])an[] = read_analog_test()for c in range(1,7):

if (an[c] != exp[c]):FAIL()

else:PASS()


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Test Sequence

Test Algorithm:

for chan in range(1,7):set_output_channel(chan)for val in range(1024, 16384, 2048):

set_output_voltage(val)set_expected_voltage(exp[chan])an[] = read_analog_test()for c in range(1,7):

if (an[c] != exp[c]):FAIL()

else:PASS()


• Discovered a “feature” of the SSS: The first command sent to it does not execute.• Discovered it is prone to memory overflow.• More testing to be concluded.

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Outcomes of the test


• TestStand looks like a good solution• Provides a logical interface for test developers• Automatically produces customizable test reports• Can debug test runs• Offers the possibility of deploying a test system

• So test engineers do not have the capability of editing test sequences inadvertently.

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Running flight simulations


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Flight Simulation Methodologies (2)

Sub-team/Area Goals for spring 2020

Functional

testing








simulator








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FT Framework Document

• M631-036• Draft document (work in progress)• Describes commands to be sent to test equipment and replies to these commands• 32 pages long already!• Will be released by the end of the semester.


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A familiar picture revisited


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Plan for Upcoming Months

Period Goals

Now to

End of June

• Hook up iMTQ Simulator to OBC EM or FM

• If EM, needs OBC team

• Fix remaining issues when connecting simulators to ADCS Orbital Simulation

• Write report on where to add code in ADCS Orb. Sim. for communicating to SSS, iMTQ Sim.

• Finish and report on SSS TestStand test

• Have discussions with OBC and GS teams on FT Framework

• Release first version of FT Framework Document

Autumn 2020 • Continue work on ADCS HIL

• Get all subsystems running

• Implement new command structure (per FT Framework Document) on all sides of the communication

• Implement test sequences in TestStand

• Long-term testing

• Include EPS test in TestStand

• Add commands to SPS GUI

• Test

• Aim to run ADCS and EPS HIL tests as part of Alejandro’s thesis

• Interact with OBC team

• Add ADCS NG task to OBC Software

• Implement (subset of) FT Mode in OBC Software

• Test FT Mode on OBC FM/EM


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Conclusions







o Implement and test communication interface between SSS and Simulink orbital model C orbital

model



simulator







9. Master Thesis NanoProp

Victor Gonzalez

19/05/2020 Victor Gonzalez. KTH, Stockholm, Sweden

1. Performance Assessment• Thrust measurement• Thrust misalignment• Specific impulse

2. Attitude & Orbital Manoeuvres• iMTQ de-tumble function evaluation• ∆V manoeuvre along velocity vector

3. In-orbit Mission Operations• Commissioning (checkout and initial use)• Experiments (normal use)• Decommissioning (passivation plan)

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1. Performance Assessment• Estimations

• Angular velocities -> Thrust & Misalignment -> Mass flow rate -> Specific impulse

• Modelling and Simulation of Kinematics and Dynamics of MIST• External Torques (Thrusters)• Misalignment

• Variation in Thrust (Main Cause!!)• Angle deviation from axis of reference

• Modelling and Simulation of Gyro Board • Measurement of angular velocities (Performance assessment & FDIR strategy)• Noise, Bias and Resolution of gyroscopes• Kalman Filter

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2. Attitude & Orbital Manoeuvres• iMTQ de-tumble function evaluation

• Modelling and Simulation of Bdot control• Resolution of magnetometer and magnetorquer• Bias of actuation level

3. In-Orbit Mission Operations• MIST mission evaluation

• Thermal constraints• Communication windows• Power budget• Telemetry budget

• Automatic operations, NanoProp will be controlled by OBC!• Flowchart of Operation• FMEA & FDIR analysis

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Simulation: F1=1mN, F2=0mN, F3=0mN, F4=2mN

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+Y

+Z

+X

Thruster 1 Thruster 4Thruster 2 Thruster 3

+Y

+Z

F1F4

+X

Angular Velocities

*10 Hz, MPU-6050


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Results

Torques iMTQ de-tumbling


*1 Hz, iMTQ ISIS subsystem

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Additional work

1. Performance Assessment• Thrust measurement• Thrust misalignment• Specific impulse

2. Attitude & Orbital Manoeuvres• iMTQ de-tumble function evaluation• ∆V manoeuvre along velocity vector

3. In-orbit Mission Operations• Commissioning (checkout and initial use)• Experiments (normal use)• Decommissioning (passivation plan)


19/05/2020 Names. KTH, Stockholm, Sweden 167

MIST Team 11 Final Presentation

Documents

Transcript of MIST Team 11 Final Presentation