Emin Batur Dizdar 21201094 Summer Practice Report

BILKENT UNIVERSITY

ELECTRICAL AND ELECTRONICS ENGINEERING DEPARTMENT

SUMMER PRACTICE REPORT

TURKISH AEROSPACE INDUSTRIES (TAI)

EMIN BATUR DIZDAR / 21201094

SUMMER PRACTICE 1 (EE 299) REPORT

16/06/2014 – 11/07/2014

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Emin Batur Dizdar 21201094 Summer Practice Report

TABLE OF CONTENTS

I. Introduction……………………………………………………………………… ….3

a. Lectures Taken…………………………………………………………... ….3

i. Job Safety and Health Care in TAI……………………………… ….4

ii. Organizational Structure of TAI………………………………… ….4

iii. Dangers of FOD…………………………………………………. ….5

iv. Security Rules in TAI……………………………………………. ….5

v. History of Aerospace Industry in Turkey ……………………… ….6

II. Current Projects of TAI……………………….…………………………………. ….6

a. Construction of Aircrafts……………….……………………………….. ….6

b. Modernization of Aircrafts……………………………………………… ….7

c. ANKA…………………………………………………………………… ….8

d. HURKUS………………………………………………………………... ….8

e. TURNA and SIMSEK ………………………………………………….. ….9

f. ATAK Helicopter……………………………………………………….. ….9

g. Space Systems & Satellites……………………………………………... ….10

III. Work Done (Researches)……………...………………………………………… ….10

a. Virtual Machine………………………………………………………… …..10

i. System Virtual Machine………………………………………… ….10

ii. Process Virtual Machine………………………………………… ….12

iii. Techniques for Creating Virtual Machine Creation…………….. ….13

b. Hypervisor……………………………………………………………….. ….14

i. Type1…………………………………………………………….. ….14

ii. Type2…………………………………………………………….. ….14

iii. Hypervisor in Embedded Systems………………………………. ….15

iv. Use of Virtual Machines in Spacecrafts………………………… …..16

c. Research on Bus Protocols (Mil-Std-1553B & CAN Bus)………………. …..17

i. MIL-STD-1553B………………………………………………… …..17

ii. CAN Bus Protocol…………………………………………………..19

iii. COMPARISON BETWEEN CAN BUS & MIL-STD-1553B… ...…21

d. Research on European Satellite Systems……………………………………22

i. BIRD…………………………………………………………………15

ii. BeeSat-1………………………………………………………. ……18

iii. COMPARISON TABLE BETWEEN SOME SPACECRAFTS……28

IV. Conclusion……………………………………………………………………….. ….. 30

V. Resources………………………………………………………………………… …..31

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I. Introduction

Turkish Aerospace Industries is a company that both designs and produces military and

civil aerospace systems. Each year they accept many students from different cities as

interns and assign them to one of five main departments in TAI. These departments are

Unmanned Aerial Vehicle (UAV) Department

Helicopter Department

Production Department

Aircrafts Department

Special Programs Department

Space Systems Department

All these departments work in cooperation in the process of designing new projects or

advancing old projects. The department I did my internship was space Systems

Department. There were 25 other interns with me at the same department with

different jobs. I was assigned to the software development section for upcoming satellite

project; namely the Göktürk-3 satellite.

Lectures Taken

The first two days of TAI are covered with some briefings and lectures to introduce

the company and its rules and regulations to the interns. At these lectures some safety

protocols, general information about TAI and the campus and the rules to be followed at the

company are explained.

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Job Safety and Health Care in TAI

At this lecture, the importance of following the safety regulations are explained with

real life statistics of employee number/work accident. The type of work accidents that can

happen at TAI are explained and the measures that must be taken to avoid these accidents are

told to interns. The location of the health care center is shown and the regulations that should

be followed if any injury occurs are explained in detail.

Organizational Structure of TAI

The hierarchical structure of TAI is explained

starting from the top director Muammer Dörtkaşlı

through the engineering chiefs of teams and heads of

all departments. The schema that shows this structure

is given at left.

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Dangers of FOD

In this lecture, a concept well-known to everyone who works in an aerospace company

or any job related to aircrafts, Foreign Object Damage(FOD) is explained. Getting protected

against the FOD’s is of vital importance because of the sensitivity of the materials and

machines that are built at aerospace industries. Even the littlest material (such as a screw or a

nail) can cause millions of dollars damage to the aircraft or even cause serious injuries and

death. For that reason a 2-hour informatory video is shown followed by another 2 hours of

briefing about the dangers of FOD, the problems they can cause and the measures that must

be taken to prevent it.

Security Rules at TAI

Since TAI also works with military, they follow a highly complicated and serious rules

of security. At that lecture the interns were informed of these security rules and regulations.

First of all TAI is divided into many different sections where different works are done by

different departments. That’s why everyone has electronic ID cards which can open the doors

of their working areas. It is forbidden to pass to other sections if someone doesn’t have the

permission to and that’s why the cards won’t open other doors. Secondly, all the computers

are connected to each other via intranet over a server which is called TAI portal. This server is

isolated and can’t be reached from the internet. Internet can only be accessed through internet

computers of which there is only 1 for every 5 or 6 employees. Finally, bringing outside

document to TAI or leaving with documents from TAI can only be done after following a

protocol which includes one to sign some papers.

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History of Aerospace Industry in Turkey

In this lecture Turkey’s accomplishments in the area of aerospace are explained

starting from 1920’s until today. At this lecture interns are informed especially about Vecihi

Hürkuş, a pilot and an engineer who was one of the most successful engineer in Turkey’s

history. In addition, the background of TAI and how it is first established and who is its

owners are explained in detail.

II. Current Projects of TAI

Construction of Aircrafts

Today, TAI is able to manufacture many complex aircraft pieces which are then sold

internationally to produce whole airplanes. In addition, TAI also does some merging

operations where they take in smaller aircraft parts and building bigger parts in some cases

whole aircraft body parts. Some of the parts that TAI produces are:

A318/A319/A320/A321 Section 18 Panels

F-35 JSF Center Fuselage

A 400M Center Fuselage and Forward Fuselage

Moreover, TAI also produces some unique aircrafts that is designed by TAI engineers. Those

are ANKA and HÜRKUŞ.

In addition to these, TAI has ongoing projects (some of them secret) done in cooperation with

BOEING, AIRBUS and LOCKHEED MARTIN.

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Modernization of Aircrafts

TAI has a great number of ongoing modernization projects which are huge both in

means of the resources the project needs and the complexity of the project. The biggest of

these modernization projects is the modernization of C-130 cargo plane. It needed great time

and money because first a great deal of research was needed before even starting the

modernization and later, there were many difficulties during the applications. However, it is

said that this project was very beneficial to the company in means of experience and

knowledge.

In addition to this TAI also owns a huge part of F-16 modernizations throughout the

world which is done in cooperation with the Lockheed Martin. Currently, they were busy with

the modernization of some planes for Pakistan.

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ANKA

Anka is a genuine Unmanned Aerial Vehicle (UAV) produced by TAI. It is an

advanced Medium Long Endurance class UAV with dual-redundant flight control systems

allowing it to stay at flight for nearly 24 hours. It is made with the purpose of doing long-

time reconnaissance and target detection under harsh weather conditions. It has an

Advanced Ground Control Station and heavy fuel engine with ice protection which allows

it to link data over 200km from 30000 feet high at harsh air conditions.

HÜRKUŞ

Hürkuş is a training plane with a single turbine motor which is used both as a military

and civil training plane. It is designed entirely by TAI engineers and is accepted

internationally as a medium speed quality training plane.

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TURNA & ŞİMŞEK

Turna and Şimşek are high-speed drones that can be used as targets during trainings by

simulating the behaviors of enemy aircrafts or missiles. In addition they can be used for

maintenance tasks. Şimşek is the superior of the 10 year old Turna with higher speeds but less

flight times. Şimşek has 740km/h top speed with 1.50m wingspan. Turna has 330km/h with

2.7m wingspan.

ATAK Helicopter

ATAK (T129) helicopter is a multi-tasking armed combat helicopter with advanced

controls and low maintenance costs. It can be used for:

Armed Escort,

Attack,

Security Missions,

Armed Reconnaissance,

Defensive Military Support,

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And many other military operations. It can survive better at harsh weather conditions

compared to other attack helicopters of his class.

Space Systems & Satellites

In addition to aircrafts and helicopters, TAI also works on space stations and

satellites. On December 2012, GÖKTÜRK II, an Earth Observation Satellite which is made

by the collective work of TUBİTAK and TAI is launched. The GÖKTÜRK project is the

major part of the work of the space department at TAI. They are currently working on the

GÖKTÜRK 3 satellite which will be an improved version of the GÖKTÜRK II.

III. Work Done (Researches)

In TAI the team I worked under was currently in a phase of research for the new satellite

that is going to be built “Göktürk 3” That is why all their work was about finding

alternative/better/more efficient systems to be used in Göktürk3. For this reason, our

assignment as interns under this department was to expand this process by researching the

subjects we are given. Therefore, my main assignments were the following:

To learn more about virtual machines and their use in spacecrafts

To provide background knowledge for how to implement a virtual machine

Most widely used bus control systems in spacecrafts and a comparison between

them

Overall research about different satellites and preparing a table comparing the

objectives and systems of these satellites

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Virtual Machine

A virtual machine can be defined as an emulation of a computer on a software level. They can

basically be thought as the computer itself without the hardware. Just like a physical machine

it can operate and execute programs although it is just a software implementation. Virtual

machines are divided into two classes based on their correspondence to a real machine:

1. System virtual machine

2. Process virtual machine

System Virtual Machine: A system virtual machine provides a complete platform where it

usually emulates an existing architecture to support the execution of a complete operating

system (OS). They are built either to enable the running of programs where the real hardware

is not available or to increase the efficiency in using the resources of a computer.

What caused the invention of virtual machines was the desire to run different

operating systems on the same physical machine. This would allow the time sharing of a

single computer between several single-tasking operating systems. This gives an advantage to

the programmer by allowing the usage of different I/O components not allowed by the

original system.

There are several advantages and disadvantages of virtual machines which can be

listed as below:

Advantages:

Several different operating systems can co-exist on the same physical machine with

strong isolation from each other.

VM can provide a different instruction set architecture(ISA) than the original system

It allows disaster recovery, improves efficiency, helps maintenance.

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Disadvantages:

It is less efficient than the real machine in means of accessing the hardware, since it

accesses it indirectly.

Unless proper techniques are used to isolate them, different virtual machines on the

same host can show unstable performance which depends highly on the workload

imposed by one system on the other.

An example of this type of virtual machine can explained as having Microsoft Windows

and Linux in the same computer at the same time. The use of virtual machines is becoming

more and more popular with embedded systems. A typical use is to have a real-time operating

system and a high-level OS such as Linux at the same time. For example, in the 2001

microsatellite project Bird, the real time operating system BOSS worked as a guest on Linux,

which allowed all the programs to be written in BOSS to be executed in Linux.

Process Virtual Machine: A process virtual machine is built with the intention of running a

single program unlike the system virtual machine where the whole OS is emulated. They are

usually suited to only one or two programming languages and they are used in order to

increase the adaptability and portability of a program amongst different components.

Process VM’s are created when the process is started and exits when the process ends.

This is because it is specific for that process only and has no use when the process doesn’t

continue. Its purpose is to allow a process to be run in any platform regardless of the hardware

of that platform. In other words, it abstracts the process from the underlying hardware or

operating system. Therefore, it provides a high-level abstraction different from the system

virtual machine where the VM provides a low-level ISA abstraction.

A great example for process virtual machine which also made this type of

virtualization highly popular is Java Virtual Machine (JVM). JVM is implemented into

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everything that works with java from computers to ATM’s and even microchips. When the

java code is executed, it is executed in the JVM which modifies the code such that it is

suitable for the platform it is executed on.

Techniques for Virtual Machine Creation

Raw hardware emulation (native execution):

This method to implement a virtual machine is explained as full virtualization of the

hardware. There can be two approaches for this virtualization; using a Type1 hypervisor or

using a Type2 hypervisor. Then, a user can run different “guest” operating systems on

separate virtual computers which are supported by the underlying hardware.

Full virtualization is particularly helpful while developing a new OS. The programmer

can run the written OS code on older or more stable versions of the OS while at the same time

experimenting on it in the new OS.

Non-native system emulation:

As explained before, while virtual machines can run a whole operating system, they

can also work as an emulator for a specific software application or operating system, allowing

them to work on different architectures than they are originally written for. A few examples

for virtual machines which use this technique can be given as; Java Virtual Machine and The

Common Language Infrastructure virtual machine of the Microsoft .NET initiative. Although

this allows different systems to run any software written for that VM, the virtual machine

software still needs to be written separately for each different type of computer.

Hypervisor

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A hypervisor is a layer which is a computer software, firmware or hardware that

creates and runs virtual machines. In a computer which a hypervisor runs one or more virtual

machines, all virtual machines are called guests, while the computer itself is the host machine.

There are two types of hypervisor defined; type1 and type2 hypervisors.

Type1 hypervisors run directly on the hardware, establishing an abstraction layer

between the hardware and all the virtual machines. In this case, even the host

operating system works above the hypervisor. Examples for this type today are: Oracle

VM Server for SPARC, Oracle VM Server for x86 processor and Microsoft Hyper-V

2008/2012

Type2 hypervisors run within a host operating system. In this case, the hypervisor

provides a mid-layer between the host OS and the guest virtual machines. VMware

and VirtualBox can be given as examples to this type of hypervisors.

Figure 1

The history and usage of Hypervisor’s is an immensely large subject which starts with

the full-virtualization attempts pf SIMMON and IBM’s CP-40 at 1967 and reaches to today.

In the process hypervisors are developed and their usage is improved by many different

developers such as Linux, Microsoft, Intel and AMD. However, there is one area hypervisors

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are used which has a greater importance for the scope of this research than any other area and

that area is embedded systems.

Hypervisor in Embedded Systems

Apart from detailed high-level operating system virtualizations, hypervisors for real-

time operating systems (RTOS) such as embedded systems are also developed. These

hypervisors needed to be designed with real-time capability in mind. However, embedded

systems differ from high-level systems in many ways.

The nature of embedded systems causes them to be resource constrained. Especially

battery-powered mobile systems, avionics systems and spacecraft embedded systems impose

the requirement for small memory sizes and low overhead. Furthermore, unlike x86

embedded world works with a wide variety of architectures.

Virtualization for embedded systems requires memory protection and it needs to have

a distinction between the user mode and administrator mode. These regulations are achieved

only in a small amount of microcontroller architectures such as x86, MIPS, ARM and

PowerPC as widely deployed architectures on embedded systems.

Embedded systems usually use paravirtualization instead of full virtualization because

the manufacturers usually have the source code to their products and also, they prefer to

benefit from the performance advantages of paravirtualization.

Use of Virtual Machines in Spacecrafts

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Virtual machines have an enormous area of use, from simple daily-life applications like

ATMs to highly integrated complex laboratories, but the use of virtual machines in aerospace

industries had a great improvement on the field.

An engineer -working initially for NASA, then found his own company-named

Christopher Grasso have found a sequencing language that depends on basic structure of

virtual machines called VML. This language allows the spacecraft to behave the way the

operators want without operators saying it what to do. Specifically, before the invention of

VML, the controllers/operators on the ground needed to determine each and individual

movement of the spacecraft and radiate it from the ground. This whole process was inefficient

and time-consuming. Now, operators on the ground write scripts-or rather blocks and

command sequences- in a high-level, human readable language and upload it to the satellite

prior to shuttle. Then when needed, the compiler in satellite can compile these scripts and act

independently in a desirable manner. Examples of these autonomous operations aboard the

spacecraft are aerobraking, telemetry conditional monitoring, and anomaly response, without

developing autonomous flight software. And in order for VML to work, a virtual machine, or

a software-simulated processor, is used onboard a spacecraft.

Grasso explains the use of VML in RESOLVE satellite as follows:

“The VML state machines are intended to coordinate all of the RESOLVE instruments—

four spectrometers, an oven, three cameras, a drill, and a chemical analyzer—to work in a

way that is very dependent on one another, VML provides not only an interpretation

capability for state machines but also a coordination capability that is not present in standard

state machines.”

VML is also currently in use on Mars Odyssey, Stardust, Genesis, and the Space Infrared

Telescope Facility (SIRTF).

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Research on Bus Protocols (Mil-Std-1553B & CAN Bus)

There are many different Bus protocols that are used in aerospace industries and

among them two types are the most commonly used ones. In overall, the main distinction

between the two of them is that while CAN bus is more simple and cost efficient, Mil-Std-

1553 is more safe, both in means of data transfer and stability. I have researched each

protocol individually and then compared them in a table.

MIL-STD-1553B

Mil-Std-1553 is a military standard bus protocol first used in F-16 flying falcon in

1973. It basically works with a master-slave communication protocol. There is a Bus

Control(BC) which is the master and it gives orders to Remote Terminals(RT) or slaves in this

case. These are connected to each other by a data bus. A general overview of this structure is

given below:

The bus can have dual or triple redundancy by adding several different wire pairs

which is why it is a lot secure than many other protocols. The data transfer frequency of Mil-

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Std-1553 is 1MHz (meaning that 1 megabit per second data is transmitted) At 1MHz, a single

bus consists of a wire pair with 70–85 Ω impedance. Moreover, Mil-Std-1553 has isolation

transformers between the bus and the transmitters/receivers in order to prevent short circuitry

and possible damages that might occur with excessive current flows. This ensures that the bus

doesn’t conduct current through the aircraft. In fact, the transformers ensure that the output to

be between 18V to 27V and eliminate any possible DC-signal. These cautions are taken while

creating Mil-Std-1553 because it is widely used in aircrafts and should be stable and secure

enough so that when the aircraft is hit by lightning mid-air its communication systems won’t

fail.

The master-slave protocol of the bus works by using the Manchester Code to transmit

the signals. Specifically, there are 3 message words used by the system: command, data and

status. All the words are consisted of 20bits where 3bits are for synchronization, 16-bit for

word and 1-bit for parity check. The Manchester Code schema is given below:

CAN Bus Protocol

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Controller Area Network or CAN bus protocol, developed by Bosch in 1986 is a

multi-master serial bus standard, which is composed of two or more nodes. Each of these

nodes include a:

Central processing unit, microprocessor, or host processor,

CAN controller; often an integral part of the microcontroller,

Transceiver,

where; the host processor analyzes the received message and understand what it says and

determines the corresponding answer to be transmitted, CAN controller stores the received

signal and checks if it is an entire message which can be read by the host processor as well as

transmit the message sent by host processor bit by bit on to the bus when the bus is available

and transceiver converts the data stream from CANbus levels to levels that the CAN

controller uses while receiving and CAN controller to CAN bus while transmitting.

Basically, every unit (node) in a multimaster system is like a host and when the bus is

free any unit might start transmitting. In order to avoid conflicts, CAN uses a message priority

system where the unit with the message of higher priority gains bus access.

Figure displaying a CAN bus node.

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CAN has a transmit rate up to 1Mbit/s and has a standard data transmission format of

11-bits. (29bits for CAN2.0B) where a 0 represents a dominant bit and a 1 represents a

recessive bit. When all the transmitting nodes are transmitting, all nodes(including the

transmitting nodes) acquire all the bits in the bit stream. Then, every node only reads the most

prioritized message and neglects the others. So for instance if all nodes transmitted 1 and a

single node transmitted a 0, only the message of the node that transmitted the 0 will be read

by all the nodes. Meanwhile, as the transmitting node that transmit 1 also acquires a 0, it

understands that there is a more important message than the one it is sending and therefore it

delays its transmission. Therefore, the bit stream stays clean.

Although the whole process seems to be in synchronization, actually CAN is an

asynchronous bus since there is not a system clock. Every node in the bus has its own clock.

Looking at the structure of CAN it is easily seen that CAN is very efficient, simple

and secure for non-complex system. However, as the number of nodes increase too much and

each system(node) gets bigger and more complicated in itself, CAN bus can be very hard to

implement efficiently or cheaply. That is why CAN is generally used in smart-home systems,

simple electronic machines (like washing machines) or automobiles.

However, because its components are commercially available and it has readily

available VHDL cores, there is a growing interest in using CAN bus in spacecrafts. Studies

are being made on how to make CAN’s implementation to spacecrafts easier and CAN has

already started to be used in some basic research satellites. One example for that is BeeSat-1.

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COMPARISON BETWEEN CAN BUS & MIL-STD-1553B

CAN BUS MIL-STD-1553B

→ message based protocol half-duplex command/response protocol

→

the number of nodes(frames)

differ with the systems

complexity

Up-to 31 remote terminals

→

lossless bit-wise arbitration

method of contention

resolution

Manchester Code: clock and data are

on the same wire to eliminate DC

signals

→up-to 1Mbit/s data transfer

rate1Mbit/s data transfer rate

→multi-master serial bus

standardMaster/slave protocol

→ Has multiple redundant physical layers

→wire pairs have 70-85Ω impedance at

1MHz

→transmitters/receivers are coupled to

bus via isolation transformers

Advantages

CAN BUS MIL-STD-1553B

→ very low costsafer and more stable than most other

BUS

→ high reliability relatively faster transmission

→

emerging higher level

protocols

that can be used over CAN

bus

complex systems are implemented

easier

with MIL-STD-1553B

→readily available commercial

components and VHDL cores

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Research on European Satellite Systems

In this assignment, in addition to the overall research about different satellites and

preparing a table comparing the objectives and systems of them, I have also made a trough

research among two of the specific satellites BIRD and BeeSat-1.

BIRD

BIRD (BiSpectral Infrared Detection) is a DLR (German Aerospace Center) mission

for microsatellite technology demonstration. The overall objectives of this mission can be

listed as:

Observe fires/hot spots on Earth(caused by lightning, volcanism, oil wells and by

man).

Demonstration of a new type infrared sensor system on a microsatellite.

SpaceCraft:

The S/C (spacecraft) is structured as a cube with each side being 62cm long. It consists

a service segment, an electronics and payload segment and has one fixed and two deployable

solar panels. The total S/C mass is 94kg, its average power is 40W(200W max) uses 8NiH2

battery cells and its design life is 1 year. The on-board recorder has 2x1 Gbit of capacity.

Sub-Systems:

Its attitude is measured by two star sensors which are 30 degrees apart from each other. In

addition, the S/C includes a 3-axis laser gyroscope which provides a resolution of 2.7 arcsec

with a drift rate of 10/h. The actuators of its ACS (attitude control system) are 3 pairs of

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magnetorquers and 4 reaction wheels. For real-time orbit determination, a GPS receiver

GEM-S (GPS Embedded Module) of Rockwell-Collins is used.

Basic communication specifications of the spacecraft are as:

RF communications are in S-band.

Downlink transmitter frequency: 2201.7 MHz

Downlink data rate: 2.2Mbit/s for recorder dumps during a station pass

Downlink modulation: PCM/BI-F-L/BPSK

Uplink frequency: 2032.5 MHz

Data rate: 19.2 kbit/s

Uplink modulation: PCM/GMSK/PM

Communications with the ground segment are done by CCSDS protocol suite.

On-board Computer of the Spacecraft :

In the S/C a 4 node redundant control computer with a totally symmetric architecture

is used. One of the nodes is the worker node and one of them is the supervisor, while the

other two are spare parts and disconnected. The worker controls all systems of the

spacecraft, while the supervisor actively waits. If something ever happens to the worker

node to cause any malfunctions the supervisor becomes the worker node and the worker

node takes the place of supervisor. Then the repair protocol is applied to the supervisor

computer. If it succeeds and it is repaired, it continues to stay as the supervisor to change

places with the worker again until the worker computer malfunctions. However, if it can’t

be saved with the repair protocol, it is considered as trash and one of the spare nodes takes

place of that node. With this method the S/C is protected during at least 3 malfunctions.

The computers are made up of MPC623 processor with 4Mbyte FLASH memory and

8Mbyte DRAM as peripherals. It uses the BOSS as operating system which stands for

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“Bird Operating System Software”. BOSS is also available as a guest level

implementation on top of Linux. With is, it is possible to implement and test all the

application software on Linux workstations and move them to the target system without

any changes.

Additional sensors of the S/C :

HSRS (Hot Spot Recognition Sensor): This is an infrared imaging instrument which

enables the satellite to achieve its objective to detect ground surface hot spots.

WAOSS-B (Wide-Angle Optoelectronic Stereo Scanner, BIRD version): is a compact

device based on 3 CCD lines which can take simultaneous images in the nadir, forward

and backward directions

HORUS (High Optical Resolution Utility Sensor): HORUS was added to WAOSS-B and

is an optical sensor to verify AOCS performance of BIRD (snapshot instrument).

BeeSat-1

BeeSat is a student project which is under development at Technical University of

Berlin. The overall objectives of the project can be described as:

1. To demonstrate and verify new component technologies for picosatellites.

2. Improving the attitude control capabilities of CubeSat.

3. Obtaining a flight validation for the microwheel system.

SpaceCraft:

BeeSat is a picosatellite which conforms to the CubeSat standard. It has the size of 10cm x

10cm x 10cm and with a mass limit of 1kg. The satellite is controlled by microwheel system.

A common electronics board which has a CAN interface controls the microwheels.

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Figure2(CAN control interface)

These microwheels are used in the ADCS(Attitude Determination and Control Subsystem)

which maintains a 3-axis stabilization.

On-board Computer of the Spacecraft :

The OBDH(Onboard Data Handling Subsystem) of the satellite is based on two redundant

units which include “an ARM7 microcontroller (Philips LPC2292), a 16 MB flash memory

for program code (1MB for telemetry data and 2 MB SRAM) and a redundant CAN bus

interface for the communication with the microwheels.”1 The OBDH is controlled via the

TinyBoss operating system, which is an adapted version of BOSS which was used during the

BIRD satellite mission of DLR. In fact BOSS stands for “BIRD Operating System(Simple)”.

OBC in overall has the features:

MCU: NXP LPC2292, 60MHz

2MByte SRAM, 20 MByte flash memory

48 measurement acquisition channels with 12 bit resoluıtion

Typical electrical power consumption: 150mW. 2

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RF-Communications:

0.5W output power

UHF amateur radio band (435-436MHz)

Bit rate of 4.8 or 9.6 kbit/s & GMSK (Gaussian Minimum Shift Keying)

modulation

Uplink bit rate: 4.8 kbit/s

CCSDS standard

Additional sensors of the S/C :

BeeSat has a micro-camera which provides VGA snapshot imagery of the Earth’s

surface in the visible range. The sensor itself has an 8-bit microcontroller equipped with 1

MB of SRAM for configuration and critical operations. The images are stored in a non-

volatile memory of PDH (payload data handling) system and are transmitted to ground

during station passes.

RW-1 (Reaction Wheel-1):

RW-1 is basically a micro-reaction wheel assembly. It’s an highly integrated system

with an external WDE (Wheel Drive Electronics) device for controlling up to four wheels.

In order increase its adaptability, it is designed to support different types of data

interfaces. The customer choose between four standards: CAN2.0, SPI, RS232 and

RS485.

The WDE of the RW-1 is based on an FPGA component. The FPGA controls the core

of the reaction wheel. It can control the speed and acceleration of the wheels as it is a

standard PI (or PID) controller.

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Emin Batur Dizdar 21201094 Summer Practice Report

Figure3

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Emin Batur Dizdar 21201094 Summer Practice Report

Satellite Region/Country/Producer Mission Purpose Bus Protocol Microcontroller/OBC OBSW Phsyical Aspects

BirdDLR

(German Aeorospace Center)

1.Observe fires/hot spots on Earth(caused by lightning, volcanism, oil wells and by man).2. Demonstration of a new type infrared sensor system on a microsatellite.

Several busses with different

protocols

4 node reduntant control computer

based on PowerPC PMC623 +

4Mbyte FLASH + 8Mbyte DRAM

BOSS OSBody Shape: Rectangular

Total Mass: 94kgAverage Power: 40w

BeeSat-1Germany/TUB

(Technical University of Berlin)

1.To demonstrate and verify new component technologies for picosatellites. 2.Improving the attitude control capabilities of CubeSat.3. Obtaining a flight validation for the microwheel system.

CAN interfaceARM7 microcontroller

(Philips LPC2292) + 16MB flash

TinyBOSS

Body Shape: CubeTotal Mass: 1kg

Average Power: 0.5wSize: 10cm x 10cm x 10cm

CyroSat-2 ESA (European Space Agency)

1.To monitor the thickness of land ice and sea ice2.Help explaining the connection between melting of the polar ice and the rise in sea levels3. Find out how does melting contribute to climate change.

MIL-STD-1553B for

low rate data channels

SpaceWire for two

interferometric data channels

ERC 32 microprocessor

+ on board solid state memory of 2x128Gbit

-

Body Shape: RectangularTotal Mass: 720kg

Size: 4.6m x 2.34m x 2.20m

COMPARISON TABLE BETWEEN SOME SPACECRAFTS

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Emin Batur Dizdar 21201094 Summer Practice Report

Satellite Region/Country/Producer Mission Purpose Bus Protocol Microcontroller/OBC OBSW Phsyical Aspects

ORS-1 Operationally Responsive Space Office (ORSO)

1.Operational Imaging2. Providing ISR to U.S. military troops in the fields on an active operation3.Adress Emerging4. Unpredicted necessities through: a)augmentation b)reformation5. Space support capabilities

MIL-STD-1553B

Total Mass: 475 kgMax Power: 900 W

Raiko Japan Demonstrate technology and technology development

Several busses with

different protocols

Total Mass: 2.66kgSize: 10cm x 10cm x

22.7cm

Himawari 8/9 Japan Meteorology and air traffic satellite.

SpaceWire MELCO DS-

2000- - Total Mass: 1300kg

Size: 5.2m x 8.0m x 5.3m

Copernicus Sentinel-1

ESA (European Space Agency)

1.To monitor sea ice zones and arctic environment.2.Surveillance of marine environment .3. Monitoring land surface motion risks.4. Mapping of land surfaces: forest, water and soil agriculture.5. Mapping in support of humanitarian aid crisis situations.

PRIMA bus of TAS-1 with a mission specific payload module

Atmel ERC32 + two MIL-STD-1553B buses

+ 1.4Tbit solid-state mass

memory

-Total Mass: 2300kgSize: 3.4m x 1.30m x

1.30m

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Emin Batur Dizdar 21201094 Summer Practice Report

IV. Conclusion

My internship at TAI were 20 workdays but in huge industrial or design companies such

as TAI, every project needs long times and big resources. Especially in the department I was

appointed (Space Systems) some projects such as satellite projects can take up to 10 years.

That’s why the interns working in our department weren’t given any laboring task. Instead,

we were given research projects that could help the company’s future projects and accelerate

the completion of projects in addition increasing our knowledge as engineers in fields we

might work in the future.

The project chief I worked under was especially working with the emulation and

simulations of satellite systems before they were shuttled to space. Because of this, me and

my co-workers (other interns) were assigned with researching QEMU & QERX, two different

emulation programs. Later as we looked into these, we found out that the topic was too

detailed and deep and in order to make a good research we split up the subjects and looked

into specific things that would help understanding how to implement the best emulation

program to the current systems of TAI and in the process, I researched the concepts of Virtual

Machines and HyperVisors. After that our chief assigned us each with a particular satellite

research in order to create a database on the electronic communication systems and electronic

machinery of a satellite and we compared the system properties of these different satellites in

a table.

Briefly, I can say that my first summer internship (EEE 299) was mainly a research

internship at a large industrial company. During the internship they showed around the facility

to us. It was a good experience in means of knowing how things work in large industries and

the working conditions of the engineers there.

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Emin Batur Dizdar 21201094 Summer Practice Report

V. Resources

https://directory.eoportal.org/web/eoportal/satellite-missions/b/bird

https://directory.eoportal.org/web/eoportal/satellite-missions/g/gokturk-2

https://directory.eoportal.org/web/eoportal/satellite-missions/b/beesat-1

http://spinoff.nasa.gov/Spinoff2013/it_5.html

http://www.techbriefs.com/component/content/article/6-ntb/tech-briefs/software/456

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1036829&url=http%3A%2F

%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1036829

http://snebulos.mit.edu/projects/reference/MIL-STD/MIL-STD-1553B.pdf

Other resources were given us from TAI and were forbidden to use outside TAI.

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