Hey, this is the new one seminar on "Role of Instrumentaion and Control in Space". There are many instruments that play a very important role in space ship/rocket. Few are discused here.

1. Seminar on Role of Instrumentation
and Control in Space
Presented by: Onkar Dhawale.
Seminar Guide: Pandit Sir.

2. What is Space?
- Space seeks submissions that will contribute to the intellectual foundation for
the integration of space into overall security studies.
Why is there any role of Instrumentation and Control
Engineer?
- Control and Instrumentation (C&I) engineers are responsible for designing,
developing, installing, managing and maintaining equipment which is used to
monitor and control engineering systems, machinery and processes.

3. Topic
SPACE
- Thermal Control of Satellite.
- What is an Attitude Control ?
- Attitude Control of Satellite.
- Attitude Sensors and Actuators.

4. Thermal Control of Satellite
Purpose of thermal control in Satellite
Throughout the mission, thermal control ensures that each item of equipment is maintained at
temperatures consistent with nominal operation.
Most equipment only operates correctly if maintained at right temperature and temperature
changes are within acceptable limits.
In our terrestrial environment or in laboratories, temperature is often regulated “naturally”. Satellite
environment in orbit are completely different ( vacuum, microgravity, radiations, etc.).
This means that thermal conditions are very particular and likely to cause dangerous change in
temperature. Correct temperature can only be achieved by applying scientific method and specific
“thermal control” technology.

5. How does thermal control system works?
External Thermal Insulation
To maintain the satellite at a mean temperature close to
200C and to protect the satellite from thermal radiations,
the surfaces of satellite are covered by so-called “super-
insulating” blankets which are incredibly efficient in the
space vacuum (one hundred times better than
polystyrene).
In photographs of the satellite, the radiators look like
blueish mirrors. The multi-layer insulation has a golden
yellow colour due to the use of aluminium-coated
polyimide films, which consists of number of layer of
vapour deposited aluminium, silver or gold

6. Internal Thermal Arrangement
The typical block diagram of thermal control arrangement is as shown in fig.
During cold or too hot mission phase and in particular when the equipment is not
very active, it has to be kept warm by resistive electric heaters or cold by
thermoelectric coolers.

7. Thermal Control Components
• Electric heaters
• Space radiators
• Cold plates
• Doublers
• Heat pipes
• Louvers
• Temperature sensors
• Thermal isolators
• Thermoelectric coolers

8. Attitude Control System of Satellite
What is an attitude Control?
The path of the satellite through space is called its orbit; the orientation of the
satellite in space is called its attitude.
Control of the orbital path is required to ensure that the satellite is in the correct
location in space to provide the services required of it.
Attitude control is essential on the spacecraft to prevent the satellite from tumbling
in space and to ensure that the antennas remain pointed at a fixed point on the
Earth’s surfaces.
These functions are the responsibility of the Attitude and Orbit control subsystem.

9. Attitude control of Satellite
Unlike an aircraft which uses its attitude to control its trajectory (pitching to go up, banking to turn,
etc.) the angular motion of a satellite, which is travelling in a vaccum, has practically no effect of its
trajectory (i.e. its orbit).
The satellite orbit is determined by the initial velocity given it by the Ariane launcher, and then by
the small corrections made regularly by micro-thrusters.
The disturbances to the attitude control (angular orientations) are torque produced by the
environment, gravity due to the Earth and the Moon, and movement of mechanical parts, etc.
The attitude is continuously controlled by a programmed control loop (fig.a.2.2). Sensors measure
the satellite’s attitude, the onboard computer then processes these measurements and generates
commands which are carried out by the actuator, to ensure correct pointing

11. The local orbital reference system is defined at each point of the orbit by three unit
vectors. These vectors are derived from the satellite position and velocity vectors
shown in fig.
1) Vector L is collinear with position vector P (on the axis between the Earth’s
centre and the satellite). It defines yaw axis.
2) Vector T is perpendicular to the orbital plane (vector L, vector V). It defines the
pitch axis.
3) Vector R completes the set of orthogonal axes. It lies in the plane defined by
vectors L and V and defines the roll axis. It does not coincide exactly with the
velocity vector due to the eccentricity of the orbit.

12. Axes Xs, Ys, Zs represents an
orthogonal reference frame related to
satellite (satellite axes). Nominal
attitude pointing consists of the best
possible alignment of this set of axes
with the local orbital reference system.
With perfect geocentric pointing,
Xs= -T
Ys= -R
Zs= L

13. Actuators
Thrusters
A thruster is a spacecraft propulsion
device used for orbital station-
keeping, attitude control, or long-
duration, low-thrust acceleration, often
as part of a reaction control system.

14. Solar Salis
Small solar sails (devices that produce
thrust as a reaction force induced by
reflecting incident light ) may be used to
make small attitude control and velocity
adjustments.

15. Sensor
Gyroscope
Gyroscopes are devices that sense
rotation of three-dimensional space
without reliance on the observation of
external objects. The orientation of
oscillation is fixed in inertial space, so
measuring the orientation of the
oscillation relative to the satellite can be
used to sense the motion of the
satellite.

16. Horizon Sensor/Earth Sensor
A horizon sensor is an optical
instrument that detects light from the
‘limb’ of the earth’s atmosphere that is
at horizon. Thermal infrared sensing is
often used, which senses comparative
warmth of the atmosphere, compared to
the much colder cosmic background.

17. Sun Sensor
A sun sensor is a device that senses
the direction to the sun. This can be as
simple as some solar cells and shaded,
or as complex as a steerable telescope,
depending on mission requirements.

18. Satellites Communication
Satellites communicate by using radio waves to send signals to the antennas on
the Earth. The antennas then capture those signals and process the information
coming from those signals. Information can include:
● scientific data (like the pictures the satellite took),
● the health of the satellite, and
● where the satellite is currently located in space.

19. Conclusion
I have studied published literature in the area of Role of Instrumentation in
Space.There are several systems which are based on feedback control principle.
Out of these those which have illustrated in this seminar are the applications of
this feedback control in space and defence that are, thermal and attitude control of
satellite, guided missile, etc. For the satellite it is important to survive and function
continuously for the periods up-to 15 years. Without proper instrumentation and
control it is very difficult for the satellite to survive for many years for space
mission. Continuous determination of satellite parameters such as temperature,
attitude, etc. is important to control them with desires manner.

20. Reference
- https://digitalcommons.unomaha.edu/spaceanddefense/
-https://iticollege.edu/blog/the-role-of-instrumentation-and-control-systems/
-https://iopscience.iop.org/article/10.1088/1742-6596/2134/1/012026/pdf
-
https://www.nasa.gov/directorates/heo/scan/communications/outreach/funfacts/txt
_satellite_comm.html

21. 1. C. Durham and P. Norris, "The role of onboard software in space instrumentation," IEE Colloquium on Satellite Instrumentation, 1988,
pp. 12/1-12/3.
2. N. Kumar, J. Jayarajan, Amarnath and R. Thaker, "Analysis of circuit parameter variations in discrete clock driver designs for high
capacitive load detectors for space applications," 2017 International Conference on Intelligent Computing, Instrumentation and Control
Technologies (ICICICT), 2017, pp. 613-617, doi: 10.1109/ICICICT1.2017.8342633.
3. R. Das and A. F. Christopher, "Automated Testing for Launch Vehicle Instrumentation," 2018 Fourteenth International Conference on
Information Processing (ICINPRO), 2018, pp. 1-4, doi: 10.1109/ICINPRO43533.2018.9096677.
4. M. Ji-Feng, "Research on Space Mission Plan Based on Agent and Pervasive Computing Technology," 2013 Third International
Conference on Instrumentation, Measurement, Computer, Communication and Control, 2013, pp. 706-711, doi:
10.1109/IMCCC.2013.156.
5. J. Lu, D. Xu, F. Zhang and L. Zhang, "Simulation study on defense process of space targets," 2012 International Symposium on
Instrumentation & Measurement, Sensor Network and Automation (IMSNA), 2012, pp. 244-247, doi: 10.1109/MSNA.2012.6324559.
6. D. Neculescu and R. Jassemi-Zargani, "Extended Kalman filter based sensor fusion for operational space control of a robot arm," IMTC
2001. Proceedings of the 18th IEEE Instrumentation and Measurement Technology Conference. Rediscovering Measurement in the
Age of Informatics (Cat. No.01CH 37188), 2001, pp. 915-918 vol.2, doi: 10.1109/IMTC.2001.928212.
7. N. Hongshan, H. Zhijian, D. Jietao, L. Qiang, Y. Hongqi and Y. Wei, "Research on Space-Based Space Target Detecting and Tracking
Algorithm," 2010 International Conference on Intelligent System Design and Engineering Application, 2010, pp. 253-256, doi:
10.1109/ISDEA.2010.180.
8. Xingwang Du, Liangcai Liao, Jinyuan Liu and Xudong Tang, "An ant colony algorithm for scheduling instrumentation ship at sea of
space launch mission," 2016 2nd IEEE International Conference on Computer and Communications (ICCC), 2016, pp. 1340-1344, doi:
10.1109/CompComm.2016.7924922.
9. J. Vallerga, J. Hull and M. Lampton, "Construction and evaluation of an imaging focussed-mesh electron multiplier for space
instrumentation," in IEEE Transactions on Nuclear Science, vol. 35, no. 1, pp. 539-542, Feb. 1988, doi: 10.1109/23.12781.