Cube Satellites are standardized Nano-satellites for space researches and applications. CubeSat can be created using COTS Hardware and is a very creative utilizing of the knowledge of Embedded Systems and various MEMS sensor devices
2. CONTENTS
1. INTRODUCTION
2. PURPOSE OF CUBESATS
3. SUB - SYSTEMS OF A CUBESAT
4. SENSORS AND ACTUATORS
5. MICROCONTROLLER REQUIREMENTS
6. ADVANTAGES AND DISADVANTAGES
7. APPLICATIONS
8. FUTURE SCOPE
9. REFERENCES
CUBESATS
3. INTRODUCTION
• Standardized artificial nano satellites for remote sensing application and
research purposes.
• CubeSats are taking over the space industry. The industry norm has been to
use a single, multi-billion dollar, massive satellite in geostationary orbit with
multiple purposes. However, this has been changing, and these single
massive satellites are being replaced with constellations of smaller, cheaper,
easier to replace satellites in low Earth orbit, called CubeSats.
4. PURPOSE OF CUBESATS
• The primary mission of the CubeSat is to provide access to space for
small Payloads.
• The purpose of the CubeSats is to provide a standard for design of
Nano-satellites to reduce cost and development time, increase accessibility to
space, and sustain frequent launches.
• Presently, the CubeSat Standard is being used to develop picosatellites by
high schools, universities, Government agencies and private companies all
over the world.
5. SUB-SYSTEMS OF A CUBESAT
There are multiple sub-systems which contribute towards building a satellite
• Electrical Power System(EPS) - consists of solar panels and batteries. Solar
panels hold solar cells that convert the solar light from the sun to electricity.
• Communication system – Consists of an antenna (20 cms) and uses radio
communication and operates in the 435-438 MHz frequency band.
• Attitude Determination and Control System (ADCS) - ADCS controls the pitch,
yaw and roll of the satellite based on the instant parameters the satellite is
experiencing.
• On - Board Data Handling System(ODHS) – Responsible to execute all
operations and housekeeping that controls the satellite.
6. SENSORS AND ACTUTORS INTERFACES
1. Magnetometer –
• For the satellite to run its attitude determination and control algorithms, there is
a requirement to determine the magnetic field due to the Earth.
• A three axis magnetometer is used to measure the direction and magnitude of
the Earth’s magnetic field in the satellite body frame.
MEMS magnetometer device (HMC6343)
7. SENSORS AND ACTUATORS INTERFACE
2. Sun Sensor –
• Indicates the tilt of the satellite.
• The sun sensor has an output based on 3 parameters –
1. Intensity of light falling perpendicular to the surface.
2. Temperature of the Sun Sensor.
3. Wavelength of light incident on it.
• In order to obtain the position of the Sun, the sun sensors have to be placed in 3
mutually perpendicular axes.
• Since five sides experience sunlight, five sun sensors are mounted on the
satellite and they are placed in such a way that the 3 angles needed to get the
sun vector are acquired.
Slcd-61n2 Sun Sensor
8. SENSORS AND ACTUATORS INTERFACE
3. Temperature Sensor –
• Extreme changes in temperature occur as the satellite revolves around the earth.
• Critical components in the system are sensitive to temperature changes and
require an independent cooling solution.
• The temperature sensors will be placed at several places inside the CubeSat to
monitor the temperature variations for various subsystems. An additional temper
ature sensor will be placed on the outside surface to measure the ambient atmos
pheric temperature.
9. SENSORS AND ACTUATORS INTERFACE
4. Magnetorquers –
• Common method for actuation in nano satellites.
• The satellite has to stabilize in 3 dimensions, a magnetorquer was installed at
3 sides in different dimensions of the satellite.
10. MICROCONTROLLER REQUIREMENT
• Considering the power budget of a nano-satellite, a low power consumption
system has to be assembled.
• Low Supply Voltage Range: 3.6 V Down to 1.8 V.
• Ultralow Power Consumption
• Wake-Up From Standby Mode in 3.5 µs
• Flexible Power Management System
11. ADVANTAGES AND DISADVANTAGES
Advantages –
1. Compact – Dimension 10 cms x 10 cms x 10 cms
2. Weight – up to 1.33kgs
3. Power – up to 10W
4. Low Building cost – 8000$ (approx.) whereas satellites costs up to 30,000$.
5. Less Launch cost
6. Less development time
7. Sustain Frequent launches
8. More up-to-date Technology
Disadvantages –
1. Its size – Small size of a Cubesat restricts its capabilities.
2. Lifetime is less than of a conventional Satellite.
3. Not capable of interplanetary missions.
12. APPLICATIONS
1. Technology Experiment and Demonstration –
• Space industry needs more drastic end effective way of technology experiment
• CubeSats has become a test bed for new technologies, before a large sum of
money is invested on a payload, a CubeSat (which cost few thousands) is
used to test that payload.
Example:- The Aerospace Corporations created about three CubeSats called
AeroCubes 1,2 and 3 out of which only ‘AeroCube 3’ was placed in the orbit
successfully.
14. APPLICATIONS
2. Scientific Research –
• To understand the universe has been the center of most space research
• All CubeSats based on Chemistry and Physics Applications.
Example – ‘SWISSCube-1’ developed by Ecole Polytechnique Federale de
Lausanne (EPFL) to measure the constituents of Upper atmosphere.
15. APPLICATIONS
3. Biological Experiments –
A few missions have been flown for biological applications, and others are still
undergoing designs.
Example - NASA Ames developed ‘GeneSat’ which carried bacteria into space to
study how microgravity affects the human body.
16. APPLICATIONS
4. Earth Remote Sensing –
• All missions on environmental and topology, metrological and agricultural
purposes are subbed into this application.
• This gathers data on relevant Earth characteristics, such as Geology,
environment, and climate change etc.
Example - The CSSWE CubeSat built by University of Colorado at Boulder was for
general Space Weather Research.
17. APPLICATIONS
There are many more applications of CubeSats.
1. Military Projects
2. Navigation
3. Terrestrial Thermal Imaging
4. Real Time Cloud Monitoring for Early Cyclone detection
5. Weather Forecasting
6. Communications
7. Education and Training (80% of CubeSats are Student designs) etc.
18. FUTURE SCOPE
1. Interplanetary Missions –
• The space program is always on the lookout for ways to make missions cost
effective.
• A CubeSat may not at the present be used for an entire interplanetary mission
since it doesn’t includes a safe landing system.
2. Researches are going on to how to make this CubeSat more compact and
add a propulsion system to it.
3. Television Broadcast –
Due to its small size the radio signal from a CubeSat isn’t going to be as narrowly
focused as it could be with a larger antenna. Therefore, scope of improvisation
exists.
19. REFERENCES
[1] ‘Design of a CubeSat Computer Architecture using COTS Hardware for
Terrestrial Thermal Imaging’. Chandrasekhar Nagarajan, Rodney Gracian D'souza,
Sukumar Karumuri, Krishna Kinger
[2] https://www.fictiv.com/blog/posts/satellite-101-what-is-a-cubesat
[3] https://www.isispace.nl/cubesats/
[4] Applications of CubeSats. Chris Adolphus Esionwu Jnr
[5] https://insights.globalspec.com/article/12083/what-s-inside-a-cubesat
[6] https://www.space.com/34324-cubesats.html