Shifting Captured Debris To The Recycling Unit

Published Date: 02 Nov 2017

Introduction

From last few decades, human activities in space resulting the increase in space debris linearly. These include non-functional and/or uncontrolled man-made objects and component parts. The creation of thousands of pieces of space junk poses major risks to the sustainability of mankind’s exploration and use of outer space especially in the field of communication and navigation satellites, environmental monitoring satellites.

Humanity is on the edge of a New Frontier, and the possibilities are exciting! More than 10 nations have ability to launch satellites and over 60 countries own or operate satellites. The creation of space debris poses major risks to the sustainability of mankind’s exploration and use of outer space. Thus space debris removal in low earth orbit (LEO) is an urgent issue to be faced to protect the safety of the current and future space activities. Space Venture believes that humanity possesses sufficient technology to devise a workable space. We have designed Adwitya (fig 1.1) to characterize and setting up of a possible solution that embraces the debris element, closes around it and drag it to the disposal position in space using carrier space craft.

Adwitya is an Indian word signifying unique and second to none or peerless. We believe in the idea of VASUDEV KUTUMBAKAM which means that the whole world is a small family and our goal is to help this global family.

TECHNICAL STRATEGY

1.1 FUNCTION

1.1.1 UNIQUENESS OF STRATEGY

The space debris mitigation strategy focuses on, and emphasizes the mitigation of the rate at which new pieces of space debris are generated during space activities. However, in view of the huge amount of debris already in existence in LEO, Space ventures suggest an active process for the removal of debris from space and to recycle the collected material. In addition to the mitigation efforts we guarantee its sustainability in the long-term.

Our overall mitigation strategy will be covering two aspects:

Collection of statistical data about debris by GBO and Zenith followed by capturing process by Adwitya.

Shifting captured debris to the recycling unit (Neel Kanth)

During this crucial autonomous mission so many operation functions, e.g. propulsion, communication, grappling and docking with the target, and power rising are related. After conducting the comprehensive research in the area of technological aspects of observation, modeling, protection and mitigation of the active removal of both small and large uncontrolled objects to clean space are outlined below:

Selection of target debris and their characterization (statistics on physical parameters, attitude motion)

Target approach using guidance and navigation systems.

Capture and removal technology, using net, robotic tentacles and gravity unit systems.

Shifting grappled debris to the recycling station.

Immediately after getting the contract, we will start recruiting the scientists and carry out the research and planning. Because of the wide range of possible sizes, and trajectories, there would be a range of challenges involved in capturing and recycling of the debris.

Space ventures, with the help of the observatories (Zenith and Ground Based Observatory) will monitor various orbits and model the target debris altitudes / inclinations above 400km. In initial phase, two Adwityas will be launched to the near polar parking orbit (at altitude 400 km) to grab debris up to 2000 km at inclinations 80°-85° and 95°-100° respectively as interpreted from the graph [1] (Ref. appendix: fig 1.2 and table A-1) to ensure the capturing of at least 75% of debris within five years i.e. before 2075.

Since total time of parking and capturing for one orbit is 150 minutes, there will be approximately 3200 revolutions around the Earth in one year. The above referred graph explains that 75% of the junk is present in the above said inclinations, which needs 16000 revolutions of Adwitya for capturing. This comes out to be 5 years of time span.

After every round, inclination of Adwitya as guided by Ground base and Zenith will be changed for next capturing.

The parking orbit inclination needs to be very close to the target orbits' inclinations; otherwise plane changes will need more thruster fuel. Such parking orbits have advantage of the perturbation of orbital planes to naturally intercept the orbital planes of the targets during chasing and capturing mission. When the orbital planes of the target and Adwitya align, it transfers from the parking orbit to the target orbit using its own propulsion system and starts capturing process.(fig 1.3)

1.2 RETRIEVAL MISSION

1.2.1 OBSERVATORY

ZENITH (fig 1.4a) is our space debris observatory, which is positioned at upper and lower spots of Adwitya (fig1.4b) and will play a pivotal role in observing orbital parameters of debris. The aim of observatory is to bring the capturing unit at a point where it can capture the debris. We are providing active and passive sensors for detection of junk.

1.2.1.1 ZENITH STRUCTURE

Zenith [1a] is light weight unit having the shape of capsule, mounted on the movable unit and provided with wide field-of-view (FOV), 1.3-m telescopic aperture surveyor having cameras for debris detection from all the dimensions without coming in physical contact with them. The telescope's charge coupled device (CCD) technology similar to what exists in digital cameras consists of 0.3m Schmidt camera curved imagers and a high-speed shutter that allows for both fast scans and high sensitivity This unit recognizes the volume, size, rate of rotation and speed of debris. The difference in altitude between the Zenith and the target will produce a relative speed between them. This far-range rendezvous will adjust Adwitya on the target and wait for a time to capture it.

1. M. Scheper, E. Pinarello,et.al.,’P²-ROTECT Active De-orbiting of Large LEO Space Debris by OTV Task 5.2’, P2-ROTECT FP7-SPACE-262820, First P²-ROTECT workshop Ankara, 20-21 March 2012

1a. http://www.esa.int/SPECIALS/NEO/SEMVXVB1S6F_0.html

2. http://saturn.jpl.nasa.gov/spacecraft/safety/safetyeis/

Further it directs different parts of Adwitya (ref. section 1.2.2) to capture the different sized debris. The total mechanism and working on Zenith is done by on-board HDDM - Hold-Down Deployment Mechanism (Hovering above specific altitude from Debris). This mechanism helps in maintaining the distance between target debris and Adwitya (through Zenith) with the help of four Vernier rockets (ref fig 1.8) The Backup is available if any function of Zenith encounters any problem. The on-board automated fault protection software will sense any unusual conditions and attempt to switch to backups. Apart from this Radioisotope Heater Unit [2,3] (fig 1.5) will be provided to keep the structure, system and instruments warm enough to operate efficiently. Heat will be supplied to all the instruments without moving any parts or intervening electrical circuits.

For providing power to the gadgets and the instruments used in Zenith, CSG Solar panels have been used on its exterior structure of Adwitya (fig 1.8). The communication subsystem of Zenith consists of a 1m dish high-gain antenna (fig 1.4b). Low-gain antennas have also been provided for back-up, all working in X- band [4]. A passive thermal design has been selected for Zenith to protect it against high temperature and radiations.

1.2.1.2 OBJECTIVE

From 2070 onwards Zenith will make scientific observations over the debris till the capturing is completed. The advanced instruments mentioned below will be able to detect precise data of debris at different directions in terms of their size, shape, angular direction, range, range rate, amplitude and phase simultaneously.

Advanced Instruments Used [5] Zenith is equipped with many advanced technological instruments which will monitor debris are mentioned below

Spectroscopic Instrumental cameras

1. RADAR[6] :(ref fig 1.4) Narrow-band mono-pulse L-band radar generating high-frequency pulses (1 ms pulse length) of typically 1 to 2 MW peak power is used for the detection and tracking of debris. Also Ku-band imaging radar generating linear frequency modulated pulses (256 ms pulse length and 800 MHz bandwidth) of typically 13 kW peak power is operated simultaneously with tracking radar on the same target having parabolic antenna.

2. UV photometer: (ref fig 1.4) Two micro channeled plated photometer cameras are operated in the photoelectrocounting mode as imaging camera with rapid readout (370 Hz) and 256 x 256 pixel resolutions, where photocathodes are employed as a photometer. These will be operated at solar wavelengths of 180-185 nm, where debris radiates strongly, in order to filter out most of the aurora emissions. It is the instrument which is deployed for detecting debris trajectory by observing its radiated tail emissions.

3. UV spectrograph: (ref fig 1.4) Two cameras are deployed to be sensitive to UV light in the range 160 - 290 nm (for solar blind images) and equipped with a UV transparent lens with a 130 degree field of view. There is a large 1000 x 1000 pixel camera that takes relatively long exposures (1 per second) of the debris. A transmission grating will create slit-less spectra with a resolution of better than 2 nm / pixel. Analysis of the UV images will help in observation of concentration of debris.

4. IR and Visible camera: (ref fig 1.4) Visible camera is operated at wavelengths 300 - 800 nm and equipped with a transmission grating for optical spectroscopy. The infra-red camera performs a survey at wavelengths 8 to 120 μm, at LEO. The data has been analyzed in order to characterize the infrared emission of debris. Images are recorded in a buffer at a rate of 20 Hz, but only those images are downloaded that coincide with the debris detection in the ultraviolet emissions.

3. Fact Sheet By Department of Energy, Office of Space and Defence Power Systems

4.

http://www.esa.int/SPECIALS/Mars_Express/SEMUC75V9ED_0.html

5. www.lpi.usra.edu/meetings/lpsc2009/pdf/2305.pdf

6. http://www.fas.org/man/dod-101/navy/docs/es310/radarsys/radarsys.htm

7. http://www.antdevco.com

http://www.esa.int/SPECIALS/Mars_Express/SEMUC75V9ED_0.html

Supportive instruments used

S-band antenna [7]: - This antenna enables Zenith to transmit the signals to the space base and earth observatory. This antenna helps in broadcasting course of mission to the observatories and receiving commands for the operation. It will maintain interlinking service through incorporation of satellite network while grabbing the debris.

2. CSG Solar panels [8] (ref fig1.8) Crystalline Solar Glass technology used in Zenith solar panels helps to increase efficiency for electric output more than 30% than any other silicon thin layer technologies used in other solar panels for satellites. Lithium -Ion batteries[9] will be provided inside the Adwitya to store electric energy.

1.2.1.3 WORKING OF ZENITH

Zenith located inside Adwitya start will analyze the physical characteristics of debris when Adwitya however the target. The scientific observations will be carried out with advanced instruments mentioned above. For detecting the debris path Radar and UV photometer are used. Since reflection of sun light from debris provides tracking angle information, therefore it will be used to map information of target debris for accurate positioning. The images of debris and their surroundings would be taken by UV spectrograph[10]. Zenith will also receive data from ground based observatory (GBO) and after superimposing the signals it will direct Adwitya for capturing mission. The radar would start functioning as soon as Adwitya reaches its desired orbit. It could be operated and brought to any point from where it would scan the debris movements and its rotation axis. To take more comprehensive and integrated images of capturing process (the working of Adwitya) visible cameras would be used. The whole system is managed efficiently in such a way that it would work in less time.

Zenith will use relative positioning to bring the Adwitya to a parking orbit. It will continuously send signals to GBO with the help of S-band antenna. The 3D images of debris would be received after every day.

1.2.1.4 Ground Based Observatory (GBO)

GBO (fig 1.6) will quantify the targets to be captured by scanning debris with the help of RADAR and radio and optical telescope systems. Optical telescope[11] will be used to gather and focus light mainly from the visible part of the electromagnetic spectrum, for directly viewing a magnified image, making a photograph etc. It will have concave mirror (polished to an accuracy of 1/20 of about 30 nm) of diameter 6 meters. It will be used for observation ranging from ultraviolet to near infrared. It will record rotation and physical characteristics of targets and relay the data to the Zenith.

During the execution of mission the commands will be updated by GBO. That is it will direct Adwitya that which section of it will be used to capture the target debris. GBO will observe the capturing process continuously by receiving the data from Zenith (fig1.7).

1.2.2 STRUCTURE OF ADWITYA

1.2.2.1 BASIC DESIGN

8. www.csgsolar.com/downloads/CSG_Press_SEnergyJune2004.pdf

9. http://phys.org/news/2013-04-life-lithium-ion-batteries-electric.html

10 http://en.wikipedia.org/wiki/Ultraviolet%E2%80%93visible_spectroscopy

A variety of different capture mechanisms were considered. They were assessed for their strengths and weaknesses and whether they would satisfactorily meet the missions requirements. The structural design of Adwitya (fig 1.8) consists of a crossed cylindrical shape which contains electric and mechanical instruments having significant degree of autonomy which will affect the data handling to operate various functions. Four Adwityas have been provided with hybrid capturing technique to capture physically, different sized debris from 4Ï€ stradian. Different components of Adwitya performing various mechanisms in the capturing process are discussed as given below:

Tether net

For the small sized debris (below 10 cm) flexible tether-net system (eight in number) attached at the top of Adwitya (fig 1.10) supported by an inflatable boom structure allows capturing up to the range of larger distance (maximum up to 2 km) between the target and the chaser. This lowers the collision chances of debris. The stretched diameter of each mesh is 20 cm. These will be supported with six flexible copper tubes having two joints each. The setup would be attached with tendrils of maximum lengthy 2 km each. Theses tendril will be operated with the help of a spring driven reel system. It could be wounded or re-wounded according to the requirement. The non contact breaking reel using eddy current will be provided to slow down tether net system when it will reach at the end of its extension, to protect from jerks.

Advantages

These reduce both the capture precision requirements and the stress concentration.

These are lightweight, with a quite limited volume giving room for multiple captures of different geometries and disposals within the same short.

These capture the debris without creating additional space junk.

Working

During a rendezvous phase with the target, the net is folded inside the flexible tubes (fig1.8). At the correct distance from the target debris, the tendrils will be unfolded like umbrella with the help of pressure sensors. The mesh will open gradually while approaching towards the debris. At a fixed distance from the target, these tendrils will deploy the mesh in the circle shape as shown in the fig (1.10).

Once the debris hit the mesh, the flexible tubes will fold itself because of the impact, resulting in trapping of debris around the mesh. After capturing process is over the fleet of meshes will be re wounded towards the jumbo craft and the captured debris will be dumped in it for next procedure. Diagrammatical representation is as shown in fig 1.11 (i-v).

Robotic Arms [12]

11.http://www.google.co.in/imgres?q=working+of+optical+telescope&hl=en&biw=1366&bih=587&tbm=isch&tbnid=4cl2S5ifeVt3RM:&imgrefurl=http://www.howstuffworks.com/telescope1

12. DECOM Mission: Debris Capture and Orbital Manipulation, Department of Aeronautics & Astronautics

University of WashingtonTo seize large sized (greater than 10cm) non cooperative (unpredictable relative motion and error in the rendezvous control) debris two extendable boom robotic arms having 6 degrees of freedom (1 linear / 5 rotational) are provided at its sides. Each arm consists of rods with rack and pinion arrangement to buffer and break residual motion of debris which cannot be anticipated. Maximum maneuvering extension of robotic arm (fig 1.9) is 10 m to maintain a safe distance from Adwitya. The end unit at of the arm have pitch elbow joint, and pitch and jaw joints at the wrist as shown in the fig (1.12a). The wrist end has robotic hand provided with two joints, making the system handy and flexible enough to capture various types of debris. These arms will slow down the captured debris and further transfer them into the Jumbo space craft (fig 1.12b) . Clutches of the arms provide anchoring force to capture debris strongly. The basic configuration of robotic arm includes rotational and translational hand controllers at the centre of Adwitya.

Advantages

These arms can conceivably grab fast moving debris at variable velocities strongly with high precession and accuracy by using rack and pinion arrangement.

Large and small tumbling objects can be captured easily by using robotic arms.

The arms can be folded when no debris is captured (fig1.8).

Working

After receiving the commands from Zenith, the Adwitya autonomously drift toward the target with partially outstretched arms. On approaching the target, arms extend fully and capture the target with the end-clutches.

The gripping process starts with the lowermost junction of each robotic arm. Once the clutches grips the debris by using anchors, tactile sensors will measure the contact forces, texture, materials and shape and further convey information about the state of grip to determine the change if required in positioning of the junctions. After grapping the tumbling of the debris will be stopped and the clutches will reorient the system as directed by the automated programs to de-orbit maneuvers and dump them in the Jumbo space craft.

Gravity well Module

Third unit is placed in the opposite side of the tether-net to capture fast moving bullets in space. This is made up of a fulcrum shaped metallic surface having 15 m diameter rotating with 35 rpm providing pseudo gravity 10 times as that of Earth to attract space debris. The debris will automatically attract inside the fulcrum (fig 1.13) and will reach at Jumbo space craft.

Advantages

This mechanism is independent from the size, shape and nature of material of the debris.

It can capture and dump the debris in single procedure.

When fast moving debris are trapped by the gravitational module, they shift towards the throat of the module without producing any additional junk.

Working

As this module rotates with the help of two motors of 500 Horse power, intense gravity will be produced on the inner surface of fulcrum redirects the path of the debris. It will bend the orbits of nearby debris, causing warping and spiral inwards. The velocity of debris will continues increases as the funnel throat gets smaller and smaller. Due to the inverse-square nature of gravitation, the wide end of gravity well will produce rotational motion mostly. While the narrow end of the gravity well will produce translational motion mostly. Hence the debris will acquire translational and rotational motion simultaneously inside the deep gravity well while falling into a gravitational potential. Once a debris mass is near a rotating surface, it will trap it and will never allows it to escape.

Power unit [13, 14]

13.http://www.thirdwave.de/3w/tech/spacecraft/spacecraftpowergen.pdf

14.http://www.qrg.northwestern.edu/projects/vss/docs/power/1-what-are-fuel-cells.htmlBelow the tether net structure inside the pyramidal shape of Adwitya (fig 1.14) the power distribution unit will be provided. The source of electric energy for whole processes will be the regenerative fuel cells. In these cells hydrogen and oxygen molecules are separated and on combining exothermally they release large amount of energy and heat which provide power up to 7Kw (7000W) of continuously. Waste product during such reaction will be only water. Electrolysis of water will again split oxygen and hydrogen molecules for refueling these cells. For this solar panels will provide external secondary power.

Jumbo Space Craft

Fourth but one of the most important units of Adwitya is Jumbo carrier. It will serve the dual purpose, one as debris collector intend to piggyback and other as carrier from Adwitya to Neel Kanth. Its structure (1.15) will be of cylindrical shape having volume of 2350 m3. It will get feeding of space junk from all the three parts of the sweeping unit. As it will be completely filled, it will get detached from the Adwitya (fig1.16) using propellant engines attached at its back. Very soon as the Jumbo filled with captured debris detaches (fig 1.17) and starts its journey towards Neel Kanth another empty Jumbo space craft comes at its place (fig 1.18) so that the removal mission should continue uninterrupted. At the position where Jumbo embeds in the Adwitya, curved metallic spokes will be provided having diameter of 1m. It docks with Neel Kanth and shifts the debris in it.

Advantages

Because of large volume of Jumbo, it will be able to dump large number of debris at a time.

The fuel tanks would be provided inside the Jumbo and the feed line link transfer fuel & acts as a gap for isolation between cylinder & engine.

Working

Docking procedure will be carried out by magnetic initial capture technique (fig1.8) provided in metallic spokes. This technique eliminates the need to rely on speed of approach and enables smooth flow of cargo. Loading of debris in Jumbo will be done by two feeder lines connected from opposite sides, one grabs the debris collected by teether nets and other grabs debris from gravitational module. Front and top loading of debris will be done by robotic arms. Thus the grabbing process takes place from all the four sides using the large capacity of Jumbo efficiently.

1.2.2.2 DESIGN FEATURES

Space ventures have evolved special design features for Adwitya’s basic structural. These features are mentioned below:-

Thermal Protection System (TPS) [15] (ref. fig 1.19)

The most visible aspect of new developed Thermal Protection System are Adwitya’s external tiles (fig 1.19) which consist of combination of materials and technologies that work together to protect Adwitya. These tiles are composed of carbon-carbon composite structure which is a three dimensional (3-D) carbon fiber grid and a carbon matrix. This is capable of protecting the structural parts of Adwitya from external thermal erosions in the minimum range of 2000-7000°C.The organic fiber/epoxy coating is bonded to the underside of the metallic structure this increases the mechanical strength of the TPS and diminishes the Thermal Flux to the interior of Adwitya.

Material used (ref. appendix Table A-2)

.

15. http://www.azom.com/details.asp?ArticleID=3904The framework of Adwitya made up of titanium because of its property of high strength in order to protect the structure from fast moving debris. On the basis of different functions, the selections of various materials are different for different attachments.

A primary characteristic of material for the tether-net system should be easily folded, very flexible in bending, light, strong and tough. The materials used to fabricate the wires include alloyed titanium fibers mixed with matrix of polymeric materials to impart flexibility. Carbon, Glass, Kevlar and Boron materials are mixed to Epoxy in order to make them strong that is debris resistant. Thousands of such wires will be coiled together to form strong ropes. These ropes will be bound together to form strong cables to make mesh.

The tubes on which the net is mounted are made up of titanium and copper materials to make them flexible.

The robotic arms are primarily constructed from carbon composite materials. These clutches are having tactile sensors, which are sensitive to force, pressure and touch. The minimum bandwidth of a these sensors is 100Hz.

The gravity module is consists of a funnel shaped cylinder, made up of titanium strips because of its property of high tensile strength.

Jumbo carrier is made up of the multi layered hybrid materials considering their basic properties of Strength and thermal shielding. Skelton of the Jumbo is made up of titanium, which is surrounded by two consecutive layers of Nextel and kevler-49[16]. The properties of the materials are discussed in the appendix table A-2.

Shock Insulation System [17] (SIS)

Adwitya has been developed in such a way that it is free from any kind of jolts and jerks. This will be achieved with the help of the SHOCK RINGS (ref fig 1.20) which are installed on joining region of every section of Adwitya’s CENTRAL CYLINDRICAL CHAMBER. This technology reduces high wave impacts on Adwitya due to striking of debris and /or thrusters.

Monopropellant systems of Adwitya:

Four Vernier rockets[18] (fig 1.21) are provided around Adwitya, which will maintain the altitude and direction of it. These Vernier rockets will also maintain the distance between debris and enabling it to capture them without losing its orbit. At the time of launch, initial propulsion system would be attached to the central cylinder for enabling an easy launch of Adwitya. This initial propulsion system will use 0.5 N to 400 N hydrazine and Argon thrusters use storable monopropellant N2H4 as its basic fuel. We have also provided oxidizing injecting valves which will supply oxygen (used as oxidizer) to the Vernier rockets. Thrust is produced by the decomposition of hydrazine as it passes through a catalyst .Thrusters are designed for operation in both steady state and pulse mode operation over a wide pressure range and are thus ideal for propulsion systems operating in blow-down mode (Speed variation modes including Hovering over debris).

There will be four other components which will be part of propulsion system: a power source, a power processing unit (PPU)[19] (fig 1.14), a propellant management system (PMS), and a control computer. The PPU converts the electrical power generated by the power source into the power required by each component of the thrusters. The PMS will control the propellant flow from the propellant tank to the thrusters and hollow cathode. It controls the computer and monitors system performance.

16. http://enpub.fulton.asu.edu/cement/papers/deju_mobasher_rajan_mteng-69_p1.pdf

17. http://www.csaengineering.com/brochure/pdfs/CSAEngineering_ESPA.pdf

18. http://www.grc.nasa.gov/WWW/K-12/rocket/guidance.html

19. http://www.astrium.eads.net/en/equipment/ppu-for-electric-propulsion.html

1.2.2.3 JUMBO PROPELLANT ENGINE

VASIMR - VARIABLE SPECIFIC IMPULSE MAGNETOPLASM ROCKET (ref. Table.A-3)

We are using VASIMR[20] (ref fig 1.22) engines to power Jumbo. They provide ultra compact core which works with fast spectrum simulation and reduces shield mass. This VASIMR engine has a very high payload capacity and high efficiency for orbit transfer. VASIMR engine has no moving parts, no combustion and no electrode utilization in the engine which increases flexibility and capability of this mission.

Due to high efficient electro-ion & magnetic fields mechanism Vasimr engines will provide extremely extensive space exploration capability. These engines will also reduce mission cost. Most important factor for choosing a Vasimr engine for mission is that its working can be operated conveniently according to our own demands. Jumbo’s Vasimr engine uses 0.2 tones of Argon with oxygen (as oxidizer) every year which is very less as compared to other competent thrusters. Instead of using boosting phenomenon, Vasimr engines produce electro-plasmic fields at the injection region which provides steady speed and motion to Jumbo.

RECYCLING UNIT

Neel Kanth

Neel Kanth is name of Lord Shiva (Hindu God), meaning who can swallow poison and gives out Holy water. The motive of Neel Kanth is to ‘consume’ space debris and recycle them to give out reusable materials. This Quadra torus structure having vertical spokes through which each unit is attached (fig1.23a &b) is located at 300 to 400 Km from the surface of Earth nearly at the same place as of International space station (ISS). Three pairs of vernier rockets will be attached to maintain the position of Neel Kanth

For the complete self-directed recycling process each ring is further segmented into various units. These include inspection chamber, cleaning unit, in addition with their individual functioning unit. Storage area is provided at the center of each ring to store the resulting outcome of previous procedure.

The debris that arrives (1.24) at Neel Kanth will be of many sizes and shapes. These will be unloaded, moved, stored, and managed by a completely autonomous system known as Load EXT system consisting of pair of coordinating arms with rotating base, Cargobot (fig 1.24), Electro-adhesive Layered Conveyer Belt. Debris will be maneuvered by large robotic arms attached to the tracks on the end of docks. The cargo will then be passed on to the series of Electro-adhesive Layered tracks (fig 1.25) from one processing unit into other. At the entry of the each torus inspection center is provided. It uses Laser technique to check the input material size and its physical properties. If there is any problem in the input material then Robotic arms will redirect that material towards the previous processing unit again. Various parts of Neel Kanth performing different processes are explained below:

STORAGE AND SHREDDING RING

20.http://www.nasa.gov/vision/space/travellinginspace/future propulsion.htmlTo make the recycling easy we need to squeeze the debris into small pieces. Four shredder centers of size 2m x 4m will be formed at the periphery of shredding ring of Neel Kanth, directly below the docks. When junk slides down from Jumbo it directly fall on inside the storage area of capacity ti store around 25000kg of debris from where further input is given to the shredding units through conveyor belt. The power consumed to each unit will be 30-55 KW for which it will require motor of 60 horsepower (HP). Maximum crushing capacity of each shredder is 25-45 tons per hour. It will consist of a storage compartment of dimensions 80x80x20 cm and two rollers of radius 14cm and diameter 28cm and length 80cm. Each roller consists of ten metal cutters each at the distance of 3cm. It has engagement type cutting blades i.e. one in between. Parts of metal shredder:- main frame, eccentric shaft, a large belt pulley, fly wheel, swing jaw, side guard plate, toggle plate, rear bracket, adjust gap screw, reset spring , fixed jaw , swing jaw board ,etc.

The motor will transmit power through belt and pulley, drives the swing jaw surround the eccentric shaft do periodic motion. As the swing jaw moves up, the angle between toggle plate and swing jaw increases due to which moving jaw get closes to the fixed jaw. And when swing jaw moves down, the angle between toggle plate and swing jaw decreases and moving jaw of jaw crusher moves away from fixed jaw. By pulling of rod and spring, the products after crushing will be discharged from the outlet of jaw crusher. In this way the material is crushed, grinded and broken (ref. fig1.26).

SEPARATION RING

Pressure blow technique will be used to shift squeezed debris from shredding ring to separation ring through four transportation spokes. Ten drum types Magnetic Separators[21] (fig 1.27) made up of permanent magnet are installed in four units to separate magnetic and non magnetic junk from bulk. As the material will be allowed to fall over the drum, powerful magnets holds the magnetic material to the revolving shell and non magnetic particles will fall undeflected on the lower conveyor belt inside the ring. This belt will have separate route towards de-coating ring in comparison with the belt carrying magnetic material. Impressive features of magnetic drum are that it automatically separates magnetic impurities and being enclosed designs it avoids random motion of debris.

Each drum having diameter of 60 cm and length 1 m, with the capacity of 1 tone per hour will rotate at 6000rpm produces an average magnetic intensity of 1500-2000 gauss at the surface.

DECOATING RING

Neel Kanth is provided with the LASER DECOATING [22] unit (using Nd:YAG laser[23,24]). This technique is having advantage of completely removal of even most difficult coating including power coating, electro-coating, chemical agent resistant coating etc. (ref fig 1.28) from debris without any damage to it. The energy generated by laser will be absorbed at the surface of the coating material which results in the removal and decomposition of that coat. Laser decontamination eliminates the structural failures, which were initiated by corrosion and caused by chemical residues in surfaces.

This torus structure will be provided with ten platforms out of which five platforms will be for magnetic materials and five for non magnetic materials decoating will be used. Each platform has area covered between 5.8-17.5 square feet operated at 250 W system and 46-140 square feet operated at 200 KW system. The decomposed by-products will produce carbon dioxide, water, inorganic pigment ash and trace amount of other compounds. The organic constituents will be exhausted into the space and particulate matter will be collected in the HEPA FILTERS[25] filters for further disposal.

21.http://www.gunt.de/networks/gunt/sites/s1/mmcontent/produktbilder/08328000/Datenblatt/08328000%202.pdf

22- http://www.ndcee.ctc.com/technologies/Coatings_Removal/Laser%20Decoating.pdf

23. http://en.wikipedia.org/wiki/Nd:YAG_laser

24. http://www.phy.davidson.edu/stuhome/sethvc/laser-final/ndyag.htm

MELTING RING

To get the final product the recycled unit the material is further pushed in to the melting ring. It has two major sections first section will be for magnetic material having fleet of 5 electric furnaces attain temperature up to 5432°F and second section will be for non magnetic material having same furnaces but operated in the lower temperature up to 3272 °F as melting temperature of non magnetic materials is less. The material will reach till series of furnace units with the help of conveyor belts. At the end of each furnace filters are provided, through which filtrate will be collected in the separate modules until the metals and non metals solidifies into ingots. Which will be further directed towards the storage zone situated at the center of the Neel Kanth using pair of hydraulics & adjustable grippers for maintaining its height & hold over cargo packages.

SHIFTING

Falcon-9[26,27] a carrier space craft’s will be attached at the lower plane of Neel Kanth. Two such recoverable and reusable space transportation ships will transport the processed materials towards Earth. Every ship departing from Neel Kanth will get payload of around 1200kg. Loading process in the storage zone will check and record the size and weight of material to be transferred. This identifier sends the data to GBO.

1.2.3 EXECUTION OF MISSION (ref. fig. 1.29)

The primary goal of the mission is to mitigate at least 75% of debris that is cost-effective and launch-ready by 2070. As per requirements by 2070, 75% of debris comes out to be 600,000. For wide distribution of debris in space it will no longer be feasible to grab 330debris per day (ref appendix A-1) with single spacecraft. To overcome this, multiple spacecraft could work parallel.

For lower altitudes (below 400 km), atmospheric drag provides a natural cleansing mechanism and hence lowering the cost. Moreover use of a large device, however, poses a threat to other (i.e., functional) objects and would also require active control in order to maintain it in orbit for an extended period of time. Hence it will be highly expensive and risky process to capture and recycle debris from lower altitudes. The task of capturing debris will be completed in five phases.

Phase -1

After getting the contract, an extensive research would be carried out and we would start the recruitment of scientists and mission experts which would be pivotal to carry out this mission. Four Adwityas will be constructed in seven years including testing its various operations. Simultaneously GBO will be developed before the launching of two Adwitya in January 2070.

During this phase an important task i.e. survey of debris regions will be done (Ref: appendix: Table A-1) to assess captured distance. The way to do this is:

to conduct close approach ground and space analyses;

to assess the cumulative probabilities of collision; and,

to estimate the capturing distance.

Phase -II

25. http://en.wikipedia.org/wiki/HEPA#Function

26http://en.wikipedia.org/wiki/Falcon_9#Features

27. http://spaceflightnow.com/falcon9/004/falcon9.html

In second phase Adwityas will receive commands from GBO and Zenith and will start capturing the target debris after shifting its position from parking orbit. Upon release of the captured debris in Jumbo, Adwitya will again raise its orbit to rendezvous with the next debris target. (fig 1.3).

Phase-III

Once the jumbo is full with captured debris, it will initiates a de-orbit maneuver using its own pro-pulsion system towards Neel Kanth. (fig 1.16)

Phase – IV

In this phase as the de-orbiting process of Jumbo completes, it docks with Neel Kanth. Lower vent of Jumbo will transfer collected debris into Neel Kanth and recycling procedure of materials will start.

Phase -V

The processed material, including metals and non-metals will automatically shifted in the storage zone and will be sent inside the Falcon –9 ready to transport towards Earth.

1.2.4 TECHNOLOGIES USED

Through the implementation of high Technology Readiness Level (TRL)[28] components, an effective solution to active debris removal can be achieved.

ZENITH AND ADWITYA

Remote sensing of space debris in LEO will use mixed mode RADAR. The radar beam is pointed to a pre-determined position in space and after detection the object is tracked and observation vectors are collected. From the evaluation of angular rate and range rate as a function of time, orbital elements can be derived.

For providing statistical information and rough orbit parameters for objects as small as 1 cm at altitudes up to 2000 km the observatories are coupled with higher resolution radio telescope. Radio telescope will be used to tracking data from GBO or from space. It operates in the radio frequency portion of the electromagnetic spectrum. It is basically a large parabolic dish (antenna). The diameter of dish is 150 meter. It includes reflector, sub reflector, amplifier and receiver. Dish will be comprised of 20,000 perforated Aluminum panels used to reflect signals to sub-reflector. Radio signals coming from astronomical sources are collected by reflectors and are received by receiver and are amplified at an appropriate frequency.

Because of the smaller distance between the observer and the debris and disturbing effect of the atmosphere (extinction and absorption of electromagnetic signals) in space we use telescopic cameras. When the sky background is dark, the debris are bright. For objects in LEO, this period is limited to an hour or two just after sunset or before sunrise. During rendezvous, the spacecraft will use a relative positioning navigation but an absolute altitude to collect data about the target debris in terms of position, swing rate, status of the grabbing point.

During the parking orbit, the Adwitya has to be 3-axis stabilized to maintain the communication link. So the main requirement of the phase for AOCS is to control every disturbance e.g. gravity gradient, the solar radiation and the aerodynamic drag etc.

28.http://en.wikipedia.org/wiki/Technology_readiness_level#NASA_definitions

29. http://en.wikipedia.org/wiki/Technology_readiness_level

30. http://www.nasa.gov/centers/marshall/pdf/115938main_ARIS_FS.pdf

To perform the control of the spacecraft against these disturbances, four reaction wheels will be implemented to control the attitude. They will be helped by two sun sensors and two earth sensors (one main and one for redundancy).

To perform an accurate re-entry, Jumbo will spin up to use a gyroscopic control. The design of this gyroscopic control is to determine the slew rate from the maximum precession angle that can be allowed.

Space ventures visualized the need of vibration and jerk absorbers in various components of Adwitya and structural isolation has been accomplished by introducing Active Rack Isolation System (ARIS)[30] at different locations that provides detection and isolation of vibrations. ARIS installed at different locations especially e.g. joints of robotic arms, joining part of gravitation module with central cylinder of Adwitya, tentacles of tether net systems etc. reduces vibrations using a combination of sensors and actuators. When the sensors detect a disturbance while capturing process, the actuators counter the effect by sending a reactive force between the location and the control unit. This "smart" shock absorber is finely tuned to react to, and cancel out, very minute vibrations caused due to debris collision with main structure or during capturing process. Accelerometer assemblies measure the disturbances and send data to the ARIS electronic control unit. A micro gravity rack barrier prevents accidental disturbances to the active ARIS rack. ARIS is designed to isolate all frequencies greater than 0.01 Hz, and is most effective in the 0.05- to 300-Hz range.

In addition to it the SHOCK RING TECHNOLOGY (fig 1.20) also known as ESPA Evolved Secondary Payload Adaptor[31]. These supporting rings are installed on connecting parts of VASIMR engine Adwitya.

Use of ICRF[32] (Ion-Cyclotron Resonant Frequency) avoids improper combustion of fuel in Adwitya, which directly results in raising efficiency of propellant system. This technology works at- fuel and oxidizer separating nozzle and ensures that the plasma will efficiently detach (Complete combustion) from the magnetic field to provide propulsion through a highly directed exhaust stream.

EFCU-Exhausting Fuel Control Unit enables us to control the amount of fuel required for magnetic suspension system and maintains the stability and accuracy in speed of Vasimr Engines according to our requirement. It also enhances the speed variability requirement of Vasimr. This is very important because Vasimr engine requires sophisticated control strategies and equipment to recover the effects in instability to the system.

DSN [33]-Deep Space Networking antennas (ref. fig1.30) deployed on Adwitya provide boost in sending and getting signals. The reflector surface is precision-shaped for maximum signal-gathering capability than any other DSN antennas. A major change in the design is the addition of five precision radio frequency mirrors that reflect signals along a beam-waveguide tube from the vertex of the antenna of Zenith. This antenna maintains continuous signal stability from Zenith and GBO (fig 1.31). Low gain antenna has also been installed on Zenith to communicate with GBO.

31.http://smallsatrideshare.wikispaces.com/ESPA

32 http://en.wikipedia.org/wiki/Ion_cyclotron_resonance

33. http://deepspace.jpl.nasa.gov/dsn/antennas/34m.html

Zenith receives signals from navigation and monitoring sensors to establish the state of the Adwitya, and implements controls software to activate analog to digital converter system (ADCS), power and propulsion systems to maintain the desired orbit. This system also relays information to GBO and receives commands from it during the mission. For most of the mission, when Adwitya acquires the orbit of debris or during de-orbiting, the data rates are estimated to be ≤ 1 k Bit/sec. The most data-intensive part of the mission is during rendezvous and capture, when live video of the debris is relayed to GBO for assessment (fig1.31) and determination of propulsion and robotic arm maneuvers needed to capture the target.

Data will be stored using Holographic data storage, which records 515 gigabits per square inch on storage media. Work and administrators computer data will be stored on server hard drives installed in GBO and zenith. This will allow access to that data though any such computer.

In Neel Kanth HEPA the air filters will set to filter 99.97% of the particles produced in the process of de-coating of junk from the substituent which are bigger than 0.3 micrometer which will pass from it.

1.3 TIMELINE (ref fig2.1,2.2)

For the successful completion of capturing debris mission the following phases would be pursued-

Submission and Approval (2050-2051)

Space Ventures will submit the proposal of contract covering all the requirements asked by the approval authorities. We are expecting two years span i.e. up to 31 December 2051for the approval of such a challenging project.

Recruitment (2052-2052)

After getting contract on 1st January 2052, recruit the staff including administrators, Scientists, technicians and supporting staff will be hired. The hiring process will complete up to 31 December 2052. They will operate the mission from the GBO and regularly watch the activities of Adwitya.

Training and Planning (2053-2054)

To perceive the intellectual challenges involved during the mission the staff will undergo a special training lasting approximately 6 months. This phase includes induction program. Then survey, research and planning will be carried out by these experts for two years i.e. up to 31 December 2054. This research will enable the scientists and designers to design a stable structure of Ground Based Observatory (GBO) and Adwitya.

Construction of Ground Based Observatory (2055-2057)

As the data from the planning team starts coming the construction of GBO will begin according to the given requirements in January 2055 and it will be completed within three year. GBO will be in partial working condition in around December 2055. The communication setup and the power equipments will be installed during this span and the completion dead line for this phase will be December 2057.

Pilot Plants Testing and Data Analysis (2058-2058)

To ensure the best performance during capturing process all the equipments planted in GBO will be acid tested. Parallel to this process, the background calculations which will be required for capturing mission will also be worked upon. During this phase various computing software’s and hardware’s will be analyzed to ensure the success of mission. This phase will be completed up to 31 December 2058.

Construction of Adwitya including Jumbo(2059-2065)

Once we receive the observations and vigorous data analysis results, the design of Adwitya will be finalized in December 2059 and the construction of Adwitya begins taking into considerations the provided parameters. Four units of Adwitya including inbuilt observatory will take six years span. The planning of the construction process of Adwitya will be similar to ISS that is most of its the components will be constructed on Earth and will be shifted to LEO at the altitude 400 Km and attached there. The construction will be carried out in three separate phases.

SUB PHASE I:-The construction of the Central cylindrical structure of Adwitya including gravitation module. Solar panels will be mounted on the outer structure of Adwitya for providing power to various modules installed inside it.

SUB PHASE II:-Zenith will be constructed and mounted on the Adwitya, which will act as space observatory. Also the communication antennas will also be mounted on it.

SUB PHASE III:- Jumbo the carrier space craft will be constructed in this phase. This will act as a transporter between Adwitya and Neel Kanth.

SUB PHASE IV:- This Phase will witness the construction of the detachable thrusters and their rotator control. Simultaneously, four Vesimr rockets to the Adwitya and the Vasimr engine deployed at the Jumbo will also be constructed with high precision.

SUB PHASE V: - In this Phase the teether nets and robotic arms will be constructed.

SUB PHASE VI:- All the constructed parts will be assembled together with the help of the structural joint.

The construction would take a total time of seven years. This time will also include the last six months for extensive testing of Adwitya to detect any faults or errors and rectify them on time. As Adwitya will be constructed in LEO after the completion of its construction inbuid communication system of observatory starts its tuning with GBO. It will start sending and receiving signals from GBO.

Construction of Neel Kanth (2066-2068)

The recycling unit Neel Kanth will be constructed in this phase at LEO in three years This time span will be further splitted into three sub phases as given below:

SUB PHASE I:- The framework of four rings including docking ports will be constructed in this phase.

SUB PHASE II:- The structural frame will be covered with materials in this phase.

SUB PHASE III:- As soon as the Quadra ring structure attached with spokes will be completed including thrusters the development of internal services i.e. shredding units, separation unit, de-coating unit and melting unit will be started.

During its construction span testing of various units including the testing of backbone of Neel Kanth i.e. conveyor belt will be done.

Final Testing and analysis (2069)

Space ventures will ensure the completion of the infrastructure till 31 December 2069. Then final testing phase will start analyzing all the structural parts of GBO, space observation and Grabbing procedures. This process will be completed up to 31 December 2069.

Deflection process (2070………)

In 1 January 2070, GBO will start functioning with full swing and will send signals to Zenith for processing. It will further direct Adwitya for capture the target debris. Space ventures will ensure that each year from 1st January 2070 to 31 December 2075 Adwitya will capture 330debris per day to fulfill the target of 75% capturing in first five years. The capturing process will continue up to 25 years i.e. up to 2095.

The chronological detail of capturing process is as follow-

Each Adwitya will grab 165debris per day. It includes both small debris (diameter ranging between 1cm to 10cm) as well as large sized. Maximum density of debris lies in the altitude of 800km-1000km at inclinations of 95°-100°. Thus in the first year Adwitya will concentrate in this region. Each Adwitya will grab junk according to the signals received by GBO and Zenith. The detailed analysis is provided in the appendix.

Thus at least two times each jumbo will have to deorbit itself towards Neel Kanth in a month to shift debris.

Hence, In 2095 Adwitya will complete its designated goal to protect this global family by successfully capturing of target debris in twenty five years.

1.4 TECHNICAL RISKS AND THEIR EFFECTS

We are providing the design which is technically sound and works within the laws of physics and orbital mechanics. There are few issues which can decrease the efficiency of our overall strategy but there is very little chance of mission failure. Following is the list of technical issues and how we are going to deal with them:-

Although the removal of target debris from heavily populated zone, high choices are available relatively, even then higher precession will be required to avoid slip. Two observatories GBO and Zenith are provided to accomplish the need.

The debris are non-cooperative, it can spin and tumble. Which makes the mission extremely dicey as the average speed of debris is around 28000Km/h. The rotations of these targets have to be stopped before de-orbiting. So the thrusters are designed accordingly to fulfill the need.

Main issue with Adwitya is that it cannot thrust at maximum value because it must have some margin between the average thrust and the maximum thrust since it has an active altitude control system (ACS)[34]. Adwitya will be provided with four thrusters which are double than the requirement covering the total thrust required by it.

Any thruster failure will lead to loss of altitude control and it will prove to be a big problem as the station keeping will be affected. At the station keeping point, there is no relative motion between the chaser and the target, so the chaser can stay there even if there is some failure in any sub-system.

It will require continuous station keeping in order to keep it continuously positioning in the parking orbit. Vesimer Rockets are provided to fulfill the requirement.

In space high speed debris may collide with the Adwitya and can cause vibrations, which may disturb the grabbing procedure. Active Rack Isolation System (ARIS) at different locations will be installed reducing vibrations using a combination of sensors and actuators.

34.ftp://apollo.ssl.berkeley.edu/pub/cinema/06.%20Spacecraft/3.%20Attitude%20Control%20System/vega_2009.pdfCamera shutters of Zenith can remain closed or opened in the absence of light, thus proving to be a great bottleneck for the mission’s success. For that time total control of Adwitya will automatically shift to GBO.

Communication failures with Zenith, GBO or Adwitya can lead to loss of tracking of capturing process. For such situations another Adwitya will be launched at the same location to pursue the mission. Two additional Adwityas will be provided for backup.

The capturing of debris especially of larger size than 10 cm may cause variation in center of mass of Adwitya which can change rotational axis of Adwitya. So regular repositioning of it will be required.

There are chances that one of the robotic arms may stop functioning due to certain random problem. Therefore Adwitya will be provided with two robotic arms.

Similarly eight tether nets are provided at the top of capturing unit, which will continue capturing process even if one or two out of them becomes non functional.

The gravity module can capture debris of any size and technology requirement will be less in comparison with other methods. Thus if it stops rotating even then there is certain probability that the debris may fall in the fulcrum shaped structure.

The orbital speed of debris is between 3 km/sec and 7.7 km/sec. Therefore a collision between one uncontrolled object and Adwitya can further generate more debris. The round shaped structure minimizes the impact. Also the capturing mechanisms are covering 4Ï€ space, which reduces the collision risk. Collision Avoidance Maneuver (CAM)[35] will be installed to protect Adwitya to keep it away of the target debris.

If there arises any software or hardware problem in Zenith and it becomes non functional, backup will support the functioning up till GBO corrects the problem. Most systems on Zenith will have backup available if the main system encounters a problem. Automated onboard fault protection software and GBO will sense any conditions and switch to backups.

Software error or faulty commands from GBO or Zenith will certainly be leading to mission loss. Backup data storage will be provided in GBO. In case of GBO failure Zenith will be capable to work independently.

1.4.1 COMPARATIVE STUDY WITH OTHER STRATEGIES

The other capturing strategies that were considered by Space Ventures were:-Laser Broom, Space debris elimination technique, Swiss Maid, Electro Dynamic Debris Eliminator (EDDE)[36], Aerogel[37], De-orbiting debris using rockets, electro adhesion, Nano sat, etc. Out of all these strategies, we found that fully automated Adwitya was the most promising one because its results will be measurable and perfectly controllable. The merits of Adwitya in comparison with other probable methods [38] can be explained as follows:

There is probability of Laser to hit the wrong target or the right target at wrong place, which may generate further more fragments and may cause greater devastation. Adwitya will not cause any such damage.

Space debris elimination also known as Spade elimination may not be strong enough to deflect large sized debris. This method is not for smaller debris. But Adwitya will be capable to capture small as well as large sized debris.

35.http://www.esa.int/Our_Activities/Human_Spaceflight/ATV/Jules_Verne_demonstrates_flawless_Collision_Avoidance_Manoeuvre

36. http://www.thelivingmoon.com/41pegasus/02files/Electrodynamic.html

37. http://www.aerogel.org/?p=1058

EDDE, Electro adhesive, Shielding and Nano sat methods are not cost effective in comparison with Adwitya. As first two requires regular maintenance of electromagnets and their working may be affected if the fast moving object strikes with them. Also Electromagnets lose their magnetism after a while. Method of Shielding in debris detection can’t apply on optical devices & solar panels. The working life of Nano Sat is very less and their thrust attainability level is very low. This will not be the case with Adwitya.

Swiss maid cannot target variable sized debris and apart from this limitation it is one performs capturing mechanism once in one launch. Adwitya will be able to capture more than one debris in a single mission.

Self removal technique uses rockets to de-orbit debris and hence require much propellant. It is also not very efficient technique to grab junk from the space. On the other hand Adwitya uses the Robotic arms, Gravity module and Tether net systems for fulfilling the task and each system is having higher efficiency.

Arogel technique requires more chemical and more time of capturing. Hence with this method one cannot achieve the set target. We have the calculations which show capturing of debris in the specific time by using Adwitya.

There are lot many non conventional techniques like Aerogel, electro adhesion etc. these are not efficient and hence produces unpredictable methods. Most of the techniques deflect the target debris towards the Earth atmosphere [39], which may increase risk factor for humanity. As there is probability that certain part of debris may fall on Earth, which remains un burnt even after passing through the atmosphere. Space Ventures [40] has Designed the hybrid technique to get precise and accurate results. It will be the cost effective and will complete its target uninterrupted without any major mechanical [41] or operational problems.

1.5 INFRASTRUCTURE

1.5.1 MANPOWER (ref fig 1.21)

To carry out the mission smoothly, two type of staff Administrative and technical staff will be hired. The team of technical staff includes Engineers, scientists and Technical officers. For the efficient functioning of the mission we have divided the whole staff into two departments-a) Planning and observation department b) Manufacturing department. Space Ventures is capable to identify, recruit and retain employees who possess essential/critical skills and competencies. Space Ventures will apply its capabilities to the range of mission, research, and technology work while continuing to reshape and realign workforce skills to adjust to changing requirements.

All the activities and developments of the capturing would be reported by the mission head to the president of Space Ventures who will have the highest authority in this project.

1.5.1.1 Department of planning and observation

This department will further have two sub-divisions, one working for observatories (further division Zenith and GBO) and the other for Adwitya. For Department of observatory will be bifurcated into the department of research and the department of engineering. In the department of research, the researchers would frame and coordinate the positioning of observation vehicle. They will also study the error resources and code measurement. Then there would be the department of engineering which will contribute in the field of multiple access and access control communication.

38.http://quest.arc.nasa.gov/space/teachers/suited/6work.html

39. http://en.wikipedia.org/wiki/Space_debris#Growth_mitigation

40http://www.isnare.com/?aid=1204668&ca=Automotive

41http://www.virlab.virginia.edu/nanoscience_class/lecture_notes/Lecture_11_Materials/IEEE%20Spectrum%20-%20Geckobots.pdf

41.

In the planning department of Adwitya, there will be department for research in which the researchers and the technical officers will work on major system engineering technique, functional analysis, block diagrams, design tradeoffs, design budgets, interface management and tradable parameters. In the Department of Design and system engineering, project engineers will work and consider the engineering requirements, tracking, integration, test mission operations, reliability and quality insurance. They will also work on risk management. The technical officers employed in this department would work on on-board sub systems including science instruments, communication, power management, distribution command, data handling, propulsion structure , mechanism configuration , end to end information system and flight software.

1.5.1.2 Department of manufacturing

The department of manufacturing would have two branches-the department for observatory and the department for Adwitya. The department of observatories would work in the field of material sciences for finalizing the materials of construction, in the field of sensors, power etc .The department of infrastructure would finalize the structure, system, major sub-system, data flow, service module and payloads. The department of communication will decide the required band width for communication between ground base and space, the network modulation requirement for desired interlinked communication with terrestrial ground station etc. This dept. will also work on transmitters, receivers and antennas for communication. The next department is the department of computers and electronics which would be responsible for operating system, hardware requirement for all the super computers which are used in GBO and Zenith.

Department of Adwitya Basic will have same sub departments as that of department of observatories. The department of infrastructure will consider risk factors to improve the design. Then is the department of material science which would study and select the materials needed for each part of Adwitya. They will also work on crack growth, effect of shock and vibrations etc. Then the department for instrumentation and designing which will take care of the effects of the space radiations, thermal effects and vibrations on the on-board instruments. The department of communication would design the s-band antenna, the modulation technique and they will take care of interface, types of data, standard formatted data unit, synchronization and networks and the department of computers and electronics will implant the processors, interface, mass memories (power generation and distribution), orbit control subsystems (avionics), data processing, telemetry and telecommands. Fueling department will design and analyze the advanced integration of safety while selec