SPACE ELEVATORS

PRESENTED BY-SATISH KUMAR

M.TECH(2nd sem.)IIT BHU VARANASI

Contents

• Introduction• History• Importance• Working• Components• Power source• Challenges and solution• Advantages• Future

Introduction

• Space elevators are incredibly tall structures that stretch beyond the earth’s atmosphere to transport satellites and shuttles into outer space without much cost and environmental impact of rocket fueled launcher.

PAST OF SPACE ELEVATORS1960: Artsutanov, a Russian scientist first suggests the

concept in a journal.

1999: NASA holds first workshop on space elevators after the discovery of carbon nanotubes.

2012: Obayashi Corporation announced that by 2050 it

could build a space elevator using carbon nanotube technology

Why build it ?

CURRENT

Cost of a launch is US$22,000 per kg

Huge vibrations produced and rocket fuel and hardware required which can’t be reused .

Air pollution due to explosion.

Working

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• Ribbon would stretch to a small counterweight approximately 62,000 miles (100,000 km) into space due to rotation of earth about its own axis

• Mechanical lifters attached to the ribbon would then climb the ribbon, carrying cargo and humans into space using different mechanisms.

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Main Components

The Ribbon

The Anchors

The Climbers

The Power

source

Ribbon

• This ribbon composed of thousands of 20-micro diameter fibers made of carbon nanotube in a composite matrix”.

Why Carbon nanotubes?

• They are at least 1000 times stronger than steel rods of same size.

• they are as flexible as steel.

• Light in weight(one sixth of same size of steel ).

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• The Young’s modulus has been computed to be on the order of 1.2 Terra Pascal which is 6.25 times that of steel

AnchorAnchor station is a mobile,

ocean-going platform identical to ones used in oil drilling.

Anchor is located in eastern equatorial pacific .

Weather and mobility are primary factors.

Climbers

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Climbers built with current satellite technology.Drive system built with DC electric motors or by

solid fuel like nuclear fuel rod. 7-ton climbers carry 13-ton payloads.Climbers ascend at 200 km/hr.8 day trip from Earth to geosynchronous

altitude.

Power Source1. Transfer the energy to the climb through  wireless

energy transfer while it is climbing.

2. Store the energy in the climber before it starts – requires an extremely high specific energy such as nuclear energy.

3. Solar power – power compared to the weight of panels limits the speed of climb.

Challenges and solutions

Low earth orbit objects could potentially damage or cut the cable that the space elevator is using.

Lightning, wind, clouds: avoid through proper anchor location selection.

political impact of creating a space elevator(If the space elevator’s anchor station is situated in international waters.

Technical BudgetComponent Cost Estimate (US$)Launch costs to GEO 1.0BRibbon production 400MClimbers 370MPower beaming stations 1.5BAnchor station 600MTracking facility 500MOther 430MContingency (30%) 1.6B

TOTAL ~6.9B

Costs are based on operational systems or detailed engineering studies.

Advantages

• Low operations costs - US$250/kg to LEO, GEO.

• Advantageous for Moon, Mars, Venus belts.

• No pollution.

• No launch vibrations.

Future scope

• A Japanese company, called Obayasi Corporation, recently announced that they will make fully working space elevator by the year 2050.

• Engineering development centers in the U.S., Spain and Netherlands are under development.

• Material development efforts are underway by private industry.

THANK YOU!!