JAMES WEBB SPACE TELESCOPE

PRESENTED BYSREEJA NEEE 8th SEMRGIT

CONTENTS

Introduction

History

Construction and Working

Launch of JWST

Advantages

Disadvantages

Conclusion

Reference

INTRODUCTIONIt is also called WEBB or JWST.

It is a large space based observatory telescope.

Is optimized for infrared wavelengths.

Include answering some of our most fundamental questions about the origin of the cosmos.

It will be located near the

Earth–Sun L2 point.

It is 1,500,000 kilometers

(930,000 mi) from Earth,

directly opposite to the Sun.

L2 point the combined

gravitational pull of the

Earth and the Sun .

HISTORYThis space-based observatory is named after James E.

Webb (1906- 1992).

The project represents an international collaboration of about 17 countries.

The JWST originated in 1996 as the Next Generation Space Telescope (NGST).

Launch is scheduled for 2018 on an Ariane 5 rocket. Its nominal mission length is of five years.

It is successor to NASA's Hubble Space Telescope.

CONSTRUCTION AND WORKINGIt will be the largest space telescope.

It has four main element

the telescope.

the instrument module(ISIM) .

the sunshield .

the spacecraft bus.

PRIMARY MIRROR

It consists of 18 individual hexagonal mirror(6.8mtr die).

The mirror segments is made of beryllium.

The mirrors are build in segments on a structure, which will fold up, so that it can fit into a rocket.

The mirror segments deploy and get aligned in space by

commands from Earth.

It can gather more light and resolve more details.

The hexagonal shape allows a segmented mirror with high

filling factor

Webb needs to be very cold ("cryogenic"), with its mirrors

at around -220 degrees C

SECONDARY AND TERTIARY MIRROR The single secondary mirror is perfectly rounded and

convex

The tertiary mirror is the third stop for light coming into the telescope and is the only fixed mirror in the system

The light from an object reflects off the mirrors before entering the science instruments in the back of the telescope

SUNSHIELDThe JWST must be kept very

cold (under 50 K (−220 °C; −370 °F))

It uses a large sunshield to block light and heat from the Sun, Earth, and Moon

L2 point keeps all three bodies on the same side of the spacecraft at all times.

Maintains a constant environment for the sunshield and solar arrays.

The sunshield is made of polyimide film, has membranes

coated with aluminum on one side and silicon on the other

side

It is designed to be folded twelve times so it will fit within

the Ariane 5 rocket

The sunshield was hand-assembled at Man Tech Albama

It is approximately tennis court-sized five-layer deployable

sunshield.

ISIM(Integrated Science Instrument Module )

The ISIM is the heart of the James Webb Space Telescope

This is the unit that will house the four main instruments that will detect light from distant stars and galaxies

Near-Infrared Camera

Near-Infrared Spectrograph

Mid-Infrared Instrument

Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph

Near-Infrared Camera

NIRCam will detect light from the

earliest stars

NIRCam is equipped with

coronagraph

will cover the infrared wavelength

range 0.6 to 5 microns.

Near Infrared SpectrographIt is being built by the European

Space Agency

Analyzing the spectrum of an

object can tell us about its

physical properties

Multi-object capability

Micro shutter system to control

how light enters the NIRSpec.

Mid-Infrared InstrumentMIRI covers the wavelength range of 5 to 28

microns.

Its sensitive detectors will allow it to see the

redshifted light of distant galaxies, newly

forming stars, and faintly visible comets .

The Mid-Infrared Instrument (MIRI) has

both a camera and a spectrograph

Fine Guidance Sensor It has a wavelength range of 0.8 to 5.0

microns

It is a "guider," which helps point the

telescope.

The Spacecraft BusThe spacecraft bus provides the

necessary support for the operation

The bus is the home for six major subsystems:

Electrical Power Subsystem

Attitude Control Subsystem

Communication Subsystem

Command and Data Handling subsystem

Propulsion Subsystem

Thermal Control Subsystem

ADVANTAGES

infrared light emitted by these regions can penetrate this dusty cloud and reveal what is inside.

JWST will offer unprecedented resolution and sensitivity from long-wavelength visible to the mid-infrared

Understands the formation of stars and planets.

DISADVANTAGES

James Webb telescope so far from the Earth.

EAGLE NEBULA

SUPERNOVA

CONCLUSION

James webb space telescope capabilities will enable a

broad range of investigations across the fields

of astronomy and cosmology. It observes some of the

most distant objects in the Universe, beyond the reach

of current ground and space based instruments

REFERENCEhttp://www.jwst.nasa.gov

The Scientific Capabilities of the James Webb Space Telescope – Jon Gardner

Comparative Planetology: Transiting Exoplanet Science with JWST – Mark Clampin

Planetary Systems and Star Formation with JWST –George Rieke

Study of Planetary Systems and Solar System Objects with JWST – George Sonneborn