the james webb space telescope is about to revolutionize humanity's comprehension of
the cosmos on its five-year mission it'll gather heretofore unimagined insights into the birth of
galaxies and offer a realistic shot at finding life on other planets or some worry it'll simply
fall apart during its insanely complicated deployment are our collective minds ready
to be blown let's hope so join us today as we look into the james webb space telescope
theoretically posited as a successor to the famous hubble telescope back in 1989
what eventually became known as the james webb space telescope or webb after science
mad nasa administrator james e webb has four broad mission goals to peer across the gulf of space and
therefore back in time to examine the formation of the very first galaxies to investigate the birth
of stars and planetary systems to compare early galaxies with their more recent relatives to test
theories about their evolution distribution and the role of dark matter and finally most
excitingly to assess the chemical makeup of distant planets including our own solar neighbors
to accurately discern their potential to harbor life so how is webb different to hubble hubble
had a seven foot ten inch mirror webb has a 21 21-foot mirror size matters when you're capturing
light from distant worlds just as a bigger bucket will capture more rainwater than a smaller bucket
more important than webb's size is its operational wavelength hubble was designed to capture light
in and around the visible spectrum that helped it generate ravishing images like these which
delighted and inspired a generation of stargazers but visible light has several limitations webb
sees in infrared and as such it's technically more akin to the lesser known spitzer space
telescope only 60 times larger why infrared for one it enables scientists to peer further
away and further back in time the first galaxies formed some 13 billion years ago and owing to the
constant expansion of the universe the wavelength of the light they produced has been progressively
stretched from its original blue and white wavelength into the red spectrum so if you're
not looking in the infrared you won't be able to see them more excitingly red light's long
wavelength means it can pass through irritating obstacles like dust that means webb will in effect
see right through these gorgeous but maddeningly opaque dust clouds that baffled hubble that alone
opens up great unfathomable expanses of sky for astronomers to pour over again for the first time
ever so what actually needs to happen on the web mission before we get to ogle those pesky hiding
galaxies all being well in late december web will blast off from the european space agency
the esa's spaceport in kuru french guyana on an ariane 5 rocket webb is an international
collaboration by the way between project leaders nasa the esa and the canadian space agency its
ultimate destination is the appropriately gallic sounding l2 lagrange point this interplanetary
sweet spot is one of only five locations in space where the gravitational pull of our sun
and that of earth balance the centripetal force spacecraft need to move alongside them uh what put
simply conditions at the l2 lagrange point help web use gravity to save fuel but this location is
also useful for other reasons as it moves through space essentially parallel with the night side of
earth where we'll always be in range of nasa's deep space communications array it'll always
have sunlight to power its solar cells and because it's always moving over the course of a year it'll
eventually have a clear view of the entire sky webb has a packed itinerary on its million-mile
voyage out to the lagrange point unfurling its delicate machinery from ariane's compact fairing
like a high-tech butterfly emerging from a chrysalis in total some 178 release mechanisms all
need to work perfectly no wonder there's thousands of anxious space nerds nervously awaiting this
particular launch anyway half an hour after blast off the first solar panels will deploy
after two hours the communications antenna will unfold ten hours after that the first of three
course correction maneuvers will occur remember everything has to work just so within a day and
a half webb will have soared past the moon's orbit a day after that the sunshield will commence its
steady painstaking deployment less eye-catching maybe than those giant gold mirrors up top
webb's sunshield is nevertheless a critical piece of kit about the size of a tennis court
the five-layer shield is designed to keep the actual telescope as cold and dark as can be
this is essential when you're working in infrared as any interference would be catastrophic for the
mission the sunshield's kite-shaped structure comprises five shiny gossamer thin layers the
0.05 millimeter thick outer layer is expected to absorb temperatures of around 260 degrees
fahrenheit while the four other layers each around half that thickness progressively
reduce heat transfer to the point the telescope gear itself maintains working temperatures as
low as -447 degrees fahrenheit the membranes themselves are made from heat resistant kapton
and coated with a 100 nanometer film of aluminium and a 50 nanometer film of silicon doped in order
to be electrically conductive just unfolding and tensioning this heat shield which occupies much of
webb's first week on the road involves 70 hinge assemblies 400 pulleys 1 312 feet of cable and
8 deployment motors and if any of that fails the 10 billion mission may as well abort straight away
no pressure week two of webb's galactic odyssey focuses on the telescope itself around day 10 a
25-foot tripod will extend incorporating webb's secondary mirror which captures light from the
primary mirror and directs it to the tertiary mirror and thence to its scientific instruments
an additional radiator will also emerge for that all-important heat reduction over the following
days all 18 hexagonal primary mirror segments will slowly unfurl with their finely calibrated
hinge mechanisms and 132 actuators designed to help the mirror attain its perfect final form
the mirrors are made from beryllium chosen because beryllium is light strong and robust at holding
its shape across a vast range of temperatures each hexagon is coated with a layer of gold just 700
atoms thick why gold it's the optimal material for infrared astronomy apparently and a smart flex on
behalf of humanity if we bump into any especially bougie aliens a month after its launch webb's
final course correction will put it into a halo orbit around the lagrange point this is when the
cooling begins in earnest project leaders reckon a week will be needed before the near cam or
near-infrared camera which calibrates and irons out any imperfections in the mirror alignment
is cool enough to function properly three weeks after that the shady portion behind
webb's sunshield will cool down to the necessary minus 380 degrees fahrenheit or 40 kelvin for work
to begin one of several design innovations web employs to lower its temperature is its
distinctive open structure as opposed to the familiar self-contained tubular format of hubble
and the telescope in your attic still even that isn't cold enough for the miri or mid-infrared
instrument it needs a dedicated cryo-cooler to chill it still further down to a refreshing minus
447 degrees fahrenheit or just 7 kelvin that takes 100 days by the way around the same time needed
to perfectly align those gold mirrors after a few more days calibrating its onboard instruments web
will be good to go what will the instruments be doing two things broadly taking photos
and capturing spectra what a spectra spectra is the plural of spectrum webb is equipped with 11
distinct modes of spectrograph these employ a mixture of clever filters smart detectors and
fine micro shutter arrays to break down light from distant objects into their component colors why to
enable scientists for the first time to directly observe the chemical makeup of countless distant
worlds that's a huge deal because the presence of certain elements say methane might indicate
the presence of alien life all being well webb will be relaying images back to our spellbound
species by summer 2022. we'll get to see further away and further back in time than humans have
ever managed before and that in itself should lead to some striking discoveries everything
hinges on that delicately choreographed launch and deployment sequence though so mind-bending
engineering has gone into its planning for instance we all know most materials shrink
at ultra cold temperatures so webb's designers have built many of its components precisely
wrong so they shrink to the perfect size and dimensions in situ why is that so nerve-wracking
as nasa mission systems engineer mike menzel puts it when you're a million miles away from earth you
can't send someone to fix it what do you think are we on the cusp of a new era of discovery let
us know in the comments and don't forget to subscribe for more web slinging tech content
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