It's the most expensive science probe ever built costing upwards of 10 billion and took decades to
get into space but the hand-wringing anxiety for nasa and the other space agencies is far from over
the James Webb space telescope launched beautifully on Christmas morning
taking admirers the world over with it on a spectacular journey to a spot called L2
from there it becomes humanity's time machine peering back to the earliest epic of history
when our universe was in its most embryonic stages entire careers of so many dedicated workers around
the globe have been spent to see this mission through but for this dream to be realized so much
must go right out in the dark and cold reaches of space and so many things can derail this historic
mission that is captivating the world welcome the Factnomenal today we'll look at what's on Webb's
horizon in the coming days and weeks and the key moments that must go as planned and practiced
what could possibly go wrong you ask plenty and then some Mike Menzel Webb lead mission system
engineer for NASA's Goddard space flight center GSFC in Maryland had this to say during a November
news briefing there are 344 single point of failure items on average approximately 80 percent
of those are associated with the deployment it's hard to avoid when you have a release mechanism
it's hard to put full redundancy into that crystal puga web spacecraft systems engineer for Northrop
Grumman noted at the same event that Webb's 144 release mechanisms all must work perfectly
Menzel said the web team decreased the number of release mechanisms and thus single points
of failure as much as possible and conducted extra inspections and tests on all that remained
remember this system must operate at a few degrees above absolute zero protected by five
membranes the thickness of a human hair combined into a tennis court-sized kite-shaped sunshade
so the space origami that is Webb is now unfolding
this Menzel added is hands down the most complicated space activity we've ever done
by the end of the James Webb space telescope's first week in space the solar array was
successfully deployed two trajectory correcting thruster firings were executed flawlessly
a high gain antenna was unlimbered and pointed at earth and the forward and aft pallets holding the
sunshade membranes were rotated into position Webb's primary mirror and instruments were
lifted about 1.2 meters or 4 feet above the folded sunshade to allow them to cool new year's eve saw
two telescoping booms pull the kapton membranes into their kite-like shape on Monday January 3rd
the one deployment that is time critical entered its final phase the deployment of Webb's sunshield
and it was delayed two days why engineers took a much-needed break on new year's day and then
spent Sunday January 2nd working through what are described as minor issues of course with the
scientific world and during what nasa has called 29 days on the edge everything is tension and
nothing qualifies as minor first the space agency decided to spend Sunday Webb's ninth day in space
analyzing how the power subsystem is operating now that several of the major deployments are complete
Bill Ox web project manager at NASA's GSFC said in a statement Sunday nothing we can
learn from simulations on the ground is as good as analyzing the observatory when it's up and running
now is the time to take the opportunity to learn everything we can about its baseline
operations so what were the two minor issues the first was the set of motors for sun shield
tensioning being slightly warmer than expected due to sunlight shining on them even though they
were well within the operating margin engineers reoriented Webb to shade the motors more and their
temperature dropped secondly flight controllers in Maryland reset the solar panel to draw more power
after finding a preset max duty cycle in an array regulator module was limiting power needed by web
in the words of Amy Lowe a lead engineer for Northrop Grumman
everything is hunky-dory now what's next did someone mention tension
the next step for nasa is tensioning the five sunshade layers remember those 344 single point
failures possible those non-redundant systems required for deployments that each must work
for web to function with no backups nasa says the sunshield has up to 140 release mechanisms
400 pulleys 70 hinge assemblies and 90 cables every single release device is a single point
of failure for webs mirrors and instruments to register infrared traces of the first
stars and galaxies in the universe they must be nearly 400 degrees fahrenheit below zero
each of the super thin layers must be pulled tight by motor driven cables using an array of pulleys
all while keeping each layer separate to allow heat to dissipate why not just one thick sunshield
layer because each successive layer is cooler than the one below the heat radiates in the separation
between the layers and the vacuum in between works as an insulator one large sun shield
would directly conduct heat from the bottom to the top the sun shield must be fully tensioned
before Webb's secondary mirror is deployed followed by the side wings of the primary mirror
Lee Feinberg optical telescope element manager for web at GSFC says the sun shield itself is
of all our deployments that's the one that is the most complex it has the most moving parts
while the tensioning is ongoing at this time the sunshield has been successfully deployed
mission team members tweeted on Webb's account shine bright like a diamond
with a successful deployment of our right sun shield mid boom or arm Webb's sunshield now
has taken on its diamond shape and space now comes more work that's never been
done before using instruments and procedures that had to be invented just for this purpose
the primary mirror will be assembled from 18 smaller gold-plated hexagonal mirrors
made of beryllium that will span over 6.5 meters or 21 feet across
each smaller mirror weighs approximately 20 kilograms which is 46 pounds
to see what astronomers hope to see which is our universe almost 14 billion years ago these
complex mirrors must assemble far beyond the moon with no chance of engineers swinging by to adjust
the spacecraft's internal system will be commanded to fully extend and latch the iconic primary
mirror which was done in practice in Webb's testing room in Redondo Beach California seven
months before the Christmas launch the command in may came after acoustic and sign vibration
testing in October 2020 to simulate what Webb will experience on launch day and while in space
let's get back to the gold-plated hexagonal mirrors all 18 of them
while unfolding the space origami is clearly a major step for nasa engineers will also
hold their breaths as Webb's mirrors are slowly and carefully brought into focus
each segment of the primary and secondary mirrors is moved by actuators tiny mechanical motors of
which six are attached to each mirror piece mirror deployment is expected within two weeks of launch
remember there are no second chances to get this right getting nervous yet
once the telescope cools in the shade of the deployed sunshield warm electronics will be turned
on and flight software initialized when Webb's mirrors are fully deployed there will be many team
members exhaling with a sigh of relief however a different group of scientists engineers designers
and instrument builders will collectively inhale and hold their breath through the next several
weeks all of Webb's instruments will be tested and calibrated in a process that will take
months at about 29 days there will be one final thruster burn and JWST will come to its position
at lagrange point 2 or l2 at about 33 days after launch the complex instrumentation will be turned
on and operated the first NIRCam image will be made of a crowded group of stars to see that
light is getting through the telescope and into the instruments the image will not be focused as
the mirror fine-tuning described earlier will not have been done but nasa will know the process is
working around the 44 day mark the intricate work of adjusting the primary mirror segments begins
with identifying each segment with its image of a star in the camera the third month after
launch for the James Webb space telescope is also critical to its success it is then that engineers
will align the gold-plated primary mirror segments to work together as a single optical surface all
18 of them Lee Feinberg Webb Optical Telescope Element Manager at NASA Goddard explains the
incredible technical features that engineers and scientists working on the telescope literally had
to invent themselves aligning the primary mirror segments as though they are a single large mirror
means each mirror is aligned to one ten thousandth the thickness of a human hair the mid infrared
instrument miri will also be turned on at this time and astronomers expect to be able to take
the first science quality images after 90 days then comes weeks of testing and calibration of
instrumentation and with any luck routine science operations by late June make that lots of luck
though it's unlikely to ever be used NASA included something on JWST just in case the possibility
opens for a tune-up or to add more propellant stickers on the back of the spacecraft serve as
targets for possible robotic visitors in the future they are reference points to tell the
visiting craft where to attach to JWST likely no a fascinating possibility absolutely so what do
you think about Webb and the many tense weeks coming for astronomers and engineers is the
payoff worth all the tension and hand-wringing as this technological marvel opens the doors of
the universe for humanity tell us in the comments and as always thank you for watching Factnomenal