The James Webb Space Telescope

After several delays, we expect to launch the James Webb Space Telescope later this year. Where is it going, what is it looking for, and how did it lead to Jonathan getting a tattoo?

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Episode Transcript

Speaker 1 (00:04):
Welcome to Tech Stuff, a production from I Heart Radio.
Hey there, and welcome to tech Stuff. I'm your host,
Jonathan Strickland. I'm an executive producer with iHeart Radio and
I love all things tech and the long time listeners
of this show know that I'm really interested in space

(00:25):
and the technology we use to expand our understanding of
the cosmos. As I record this, I am actually reading
up on how the NASA Perseverance Rover has deposited the
Ingenuity copter on the service of Mars, which is super exciting.
But I'll have to do a follow up episode about
the Perseverance and Ingenuity later on after more has actually happened.

(00:49):
So let's get back to what I'm talking about today. Also,
longtime listeners will know that I like to point out
that space is always always trying to kill you, from
the lack of oxygen to the proliferation of radiation that
could really mess us up, to the long term effects
of micro gravity. Spaces not where you want to spend

(01:11):
any appreciable amount of time. There's just no atmosphere, you
know what I'm saying. But dad jokes aside, I do
really love learning about space, and moreover, learning about the
tech we use to pursue that learning. To that end,
I thought I would do an episode about the James
Webs Space Telescope. And you know, I'm I'm really interested

(01:32):
in this telescope because I actually have a tattoo that's
part of NASA history connected to this telescope. I even
got that whole thing shot on video while I was
getting the tattoo. But I'll talk about that a little
bit more towards the end of the episode. So let's
get into this now. I'm not going to dive into

(01:53):
all the instruments and all the technology behind the James Webb.
Maybe I'll do a second episode where I go into
that more detail because it is incredibly technical. Um it's
it's phenomenal the technology that's going into place to make
this thing work. But I really wanted to give more
of a high level look at what the James Webb

(02:15):
Space Telescope is and what it is supposed to do.
So first things first, who was James Webb? Well, James E.
Webb was the second person appointed as head of NASA.
He served in that position from February nineteen sixty one
until October nineteen That meant he led NASA during the

(02:36):
crucial years that saw the agency launched the first American
into orbit, that would be Alan Shepard in May nineteen
sixty one to just before the launch of Apollo seven,
which was the first Apollo mission to send an entire
crew into orbit. The manned missions that NASA was pursuing
understandably received a ton of attention and coverage, but Webb's

(02:59):
goal was to balance the narrative of sending astronauts to orbit,
you know, the human achievement of going into space and
and later on going to the Moon. He wanted to
balance that with the need to actually use those missions
to help expand our understanding of science. He felt that
he needed to make certain that there were always scientific

(03:21):
elements to those missions in order to link the space
race to gaining knowledge, to expanding our understanding of the universe. Otherwise,
sending people out into space could potentially get reductive. It
could end up being a political statement because really the
United States was locking horns with the then Soviet Union

(03:42):
in the space race. So he wanted to make sure
that we were building a foundation to learn more, not
just to you know, show off. And I don't mean
to reduce the achievements of the men and women who
worked in the space industry at the time. Rather, this
is all about perception and the political part of trying

(04:03):
to get space programs together. The science is pretty darn
cool no matter how you look at it. Well, anyway,
Web himself wasn't a scientist, but his work really helped
shape NASA and allowed the organization to benefit from the
support that he was able to get politically in order
to conduct scientific experiments that we otherwise would not be

(04:25):
able to do. Web was also able to form and
leverage political relationships to make sure that the scientists and
engineers back at NASA could realize their ambitions and goals.
In fact, he was an expert at creating and maintaining
those relationships like that was that was his forte and

(04:45):
that's why NASA chose his name for the space Telescope.
All right, So let's get back to that story now. Currently,
the plan is to launch this spacecraft in October of
this year, this year being twenty one in case you
are listening to this at some point in the future
and you're just going through the back catalog of tech
Stuff episodes. Now, that is after several delays and hiccups

(05:09):
that have pushed back this project that has had about
a thirty year history, in fact longer if you want
to be a little lucy goosey with definitions of history.
And by that, I mean you could argue that the
James Webb Space Telescope began its journey all the way
back in September nine nine. That was before its predecessor,

(05:30):
the Hubble Space Telescope, had even launched. The Hubble would
go up in but scientists were already talking about the
next step what would come after the Hubble. And this
is one of the really cool things about science and technology.
It's not enough to tackle really big challenges and then
get them off the ground, so speak, you already need

(05:53):
to be thinking ahead about what is going to come next,
which sounds pretty exhausting to me, but really cool all
the same. Also, I can kind of identify because I
can't really reflect on the show I'm recording. I gotta
already be thinking about the next show now. Granted that's
orders of magnitude less complicated than I don't know, sending

(06:13):
stuff into space anyway. In September, n NASA co hosted
a workshop that focused pun intended on the next generations
space telescope, and the other co host was the Space
Telescope Science Institute or st S little c I. More

(06:34):
than one experts in the fields of astronomy and engineering
gathered to to start the process of outlining what the
next generation of space telescopes should be able to do,
How would we be able to make it do those things,
where would we need to actually position the telescope in
order to do it, and so on. Initially, the group

(06:54):
considered the possibility of designing a near infrared telescope that
would call the Moon home, or perhaps a very high
Earth orbit. As it would turn out, we would go
to a very specific high Earth orbit. Actually it's not
really so much an Earth orbit, high solar orbit. Now,
these discussions weren't resolved in a weekend or anything like that. Rather,

(07:17):
they carried on for years as the experts debated the
best course of action that would in theory, return the
best results assuming mission success, of course, which is never
a guarantee when we're talking about launching stuff into space.
If you look at the list of attempted space missions
over the course of our relatively brief space history, you

(07:39):
know there's like a fift success rate depending on which
versions you're looking at, so it is not a sure thing.
A committee with formal recommendations wouldn't present their conclusions until
seven years after those initial meetings, and I think that
really helps illustrate that we're talking about really complicated technologies

(08:01):
and missions here, and that that seven year span from
initial ideation to recommendation is a great guide on how
the project has slowly taken shape sense slowly but methodically,
Like it has to be methodical because we're talking about
plans where once we launch it, there's not a whole

(08:24):
lot of opportunity to fix things if they go wrong.
But in the meantime, while discussions were ongoing as to
what type of telescope would follow the Hubble, we got
the Hubble, while the James Web Space Telescope first began
to take shape during conversations that started in nine The
Hubble's conception dates all the way back to the nineties.

(08:46):
Before we called it the Hubble, it had a different
and rather mundane name. We called it the Large Space Telescope,
which is descriptive at least. But why would we bother
with a space telescope in the first place, Well, here
on Earth We've got lots of telescopes. Some of them
are purely optical telescopes using lenses. They are all about

(09:10):
capturing and bending light so that we can actually look
at stuff that's really far away. We also have some
that are radio telescopes. These are giant dishes that pick
up faint radio signals, which then we process and interpret
to determine what might have made those radio waves way
on space, stuff like stars, quasars, galaxies, that kind of thing,

(09:32):
not necessarily, you know, aliens, not necessarily like artificially created
radio signals. Typically we're talking about actual celestial bodies that
generate radio waves. But these types of telescopes have a barrier,
and that barrier is Earth's atmosphere. While we depend upon
that atmosphere because you know, without it we would die,

(09:53):
the atmosphere also absorbs, reflects and otherwise blocks some stuff
from getting through. This isn't all bad, mind you. Our
atmosphere is part of the protective layer we have that
keeps us from being bombarded with cosmic radiation. But it
does mean that if you're making observations of deep space
and you're fighting against those layers of atmosphere in order

(10:14):
to do it, and you're going to run up against
some fundamental limitations of how sharp an image you can produce.
I mean, it's all these things just happen, right. We
we've it's like having a foggy lens. You you're not
able to see as far away. You're not able to
see as clearly because we've got this atmosphere that's blurring
the image. Putting a telescope out into space gets around

(10:34):
that problem, right, I mean, the telescope can be outside
the atmosphere and we get a clear view of the
depths of space. A space telescope with the proper sensors
can examine wavelengths of the electro magnetic spectrum that wouldn't
be able to penetrate the air's atmosphere very effectively. I
should also mention that the Hubble was not the first

(10:54):
space telescope, but it did mark the most ambitious space
telescope project at that time and for many decades. While
the paper in nineteen six was the first to propose
putting a telescope in orbit, years before anyone had managed
to even launch the simplest of satellites, the first working
group to concentrate on this challenge didn't really happen until

(11:16):
nineteen seventy four. The US Congress approved the project in
nineteen seventy seven, and the following year engineers began to
build the primary mirror for the telescope. The purpose of
the telescope's mirror is to focus incoming light from far
distant astronomical objects onto really a secondary mirror which then
reflects that light into sensors. And now it's time to

(11:40):
learn about optics. And I'm not using optics in that
corporate speak way of this is gonna look bad for us,
and our shareholders are going to be angry. I'm using
optics the proper way. Gosh darn ittt, I hate corporate speak,
all right. So, a refracting telescope is one that uses
lenses made out of curved glass to collect and focus
LIE eight so that we can get a good look

(12:01):
at distant objects. A simple refracting telescope would have two lenses.
You've got one which is the at the large end
of the telescope. This is the end that's pointing up
towards the sky. That lens gathers light and it bends
that light, the incoming light, into a pathway that converges
on a point that's inside the telescope, and rather than

(12:24):
the light just traveling straight down the tube of the telescope,
if there were no lens there would just go straight instead,
it all gets focused onto that single focal point. At
the other end of the telescope is a eye piece,
a second piece of curved glass much smaller in size,
and it acts like a magnifying lens with a focal
point that hits that same spot inside the telescope. This

(12:47):
lens effectively unbends the light so that we can see
a representation of what is out there in space as
if that stuff were much much closer to us. For
this to work, the lenses have to be very smooth,
they have to be curved precisely, and they have to
be the right distance apart from one another, otherwise the
image won't be clear. Focusing a telescope is a matter

(13:10):
of making very fine adjustments in the distance between the
eye piece and the other lens so that those focal
points line up properly. And lenses work okay, but they
have some pretty major drawbacks. One is that they get
pretty heavy, especially the bigger they are. It's hard to
make thin curved glass that can serve as a lens,

(13:31):
and so as lenses get larger, they get thicker, and
they get heavier and heavy is not a great feature
when you're talking about shooting stuff up into space where
every pound or kilogram really counts. You also can't, you know,
collapse it. You can't make it go into a smaller
form without crushing the glass and turning it into silica.

(13:51):
So that's not not a great great solution. However, we
can make really thin mirrors curve to mirrors, and mirrors
bend light as well, though now you're talking about reflecting
light rather than refracting light. So a typical reflecting telescope
looks kind of like a cylindrical drum that has an

(14:13):
eye piece near the top end of it, and at
the base of the cylinder is a curved mirror that
collects light that's coming into the telescope. It reflects that
light up to a smaller mirror closer to the top
of the telescope, and the smaller mirror is angled to
reflect that light toward an eyepiece which you look into
um and that may still have a magnifying lens part

(14:35):
attached to it. This approach does mean, however, that that
secondary mirror can block a little bit of the incoming light,
so the image can be a little dim Depending upon
the design of the reflecting telescope, mirrors can weigh way
less than lenses. You just need a very reflective surface,

(14:57):
and so they are ideal for the purpose says of
a space telescope. Using curved mirrors around a detector allows
the telescope to collect and then direct light that can
then be captured by whatever that detector is, which is
effectively acting like the eye piece lens. It's it's typically
like a camera or some other sensor. The Hubble's primary

(15:19):
mirror measured two point four meters across or seven point
nine feet. The company making the mirror was the Perkin
Elmer Corporation, and it took years to make this mirror.
The cameras aboard the Hubble would be able to take
images in the visible, infrared, and ultra violet bands of light,
but primarily was focused on again pun intended the visible spectrum.

(15:43):
In n three, the Large Space Telescope officially became the
Hubble Space Telescope, honoring Edwin Hubble, this astronomer who had
passed away in nineteen fifty three had proven that what
we once believed to be merely clouds of gas and
dust out there in space were in fact other galaxies,
and that they were moving away from our galaxy. So

(16:05):
naming the telescope after him was a fitting tribute. Work
continued on the Hubble tragedy would delay the planned launch
of the space Telescope WIN. On January ninety six, the
Space Shuttle Challenger broke apart a little more than a
minute after it had launched, losing all hands aboard. NASA

(16:26):
suspended the Space Shuttle program for more than a year
in order to investigate the cause of the disaster and
to take measures to prevent it from happening again. And
since the Hubble was to be lifted into space inside
a Space Shuttle, ad meant that its own launch would
have to be pushed back. Hubble would launch in nineteen,
as I mentioned earlier, a year after scientists were already

(16:49):
talking about the next space telescope. A few months after deployment,
scientists discovered that the Hubble's mirror had a slight imperfection
in the heurvature. And by slight, i'm talking about an
error that measured just to microns, and a micron is
point zero zero one millimeters, So we're talking about an

(17:11):
error that would be imperceptible to humans without the aid
of special instruments to measure it. When we come back,
I'll talk briefly about the mission that's set out to
adjust for this error, and then we'll move on to
the James Web Space Telescope. But first, let's take a
quick break. All right, let's get back to that mistake

(17:39):
in the Hubble. So that tiny mirror curvature error meant
that the Hubble was unable to achieve the level of
focus that scientists were hoping for. It could still take pictures,
it's just they weren't quite as sharp as they were
supposed to be. So it worked just not as well
as anticipated. The scientists and engineers who designed the Hubble

(18:00):
had always intended it to be a technology that could
be upgraded by sending astronauts up there to make adjustments.
I mean, the Hubble was and still is in Earth orbit.
It's it was accessible for Space Shuttle missions, so that
was always part of the plan, and so some of
the early work in that regard of upgrades really revolved

(18:22):
around finding ways to work around this tiny error in
the mirror's curvature. The first mission to really address this
happened in late nine when astronauts installed two new instruments
that can actually accept light from this imperfect mirror, and
the kind of a post processing approach correct for that error. So,

(18:46):
in other words, they didn't fix the mirror because that
would have been incredibly difficult. I'm not even sure how
they would have managed it. So instead they installed sensors
or cameras with systems that could correct for that imperfect action,
which was a pretty neat approach. The Hubble played a
central role in expanding our understanding of the universe. Scientists

(19:08):
used it to study questions about the age and evolution
of the universe itself. Hubble observations led to the confirmation
that supermassive black holes do in fact exist at the
centers of galaxies. Using the Hubble, scientists were able to
figure out how far away other galaxies were from our own.
The Hubble captured images of weird stars, some of them

(19:31):
much more active and unstable than our own son. We
should be thankful for that, because our son mostly behaves itself.
The Hubble looked at how pieces of a comet crashed
into Jupiter, leaving behind large marks on the planet's surface.
Scientists used the Hubble to study various moons in our
Solar System, leading to the discovery that Jupiter's moon Europa

(19:53):
has oxygen in its atmosphere. The Hubble caught images of
proto stars and wide angled views of the universe that
showed more than fift nd galaxies out there, all before
the formal recommendation to NASA and the European Space Agency
that they get to work on the next space telescope.

(20:14):
But let's move on. Even though we could talk a
lot more about the Hubble, the Hubble is still in
operation today, even though the last servicing mission was way
back in two thousand nine. The James Webb Space Telescope
won't be able to get that kind of upkeep, and
that's because it's going to occupy an orbit far away
from Earth, far too far away for us to access

(20:35):
easily for stuff like maintenance, and that means we need
to make sure everything is right before we deploy it.
Construction on the James Webb Space Telescope began in two
thousand four, and it took seven years to make all
the mirror segments. They're eighteen in total. Their hexagonal mirror

(20:55):
panels that fit together and collectively they serve as the
primary mirror for the telescope. So the James Web Space
Telescope is going to orbit the second lagrange point a
K A L two. But those are just words, right,
I mean, what does that actually mean? Well, getting stuff
into space is hard, but getting stuff to stay where

(21:17):
you need it to once you get it out in
space is also hard. You can include stuff like thrusters
to help a spacecraft maintain its relative position to some
other point of reference, but thrusters require energy to operate,
so you can use fuel that fuels heavy has a
limited resource. There's no refueling stations out there, so you

(21:38):
can't top off the fuel tank once it runs low.
So you could potentially use like an ion drive and
power it some other way, such as with a radioactive
decay or something. But it would be way easier if
you could just PLoP something onto a specific point in
space and it would just kind of stay there. And
by specific point, I mean relative to something else. It's

(22:00):
not just occupy a a a point in space and
that's where it stays. As the rest of the Solar
system continues to move away from it. So a smarty
pants mathematician named Joseph Louis Lagrange began to think about
orbital paths and whether or not it might be possible
to find points in which three different bodies could orbit

(22:22):
each other but stay in the same positions relative to
one another. So, in other words, unlike say Earthen Mars,
let's use that as an example, We've got the Sun,
We've got Earth, We've got Mars. Three bodies. Earthen Mars
both orbit the Sun, but they both do so at
different rates. So sometimes Earthen Mars are on the same

(22:44):
side of the Sun, like they're both on. Let's if
we're looking top down, let's imagine that both the Earth
and Mars are on the right side of the Sun.
Mars is a little further out from Earth. Other times though,
during those orbits, you get them on opposite sides of
the Sun. Maybe the Earth's on the right side but
Mars is on the left side. The Sun's in between them,
so they are not in the same position relative to

(23:06):
each other throughout their orbits. In fact, it takes about
two years for the two planets to get close to
each other. That's why any planned missions to Mars that
involves sending people up there usually also involved camping out
on the planet for you know, a couple of years
in order to be able to return. However, a stable

(23:28):
orbit would mean that the three bodies would remain in
their same relative positions. So if Earth is one of
the three and the Sun is another, the third body
would remain in the same relative position in its orbital path.
So this would be like if the Earth and Mars
were always lined up in their respective orbits around the Sun.
So Mars would always be behind Earth further out, and

(23:52):
that would mean Mars would have to be traveling faster
through space to keep pace right, because it's traveling greater distance.
It's a it's orbit is arger, it's traveling further. It
would have to go faster in order to maintain the
same position relative to the Earth. That's not happening. However,
through mathematics, Lagrange identified five points where this sort of

(24:14):
orbit would be possible. So there are five points we've
identified where something in that position would pretty much stay
there relative to the Earth and the Sun. And that's
because these bodies would be exerting roughly equal gravitational forces
on that third body out in space, and the same
amount of force as that third body was experiencing in

(24:35):
the form of centripetal force. That's a lot of words.
I know it sounds confusing, but imagine you've got a
game of tug of war going on, right, and both
sides are of equal strength, and you've got a flag
in the center of the tug of war rope, and
both sides begin to pull, but they are equally matched.
Neither is able to gain any ground on the other,
so that flag just stays put. It's being pulled in

(24:59):
both directions, but at equal strength, so it's not moving anywhere.
That's kind of what a lagrange point is like, only
there's no physical rope holding anything because it's all about
gravity and centripeleical force. Lagrange point one is between Earth
and the Sun, and it's at this point that we
put solar observatories like the Solar and Heliospheric Observatory Satellite

(25:22):
or SOHO. And as you would imagine, the point for
these kinds of observation platforms is to have instruments dedicated
to observing the Sun and solar events. But it's not
a great location to put something if you want to
look at other stuff further out in the universe. Because
the amount of electromagnetic energy that's given off by the

(25:44):
Sun tends to drown out everything else, it's not a
good place to put that kind of thing. Lagrange point, to, however,
is on the opposite side of Earth from the Sun,
and it's at a distance of one point five million
kilometers or around one million miles from Earth. The Moon,
by comparison, is three eight four thousand, four hundred kilometers

(26:06):
or two d thirty eight thousand, nine hundred miles from Earth,
so the James Webb Space Telescope will be a far
away from Home, much further away than the Moon is.
L two is the old stomping grounds for a few
other instruments that we had previously placed there. One was
the Wilkinson Microwave and asotropy probe. And I have no

(26:27):
idea if I'm saying that correctly. I probably should have
looked up the pronunciation beforehand. I apologize for that. We'll
call it woe map w m a P. It taught
us an enormous amount about the universe, largely by studying
cosmic microwave background radiation or CMB radiation. That's the oldest
light in the universe. It's the stuff that occurred shortly

(26:48):
after the Big Bang according to the Big Bang theory,
and that is it blows my mind to read up
about that stuff. The second instrument that was previously at
L two was called PLANK and it also studied CMB.
The third was the Herschel Space Observatory, which was another
infrared space telescope. That one operated until until it ran

(27:12):
out of coolant, and all three of those instruments have
long been deactivated and relocated to an orbit outside of
L two, making it free for the James web Space Telescope,
now the Hubble Space Telescope orbits the Earth, but again
the James Webb Space Telescope orbits the Sun. Technically it's
also orbiting the L two point itself, So if you

(27:35):
think of the L two point as orbiting the Sun,
this is orbiting the L two point kind of like
how the Moon orbits the Earth and Earth orbits the
Sun similar to that. So it will have a path
that takes it around the orbit of L two every
six months or so, and it will stay in line
with Earth during Earth's own orbit of the Sun. So

(27:57):
in other words, the James Web Space Telescope is always
going to be uh right back behind where the Earth
is in its orbit. The James Webb Telescope will occasionally
need to make some slight adjustments in order to maintain
its position and orientation. It turns out that those lagrange points,
some of them are stable, meaning if you put something there,

(28:19):
it's just gonna stay there, and some of them were
kind of semi stable, and they require minute adjustments in
order to maintain position. The L two is one of those,
so once in a while, in fact, like every twenty
three days or so, they'll have to be a very
slight adjustment in order for the James Web Space Telescope
to maintain its position. It's not a lot of work

(28:39):
to do it, but it is something that has to
happen regularly, or as you would imagine, you quickly start
to fall out of step. Now, the James Webb Space
Telescope has a large shield that will protect it from
radiation coming from the Sun. That shield is actually made
up of a membrane. I'll talk about it a little
bit more, uh in a second and down. It's also

(29:01):
to protect it from radiation that's reflected off of bodies
like the Earth and the Moon. It will effectively shade
the mirror side of the telescope so that the telescope
can gather distant light. It's orbit around L two will
also mean that the spacecraft is going to avoid shadows
that are cast by Earth in the Moon, which would
otherwise affect its view outward to the universe. Now, the

(29:24):
type of light that the James Webb Space Telescope is
really relying upon is primarily light in the infrared spectrum.
We can feel infrared light, we can experience it as heat,
but we can't see it unaided. Right it's outside the
visible spectrum of light. The telescope will be seeking out
infrared light from distant sources, which means trace amounts are

(29:46):
going to be very faint, and that's why the telescope
needs an effective heat shield, or else the heat from
nearby sources primarily the Sun and surfaces that are reflecting
light from the Sun, that would be all the Tell
scope would be able to pick up otherwise. In fact,
the telescope is so sensitive that the electronics and computer

(30:07):
that attached to it are on the shield side of
the spacecraft because they generate heat, so rather than have
them close to the telescope part and potentially corrupt results
because the heat generated by the electronics is strong enough
to to affect it. It's actually located on the other
side of the heat shield, on the hot side and

(30:28):
on the cold side. On the shield side facing the sun,
the temperature on that surface will reach around eighty five
degrees celsius or a hundred eighty five fahrenheit. So if
it got much warmer, it would be possible to actually
boil water on that side of the spacecraft. But on
the mirror side, the telescope side, things are way different.
The temperature will be around minus two hundred thirty three

(30:51):
degrees celsius or minus three fahrenheit. Now you can see
from this incredible difference in timber chures that it is
of paramount importance to keep the telescope in the proper
orientation with the shield side facing the sun. That's one
of the big reasons we're putting it at L two.
After launch, it will take the telescope about thirty days

(31:14):
to reach the L two orbital point. But here's the thing.
It will make most of that journey right away it's
that last bit that takes the longest, as the goal
is to give the telescope a push just hard enough
so that it arrives at its proper spot to enter
its orbital path around L two. And I think of

(31:35):
it kind of like curling the sport, where you know,
you slide weights down an iced surface, only you know,
in this case we're talking about three dimensions, not two,
and we're also talking about being in space, not on
the ice. And also the weight in this case is
a telescope that's worth a few billion dollars. Also, there
are no Canadians out there sweeping ice into or out

(31:56):
of the pathway. But otherwise it's exactly the same as curling.
Another reason we're putting it in the L two orbit
is that because it will always be in the same
position relative to Earth's orbit, which means we can communicate
with that telescope relatively easily. Communications will carry out through
radio signals, and one of three large antennas here on
Earth will be in contact with the spacecraft at any

(32:17):
given time. They are located in California in the United States, Spain,
and Australia, so that at any time of day, there's
the chance to be able to establish communications with the telescope.
This collectively is called the Deep Space Network, which sounds
like we've got a lot of antenna floating out there
in space, but really it's more about having the infrastructure

(32:40):
here on Earth that lets us monitor our instruments that
are out in space, no matter what part of Earth
is facing towards those instruments at any given time. Up
to twice a day, the telescope will connect with Earth
so that scientists can upload new instructions to the telescope
and download the gathered data from the telescope. The plan, however,

(33:00):
is to really upload a whole week's worth of commands
all at once, and then occasionally do updates, like if
you need to tweak things, you could send up another
up link later in the week. I think it's worthwhile
to talk a bit about the planned launch for the telescope.
It's to happen in French Guyana, that's the chosen launch point.
It will be carried up into space on an Arean

(33:23):
five heavy lift launch vehicle. That name a vehicle might
sound a little unfamiliar to my fellow Americans. It was
to me, and it's a vehicle that's used by the
European Space Agency or e s A. The launch up
to space will take about eight minutes of thrust to
get up there, and a half hour after its launch,

(33:44):
the telescope will separate from its uh it's little faring
with the remains of the launch vehicle and continue on
its journey by itself. The telescope will be on its
trajectory out toward L two, though there will be a
couple of different trajectory correction maneuvers made along the way
to ensure it reaches its destination properly. When we come back,

(34:07):
I'll walk through the rest of the deployment process of
the telescope, and we'll talk a little bit about the
telescope itself and some of the things it's going to
be looking for, and we'll also get to talk about
my tattoo. And like I said, perhaps in a subsequent episode,
I'll go into more detail about the telescopes mechanical systems

(34:30):
and instruments. But let first let's take a quick break.
So before the break, I talked about the launch and
the separation of the James Webb Space Telescope from the
launch vehicle, and assuming all of that goes as planned,
here's what should happen in the following minutes, hours, days, weeks, etcetera.

(34:55):
At about thirty three minutes into the mission, the spacecraft
will deploy it's solar array. This is an array of
solar panels that will harvest energy from the sun help
power the telescope. So it's on one side of this telescope.
It's on the aft side, the rear side of the spacecraft,
if you think of it that way. It's a little

(35:16):
weird to call it aft because until the whole thing
is deployed, you can't really tell what is for and
what is aft. It looks kind of like a rectangular
spacecraft floating out in space, and one panel on one
side of the rectangle folds down, and that's your that's
your panel of solar or your rather your array of

(35:36):
solar panels, I should say. Well. Two hours after having launched,
the spacecraft will release its high gain antenna. This is
a focused directional antenna designed to target radio signals with
great precision. This is how we communicate with the James
Web Space Telescope. It's the antenna that receives and transmits

(35:57):
information and it's uh the same sort of thing that
we use for long range wireless networks here on Earth.
It will actually fully deploy within that first day of
the mission. It's released early on, but it takes a
while for it to fully deploy. Twelve hours into the
journey and we'll get our first trajectory correction maneuvers. The
spacecraft has small rocket engines on which it can fire

(36:18):
thrusters and very quick precise burns and thus make course corrections.
Another trajectory correction will happen a couple of days later
as it continues its journey. The spacecraft's sun shield is
in two very large panels, or palettes as NASA calls them.
The shield that is opposite the solar arrays. Remember that

(36:39):
that folds down first, while on the opposite side of
the spacecraft is what is called the forward shield, and
that will first deploy by folding down away from the telescope,
so it's opposite where the solar panel arrays have folded down,
and once deployed, the aft palette will do the same. Now,
this one's on the aim side as the solar array,

(37:02):
so it folds down and it ends up being parallel
to the solar array. The series of panels that are
collecting light and powering the telescope. Then the telescope apparatus
will extend outward from the base of the spacecraft. It
kind of telescopes out if you will. This part of
the process is called tower deployment. So really it's just

(37:25):
like if you think of an old radio antenna where
you would extend the antenna. That's effectively what's happening here.
It's about creating a little more distance between the telescope
itself and the solar shield so that there's not any
heat transfer, because again, this thing is incredibly sensitive to heat.
Then the spacecraft will deploy a solar membrane. It's kind

(37:47):
of like foil, and by deploy, I mean it unrolls
this foil so that it spreads across the aft and
forward sun shield palettes and then connects to two ex
endable arms. Those extendable arms then extend, pulling that membrane
further outward to form the solar shield. And I get

(38:10):
that it can be a little hard to understand what
I'm talking about here, but imagine it's kind of like
stretching a blanket outward, only in this case, the blanket
is meant to keep the heat off the telescope rather
than trap heat. In eleven days into the mission, the
telescope will start it's cryo cooler to start to cool
the telescope components down to operating temperature, and then the

(38:32):
telescope will deploy its secondary mirror. So let's talk about
that for a second. Imagine a satellite dish like the
kind we would have here on Earth for you know,
cable or whatever. Now, normally you would have the dish
and then suspended above and the dish like at the
center of the dish and above it you would have
an antenna be held there, and the idea being that

(38:55):
this parabola of the dish is reflecting radio signals up
to that antenna so that you get a good, strong signal.
That's the idea here. Well, the telescope is similar, except
instead of having an antenna suspended above the parabola, it's
a small mirror and it's this mirror's job, the secondary mirror,

(39:18):
to reflect light from the primary mirror down into the
sensors for the telescope. It's it's actually directing the collected
light to the instruments on the James Web Space Telescope itself,
So it's a mirror that's pointing back. It's kind of
selfie like it's pointing back at the telescope. Now, twelve

(39:38):
days in, the telescope will begin wing deployment. Now, these
wings aren't meant for flying, the rather wings of the
primary mirror. You might remember I mentioned that the primary
mirror for the James Webb Space Telescope is made up
of hexagonal panels, eighteen of them. And those hexagonal panels
mean that you can actually have these foldable seg mints

(40:00):
of the telescope unfold and connect together so that the
edges of one hexagon line up with the edges of
other hexagons, and collectively the eighteen hexagons make the primary mirror.
This is different from the Hubble Space Telescope, which had
an unbroken single piece as a mirror. So a very

(40:21):
interesting approach here. Uh. Those panels, by the way, are
incredibly reflective and very sensitive. They look amazing. You can
see pictures and videos of them online. I highly recommend
you check them out. They're gorgeous. So the first wing
unfolds and joins the central collection of hexagonal panels twelve

(40:44):
days in and fourteen days in the secondary wing will unfold,
and then you have the full primary mirror made up
of all these hexagons. However, it won't be actually focused yet,
it'll just be in the main position where they're all
kind of, you know, next to each other. At thirty
three days, the telescope will begin effectively field testing. The

(41:08):
instruments will come on and engineers will point the telescope
to a crowded area of space, you know, someplace it's
got a lot of stars in it, it's generating a
good amount of light. This is just to make sure
that the telescope is in fact detecting light, that the
light is hitting the mirrors, that's getting reflected and it's
being picked up by the telescope sensors. So at this

(41:28):
stage the mirrors are not aligned properly to get super
sharp images. It's really just to verify that everything is
actually kind of working, assuming it is. Then around forty
four days into the mission, the telescope will begin making
fine adjustments to each of the mirrors that have them
line up to form the prime mirror, and the secondary
mirror will also get fine tuned adjustments in order to

(41:51):
start to bring things into focus. And this is a
painstaking process. It's one that involves lots of motors that
will talk out in a subsequent episode, but just know
that it's about a lot of tiny adjustments. It will
take actually about three months after the launch for the
telescope to start returning images that are around the quality

(42:14):
we would expect from it for the rest of its mission.
It will, however, be about six months after launch before
the telescope actually gets down to some serious work and
starts to collect data we hope will tell us more
about our universe. So what kind of stuff is it
going to be looking for. Well, part of that will
be evidence of how the first galaxies formed billions of

(42:35):
years ago, to learn more about the evolution of the
universe itself. We've got a lot of hypotheses about how
the universe formed. This telescope is going to seek out
information that will either lend support or maybe call into
question those hypotheses. It will also look at dust clouds
so that we can learn more about how stuff like
stars and planets form over billions of years. Again, we

(43:00):
got a lot of thoughts about this, and this telescope
will help us gain a deeper understanding of cosmological events
and because the James Webb is relying on infrared light
that in for a light it can penetrate stuff like
dust clouds, so we'll be able to get better information
about those formations in the universe. For a telescope like
the Hubble, which primarily relied on visible light, we were

(43:22):
really limited because the dust clouds appeared opaque to that
kind of telescope. But the James Webb will be able
to see through and into these dust clouds and we'll
get a lot more information about them. So a lot
about what the James Webb Space Telescope is going to
be exploring will relate to questions about how massive celestial

(43:43):
bodies form over time, from planets to suns to entire galaxies,
and how they evolve. These are really big cosmological subjects.
But the telescope will also come in handy when we
start looking at various extrasolar planets, meaning it's outside of
our own Solar system. The telescope will give us more
information about stuff like the atmosphere around distant planets. We've

(44:07):
identified a lot of exoplanets that exist in what we
call the Goldilocks zone, that is, the planets exist in
an orbit that's the right range of distance from their
host star, so that liquid water could potentially exist on
those planets. Now, that doesn't actually mean that there is
water on any of those planets, but rather that the

(44:30):
planet should be at a temperature that is warm enough
to have liquid water on it, but not so warm
that liquid water would just evaporate off of it. The
distance a planet should be from its host star is
dependent upon stuff like the star's size and its age.
That tells you how far away a planet would need
to be in order for liquid water to exist there.

(44:51):
There are other elements as well. That's getting into a
whole rabbit hole. Well, the James Web Space Telescope should
be able to tell us about whether planet it's like
that have an atmosphere and what that atmosphere's composition should be.
To do this, they'll use a couple of different things together,
the transit method, which is where you're looking for the

(45:13):
existence of planets by looking at the dimming of light
coming from a star. That indicates that something has passed
between the star and you. So if you detect this
and it's happening at regular intervals, you can make the
guess that there is an orbit there's something in orbit
around that star that's blocking a little bit of light

(45:33):
at every given increment of time, however long it may be.
And then we would also use spectroscopy, which is in
practice where you measure the intensity of light at different
wavelengths of light. So by determining which wavelengths of light
are more present, we can start to draw conclusions about
stuff that might be in a planet's atmosphere. So we

(45:57):
have to remember that's light that's passing through the atmosphere
from its host star. So you kind of take a fingerprint,
a spectral fingerprint of that star's light. You say, this
star is giving off light, and these are the the
intensity of the different frequencies of light it's giving off. However,
when the planet passes over the star, we start to

(46:20):
detect little changes in that digital fingerprint that to us
would indicate things that are in that planet's atmosphere that
could be absorbing those wavelengths of light. And thus we
can say, hey, turns out we think there's oxygen on
the atmosphere or in the atmosphere of this planet, which
is really cool, right. Well, scientists will also use the

(46:42):
telescope to study stuff that's in our own solar system,
not just outside of it, like our good buddy Mars.
Working in concert with orbiters and landers that are dedicated
to studying Mars, the James web Space Telescope will help
us get a better understanding of Mars' atmosphere, it's weather,
pa letterns, it will help us, you know, back up

(47:03):
the information that's being found by these other instruments, and
it will also study other bodies within our own solar system,
not just Mars, but other planets as well. It's all
really exciting stuff, in fact, exciting enough for me to
choose to get a tattoo representing the mission of the telescope.
So here's the story. Back in November, NASA selected a

(47:25):
group of artists to take part in a big art
project inspired by the James Webb Space Telescope. Among those
artists was a tattoo artist from Atlanta named Brandy smart.
So she pitched an idea she would create eighteen tattoos
to represent those eighteen mirrored panels for the primary mirror

(47:45):
of the James Webb Space Telescope. Each tattoo would represent
something that the James Webb Space Telescope would be looking
for and She started to search around for people who
wanted to participate in our project, and I volunteered and
she took me up on it. So in I went
to get my space tattoo from Brandy Smart, and I

(48:06):
chose the image of a proto star. This image was
actually caught by the Hubble Space Telescope. I mean, obviously
I couldn't pick anything from the James Webb Space Telescope
because it hadn't launched yet. So I like the idea
of going with the proto star. That's a body that
could continue to gain mass and develop and become a

(48:27):
true star. Or it might not. It might not gather
enough mass, there might not be enough gas and particles
and dust for it to gather enough to become a star.
It could eventually just fizzle out. I feel like that
speaks to me on a deep personal level. So that's
what I chose. And we actually shot a video for

(48:49):
the series I used to host years ago called Forward Thinking,
and in that video I was talking about the James
Webb Space Telescope as well as showing me getting that
to The video published in December. At the time, the
James Web Space Telescope was aiming to launch in but
clearly that just didn't happen anyway. The video title is

(49:12):
Staring into Space and it's on the Forward Thinking channel
f W. Colin Thinking. If you're curious, the full collection
of Brandy's project is viewable on the website j W
s T dot nasa dot gov slash content, slash features,
slash j W st art. Yeah, that's um, that's how

(49:38):
government websites work. Anyway, Look for Brandy Smart's name if
you look at that website. My tattoo is in the
hexagon that's just below the blank center spot in that group.
So yeah, my skin is part of NASA's history, I guess,
and it means I feel a special connection with this
amazing piece of technology, particularly when the ditches and imagined

(50:02):
to see it get to L two and start capturing
amazing images. So, like I said, I'll probably do a
follow up episode where I'll dive into greater detail in
the technology and instruments of the James Webb Space Telescope,
how they work and what sort of way they will
operate in order to bring this kind of information back
to us and the kind of scientists who study this

(50:23):
sort of stuff. But that will have to wait for
the next episode, or at least a future episode. I
don't know that it will be the next one, but
we'll see. And in the meantime, if you have suggestions
for things I should tackle in episodes of tech Stuff,
let me know. Reach out to me on Twitter. They
handle for the show is tech Stuff H s W
and I'll talk to you again really soon. Text Stuff

(50:50):
is an I Heart Radio production. For more podcasts from
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