five four three
two one nasa spacex and blue origin
are practically synonymous with rockets
those massive
powerful vehicles allow us to travel
beyond earth
but while the ongoing competition to
launch the world's next best rocket
tends to dominate news headlines
there's a little-known mission in nasa
to develop a new kind of space telescope
and this project is using something else
entirely
balloons
you can do more science in a single
balloon flight
than you could do from years and years
of observing from
any of these existing observatories you
can take
technological risks on a balloon that
you would never be able to take
on a space mission so you can do all
kinds of crazy things
like sending massive telescopes that are
cool to near absolute zero to the edge
of space
these ultra cold balloon telescopes
could heighten our understanding of the
universe overnight
so not only can you see things that you
wouldn't be able to see
with these existing observatories but
you can look for things well beyond
our own galaxy and even to the edge of
the universe
all the way back to the big bang
they're a little bit more complicated
than just a simple balloon
we can get to 120 000 feet and we can
keep you at that altitude for
a day to two days to you know the
longest we've flown is 55.
and the sheer size of these nasa
balloons can be massive
they can reach up to 1.7 million cubic
meters in volume
which is equivalent to more than 200
goodyear blimps
and they can stretch to a diameter of
more than 160 meters when floating
which is about the size of an entire
football stadium
a lot of people have no knowledge that a
balloon program even exists
and we can take payloads as big as a
small
car up to the stratosphere four times as
high as a plane flies
we fly a lot of astrophysics payloads we
have some heliophysics payloads
and almost every technology that has
flown on a space mission has flown first
on a balloon the balloon program tested
the supersonic parachute that would
later help the perseverance rover
successfully land on the surface of mars
so when mars perseverance was coming in
i got
chills when we knew that the parachutes
deployed and started
slowing down the rover and brought it
into the atmosphere
because the bloom program in our own
little way
helped them to advance the technology so
that ultimately they were successful
very safely on the surface of mars
[Applause]
it's one of those things that i never
knew about growing up
and really never had even thought about
but ballooning can open up so many
avenues for science
one such avenue is using these balloons
as affordable and efficient space
viewing observatories
the best comparison is that a balloon
telescope
can do ninety percent of what a space
telescope could do
for maybe ten percent of the cost and it
can do
a hundred thousand times better than a
ground-based telescope
these floating observatories can help
answer questions we have about our
universe
that ground telescopes can't always do
99
of all the photons in the universe come
from the big bang actually
and over 90 percent of the light after
the big bang emitted by stars
is actually at infrared wavelengths now
in order to see this
you need to be above the atmosphere
that's because earth's atmosphere
absorbs a lot of the infrared light that
passes through it
already existing space telescopes like
hubble do a wonderful job of peering
back
in time to take images of the distant
universe but
the space missions are relatively few
and far between and they tend to be
expensive the
price tag starts at about 100 million
dollars and creeps up from there
whereas the balloons they're much
cheaper and you get your payload back
so if you try something that's really
cutting edge
and it doesn't quite work the first time
you can get it back tweak it
fly it again the next year that's where
bobcat comes in this nasa project is
short for the balloon-borne cryogenic
telescope testbed
its purpose is to fly large telescopes
on balloons above the atmosphere
but it's easier said than done if you're
trying to put a
large telescope up on a balloon you've
got to protect it you've got to find
some way of keeping it cold
that's because most of the light in the
universe is emitted as heat radiation in
the infrared wavelength range
so heat from the telescope could obscure
the image
so we typically would put it into a
dewer flask
it's an insulating container very much
like a travel mug
except instead of putting hot coffee
into it we put ultra cold liquid helium
into it that's only a couple of degrees
above absolute zero
but the problem is if we make the
dewar's three or four times larger
the doer itself weighs four or five tons
and it's more weight than the balloons
can carry
so al and his team are working on a cool
way to lighten the load
what we're doing with bobcat is
realizing that we're never going to look
through this telescope on the ground
we're going to look through the
telescope when it's up there 25 miles up
at the edge of outer space
at that altitude the doer experiences a
fraction of atmospheric pressure would
encounter closer to the ground so the
dewar walls instead of being
real heavy thick stainless steel they're
stainless steel
not much thicker than a beer can so we
sometimes we call this the beer can
project
the nasa team first tested this
cryogenic concept on a balloon in 2019.
bobcat 1 was a relatively short flight
once we were up there we were able to
perform our cryogen transfer
and measure the helium boil-off rate the
next step which we hope to do this
summer
is to fly the first version of an
ultralight doer
which has maybe a 20 percent of the
weight
of a conventional doer to show that
these uh construction techniques that
we're talking about
actually work the actual telescope will
come
a few years in the future once we've
demonstrated that
you can build and fly these ultralight
doers and that you can scale them up
from the size of a couch to the size of
a whole living room
and a larger telescope and doer comes
with an increase in the telescope's
sensitivity
a telescope like that with that kind of
sensitivity could look at
planets transiting in front of stars
outside our own solar system
you can look at clouds of gas and dust
in our galaxy
to see where and how stars are forming
to understand
what's the process by which stars and
planetary systems like our own
form if you were thinking that time
would be a constraining factor for these
new observatories
well think again the team plans to
launch telescopes on balloons that stay
afloat for weeks to months
at that point it's really getting
observing times into the ballpark of a
small satellite
but instead of a small satellite you're
talking a gigantic telescope
this approach allows the telescope to
return to earth and then launch again
and again and again
i would say that ballooning is an
unknown
gem in space science so a lot of people
don't even know we exist
don't realize what has been done on
balloons
and as they find out they're oftentimes
amazed
i get inspired by being able to provide
a unique platform for science the bobcat
mission
is really exciting and when he's
successful it'll open up not only his
science
but potentially other science the
balloons really are
nasa's breeding ground for new
technology and it's
it's a wonderful capability to have the
bobcat program here is a first step
towards showing that this technology
actually can work that we understand all
the problems and can demonstrate them
in the harsh conditions that exist at
the edge of outer space
[Music]
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