in february of 1987
astronomers looking at the nearby galaxy
called the large magellanic cloud
witnessed a rare event
a supernova explosion
the spectacular death of the star
astronomers around the world have
eagerly studied supernova 1987 a with
sensitive telescopes hoping to learn
what will happen to the expanding debris
and the fiery core of the star
has the inner core collapsed as
scientists expect into a tiny dense
pulsing neutron star at the center
in the exploding gas in giant supernovas
in hundreds of millions of stars
in huge spiraling galaxies
in distant quasars whose light has been
traveling to us since the beginning of
the universe
in these fantastic objects
astronomers have learned that great
forces heat gasses to extreme
temperatures above tens of millions of
degrees
causing them to emit massive amounts of
x-rays
the space shuttle will carry sensitive
new telescopes into orbit to study the
cosmos
one telescope measures x-rays emitted
from supernovas quasars and other high
energy targets in space
priceless new information from this
broadband x-ray telescope will help
scientists uncover more pieces in the
puzzle of knowledge about the
universe go for main engine start
four three two
one
and
liftoff liftoff on columbia and its
return to flight
in the spring of 1990 the space shuttle
columbia will lift off on a special
mission called astro one
dedicated to scientific observations of
our universe
once in orbit four new telescopes will
be operated from the shuttle's payload
bay
bbxrt the broadband x-ray telescope
analyzes x-rays emitted by extremely hot
and energetic stars and galaxies in
distant
space three other telescopes mounted
together on a pointing platform examine
ultraviolet light emitted from nearby
objects in our solar system and from
stars and distant galaxies
these telescopes must be operated in
space
because the earth's atmosphere prevents
most radiation including x-rays and
ultraviolet light from reaching the
ground
the visible light that we can see is a
surprisingly small portion of the
radiation that is emitted in space
we know that massive amounts of
radiation are emitted in the invisible
portion of the electromagnetic spectrum
including ultraviolet light and x-rays
each type of radiation provides
different clues about the nature of the
object
the broadband x-ray telescope studies
radiation emitted in a large portion of
the x-ray spectrum which has never been
studied before in great detail
for example bbxrt can detect which
chemical elements are present in an
x-ray source such as oxygen magnesium
silicon
sulfur and calcium
elements that are abundant in space and
essential to life on earth
bbxrt is the first x-ray telescope used
in space that can detect the presence of
iron in a broad variety of targets
because iron is one of the most abundant
elements in the universe its presence in
an x-ray source provides tell-tale
evidence about that object for example
its size temperature how old it is
whether it rotates and at what speed and
other physical conditions
the dream of building and launching a
broadband x-ray telescope into space
began more than 12 years ago here at
nasa's goddard space flight center in
greenbelt maryland
over 40 satellites have been built and
tested at goddard countless others have
been managed by nasa's greenbelt
facility
in the late 1970s
dr peter cerlamitsos working in
goddard's high energy astrophysics
laboratory developed a light and
inexpensive mirror sufficiently smooth
to reflect x-rays
it was made from shiny aluminum foil
coated with acrylic and gold the mirrors
were nested together in a housing to
provide the large surface area needed to
gather x-rays
these foil mirrors made the telescope
light enough to be carried into space on
the shuttle
once the telescope was approved for
flight teams of up to 100 goddard
scientists engineers and technicians
worked for five years to build the
instrument and a unique reusable
pointing system for the telescope
payload manager frank volpe describes
the challenges of building the telescope
when you fly in the orbiter the the key
most criteria is to make sure it's safe
so we have gone through extensive
testing and design to ensure that in no
way jeopardize the health and safety of
the crew and the orbiter
to that extent you also must make sure
that it is its limits of weight
and power and thermal requirements all
within the constraints of the orbiter
itself we had to take some
exceptional uh
steps to ensure that
the thermal systems remained within its
limits at one end of the telescope
we have elements operating at a very
very cold temperature around 40 degrees
kelvin
at other places on the telescope and the
payload we have
boxes that like to operate near room
temperature
once the telescope was built it was
lowered into the two-axis pointing
system structure
during the integration and testing phase
the complex electronic systems
controlling the telescope and the
support structure were wired together
and repeatedly checked
blankets were attached to achieve the
required thermal insulation in space
vibration acoustics and thermal vacuum
tests were conducted on the telescope to
simulate conditions encountered during
the mission
some of the shuttle astronauts shown
here in their anti-contamination suits
came to goddard to get a first-hand look
at the new telescope that they will
carry into orbit
goddard scientists have carefully chosen
the x-ray sources that the bbxrt will
observe
these unusually hot and energetic
targets vary from tiny neutron stars
drawing gas from a larger companion star
to giant clusters of galaxies
a prime bbxrt target is a supernova
remnant the exploded outer shell of a
star which occupies vast areas in space
the outer edges heated to extreme
temperatures by shock waves emit
millions of x-rays
in these regions
bbxrt can detect the presence of heavy
elements such as iron and many other
elements that make up our own bodies
by studying the supernova the x-ray
telescope will contribute new
information about how these important
elements are manufactured inside stars
bbxrt principal investigator dr peter
cerlemitsos
everything we learn from it is telltale
evidence of what was inside the star
you know how we're going to study what
the star is forming inside we're waiting
for it to spew this matter out in the
interstellar space and therefore
from the pieces out there we see the
x-ray emission that tells us what was
forming the star what how much iron how
much silicon and so forth
as the exploded outer shell of supernova
1987a dissipates into space
it may be possible for bbxrt to observe
the existence of a neutron star at the
center
neutron stars are formed during a
supernova explosion when the inner
region of a star collapses into a tiny
core
pulsars are neutron stars that rotate
extremely quickly some as fast as one
thousand times a second
they emit light and x-rays in
searchlight beams making them appear to
blink on and off
scientists believe that neutron stars
are unimaginably dense
one teaspoonful of matter from a neutron
star would weigh over a billion tons
many neutron stars are often paired with
a much larger companion star
in this binary star system the tiny
neutron star exerts an extremely strong
gravitational pull which draws gas from
the companion star
the gas flows into an accretion disk
around the neutron star
as it approaches the star
the gas is heated to millions of degrees
and emits large amounts of x-rays
in some systems
the gas flows onto the pole of the
neutron star along its magnetic field
scientists believe that some binary
systems may contain a mysterious black
hole instead of a neutron star
x-rays are admitted as the swirling hot
gas is drawn into the black hole
the gravitational force exerted by the
black hole is so strong that neither
light nor matter can escape once they
are drawn in
the physical conditions found inside the
black hole are totally unknown
the x-ray telescope will study a
suspected black hole in our galaxy
called cygnus x1
scientists hope bbxrt
will confirm the theory that material is
actually spiraling around the black hole
as it is drawn into it
perhaps none of bbxrt's targets are as
mysterious as the quasars
though they look like stars
quasars are believed to be the center of
distant galaxies formed billions of
years ago
yet a single quasar radiates more energy
than 100 normal galaxies combined
it is believed that quasars may be
powered by a massive black hole
quasars are the furthest objects from
earth ever observed
so the light emitted from them dates
back to a time much closer to the big
bang
the indescribably huge explosion that
scientists believe was the beginning of
the universe
bb xrt co-investigator frank marshall
quasars have been known for i guess more
than 20 years now but it's still not
known what the
real energy generation mechanism
in quasars is but x-rays allow you to
look very close into the central engine
of quasars which is where most of the
action is going on so we'll look very
close to what we think is the black hole
at the at the center of the quasar and
get a measurement of perhaps how the
material is is falling into the into the
quasar
and how large the object the center of
the quasar is
the largest areas bbxrt will study are
clusters of galaxies where hundreds of
galaxies move around each other in their
own gravitational system
previous x-ray instruments have
discovered an extremely hot gas that
covers an enormous region within the
cluster
bbxrt will analyze the chemical makeup
of the gas
clusters of galaxies what is the gas
that is in them how hot it is and what
it is
is it just hydrogen from from the big
bang or is it something that the
galaxies that are going in this cluster
that has
been spewing out and now it's heated up
in the middle of the cluster in
astrophysics this is important
information and instruments like bbxrt
give you that information it's just that
a lot of this information simply does
not exist right now and bbxrt will be
producing this information
the weeks prior to the launch are a time
of great anticipation for the men and
women who work to build a telescope
together with the ultraviolet telescopes
bbxrt is positioned into the shuttle's
payload bay at the kennedy space center
during the mission the x-ray telescope
will be controlled from the goddard
space flight center
several flight simulations are held
prior to launch
many of the scientists and engineers who
built and tested the telescope practiced
the commands and procedures to be used
during the mission you can enable taps
in bbxrt for command at this time
astro will be around the clock mission
nearly every orbit the astronauts will
adjust the orientation of the shuttle
then the telescopes will make fine
adjustments toward new targets
for part of the mission all the
telescopes will point at the same target
such as supernova
1987a by comparing simultaneous
information taken in two different bands
of the electromagnetic spectrum
scientists will gain a more complete
understanding of these targets
at other times the x-ray and ultraviolet
telescopes will be pointed at different
targets
all data from the telescopes will be
analyzed over the coming years
what's been exciting about this project
is that science was conceived here
the instrument was developed here the
rest of the payload was developed and
integrated and tested here
and the whole payload will be controlled
from the goddard space flight center
control center
largely we don't know
exactly what we're going to see which is
part of the excitement
the 10 days will produce for us and
discovering exactly what
what we do find because in the past
x-ray astronomy new x-ray astronomy
missions have always produced something
we didn't anticipate
in many circumstances those are the most
have been the most exciting results
and i'm very hopeful that the same will
be true for bbxrt
the broadband x-ray telescope
along with the astro ultraviolet
telescopes
stands ready to deliver brand new
information to scientists all over the
world
about the greatest mysteries in the
universe its origin
its evolution
and its future
do
you