Category: astronauts

Dark Matter 101: Looking for the missing mass

Here’s the deal — here at NASA we share all
kinds of amazing images of planets,
stars,
galaxies, astronauts,
other humans,
and such, but those photos can only capture part of what’s out there. Every
image only shows ordinary matter (scientists sometimes call it baryonic
matter), which is stuff made from protons, neutrons and electrons. The problem
astronomers have is that most of the
matter in the universe is not ordinary matter – it’s a mysterious substance called dark matter.  

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What
is dark matter
? We don’t really know.
That’s not to say we don’t know anything about it – we can see its effects on
ordinary matter. We’ve been getting clues about what it is and what it is not
for decades. However, it’s hard to pinpoint its exact nature when it doesn’t
emit light our telescopes can see. 

Misbehaving
galaxies

The first hint that we might be missing
something came in the 1930s when astronomers noticed that the visible matter in
some clusters of galaxies wasn’t enough to hold the cluster together. The
galaxies were moving so fast that they should have gone zinging out of the
cluster before too long (astronomically speaking), leaving no cluster behind.

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Simulation credit: ESO/L. Calçada

It turns out, there’s a similar problem with individual galaxies.
In the 1960s and 70s, astronomers mapped out how fast the stars in a galaxy
were moving relative to its center. The outer parts of every single spiral
galaxy the scientists looked at were traveling so fast that they should have
been flying apart.

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Something was missing – a lot of it!

In
order to explain how galaxies moved in clusters and stars moved in individual
galaxies, they needed more matter than scientists could see. And not just a little more matter. A lot … a lot, a lot. Astronomers
call this missing mass “dark matter”
— “dark” because we don’t know
what it is. There would need to be five times as much dark matter as ordinary
matter to solve the problem.  

Holding
things together

Dark matter keeps galaxies and galaxy clusters
from coming apart at the seams, which means dark matter experiences gravity
the same way we do
.

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In addition to holding things together, it
distorts space like any other mass. Sometimes we see distant
galaxies whose light has been bent around massive objects
on its way
to us. This makes the galaxies appear stretched out or contorted. These distortions provide another measurement of dark
matter
.

Undiscovered
particles?

There have been a number of theories over the
past several decades about what dark matter could be; for example, could dark
matter be black holes and neutron stars – dead stars that aren’t shining anymore?
However, most of the theories have been disproven. Currently, a leading class
of candidates involves an as-yet-undiscovered type of elementary particle
called WIMPs, or Weakly Interacting Massive Particles.

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Theorists have envisioned a range of WIMP
types and what happens when they collide with each other. Two possibilities are
that the WIMPS could mutually annihilate, or they could produce an
intermediate, quickly decaying particle. In both cases, the collision would end
with the production of gamma rays — the most energetic form of light — within the detection range of our Fermi Gamma-ray Space Telescope.

Tantalizing
evidence close to home

A few years ago, researchers took a look at
Fermi data from near the center of our galaxy and subtracted out the gamma rays
produced by known sources. There was a left-over gamma-ray signal, which could be consistent with some forms of dark matter.

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While it was an exciting finding, the case is
not yet closed because lots of things at the center of the galaxy make gamma
rays. It’s going to take multiple sightings using other experiments and looking
at other astronomical objects to know
for sure if this excess is from dark matter.

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In the meantime, Fermi will continue the search, as it has over its 10 years
in space. Learn
more about Fermi and how we’ve been celebrating its first decade in space.

Make
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Experience High-Res Science in First 8K Footag…

Fans
of science in space can now experience fast-moving footage in even higher
definition as NASA delivers the first 8K ultra high definition (UHD) video of
astronauts living, working and conducting research from the International
Space Station
.

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The
same engineers who sent high-definition (HD) cameras, 3D cameras, and a camera
capable of recording 4K footage to the space station have now delivered a new
camera– Helium
8K camera by RED – capable of recording images
with four times the
resolution than the previous camera offered.

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Let’s compare this
camera to others
: The Helium 8K camera is capable of
shooting at resolutions ranging from conventional HDTV up to 8K, specifically 8192
x 4320 pixels. By comparison, the average HD consumer television displays up to
1920 x 1080 pixels of resolution, and digital cinemas typically project 2K to 4K.

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Viewers can
watch as crew members advance DNA sequencing in space with the BEST
investigation, study dynamic forces between sediment particles with BCAT-CS,
learn about genetic differences in space-grown and Earth-grown plants with Plant
Habitat-1
, observe low-speed water jets to improve combustion
processes within engines with Atomization
and explore station facilities such as the MELFI,
the Plant
Habitat
, the Life
Support Rack
, the JEM Airlock and
the CanadArm2.

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Delivered to the station aboard the fourteenth SpaceX
cargo resupply mission through a Space Act Agreement between NASA and RED, this
camera’s ability to record twice the pixels and at resolutions four times
higher than the 4K camera brings science in orbit into the homes, laboratories
and classrooms of everyone on Earth. 

While
the 8K resolutions are optimal for showing on movie screens, NASA video editors
are working on space station footage for public viewing on YouTube. Viewers will
be able to watch high-resolution footage from inside and outside the orbiting
laboratory right on their computer screens. Viewers will need a screen capable
of displaying 8K resolution for the full effect, but the imagery still trumps
that of standard cameras. RED videos and pictures are shot at a higher fidelity
and then down-converted, meaning much more information is captured in the
images, which results in higher-quality playback, even if viewers don’t have an
8K screen.   

The full UHD files are available for download for use in broadcast. Read the NASA media usage
guidelines

Optical Communications: Explore Lasers in Spac…

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When we return to the Moon, much will seem unchanged since
humans first arrived in 1969. The flags placed by Apollo
astronauts will be untouched by any breeze. The footprints left by man’s “small
step” on its surface will still be visible across the Moon’s dusty landscape.

Our next generation of lunar explorers will require
pioneering innovation alongside proven communications technologies. We’re
developing groundbreaking technologies to help these astronauts fulfill their
missions.

In space communications networks, lasers will supplement
traditional radio communications, providing an advancement these explorers
require. The technology, called optical communications, has been in development
by our engineers over decades.

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Optical
communications
, in infrared, has a higher frequency than radio,
allowing more data to be encoded into each transmission. Optical communications
systems also have reduced size, weight and power requirements. A smaller system
leaves more room for science instruments; a weight reduction can mean a less
expensive launch, and reduced power allows batteries to last longer.

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On the path through this “Decade of Light,” where laser
joins radio to enable mission success, we must test and demonstrate a number of
optical communications innovations.

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The Laser Communications Relay Demonstration
(LCRD) mission will send data between ground stations in Hawaii and California
through a spacecraft in an orbit stationary relative to Earth’s rotation. The
demo will be an important first step in developing next-generation Earth-relay
satellites that can support instruments generating too much data for today’s
networks to handle.

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The Integrated LCRD Low-Earth Orbit User Modem
and Amplifier-Terminal
will provide the International
Space Station
with a fully operational optical communications
system. It will communicate data from the space station to the ground through
LCRD. The mission applies technologies from previous optical communications
missions for practical use in human spaceflight.

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In deep space, we’re working to prove laser technologies
with our Deep Space
Optical Communications
mission. A laser’s wavelength is smaller than
radio, leaving less margin for error in pointing back at Earth from very, very
far away. Additionally, as the time it takes for data to reach Earth increases,
satellites need to point ahead to make sure the beam reaches the right spot at
the right time. The Deep Space Optical Communications mission will ensure that
our communications engineers can meet those challenges head-on.

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An integral part of our journey back to the Moon will be our
Orion
spacecraft
. It looks remarkably similar to the Apollo capsule, yet it
hosts cutting-edge technologies. NASA’s Laser Enhanced Mission Communications
Navigation and Operational Services (LEMNOS) will provide Orion with data rates
as much as 100 times higher than current systems.

LEMNOS’s optical terminal, the Orion EM-2 Optical
Communications System, will enable live, 4K ultra-high-definition video from
the Moon. By comparison, early Apollo cameras filmed only 10 frames per second
in grainy black-and-white. Optical communications will provide a “giant leap”
in communications technology, joining radio for NASA’s return to the Moon and the
journey beyond.

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NASA’s Space
Communications and Navigation program office provides strategic oversight to optical
communications research. At NASA’s Goddard Space Flight Center in Greenbelt,
Maryland, the Exploration and Space Communications projects division is guiding
a number of optical communications technologies from infancy to fruition. If
you’re ever near Goddard, stop by our visitor center to check out our new
optical communications exhibit. For more information, visit nasa.gov/SCaN
and esc.gsfc.nasa.gov.

World Teacher Appreciation Day!

On #WorldTeachersDay, we are recognizing our two current astronauts who are former classroom teachers, Joe Acaba and Ricky Arnold, as well as honoring teachers everywhere. What better way to celebrate than by learning from teachers who are literally out-of-this-world!

During the past Year of Education on Station, astronauts connected with more than 175,000 students and 40,000 teachers during live Q & A sessions. 

Let’s take a look at some of the questions those students asked:

The view from space is supposed to be amazing. Is it really that great and could you explain? 

Taking a look at our home planet from the International Space Station is one of the most fascinating things to see! The views and vistas are unforgettable, and you want to take everyone you know to the Cupola (window) to experience this. Want to see what the view is like? Check out earthkam to learn more.

What kind of experiments do you do in space?

There are several experiments that take place on a continuous basis aboard the orbiting laboratory – anything from combustion to life sciences to horticulture. Several organizations around the world have had the opportunity to test their experiments 250 miles off the surface of the Earth. 

What is the most overlooked attribute of an astronaut?

If you are a good listener and follower, you can be successful on the space station. As you work with your team, you can rely on each other’s strengths to achieve a common goal. Each astronaut needs to have expeditionary skills to be successful. Check out some of those skills here. 

Are you able to grow any plants on the International Space Station?

Nothing excites Serena Auñón-Chancellor more than seeing a living, green plant on the International Space Station. She can’t wait to use some of the lettuce harvest to top her next burger! Learn more about the plants that Serena sees on station here. 

What food are you growing on the ISS and which tastes the best? 

While aboard the International Space Station, taste buds may not react the same way as they do on earth but the astronauts have access to a variety of snacks and meals. They have also grown 12 variants of lettuce that they have had the opportunity to taste.

Learn more about Joe Acaba, Ricky Arnold, and the Year of Education on Station.

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5 Questions from a Year of Education on the In…

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This year, we’re celebrating a Year of Education on the Station as astronauts and former teachers Joe Acaba and Ricky Arnold have made the International Space Station their home. While aboard, they have been sharing their love of science, technology, engineering and math, along with their passion for teaching. With the Year of Education on the Station is coming to a close, here are some of the highlights from students speaking to the #TeacherOnBoard from across the country!

Why do you feel it’s important to complete Christa McAuliffe’s lessons?

“The loss of Challenger not only affected a generation of school teachers but also a generation of school children who are now adults.” Ricky’s personal mission was to bring the Challenger Mission full circle and give it a sense of closure by teaching Christa’s Lost Lessons. See some of Christa’s Lost Lessons here.

Have you ever poured water out to see what happens?

The concept of surface tension is very apparent on the space station. Fluids do not spill out, they stick to each other. Cool fact: you can drink your fluids from the palm of your hand if you wanted to! Take a look at this demonstration that talks a little more about tension. 

How does your equipment stay attached to the wall?

The use of bungee cords as well as hook and loop help keep things in place in a microgravity environment. These two items can be found on the space station and on the astronaut’s clothing! Their pants often have hook and loop so they can keep things nearby if they need to be using their hands for something else. 

Did being a teacher provide any advantage to being an astronaut?

Being an effective communicator and having the ability to be adaptable are great skills to have as a teacher and as an astronaut. Joe Acaba has found that these skills have assisted him in his professional development.  

Since you do not use your bones and muscles as often because of microgravity, do you have to exercise? What type can you do?

The exercises that astronauts do aboard the space station help them maintain their bone density and muscle mass. They have access to resistance training through ARED (Advanced Resistive Exercise Device) which is a weight machine and for cardio, there is a bicycle and treadmill available to keep up with their physical activity.

Learn more about the Year of Education on Station

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NASA’s 60th Anniversary: Humans in Space

NASA’s 60th Anniversary: Humans in Space

It is part of the human spirit to explore. During 60 years, we have selected 350 people as astronauts to lead the way. For nearly two decades, humans have been living and working aboard the International Space Station in low-Earth orbit to enable future missions forward to the Moon and on to Mars while also leading discoveries that improve life on Earth. Since we opened for business on Oct. 1, 1958, our history tells a story of exploration, innovation and discoveries. The next 60 years, that story continues. Learn more: https://www.nasa.gov/60

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Hostile and Closed Environments, Hazards at Cl…

A
human journey to Mars, at first
glance, offers an inexhaustible amount of complexities. To bring a mission to
the Red Planet from fiction to fact, NASA’s Human Research Program has organized some of the hazards
astronauts will encounter on a continual basis into five classifications.

A spacecraft is not only a home,
it’s also a machine. NASA understands that the ecosystem inside a vehicle plays
a big role in everyday astronaut life.

Important habitability factors
include temperature, pressure, lighting, noise, and quantity of space. It’s
essential that astronauts are getting the requisite food, sleep and exercise
needed to stay healthy and happy. The space environment introduces challenges
not faced on Earth.

Technology, as often is the case
with out-of-this-world exploration, comes to the rescue! Technology plays a big
role in creating a habitable home in a harsh environment and monitoring some of
the environmental conditions.

Astronauts are also asked to
provide feedback about their living environment, including physical impressions
and sensations so that the evolution of spacecraft can continue addressing the
needs of humans in space.

Exploration to the Moon and Mars will expose astronauts to five
known hazards of spaceflight, including hostile and closed environments, like
the closed environment of the vehicle itself. To learn more, and find out what
NASA’s Human Research Program is doing to protect humans in
space, check out the “Hazards of Human Spaceflight" website.
Or, check out this week’s episode of “Houston
We Have a Podcast,” in which host Gary Jordan
further dives into the threat of hostile and closed environments with Brian
Crucian, NASA immunologist at the Johnson Space Center.

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Gravity, Hazard of Alteration

A
human journey to Mars, at first
glance, offers an inexhaustible amount of complexities. To bring a mission to
the Red Planet from fiction to fact, NASA’s Human Research Program has organized some of the hazards
astronauts will encounter on a continual basis into five classifications.

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The variance of gravity fields that
astronauts will encounter on a mission to Mars is the fourth hazard.

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On Mars, astronauts would need to
live and work in three-eighths of Earth’s gravitational pull for up to two
years. Additionally, on the six-month trek between the planets, explorers will
experience total weightlessness. 

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Besides Mars and deep space there
is a third gravity field that must be considered. When astronauts finally
return home they will need to readapt many of the systems in their bodies to
Earth’s gravity.

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To further complicate the problem,
when astronauts transition from one gravity field to another, it’s usually
quite an intense experience. Blasting off from the surface of a planet or a
hurdling descent through an atmosphere is many times the force of gravity.

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Research is being conducted to
ensure that astronauts stay healthy before, during and after their mission.
Specifically researchers study astronauts’
vision, fine motor skills, fluid distribution, exercise protocols and response to
pharmaceuticals.

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Exploration to the Moon and Mars will expose astronauts to five
known hazards of spaceflight, including gravity. To learn more, and find out
what NASA’s Human Research Program is doing to protect humans in
space, check out the “Hazards of Human Spaceflight" website.
Or, check out this week’s episode of “Houston
We Have a Podcast
,” in which host Gary Jordan
further dives into the threat of gravity with Peter
Norsk,
Senior Research Director/ Element Scientist at
the Johnson Space Center.

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Regular

There’s one in every bunch.

Distance: Hazard Far From Home

A human journey to Mars, at first glance, offers an inexhaustible amount
of complexities. To bring a mission to the Red Planet from fiction to fact, our Human
Research Program
has
organized some of the hazards astronauts will encounter on a continual basis
into five classifications.

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The third and perhaps most apparent hazard is, quite
simply, the distance.

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Rather than a three-day lunar trip, astronauts would
be leaving our planet for roughly three years. Facing a communication delay of
up to 20 minutes one way and the possibility of equipment failures or a medical
emergency, astronauts must be capable of confronting an array of situations
without support from their fellow team on Earth.

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Once you burn your engines for Mars, there is no
turning back so planning and self-sufficiency are essential keys to a
successful Martian mission. The Human Research Program is studying and
improving food formulation, processing, packaging and preservation systems.

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While International Space Station expeditions serve as
a rough foundation for the expected impact on planning logistics for such a
trip, the data isn’t always comparable, but it is a key to the solution.

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Exploration to the Moon and Mars
will expose astronauts to five known hazards of spaceflight, including distance
from Earth. To learn more, and find out what our Human Research
Program is doing to protect humans in space, check out the “Hazards
of Human Spaceflight
" website. Or,
check out this week’s episode of “Houston We Have a Podcast,” in which host Gary Jordan
further dives into the threat of distance with Erik Antonsen, the
Assistant Director for Human Systems Risk
Management at the Johnson Space Center.

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