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This photo contains both flight (flat in the foreground) and qualification assembly (upright in the background) versions of the Solar Array Sun Shield for NASA’s Nancy Grace Roman Space Telescope. These panels will both shade the mission’s instruments and power the observatory.
Double Vision: Why Do Spacecraft Have Twin Parts?
Seeing double? You’re looking at our Nancy Grace Roman Space Telescope’s Solar Array Sun Shield laying flat in pieces in the foreground, and its test version connected and standing upright in the back. The Sun shield will do exactly what it sounds like –– shade the observatory –– and also collect sunlight for energy to power Roman.
These solar panels are twins, just like several of Roman’s other major components. Only one set will actually fly in space as part of the Roman spacecraft…so why do we need two?
Sometimes engineers do major tests to simulate launch and space conditions on a spare. That way, they don’t risk damaging the one that will go on the observatory. It also saves time because the team can do all the testing on the spare while building up the flight version. In the Sun shield’s case, that means fitting the flight version with solar cells and eventually getting the panels integrated onto the spacecraft.
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Our Nancy Grace Roman Space Telescope’s primary structure (also called the spacecraft bus) moves into the big clean room at our Goddard Space Flight Center (top). While engineers integrate other components onto the spacecraft bus in the clean room, the engineering test unit (also called the structural verification unit) undergoes testing in the centrifuge at Goddard. The centrifuge spins space hardware to ensure it will hold up against the forces of launch.
Engineers at our Goddard Space Flight Center recently tested the Solar Array Sun Shield qualification assembly in a thermal vacuum chamber, which simulates the hot and cold temperatures and low-pressure environment that the panels will experience in space. And since the panels will be stowed for launch, the team practiced deploying them in space-like conditions. They passed all the tests with flying colors!
The qualification panels will soon pass the testing baton to the flight version. After the flight Solar Array Sun Shield is installed on the Roman spacecraft, the whole spacecraft will go through lots of testing to ensure it will hold up during launch and perform as expected in space.
For more information about the Roman Space Telescope, visit: www.nasa.gov/roman. You can also virtually tour an interactive version of the telescope here.
The majestic spiral galaxy NGC 7331 is almost like a long lost twin to our very own Milky Way. In this close-up, the galaxy’s magnificent spiral arms feature dark, obscuring dust lanes, bright bluish clusters of massive young stars and the telltale reddish glow of active star-forming regions. The yellowish central region harbors populations of older, cooler stars. Like in the Milky Way, a supermassive black hole lies at the galaxy’s core.
Our Hubble Space Telescope took this image while observing a supernova explosion — the fiery death of a massive star — within NGC 7331. Astronomers noted that the supernova, called SN 2014C, experienced a dramatic, hasty transformation that involved a significant upsurge in hydrogen content. This observation provided a rare chance to gain insight into the final stages of massive stars.
NGC 7331 was discovered in 1784 by famed astronomer William Herschel, who discovered the planet Uranus. It was originally classified as a nebula, which is an interstellar cloud of gas and dust, because no one knew that other galaxies existed until the 20th century. It turns out that NGC 7331 and the Milky Way are among billions and billions of galaxies in the universe!
What exactly happens to the human body during spaceflight?
The Twins Study, a 340-day investigation conducted by NASA’s HumanResearch Program , sought to find answers. Scientists had an opportunity to see how conditions on the International Space Station translated to changes in gene expression by comparing identical twin astronauts: Scott Kelly who spent close to a year in space and Mark Kelly who remained on Earth.
The Process
From high above the skies, for almost a year, astronaut Scott Kelly periodically collected his own blood specimens for researchers on the ground during his One-Year Mission aboard the Space Station. These biological specimens made their way down to Earth onboard two separate SpaceX Dragon vehicles. A little bit of Scott returned to Earth each time and was studied by scientists across the United States.
Totaling 183 samples from Scott and his brother, Mark, these vials helped scientists understand the changes Scott’s body underwent while spending a prolonged stay in low Earth orbit.
The Twins
Because
identical twins share the same genetic makeup, they are very similar on a molecular level. Twin studies provide a way for scientists to explore how our
health is impacted by the environment around us.
What We Learned: Gene Expression
A significant
finding is the variability in gene expression, which reflects how a body
reacts to its environment and will help inform how gene expression is related
to health risks associated with spaceflight. While in space, researchers
observed changes in the expression of Scott’s genes, with the majority
returning to normal after six months on Earth. However, a small percentage of
genes related to the immune system and
DNA repair did not return to
baseline after his return to Earth. Further, the results identified
key genes to target for use in monitoring the health of future astronauts and potentially
developing personalized countermeasures.
What We Learned: Immunome
Another key finding is that Scott’s
immune system responded appropriately in space. For example, the flu vaccine administered in space
worked exactly as it does on Earth. A fully functioning immune system during
long-duration space missions is critical to protecting astronaut health from opportunistic
microbes in the spacecraft environment.
What We Learned: Proteomics
Studying
protein pathways in Scott enabled researchers to look at fluid
regulation and fluid shifts within his body. Shifts in fluid may
contribute to vision problems in astronauts. Scientists found a specific
protein associated with fluid regulation was elevated in Scott,
compared with his brother Mark on Earth.
What We Learned: Telomeres
The
telomeres in Scott’s white blood cells, which are biomarkers of
aging at the end of
chromosomes, were unexpectedly longer in space
then shorter after his return to Earth with average telomere length
returning to normal six months later. In contrast, his brother’s telomeres
remained stable throughout the entire period. Because telomeres are important
for cellular genomic stability, additional studies on telomere dynamics are
planned for future one-year
missions to see whether results are repeatable for
long-duration missions.
What We Learned: Cognition
Scott
Kelly participated in a series of cognitive performance evaluations
(such as mental alertness, spatial orientation, and recognition of
emotions) administered through a battery of tests and surveys.
Researchers found that during spaceflight,
Scott’s cognitive function remained normal for the first half of his
stay onboard the space station compared to the second half of his
spaceflight and to his brother, Mark, on the ground. However, upon
landing, Scott’s speed and accuracy decreased. Re-exposure to Earth’s
gravity and the dynamic experience of landing may have affected the
results.
What We Learned: Biochemical
In
studying various measurements on Scott, researchers found that his body
mass decreased during flight, likely due to controlled nutrition and extensive
exercise. While on his mission, Scott consumed about 30% less calories
than researchers anticipated. An increase in his folate serum (vitamin
B-9), likely due to an increase of the vitamin in his pre-packaged
meals, was also noted by researchers. This is bolstered by the telomeres
study, which suggests that proper nutrition and exercise help
astronauts maintain health while in space.
What We Learned: Metabolomics
Within
five months of being aboard the space station, researchers found an
increase in the thickness of Scott’s arterial wall, which may have been
caused by inflammation and oxidative stress during spaceflight. Whether
this change is reversible is yet to be determined. They hope these
results will help them understand the stresses that the human
cardiovascular system undergoes during spaceflight.
In
addition, the results from the Microbiome, Epigenomics, and Integrative Omics
studies suggest a human body is capable of adapting to and recovering from the
spaceflight environment on a molecular level.
Why Does This Matter?
The data from the Twins Study Investigation
will be explored for years to come as researchers report some interesting,
surprising, and assuring data on how the human body is able to adapt to
the extreme environment of spaceflight. This study gave us the first
integrated molecular view into genetic changes, and demonstrated the
plasticity and robustness of a human body!
We will use the valuable data to ensure the safety and health of the men and women
who go on to missions to the Moon and on to Mars.
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