Risk of Reduced Physical Performance Capabilities Due to Reduced Muscle Size, Strength, and Endurance (Muscle Risk)
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA astronaut and Expedition 65 Flight Engineer Mark Vande Hei sets up the International Space Station’s exercise bicycle, also known as the Cycle Ergometer with Vibration Isolation and Stabilization (CEVIS), inside the U.S. Destiny laboratory module. Vande Hei later strapped himself on the CEVIS and attached sensors to himself for a workout study measuring aerobic capacity in space.
NASA
Exposure to the microgravity environment causes muscle size, strength, and endurance to decline. Based on ISS data, if crew adhere to the exercise schedule and have access to adequate exercise countermeasure systems then on average, they return with minimal losses of muscle size, strength, and endurance. New exploration countermeasures systems will be different from ISS and may not have the capability to support exercise as required to maintain human performance.
On Challenger’s middeck, Mission Specialist Guion “Guy” Bluford, assists Dr. William E. Thornton (out of frame) with a medical test that requires use of the treadmill exercising device designed for spaceflight by the STS-8 medical doctor on Sept. 5, 1983. Forward lockers with data recording units and checklist notebooks are to the left of Bluford. Guy Bluford was the first African-American astronaut to fly into space.
Risk of Reduced Physical Performance Capabilities Due to Reduced Aerobic Capacity (Aerobic Risk)
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA astronaut Anne McClain is inside the Destiny laboratory module surrounded by exercise gear, including laptop computers and sensors that measure physical exertion and aerobic capacity, during a workout session aboard the International Space Station.
NASA
Spaceflight causes measures of maximum aerobic capacity to decline, which can result in impaired mission task performance. Based on ISS data, if crew adhere to existing exercise schedules and have access to adequate exercise countermeasure systems, then on average, they return with minimal losses of aerobic fitness. New exploration countermeasures systems will be different from ISS and may not have the capability to support exercise as required to maintain human performance.
How Do We Know the Earth Isn’t Flat? We Asked a NASA Expert: Episode 53
2 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
This was a magical revelation for the Greeks and the Egyptians, who were able to see from the motions of the stars and the way the Sun moved. They saw the way the Sun’s shadow worked in different places. And they figured, well, that’s only possible if the Earth is round. And they took that information and it extended into the time of the great mariners that explored our Earth by ships.
They made the first orbit of Earth by sea, and they knew the Earth was round, allowing them to go across one ocean and come back home the other way. If the Earth were flat, they would have sailed off the end. And so we knew that.
But then, at the dawn of the space age, in the late 50s and 60s, we were able to see for ourselves that our beautiful home is a gorgeous round object known as a sphere. And that was really special. It put ourselves into context of our solar system and our universe.
We have a big round Sun and a beautiful round Earth and a round Mars.
And today we use the roundness of Earth, the spherical Earth, to use methods in space geodesy to figure out where we are, where we’re going. I haven’t been lost in years. That’s pretty good.
What’s happening to the Earth, what’s happening to our oceans as we take the pulse of our planet and consider other worlds beyond as we explore those.
So as we get ready to go back to the Moon with women and men and explore other worlds, the roundness of our solar system and our universe is a special thing. And we should embrace that as we understand why our planet isn’t flat.
A chevron nozzle is installed on NASA’s Learjet for a mid-March 2001 flight test at Lorain Country Airport to verify that in an emergency, the aircraft could be flown using only the experimental engine.
Credit: NASA/Marvin Smith
Shortly after dawn on March 27, 2001, NASA pilot Bill Rieke took off from an airfield just outside of Phoenix in NASA’s blue-and-white Learjet 25 and flew low over a series of microphones for the first flight test of a groundbreaking NASA technology.
On one of the plane’s engines was an experimental jagged-edged nozzle that researchers at Glenn Research Center in Cleveland had discovered made aircraft significantly quieter. These initial flight tests were an important step toward using these “chevron nozzles” on modern aircraft, lowering noise levels for communities.
NASA Glenn has been exploring ways of reducing engine noise since the first jet airliners appeared in the 1950s. New turbofan engines in the 1960s were quieter, but the expansion of the overall airline industry meant that noise was still an issue. With the introduction of noise-limiting mandates in the 1970s, NASA and engine manufacturers embarked on a decades-long search for technologies to lower noise levels.
NASA researchers discovered that the military’s use of rectangular notches, or tabs, along an engine nozzle’s exit – to help disguise a jet fighter’s infrared signature – could also reduce engine noise by helping mix the hot air from the engine core and the cooler air blowing through the engine fan. In the 1990s, Glenn researcher Dennis Huff and his colleagues discovered that a serrated, or sawtooth, shape, referred to as a chevron, offered more promise.
Dennis Huff explains chevron nozzles, seen on a table, to U.S. Senator George Voinovich and other visitors inside the Aero-Acoustic Propulsion Laboratory facility in 2006. Huff was head of NASA Glenn Research Center’s Acoustics Branch at this point.
Credit: NASA/Marvin Smith
NASA contracted with General Electric and Pratt & Whitney to develop an array of tab and chevron designs to be analyzed in Glenn’s unique Aero-Acoustic Propulsion Laboratory (AAPL). Extensive testing in the spring of 1997 showed the possibilities for reducing noise with these types of nozzles.
Engine manufacturers were impressed with the findings but wary of any technology that might impact performance. So, in 1998, NASA funded engine tests of the 14 most promising designs. The tests revealed the chevron nozzle had a negligible 0.25% reduction of thrust. It was a major development for jet noise research.
In September 2000, Glenn’s Flight Operations Branch was contacted about the logistics of flight-testing chevron nozzles on the center’s Learjet 25 to verify the ground tests and improve computer modeling. Nothing further came of the request, however, until early the next year when Huff informed Rieke, chief of Flight Operations, that the researchers would like to conduct flight tests in late March—with just eight weeks to prepare.
Glenn’s Acoustics Branch worked with colleagues at NASA’s Langley Research Center in Hampton, Virginia, and the Arizona-based engine manufacturer Honeywell on the effort. They planned to conduct testing at Estrella Sailport just outside of Phoenix from March 26 to 28, 2001.
Bill Rieke and Ellen Tom with the chevron nozzle installed on the Learjet. NASA Glenn Research Center’s small Flight Operations team was heavily involved with icing research and solar cell calibration flights during this period, so arrangements were made for Tom, a Federal Aviation Administration pilot, to assist with the chevron flights.
Credit:Courtesy of Bill Rieke
With the required safety and design reviews, the eight-week target date would be difficult to meet for any test flight, but this one was particularly challenging as it involved modifications to the engine nacelle. While the special nozzle engineers created for the flights would allow them to switch between a six- and a 12-chevron design during testing, it also got hot quickly. This necessitated the installation of new sensors, rewiring of fire alarm cables, and the presence of an onboard test engineer to monitor the temperatures. The short turnaround also required expedited efforts to obtain flight plan approvals, verify the plane’s airworthiness, and perform normal maintenance activities.
Despite the challenges, Rieke and a small team delivered the Learjet to Estrella on March 25, as planned. The next day was spent coordinating with the large Langley and Honeywell team and acquiring baseline noise data. The pilots idled the unmodified engine as the Learjet flew over three perpendicular rows of microphones at an altitude of 500 feet and speed of 230 miles per hour.
View from below as NASA Glenn Research Center’s Learjet 25 passes overhead at the Estrella airfield with the experimental chevron nozzle visible on the left wing.
Credit: Courtesy of Bill Rieke
The flight patterns were repeated over the next two days while alternately using the two variations of the chevron nozzle. The researchers anecdotally reported that there was no perceptible noise reduction as the aircraft approached, but significant reductions once it passed. Recordings supported these observations and showed that sideline noise was reduced, as well.
The flights of the Learjet, which was powered by a variation of GE’s J-85 turbojet, were complemented by Honeywell’s turbofan-powered Falcon 20 aircraft. These flights ultimately confirmed the noise reduction found in earlier AAPL tests.
Overall, the flight tests were so successful that just over a year later the FAA began certifying GE’s CF34–8, the first commercial aircraft engine to incorporate chevron technology. The engine was first flown on a Bombardier CRJ900 in 2003. Continued studies by both NASA and industry led to the improved designs and the incorporation of chevrons into larger engines, such as GE’s GEnx.
According to Huff, the chevron’s three-decibel noise decrease was analogous to the difference between running two lawnmowers and one. Their comparatively easy integration into engine design and minimal effect on thrust made the chevron a breakthrough in noise-reduction technology. In 2002, NASA presented an innovation award to the Glenn, Langley, and Honeywell team that carried out the flights. Today, airliners such as the 737 MAX and 787 Dreamliner use chevron nozzles to lower noise levels for communities near airports.
Team Preps to Study Dark Energy via Exploding Stars With NASA’s Roman
This video sparkles with synthetic supernovae from the OpenUniverse project, which simulates observations from NASA’s upcoming Nancy Grace Roman Space Telescope. More than a million exploding stars flare into visibility and then slowly fade away. The true brightness of each transient event has been magnified by a factor of 10,000 for visibility, and no background light has been added to the simulated images. The pattern of squares shows Roman’s full field of view.
Credit: NASA’s Goddard Space Flight Center and M. Troxel
The universe is ballooning outward at an ever-faster clip under the power of an unknown force dubbed dark energy. One of the major goals for NASA’s upcoming Nancy Grace Roman Space Telescope is to help astronomers gather clues to the mystery. One team is setting the stage now to help astronomers prepare for this exciting science.
“Roman will scan the cosmos a thousand times faster than NASA’s Hubble Space Telescope can while offering Hubble-like image quality,” said Rebekah Hounsell, an assistant research scientist at the University of Maryland-Baltimore county working at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a co-principal investigator of the Supernova Cosmology Project Infrastructure Team preparing for the mission’s High-Latitude Time-Domain Survey. “We’re going to have an overwhelming amount of data, and we want to make it so scientists can use it from day one.”
Roman will repeatedly look at wide, deep regions of the sky in near-infrared light, opening up a whole new view of the universe and revealing all sorts of things going bump in the night. That includes stars being shredded as they pass too close to a black hole, intense emissions from galaxy centers, and a variety of stellar explosions called supernovae.
This data sonification transforms a vast simulation of a cosmic survey from NASA’s upcoming Nancy Grace Roman Space Telescope into a symphony of stellar explosions. Each supernova’s brightness controls its volume, while its color sets its pitch –– redder, more distant supernovae correspond to deep, low tones while bluer, nearer ones correspond to higher frequencies. The sound in stereo mirrors their locations in the sky. The result sounds like celestial wind chimes, offering a way to “listen” to cosmic fireworks. Credit: NASA’s Goddard Space Flight Center, M. Troxel, SYSTEM Sounds (M. Russo, A. Santaguida)
Cosmic Radar Guns
Scientists estimate around half a dozen stars explode somewhere in the observable universe every minute. On average, one of them will be a special variety called type Ia that can help astronomers measure the universe.
These explosions peak at a similar intrinsic brightness, allowing scientists to find their distances simply by measuring how bright they appear.
Scientists can also study the light of these supernovae to find out how quickly they are moving away from us. By comparing how fast they’re receding at different distances, scientists will trace cosmic expansion over time.
Using dozens of type Ia supernovae, scientists discovered that the universe’s expansion is accelerating. Roman will find tens of thousands, including very distant ones, offering more clues about the nature of dark energy and how it may have changed throughout the history of the universe.
“Roman’s near-infrared view will help us peer farther because more distant light is stretched, or reddened, as it travels across expanding space,” said Benjamin Rose, an assistant professor at Baylor University in Waco, Texas, and a co-principal investigator of the infrastructure team. “And opening a bigger window, so to speak, will help us get a better understanding of these objects as a whole,” which would allow scientists to learn more about dark energy. That could include discovering new physics, or figuring out the universe’s fate.
The People’s Telescope
Members of the planning team have been part of the community process to seek input from scientists worldwide on how the survey should be designed and how the analysis pipeline should work. Gathering public input in this way is unusual for a space telescope, but it’s essential for Roman because each large, deep observation will enable a wealth of science in addition to fulfilling the survey’s main goal of probing dark energy.
Rather than requiring that many individual scientists submit proposals to reserve their own slice of space telescope time, Roman’s major surveys will be coordinated openly, and all the data will become public right away.
“Instead of a single team pursuing one science goal, everyone will be able to comb through Roman’s data for a wide variety of purposes,” Rose said. “Everyone will get to play right away.”
This animation shows a possible tiling pattern of part of NASA’s Nancy Grace Roman Space Telescope’s High Latitude Time-Domain Survey. The observing program, which is being designed by a community process, is expected to have two components: wide (covering 18 square degrees, a region of sky as large as about 90 full moons) and deep (covering about 5.5 square degrees, about as large as 25 full moons). This animation shows the deeper portion, which would peer back to when the universe was about 500 million years old, less than 4 percent of its current age of 13.8 billion years.
Credit: NASA’s Goddard Space Flight Center
This Is a Drill
NASA plans to announce the survey design for Roman’s three core surveys, including the High-Latitude Time-Domain Survey, this spring. Then the planning team will simulate it in its entirety.
“It’s kind of like a recipe,” Hounsell said. “You put in your observing strategy — how many days, which filters — and add in ‘spices’ like uncertainties, calibration effects, and the things we don’t know so well about the instrument or supernovae themselves that would affect our results. We can inject supernovae into the synthetic images and develop the tools we’ll need to analyze and evaluate the data.”
Scientists will continue using the synthetic data even after Roman begins observing, tweaking all aspects of the simulation and correcting unknowns to see which resulting images best match real observations. Scientists can then fine-tune our understanding of the universe’s underlying physics.
“We assume that all supernovae are the same regardless of when they occurred in the history of the universe, but that might not be the case,” Hounsell said. “We’re going to look further back in time than we’ve ever done with type Ia supernovae, and we’re not completely sure if the physics we understand now will hold up.”
There are reasons to suspect they may not. The very first stars were made almost exclusively of hydrogen and helium, compared to stars today which contain several dozen elements. Those ancient stars also lived in very different environments than stars today. Galaxies were growing and merging, and stars were forming at a furious pace before things began calming down between about 8 and 10 billion years ago.
“Roman will very dramatically add to our understanding of this cosmic era,” Rose said. “We’ll learn more about cosmic evolution and dark energy, and thanks to Roman’s large deep view, we’ll get to do much more science too with the same data. Our work will help everyone hit the ground running after Roman launches.”
For more information about the Roman Space Telescope visit www.nasa.gov/roman.
The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory and Caltech/IPAC in Southern California, the Space Telescope Science Institute in Baltimore, and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems Inc. in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California.
