9.02.2019
NASA’s Webb Is Sound After Completing Critical Milestones
NASA's James Webb Space Telescope has successfully passed another series of critical testing milestones on its march to the launch pad.
In recent acoustic and sine vibration tests, technicians and engineers exposed Webb’s spacecraft element to brutal dynamic mechanical environmental conditions to ensure it will endure the rigors of a rocket launch to space.
During liftoff, rockets generate extremely powerful vibrations and energetic sound waves that bounce off the ground and nearby buildings and impact the rocket as it makes its way skyward. Technicians and engineers aim to protect Webb from these intense sound waves and vibrations.
To simulate these conditions, flight components are intentionally punished with a long litany of tests throughout different facilities to identify potential issues on the ground. Webb was bombarded by powerful sound waves from massive speakers and then placed on an electrodynamic vibration table and strongly but precisely shaken. Together, these tests mimic the range of extreme shaking that spacecraft experience while riding a rocket to space.
“Webb’s launch vibration environment is similar to a pretty bumpy commercial airplane flight during turbulence,” said Paul Geithner, deputy project manager – technical, James Webb Space Telescope at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “And, its launch acoustic environment is about 10 times more sound pressure, 100 times more intense and four times louder than a rock concert.”
One half of the Webb observatory, known as the “spacecraft element,” was the subject of this latest testing. The spacecraft element consists of the “bus,” which is the equipment that actually flies the observatory in space, plus the tennis-court-size sunshield that will keep Webb’s sensitive optics and instruments at their required super-cold operating temperature. Northrop Grumman in Redondo Beach, California, NASA’s lead industrial teammate on Webb, designed and built the spacecraft element, and conducted the testing in their facilities with NASA support and guidance. Northrop Grumman and NASA engineers and technicians worked tirelessly together as a team over the last few months to complete these complex dynamic mechanical environmental tests.
The initial attempt at acoustic testing last spring uncovered a problem with a specific portion of sunshield hardware, which required some modifications taking several months. Subsequently, the acoustic test was redone, and this time everything went successfully. With acoustic testing complete, the spacecraft element was transported in a mobile clean room to a separate vibration facility, where its spacecraft hardware was exposed to the bumps and shakes that occur when riding a rocket soaring through the atmosphere at high Mach speeds. Northrop Grumman, NASA and its partner, ESA (European Space Agency), are familiar with the flight profile and performance of the Ariane 5 rocket that will carry Webb into space in early 2021, so technicians tuned the tests to mimic the conditions it’s expected to face during launch.
With the successful completion of its mechanical environmental testing, the spacecraft element is being prepared for thermal vacuum testing. This other major environmental test will ensure it functions electrically in the harsh temperatures and vacuum of space. The other half of Webb, which consists of the telescope and science instruments, had completed its own vibration and acoustic testing at Goddard and cryogenic-temperature thermal vacuum testing at NASA’s Johnson Space Center in Houston prior to delivery at Northrop Grumman last year. Once finished with thermal vacuum testing, the spacecraft element will return to the giant clean room where it was assembled, to be deployed from its folded-up launch configuration and into its operational configuration, which will be the final proof that it has passed all of its environmental tests. Then, the two halves of Webb — the spacecraft and the telescope elements — will be integrated into one complete observatory for a final round of testing and evaluation prior to launch.
Webb will be the world's premier space science observatory. It will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA and the Canadian Space Agency.
Quelle: NASA
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Northrop Grumman Completes Next Critical Launch Milestones of NASA’s James Webb Space Telescope Spacecraft
REDONDO BEACH, Calif. – Feb. 8, 2019 – NASA’s James Webb Space Telescope Spacecraft Element (SCE) successfully completed acoustic and sine vibration testing at Northrop Grumman Corporation (NYSE: NOC) in Redondo Beach.
Both halves of NASA’s James Webb Space Telescope are housed in Northrop Grumman’s cleanroom as they undergo ongoing testing and integration efforts.
Acoustic and sine vibration testing validates the structural design and verifies the mechanical workmanship and integrity of the actual flight SCE by subjecting it to simulated rigors of the launch environment.
“Mission success remains our focus for Webb, a first of its kind space telescope,” said Scott Willoughby, vice president and program manager, James Webb Space Telescope, Northrop Grumman. “Successful environmental testing of the SCE builds further confidence in its structural design integrity, built to withstand the stresses of launch.”
The SCE was subjected to acoustic noise levels of 140.7 decibels (damage to hearing starts at 85dB while speakers at a concert can be as loud as 120dB or more), which simulated the high noise levels generated from rocket engines and turbulent air flow at high Mach speeds during launch. Vibration testing simulates the vibration and shaking Webb will experience during launch. During testing, the SCE was attached to a large electrodynamic shaker, vibrating it along three orthogonal axes. This back-and-forth or “sinusoidal” vibration was applied by starting at a low, subsonic frequency of 5 hertz (cycles per second) and “sweeping” up to a medium frequency of 100 hertz in the course of just over one minute. Ultimately, the SCE was subjected to protoflight vibration levels required to simulate a rocket launch experience. Testing on the ground assures that Webb can successfully withstand the rigors of its journey to space.
The completion of acoustic and sine vibration testing advances Webb’s SCE to its final environmental test, thermal vacuum testing. Post thermal vacuum testing, Webb will return to Northrop’s clean room for full deployment and integration of the Optical Telescope Element/Integrated Science Instrument Module later this year.
NASA’s James Webb Space Telescope Spacecraft Element during vibration testing at Northrop’s facility, in Redondo Beach, California.
The James Webb Space Telescope will be the world’s premier space science observatory of the next decade. Webb will solve mysteries of our solar system, look to distant worlds around other stars, and probe the mysterious structures and the origins of our universe. Webb is an international program led by NASA with its partners, the European Space Agency and the Canadian Space Agency.
Northrop Grumman is a leading global security company providing innovative systems, products and solutions in autonomous systems, cyber, C4ISR, space, strike, and logistics and modernization to customers worldwide. Please visit news.northropgrumman.com and follow us on Twitter, @NGCNews, for more information.
NASA’s James Webb Space Telescope on its way to acoustics testing at Northrop’s large acoustic test facility in Redondo Beach, California.
Team members from NASA and Northrop Grumman observing NASA’s James Webb Space Telescope Spacecraft Element being placed at Northrop’s large acoustic test facility, in Redondo Beach, California, in preparation for acoustics testing.
Quelle: Northrop Grumman
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Update: 31.05.2019
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Spacecraft element successfully endures extreme temperatures in thermal vacuum
REDONDO BEACH, Calif. – May 30, 2019 – NASA’s James Webb Space Telescope Spacecraft Element (SCE) successfully completed its last environmental test, thermal vacuum testing, at Northrop Grumman Corporation (NYSE: NOC) in Redondo Beach.
Thermal vacuum testing exposes Webb’s SCE to the extreme hot and cold temperatures it will experience in space. To test these extreme temperature ranges, the chamber uses liquid nitrogen shrouds and heater panels to expose the SCE to cold temperatures as low as -300 degrees Fahrenheit and hot temperatures as high as 220 degrees Fahrenheit. Real-time data collection via flight sensors on the SCE allow engineers to monitor Webb’s electrical/unit functionality and ensures the structure will withstand the rigors of its cold journey to and operation at the second Lagrange point.
“The world’s largest space telescope has to perform in extreme temperatures,” said Scott Willoughby, vice president and program manager, James Webb Space Telescope, Northrop Grumman. “Successful completion of thermal vacuum testing ensures the SCE can endure the volatile conditions it will face and further validates Webb’s readiness for launch.”
Webb’s SCE completed its two prior environmental tests (acoustic and sine vibration). After thermal vacuum testing, the SCE will return to Northrop Grumman’s clean room to begin post-environmental testing, including deployments. Later this year, the Webb telescope will become a fully integrated observatory for the first time through integration of the SCE to the Optical Telescope Element/Integrated Science Instrument Module.
The James Webb Space Telescope will be the world’s premier space science observatory of the next decade. Webb will solve mysteries in our solar system, look to distant worlds around other stars, and probe the mysterious structures and the origins of our universe. Webb is an international program led by NASA with its partners, the European Space Agency and the Canadian Space Agency.
Northrop Grumman is a leading global security company providing innovative systems, products and solutions in autonomous systems, cyber, C4ISR, space, strike, and logistics and modernization to customers worldwide. Please visit news.northropgrumman.com and follow us on Twitter, @NGCNews, for more information.
NASA’s James Webb Space Telescope Spacecraft Element is so large, Northrop Grumman engineers and technicians had to utilize a hydraulic elevator platform to bottom load the SCE into the thermal vacuum chamber at Northrop Grumman’s test facility in Redondo Beach, Calif.
Quelle: Northrop Grumman
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Update: 24.07.2019
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NASA's Webb Telescope Shines with American Ingenuity
To send humans to the Moon 50 years ago, an entire nation rose to the challenge. Surmounting countless hurdles, inventing new technologies while staring into the face of the unknown, NASA successfully pioneered multiple lunar landings. NASA demonstrated to the world the importance of partnerships and what a unified country can achieve.
Similarly, the task of building the world's most complex and powerful space telescope, NASA's James Webb Space Telescope has required steadfast contribution from across the United States. In total, 29 states throughout the U.S. have lent a hand manufacturing, assembling, and testing Webb components. After launch, Webb's science and data will reach a global audience.
Webb's 18 innovative lightweight beryllium mirrors had to make 14 stops at 11 different places across 8 states (visiting some states more than once) around the U.S. to complete their manufacturing.
Their journey began in beryllium mines in Utah, and then moved across the country for processing and polishing. Explore an interactive map showing the journey of the mirrors. After the spacecraft is fully assembled in California, the telescope will journey to French Guiana for lift-off, and the beginning of their final journey to space
Much like the Apollo program, NASA's Webb telescope is an exemplar of ingenuity. In order to step foot on the Moon, technology that had never been seen before was conceived and developed into existence.
To observe periods of cosmic history beyond the reaches of even the Hubble Space Telescope, the Webb team needed to invent multiple brand new technologies and testing methods to verify them for flight and service on orbit a million miles away.
"When we first thought of Webb, it wasn't technically feasible. We had to succeed at inventing some things before we could build it-not unlike the Apollo Program in this regard," said Paul Geithner, Deputy Project Manager - Technical at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Some of Webb's hardware has even seen thermal vacuum testing inside the very same historic 'Chamber A' at NASA's Johnson Space Center in Houston that was used to validate Apollo spacecraft components for their historic missions.
Named in honor of James E. Webb, who led NASA's Apollo program, the Webb telescope represents revolutionary science that not only changes what we know, but also how we think about the night sky and our place in the cosmos.
Webb will be the world's premier space science observatory. It will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, (European Space Agency) and the Canadian Space Agency.
Echoes of NASA's Apollo program live on proudly today. With the new Artemis program, NASA has set its sights on creating a sustainable presence on the Moon, to serve as a waypoint for the ultimate goal of launching humans to Mars.
Quelle: SD
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Update: 29.08.2019
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NASA’s James Webb Space Telescope Has Been Assembled for the First Time
Reaching a major milestone, engineers have successfully connected the two halves of NASA’s James Webb Space Telescope for the first time at Northrop Grumman’s facilities in Redondo Beach, California. Once it reaches space, NASA's most powerful and complex space telescope will explore the cosmos using infrared light, from planets and moons within our solar system to the most ancient and distant galaxies.
To combine both halves of Webb, engineers carefully lifted the Webb telescope (which includes the mirrors and science instruments) above the already-combined sunshield and spacecraft using a crane. Team members slowly guided the telescope into place, ensuring that all primary points of contact were perfectly aligned and seated properly. The observatory has been mechanically connected; next steps will be to electrically connect the halves, and then test the electrical connections.
“The assembly of the telescope and its scientific instruments, sunshield and the spacecraft into one observatory represents an incredible achievement by the entire Webb team,” said Bill Ochs, Webb project manager for NASA Goddard Space Flight Center in Greenbelt, Maryland. “This milestone symbolizes the efforts of thousands of dedicated individuals for over more than 20 years across NASA, the European Space Agency, the Canadian Space Agency, Northrop Grumman, and the rest of our industrial and academic partners.”
Next up for Webb testing, engineers will fully deploy the intricate five-layer sunshield, which is designed to keep Webb's mirrors and scientific instruments cold by blocking infrared light from the Earth, Moon and Sun. The ability of the sunshield to deploy to its correct shape is critical to mission success.
“This is an exciting time to now see all Webb’s parts finally joined together into a single observatory for the very first time,” said Gregory Robinson, the Webb program director at NASA Headquarters in Washington, D.C. “The engineering team has accomplished a huge step forward and soon we will be able to see incredible new views of our amazing universe.”
Both of the telescope’s major components have been tested individually through all of the environments they would encounter during a rocket ride and orbiting mission a million miles away from Earth. Now that Webb is a fully assembled observatory, it will go through additional environmental and deployment testing to ensure mission success. The spacecraft is scheduled to launch in 2021.
Webb will be the world's premier space science observatory. It will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA (European Space Agency), and the Canadian Space Agency.
Quelle: NASA
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Update: 15.10.2019
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Quelle: NASA
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Update: 22.10.2019
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NASA’s James Webb Space Telescope Clears Critical Sunshield Deployment Testing
The sunshield for NASA’s James Webb Space Telescope has passed a test critical to preparing the observatory for its 2021 launch. Technicians and engineers fully deployed and tensioned each of the sunshield's five layers, successfully putting the sunshield into the same position it will be in a million miles from Earth.
“This was the first time that the sunshield has been deployed and tensioned by the spacecraft electronics and with the telescope present above it. The deployment is visually stunning as a result, and it was challenging to accomplish," said James Cooper, NASA’s Webb Telescope Sunshield Manager at NASA’s Goddard Space Flight Center, Greenbelt, Maryland.
To observe distant parts of the universe humans have never seen before, the Webb observatory is equipped with an arsenal of revolutionary technologies, making it the most sophisticated and complex space science telescope ever created. Among the most challenging of these technologies is the five-layer sunshield, designed to protect the observatory's mirrors and scientific instruments from light and heat, primarily from the Sun.
As a telescope optimized for infrared light, it is imperative that Webb’s optics and sensors remain extremely cold, and its sunshield is key for regulating temperature. Webb requires a successful sunshield deployment on orbit to meet its science goals.
The sunshield separates the observatory into a warm side that always faces the Sun (thermal models show the maximum temperature of the outermost layer is 383 Kelvin or approximately 230 degrees Fahrenheit), and a cold side that always faces deep space (with the coldest layer having a modeled minimum temp of 36 Kelvin, or around minus 394 degrees Fahrenheit). The oxygen present in Earth’s atmosphere would freeze solid at the temperatures experienced on the cold side of the sunshield, and an egg could easily be boiled with the heat encountered on the warm end.
Webb has passed other deployment tests during its development. Equally as important were the successful disposition of issues uncovered by those earlier deployments and the spacecraft element environmental testing. As before, technicians used gravity-offsetting pulleys and weights to simulate the zero-g environment it will experience in space. By carefully monitoring the deployment and tensioning of each individual layer, Webb technicians ensure that once on orbit, they will function flawlessly.
"This test showed that the sunshield system survived spacecraft element environmental testing, and taught us about the interfaces and interactions between the telescope and sunshield parts of the observatory," Cooper added. "Many thanks to all the engineers and technicians for their perseverance, focus and countless hours of effort to achieve this milestone.”
The sunshield consists of five layers of a polymer material called Kapton. Each layer is coated with vapor-deposited aluminum, to reflect the Sun’s heat into space. The two hottest sun-facing layers also have a "doped-silicon" (or treated silicon) coating to protect them from the Sun’s intense ultraviolet radiation.
To collect light from some of the first stars and galaxies to have formed after the Big Bang, the telescope needed both the largest mirror ever to be launched into space, and the sunshield that has the wingspan of an entire tennis court. Because of the telescope’s size, shape and thermal performance requirements, the sunshield must be both big and complex. But it also has to fit inside a standard 16-foot-(5-meter)-diameter rocket payload fairing, and also reliably deploy into a specific shape, while experiencing the absence of gravity, without error.
Following Webb’s successful sunshield test, team members will begin the long process of perfectly folding the sunshield back into its stowed position for flight, which occupies a much smaller space than when it is fully deployed. Then, the observatory will be subjected to comprehensive electrical tests and one more set of mechanical tests that emulate the launch vibration environment, followed by one final deployment and stowing cycle on the ground, before its flight into space.
Webb will be the world's premier space science observatory. It will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
Quelle: NASA
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Update: 30.10.2019
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JWST schedule margin shrinks
WASHINGTON — While NASA achieves milestone assembling and testing the James Webb Space Telescope, a key manager said the mission only has a few months of schedule reserve left ahead of a March 2021 launch.
In a presentation to NASA’s Astrophysics Advisory Committee Oct. 29, Greg Robinson, program director for JWST at NASA Headquarters, said the agency and prime contractor Northrop Grumman are making progress with the integration and testing of the telescope at a Northrop facility in Southern California.
“In the past six months, we’ve seen a lot of really good progress bringing the observatory together,” he said. That included the integration of the spacecraft’s optics and instruments section with the spacecraft bus and sunshield in August. On Oct. 21, NASA announced the combined spacecraft successfully completed a deployment test of its five-layer sunshield.
Robinson said that the spacecraft has not suffered any major technical issues during recent testing. Instead, the program has been working through smaller issues. “The good news is that the team is doing all of the right work, and they’re doing it in the right way,” he said. “There are small new discoveries that cost us a day, two or three days, a week.”
One such problem is with an electronics unit called a command telemetry processor that malfunctioned during environmental testing. Robinson said engineers had problems duplicating the problem to determine the root cause and plan to replace the unit, along with a traveling wave tube amplifier used in the spacecraft’s communications system that also failed during testing.
NASA has also been working with launch provider Arianespace about concerns that residual pressure within the payload fairing at the time of fairing separation could “over-stress” the sunshield membranes. Tests on recent Ariane 5 launches confirmed that there was a higher residual pressure than the sunshield was designed for. Vents in the fairing are being redesigned to address this, Robinson said, and will be tested on Ariane 5 launches in early 2020.
However, those smaller problems, along with bigger issues like fastener problems with the sunshield found during environmental testing last year, have eroded the margin built into the revised schedule for the mission. Robinson said that revised schedule in June 2018 provided about nine months of schedule reserve, but now there was “just over two months of schedule margin” remaining.
Most missions expect to use up schedule reserve as they progress towards launch. However, earlier this year Tom Young, who chaired the Independent Review Board chartered by NASA last year to review cost and schedule problems with JWST, warned that the mission appeared to be using up schedule reserve at a higher-than-expected rate.
Program officials later said that high rate of scheduled reserve use was to address problems they felt were behind them. Robinson said that the recent deployment of the sunshield “was almost error-free” with no new problems.
He said he expected to continue to see “routine issues” during integration and testing that slow down work on the mission slightly. “Those will continue, hopefully fewer and shorter,” he said. “But right now I don’t expect anything major.”
A major problem, though, could wipe out that schedule reserve. “If we encounter a big problem, something really significant, that’s a semi-bad day, schedule-wise,” he said.
Quelle: SN