22.10.2020
WASHINGTON — NASA’s James Webb Space Telescope remains on schedule for a launch in a little more than a year, but the program is still dealing with some technical issues that could eat into its schedule reserve.
At an Oct. 19 meeting of NASA’s Astrophysics Advisory Committee, Eric Smith, JWST program scientist, said the mission was making good progress after the agency decided in July to delay the launch by seven months, to the end of October 2021. That delay, NASA officials said then, was caused in part by the coronavirus pandemic, which slowed down work on the telescope at a Northrop Grumman facility in Southern California.
Earlier this month, NASA and Northrop completed the final set of environmental tests on JWST, where the integrated spacecraft was subjected to acoustic and vibration conditions like those it will experience during launch. Smith said they are now moving to a final series of deployment tests of key telescope structures, such as its sunshield, which will continue through the spring of 2021. At that point it will be packed for shipment to the launch site in French Guiana.
That work is remaining on schedule. “We used some days of schedule reserve as we went through environmental testing. The good news is that we didn’t use all of the funded schedule reserve we have for that, so we’re able to push a few of those days forward and have them for schedule reserve later on,” he said. The mission has about 75 days of schedule reserve as of September, according to a chart he showed at the meeting, roughly 10 days more than the plan for that phase of development.
JWST is still dealing with some technical issues. One ongoing one is a concern that residual air trapped in the folded sunshield could overstress it when the Ariane 5 that launches the spacecraft jettisons the payload fairing. Smith said the program has been working with Arianespace to change air vents in the fairing.
On two Ariane 5 launches with the new vents, sensors measured residual air pressures inside the fairing nearly double the rated capability of the sunshield. “There’s a little more pencil sharpening that has to be done on this issue,” he said.
That work includes work by NASA and Northrop Grumman to see if the spacecraft can tolerate the higher residual pressures measured on the launches. If not, he said some parts of the spacecraft may need to be “patched” to handle the higher pressures, work he said would be completed by December.
“It’s only a few places in the sunshield where it feels the stress above requirements,” he said. Any patching work, he estimated, would require no more than a few days of schedule margin.
A new issue is a concern raised by Northrop from work on another program that some fasteners may not have been installed with sufficient torque. Smith said the JWST team looked at more than 12,300 fasteners and determined that about 160 needed to be retorqued during deployment tests. He said it wasn’t clear what schedule impact, if any, that work would have.
Quelle: SN
----
Update: 19.11.2020
.
James Webb on track for October 2021 launch; final testing underway
In a virtual update, NASA and Northrop Grumman confirmed the James Webb Space Telescope remains on track for launch on 31 October 2021 atop an Ariane 5 rocket from Kourou, French Guiana.
Final pre-launch processing milestones with the telescope, meanwhile, continue at Northrop Grumman’s Redondo Beach, California, facility, with teams currently working toward shipment of the observatory to its South American launch site in August 2021.
“2020 has been a challenging year due to COVID,” said Greg Robinson, James Webb Space Telescope Program Director at NASA Headquarters. “However, Webb has made significant progress regardless, and that’s because of a highly dedicated team. And we don’t take that for granted.”
Recently completed milestones include the first-ever full observatory electrical test as well as the culmination of environmental, vibration, and acoustic testing to ensure the telescope will operate in the temperature realm it will be exposed to in space as well as survive the sound and vibrations that will be imparted to it by the Ariane 5 rocket.
At present, deployment tests are underway at Northrop Grumman’s California facility, with Scott Willoughby, Vice President & Program Manager, Northrop Grumman, noting that the sunshield will be completely deployed by the end of the year and that teams will have completed all deployment tests by spring 2021 and will then begin the delicate process of folding Webb back up — this time for launch.
Meanwhile, all of the equipment and preparations needed to ship the telescope by sea are underway, with 17 of those 26 milestones remaining. “We’ll be ready for shipping much earlier than [its] planned [for],” said Bill Ochs, NASA James Webb Space Telescope Project Manager. “We’ll then ship in August. It’ll take us 12 days to get to the launch site. Then there’s 55 days of launch site processing covering about 700 tasks.”
The Ariane 5 rocket which will place James Webb into its initial orbit is undergoing build and integration operations. The payload fairings are currently being produced by RUAG and are scheduled to be completed by February 2021.
The Étage Supérieur Cryotechnique (Cryogenic Upper Stage) of the Ariane 5 rocket is currently undergoing electrical integration while technicians install the Vulcain 2 engine onto the Étage Principal Cryotechnique (Cryotechnic Main Stage).
Once launched, six key periods must be passed to formally start science operations:
- Launch and ascent
- Mid-course correction
- Deployments (2-3 weeks)
- Cooldown
- Telescope commissioning
- Science commissioning.
To ensure a smooth commissioning period, James Webb control teams are rehearsing all key aspects of the mission to fine tune their readiness should the telescope behave other than expected.
The James Webb launch and deployment timeline. (Credit: NASA Goddard)
“We completed our first launch readiness exercise, since COVID began, two weeks ago,” said Bill. “We have seven full rehearsals remaining and several smaller ones with various groups.”
“These full up rehearsals start at various points. The most recent one started at T-2 hours and went until the first course correction burn. The next one, in February, will be sunshield deployment, tensioning, and science instrument commissioning.”
A key element of these rehearsals is making them as flight-like as possible, including time of day, shift changes, and technical issues.
“In terms of getting prepared, we have teams of folks whose job is to make those participating in the rehearsals as miserable as possible,” said Bill.
“They force the team to exercise their knowledge and problem solve. They design these exercises to stress the team to make sure they’re ready.”
Part of this readiness is a pre-made “tool box” of contingency procedures the team can practice and have ready to implement if needed.
“This tool box covers everything from switching from one side of a control box to the other up to shimmying and shaking, spinning the telescope if something gets stuck and shaking it might get it to deploy,” added Bill.
“These simulations give us a chance to test procedures, react to issues, and then to debrief and have our lessons learned going forward.”
Once in operation, the James Webb Space Telescope will be an infrared observatory, capable of seeing back to some of the earliest moments in the universe while also looking at targets much closer to home — some in and around our solar system.
Equally important is the fact that James Webb will have capabilities that neither Hubble nor any other telescope in existence has, enabling it to perform observations of cold body objects in the distant regions of our solar system, sample and characterize the atmospheres of exoplanets in the surrounding galactic space, and also look back in time to the very first stars that birthed the metals and elements present on Earth today.
“[James Webb] will study how the first stars were very different from the stars around us today, because there were no metals that make up the stars of today,” said Massimo Stiavelli, Mission Head, Space Telescope Science Institute. “Stars had to make those. [James Webb] is the only telescope designed to study those early epochs.”
Speaking of the telescope’s ability, Scott Willoughby added, “Humanity is building something that will go back in time 13.7 billion years to see how the stars of then made the stuff of today. How did that happen? We’re going to be able to tell people that.”
Eric Smith, NASA James Webb Space Telescope Program Scientist, continued, “This is the plot of our existence. This is a telescope that will be used to answer the question of where we came from and how the universe of today formed. And because of its exoplanet ability, Webb could seek the answer of ‘are we alone?’”.
“Webb is aimed right at the heart of the two questions we’ve been asking for centuries.”
James Webb is an international collaboration by NASA, the European Space Agency, the Canadian Space Agency, and the Space Telescope Science Institute.
Quelle: NS
----
Update: 20.12.2020
.
NASA’s Webb Sunshield Successfully Unfolds and Tensions in Final Tests
Lengthened to the size of a tennis court, the five-layer sunshield of NASA’s fully assembled James Webb Space Telescope successfully completed a final series of large-scale deployment and tensioning tests. This milestone puts the observatory one step closer to its launch in 2021.
“This is one of Webb’s biggest accomplishments in 2020,” said Alphonso Stewart, Webb deployment systems lead for NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We were able to precisely synchronize the unfolding motion in a very slow and controlled fashion and maintain its critical kite-like shape, signifying it is ready to perform these actions in space.”
The sunshield protects the telescope and reflects light and background heat from the Sun, Earth and Moon into space. The observatory must be kept cold to accomplish groundbreaking science in infrared light, which is invisible to human eyes and felt as heat.
In the sunshield’s shadow, Webb’s innovative technologies and sensitive infrared sensors will allow scientists to observe distant galaxies and study many other intriguing objects in the universe.
Maintaining the sunshield’s shape involves a delicate, complicated process.
“Congratulations to the entire team. Due to Webb’s large size and stringent performance requirements, the deployments are incredibly complex. In addition to the required technical expertise, this set of tests required detailed planning, determination, patience and open communication. The team proved that it has all these attributes. It’s amazing to think that next time Webb’s sunshield is deployed it will be many thousands of miles away, hurtling through space,” said James Cooper, Webb’s sunshield manager at Goddard.
The Kapton® polymer-coated membranes of Webb’s sunshield were fully deployed and tensioned in December at Northrop Grumman in Redondo Beach, California. Northrop Grumman designed the observatory’s sunshield for NASA.
During testing, engineers sent a series of commands to spacecraft hardware that activated 139 actuators, eight motors, and thousands of other components to unfold and stretch the five membranes of the sunshield into its final taut shape. A challenging part of the test is to unfold the sunshield in Earth’s gravity environment, which causes friction, unlike unfolding material in space without the effects of gravity.
For launch the sunshield will be folded up around two sides of the observatory and placed in an Ariane 5 launch vehicle, which is provided by the European Space Agency.
In this test, two pallet structures that hold the sunshield upright folded down, then two huge “arms” (known as the Mid-Boom Assembly) of the sunshield slowly telescoped outward, pulling the folded membranes along with them to resemble the synchronized movements of a very slowly choreographed dance. Once the arms locked in their horizontal position, the membranes of the sunshield were successfully tensioned individually starting with the bottom layer, separating each into their fully deployed shape.
The large sunshield divides the observatory into a warm, Sun-facing side (about 185 degrees Fahrenheit) and a cold-space-facing side (minus 388 degrees Fahrenheit) comprised of the optics and scientific instruments. The sunshield will protect the observatory’s optics and sensors, so they remain at extremely cold temperatures to conduct science.
“This milestone signals that Webb is well on its way to being ready for launch. Our engineers and technicians achieved incredible testing progress this month, reducing significant risk to the project by completing these milestones for launch next year,” said Bill Ochs, project manager for Webb at Goddard. “The team is now preparing for final post-environmental deployment testing on the observatory these next couple of months prior to shipping to the launch site next summer.”
Webb has passed other rigorous deployment tests during its development, which successfully uncovered and resolved technical issues with the spacecraft. These tests validate that once in orbit, the observatory and its many redundant systems will function flawlessly.
The James Webb Space Telescope will be the world's premier space science observatory when it launches in 2021. Webb 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 program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
Quelle: NASA
+++
Northrop Grumman and NASA Complete Final Sunshield Deployment Test on the James Webb Space Telescope
REDONDO BEACH, Calif. – Dec. 18, 2020 – Northrop Grumman Corporation (NYSE: NOC) and NASA have successfully completed the final sunshield deployment test on the James Webb Space Telescope in preparation for its 2021 launch.
“The success of this important milestone demonstrates the rigor and dedication of the Northrop Grumman and NASA team,” said Scott Willoughby, vice president and program manager, James Webb Space Telescope, Northrop Grumman. “The sunshield is designed to deploy in space and that is exactly what we validated during this final round of testing.”
Webb’s sunshield is a remarkable feat of human engineering and ingenuity designed to protect the telescope from light and heat emitted from the sun, Earth, and moon, and the observatory itself. The sunshield maintains Webb’s one-of-a-kind scientific instruments in a deep cold, approximately negative 388 degrees Fahrenheit.
To fully deploy Webb’s sunshield, the team activates its components and executes a series of commands that initiates the release of devices which free the sunshield’s five layers. Following the release of several more cable restraint devices, a highly coordinated series of individual motor movements are completed, deploying then tensioning each sunshield layer one by one. Lastly, these actions allow the sunshield to take its final diamond-like form via a system of pulleys and springs.
The next series of major milestones includes completing the final wing deployments of Webb’s primary mirror to verify flight worthiness, followed by a final and complete full systems evaluation before shipping to the Kourou, French Guiana launch site.
Northrop Grumman leads the industry team for NASA’s James Webb Space Telescope, the largest, most complex and powerful space telescope ever built. NASA leads an international partnership that includes the European Space Agency and the Canadian Space Agency. Goddard Space Flight Center manages the Webb Telescope project, and the Space Telescope Science Institute is responsible for science and mission operations, as well as ground station development.
Northrop Grumman solves the toughest problems in space, aeronautics, defense and cyberspace to meet the ever evolving needs of our customers worldwide. Our 90,000 employees define possible every day using science, technology and engineering to create and deliver advanced systems, products and services.
Quelle: Northrop Grumman
----
Update: 9.01.2021
.
James Webb will be the 'launch to watch in 2021'
If the standout rocket launch of 2020 was the flight that took US astronauts back into orbit from American soil, then the major rocket event of 2021 must surely be the launch of the James Webb Space Telescope.
The successor to the mighty Hubble observatory is due to go into orbit on 31 October.
Its mission will be to detect the very first stars to shine in the cosmos.
The carrier rocket will be Europe's venerable Ariane-5 vehicle.
It's part of the deal that the European Space Agency (Esa) struck to get involved with the US space agency (Nasa)-led telescope project.
By providing the launch rocket and some instrumentation, Esa guaranteed European astronomers use of the new telescope once operational.
The workhorse Ariane-5 is nearing the end of its career. Only eight of the expendable vehicles are left, with one reserved for this special flight.
Ariane-5 has launched many important payloads down the years but none that has had quite so much time, effort and money invested in it.
JWST will go to the launch pad at Europe's spaceport in Kourou, French Guiana, with a price tag of roughly $10bn. That's the amount it will have cost to design and build, combined with the sum set aside to run the observatory for five years.
"This mission will be the mission of 2021," said Stéphane Israël, the CEO of Arianespace, the French company that markets and operates Europe's Ariane rocket.
"You know, the first contact we had with the Esa and Nasa on this project was in 2002. So, 18 years ago!"
JWST is currently undergoing final testing at the aerospace manufacturer Northrop Grumman in California.
"The first equipment for the launch campaign will arrive in [French Guiana] six months before the launch. The satellite itself, which will be 6.6 tonnes, will arrive by boat eight weeks before the launch," Mr Israël explained.
"JWST will be prepared in the [technical] facilities of our partner, the French space agency. The launch duration will be 26 minutes, and you know that the final destination of the satellite will be the famous Lagrange Point."
This destination is a gravitational "sweet-spot" about 1.5 million km from Earth. It's a location in the Sun-Earth system where spacecraft can maintain station by making relatively few orbital corrections, thus preserving fuel. It's also a place that's free from the environmental disturbances that observatories closer to Earth experience, such as intermittent shading and temperature swings.
IMAGE COPYRIGHTNASA/CHRIS GUNNAfter coming off the top of the Ariane, it will be a number of weeks before JWST reaches the Lagrange Point.
In this period, the telescope will work through a series of critical deployments of structures that were folded at launch to allow them to fit on the rocket.
These structures include JWST's 6.5m-wide mirror and its 21m-by-14m, diamond-shaped, multilayer sunshield.
None of this will be the responsibility of Arianespace. Its sole job is to get the flagship observatory safely off Earth and into space.
"We have worked with Esa and Nasa on the overall reliability of the Ariane-5. Nasa has been very demanding. This is perfectly normal," Mr Israël told BBC News.
Quelle: BBC
----
Update: 2.03.2021
.
NASA’s James Webb Space Telescope Completes Final Functional Tests to Prepare for Launch
February marked significant progress for NASA’s James Webb Space Telescope, which completed its final functional performance tests at Northrop Grumman in Redondo Beach, California. Testing teams successfully completed two important milestones that confirmed the observatory’s internal electronics are all functioning as intended, and that the spacecraft and its four scientific instruments can send and receive data properly through the same network they will use in space. These milestones move Webb closer to being ready to launch in October.
These tests are known as the comprehensive systems test, which took place at Northrop Grumman, and the ground segment test, which took place in collaboration with the Space Telescope Science Institute in Baltimore.
Before the launch environment test, technicians ran a full scan known as a comprehensive systems test. This assessment established a baseline of electrical functional performance for the entire observatory, and all of the many components that work together to comprise the world’s premiere space science telescope. Once environmental testing concluded, technicians and engineers moved forward to run another comprehensive systems test and compared the data between the two. After thoroughly examining the data, the team confirmed that the observatory will both mechanically and electronically survive the rigors of launch.
Through the course of 17 consecutive days of systems testing, technicians powered on all of Webb’s various electrical components and cycled through their planned operations to ensure each was functioning and communicating with each other. All electrical boxes inside the telescope have an “A” and “B” side, which allows redundancy in flight and added flexibility. During the test all commands were input correctly, all telemetry received was correct and all electrical boxes, and each backup side functioned as designed.
“It’s been amazing to witness the level of expertise, commitment and collaboration across the team during this important milestone,” said Jennifer Love-Pruitt, Northrop Grumman’s electrical vehicle engineering lead on the Webb observatory. “It’s definitely a proud moment because we demonstrated Webb’s electrical readiness. The successful completion of this test also means we are ready to move forward toward launch and on-orbit operations.”
Webb’s recent systems scan confirms the observatory will withstand the launch environment.
Following the completion of Webb’s final comprehensive systems evaluation, technicians immediately began preparations for its next big milestone, known as a ground segment test. This test was designed to simulate the complete process from planning science observations to posting the scientific data to the community archive.
Webb’s final ground segment test began by first creating a simulated plan that each of its scientific instruments would follow. Commands to sequentially turn on, move, and operate each of four scientific instruments were then relayed from Webb’s Mission Operations Center (MOC) at the Space Telescope Science Institute (STScI) in Baltimore. During the test, the observatory is treated as if it were a million miles away in orbit. To do this, the Flight Operations Team connected the spacecraft to the Deep Space Network, an international array of giant radio antennas that NASA uses to communicate with many spacecraft. However, since Webb isn’t in space yet, special equipment was used to emulate the real radio link that will exist between Webb and the Deep Space Network when Webb is in orbit. Commands were then relayed through the Deep Space Network emulator to the observatory at Northrop Grumman.
One of the unique aspects of Webb’s final ground segment test occurred during a simulated flight environment when the team successfully practiced seamlessly switching over control from its primary MOC at STScI in Baltimore to the backup MOC at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. This demonstrated a backup plan that isn’t anticipated to be needed but is necessary to practice and perfect prior to launch. Additionally, team members successfully sent multiple software patches to the observatory while it was performing its commanded operations.
“Working in a pandemic environment, of course, is a challenge, and our team has been doing an excellent job working through its nuances. That’s a real positive to highlight, and it’s not just for this test but all of the tests we’ve safely completed leading up to this one,” said Bonnie Seaton, deputy ground segment & operations manager at Goddard. “This recent success is attributable to many months of preparation, the maturity of our systems, procedures, and products and the proficiency of our team.”
When Webb is in space, commands will flow from STScI to one of the three Deep Space Network locations: Goldstone, California; Madrid, Spain; or Canberra, Australia. Signals will then be sent to the orbiting observatory nearly one million miles away. Additionally, NASA’s Tracking and Data Relay Satellite network – the Space Network in New Mexico, the European Space Agency’s Malindi station in Kenya, and European Space Operations Centre in Germany – will help keep a constant line of communication open with Webb.
Engineers and technicians continue to follow personal safety procedures in accordance with current CDC and Occupational Safety and Health Administration guidance related to COVID-19, including mask wearing and social distancing. The team is now preparing for the next series of technical milestones, which will include the final folding of the sunshield and deployment of the mirror, prior to shipment to the launch site.
The next series of milestones for Webb include a final sunshield fold and a final mirror deployment.
The James Webb Space Telescope will be the world's premier space science observatory when it launches in 2021. Webb 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 program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
Caption for the header: Following the conclusion of the James Webb Space Telescope's recent milestone tests, engineering teams have confirmed that the observatory will both mechanically, and electronically survive the rigors anticipated during launch. Credit: NASA/Chris Gunn
Quelle: NASA
----
Update: 9.03.2021
.
Women making the Webb Space Telescope a reality
On the occasion of International Women’s Day 2021, and as excitement builds for the launch of the James Webb Space Telescope (Webb) in October, ESA is highlighting women that play an important role in Europe’s contribution to Webb.
Webb, which is scheduled for launch on 31 October 2021, will be the next great space science observatory expected to make breakthrough discoveries in all fields of astronomy. It will look farther and deeper into the Universe than ever before: from our own Solar System, to exoplanets around other stars, and the birth of the first stars and galaxies.
ESA is one of the partners in the international Webb mission alongside NASA and the Canadian Space Agency (CSA). Europe plays a crucial role by contributing to two instruments (NIRSpec and MIRI), and by launching the telescope on an Ariane 5 rocket from Europe’s Spaceport in Kourou. ESA scientists are also supporting Webb mission operations at the Space Telescope Science Institute (STScI) in Baltimore, USA.
On International Women’s Day, which was first celebrated in four European countries in 1911, ESA joins in to honour women’s achievements in making our upcoming space observatory a reality. We have asked women working on the Webb telescope about their challenges, their career highlights, what they’re looking forward to about the Webb mission, and their advice to young people who might be considering careers in the space industry.
Diversity is placed high on ESA’s corporate agenda and the agency aims to inspire more women to pursue space careers, at ESA and beyond; to support more women at all levels of the organisation; and to encourage girls to explore their interest in science, technology, engineering or math (STEM) subjects.
Interviews: