NASA officials announced on Tuesday a statement of technical obstacles and "avoidable errors" that the launch of the James Webb Space Telescope, which is years behind schedule, will be postponed until 2020 In recent months, problems with the spacecraft bus of the observatory, the section that will take up the deployable telescope of the mission after take-off, prompted a review of the engineers planned to prepare them for take-off
"The project has many successful ones Milestones are reached, and indeed, 100 percent of the observatory's hardware is now ready, "said Robert Lightfoot, NASA's chief administrator. "However, the work performance challenges have led us to take action."
"We need to successfully integrate the two halves of the observatory into the final flight configuration and to perform some key tests after an independent assessment of the remaining aircraft parts," said Lightfoot Tuesday in a teleconference with reporters: "Honestly, the completion of the tasks takes longer than we expected, which will lead to a new target launch window, which we now expect to be around in May 2020."
NASA announced last September that JWST would miss the target date in October 2018, but Manager still expects the observatory to be ready to withdraw between March and June 2019. Officials on Tuesday said it was no longer possible.  All parts of the observatory are in a clean room at Northro p Grumman's satellite factory in Redondo Beach, California, where technicians will connect JWST's space platform under construction with the mission's telescope and science module, which will be assembled at NASA's Goddard Space Flight Center in Maryland and a cryogenic vacuum at the beginning of the year Contractor's work arrived at Houston Johnson Space Center test
The telescope and instruments passed their independent tests, but the team in cha The construction of the spacecraft had encountered problems, NASA officials said. A NASA test board found earlier this month that the mission is unlikely to be operational until 2020.
"More time is needed to test and integrate Northrop Grumman's highly complex solar and spacecraft division," said Thomas Zurbuchen, NASA's scientific mission administrator. "It takes longer and a few mistakes happened."
The flagship mission will be the most ambitious astronomical observatory of all time, building on a quarter of a century of discoveries from the famous Hubble Space Telescope. Originally proposed more than 20 years ago, the James Webb Space Telescope has been redesigned to expand its observational power and overcome numerous technical hurdles, ranging from an initial $ 1 billion projection to more than $ 10 billion in spending, along with European ones and Canadian contributions.
The new observatory will be stationed nearly 1.5 million kilometers from Earth, using a 21.3-foot (6.5-meter) mirror and four science instruments hidden behind a thermal sun-shield into the distant universe to look, to investigate the turbulent consequences of the Big Bang, the formation of galaxies and the environment of planets around other stars.
According to Lightfoot, NASA has so far invested $ 7.3 billion in the James Webb Space Telescope, named after the NASA administrator who led the agency during the 1960s Space Race.
NASA remains committed to the Observatory, but with the startup delay to 2020, the cost of developing the mission could exceed the legislator's $ 8 billion limit. When this happens, the mission must be reviewed by Congress and re-approved.
"The James Webb Space Telescope is our highest priority research project in the NASA mission," said Lightfoot. It is truly a tremendous achievement of human engineering, leaving a legacy of extraordinary science and technological innovation for decades to come. It's packed with groundbreaking technology and it's also the largest international space exploration project in United States history. "
NASA officials have not submitted a new cost estimate to complete the development of the Observatory, and the agencies' leaders will submit a report to Congress by the end of June to inform legislators about the updated schedule and mission budget
"As soon as we have indications that a breach will happen both in the timetable and in the costs, we must inform immediately," said Zurbuchen. "The disadvantage of this kind of sudden action is that we are not our entire common In fact, at this moment, we really do not fully know what the exact cost of this will be. "" If NASA needs relatively little additional money to complete JWST, future ones could Issues that are planned for the observatory's post-launch operations will be applied to the assembly and complete the spacecraft's testing on Earth, "said Zurbuchen. If the budget is well beyond NASA's previous expectation, the impact on the agency's other science missions could be more severe, provided the Congress gives the go-ahead for the final testing and launch of the observatory.
Zurbuchen and his deputy in NASA science The mission directorate, Dennis Andrucyk, said last year a number of problems that would have affected the spacecraft module of the observatory.
"There were a few technical challenges … especially in the propulsion system, we had a schedule because of a converter that was driven wrong," said Andrucyk. "We had to replace that, which resulted in a three-month hit." Wrong solvent was passed through the prop system, as a result we had to replace the valves in this system and a catalyst bed heater was inadvertently overloaded (with the wrong voltage) and had to be replaced. "
Andrucyk characterized the problems of the propulsion system as" avoidable errors ".
"The Sunshield complications also impacted the timetable," he said. "It's a very large five-layered membrane system about the size of a tennis court, and during deployment, folding, and stowage, the time we needed for these activities took longer than we expected, and we expected two for the first deployment Weeks It was a month and we expected it to be about a month and it would take two months and we have two extra ones ready to fold and stow. "
Engineers discovered seven tears over five sun visors that keep the detectors and mirrors of the observatory protected from heat and sunlight, and parts keep the spacecraft as cold as minus 370 degrees Fahrenheit or minus 223 degrees Celsius. Internal coolers cool some of the sensors of the telescopes even colder.
"Even the sunshade system, the cables that hold the sunshield in shape, developed too much play during use, causing a risk of getting stuck," said Zurbuchen. "So they had to redesign how the cables spread certain parts of the tree so this would not happen."
The sun visor cracks were repaired, officials said.
Once the telescope and spacecraft sections are connected, Northrop Grumman's ground crews will re-deploy the sunshade along with the telescopic wings and other structures of the telescope, causing the entire observatory to be electrically vibrated and audible Testing. Once these checks are completed, the technicians will rewind the entire observatory before it is put into launch configuration.
The tests are designed to ensure that missions run smoothly after the mission starts.
The sun visor and mirror must fold origami-style to fit into the cladding of the European Ariane 5 rocket, which will launch JWST of French Guiana. The Ariane 5 launcher is one of the European Space Agency's key contributions to the mission, along with key instrument hardware.
Depending on how you count, JWST will have more than 300 missions after separating from the upper tier of Ariane 5 pitchers. The Curiosity Mars rover had about 70 missions.
"Webb is really complex," said Zurbuchen. Extensive and thorough testing is needed to ensure that we can successfully complete a launch, deployment and test.
"Webb will travel one million miles from Earth, four times farther than the Moon," says Zurbuchen. "Put simply, we have a shot to get it right before we go into space, you've heard that before, and it's true for Webb, for us, failure really is not an option."
Andrucyk said NASA headquarters will in future have more oversight over JWST, including direct interaction with Northrop Grumman's president and operations manager. NASA will also be sending a project manager for the Northrop Grumman factory in Southern California, along with additional spacecraft integration and testing experts during critical operations.
NASA will also have daily and weekly flight plan reviews with Northrop Grumman reshaping the management structure. Northrop Grumman also makes personnel changes and update procedures.
Andrucyk said Tuesday at a meeting at the National Academies of Sciences that some of JWST's recent problems were "driven by poorly written procedures"
By Thomas Young, a veteran of the space industry, who is a senior executive at Lockheed Martin and when NASA's Viking Mars Lander head of mission worked, the space agency will confirm a new start date and cost for JWST.
estimated that the mission could be operational by 30 April 2020 with a confidence level of 70 percent, Andrucyk said Tuesday at the Space Academy Conference of the Academies of Sciences. As a result, the agency's heads announced that the mission was likely to run until May 2020.
As a reminder, Andrucyk, the NASA Permanent Review Board – comprised of engineers and managers who are not part of the JWST program – concluded the mission in January 2020 with 30 percent confidence.
The observatory survived a 2011 lawmakers' rejection, suggesting zeroing the mission's budget. An independent review in 2010 found that the mission needed more money to hold a launch date in 2015. Finally, NASA and Congress agreed to introduce JWST in 2018 with additional funds to provide managers with budgetary support for potential technical issues.
This funding reserve may prove inadequate and officials said on Tuesday that a 2018 launch was based on an optimistic timeline
The Webb mission is to become the most expensive robotic space exploration ever. The main mirror of the observatory, which collects light from astronomical sources, is nearly three times the diameter of Hubble, and by 2030 no other observatory of the size of JWST is planned.
Webb Enables "Science That Looks At The Universe In A Way We Have Never Seen Before," Zurbuchen said.
With a further announcement that Webb's costs are rising, some fear that the mission's budget will weaken NASA's ability for future, cutting-edge science missions. Zurbuchen said that missions such as JWST have a high priority and set limits in technology and scientific productivity that will allow future investigations.
"One conclusion one could make is that complex missions should not be done," said Zurbuchen Tuesday afternoon at the National Academies of Sciences. "I'll tell you that this would be a very serious and wrong assumption, and we should clear the envelope at NASA and with our international partners."
"What we should do is make no stupid mistakes," said he. "We should learn as fast as we can what we can."
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