28. March 2018
The eagerly awaited launch of NASA's James Webb Space Telescope ( JWST ) [Mai1965] was delayed because of the need for extensive testing and integration of its parts, which the agency claims to have expected for longer than expected, will take longer.
This is not the first launch postponement of the Observatory, which is planned to succeed the Hubble Space Telescope. JWST has faced cost overruns and delays for years.
In 2002, NASA, in partnership with the European Space Agency and Canadian Space Agency signed a $ 824.8 million contract with the Air and Space Company TRW ] for the construction of an infrared space telescope scheduled to launch in 2010. TRW was later acquired by Northrop Grumman .
By 2005, the estimated cost of the project had risen to about $ 4.5 billion. Its technology passed the Mission Critical Design Review in 2010, and is now scheduled to run for some time between 2015 and 2018.
Citing poor management and JWST Billions of dollars over budget, the House of Representatives' House of Representatives The Committee on Commerce, Justice and Science in 2011 threatened to annul the project, but changed its position on the condition that the costs be limited to 8 billion dollars.
Last year, 2018, Problems with the mounting of the telescope delayed launch from 2018 to 2019.
NASA Deputy Administrator Robert Lightfoot, Associate Administrator of NASA Science Mission Directorate Thomas Zurbuchen and Deputy Assistant Administrative Director Dennis Andrucyk announced the latest delay at a press conference on Tuesday, March 27, 2018.
"According to data from an independent review, NASA has determined that the landmark Webb launch date is from its Time to postpone baseline by more than six months, and development costs could exceed the $ 8 billion development threshold, "said Lightfoot. "If we exceed the $ 8 billion in costs set by Congress, the project must be re-approved by Congress."
The JWST Standing Review Board has recently determined that the hardware of both the telescope and the spacecraft meets the project requirements, requiring more time to successfully integrate their components. A separate Independent Review Board established by NASA will review the technical and administrative issues of the project and provide Congress with a report on its results and recommendations this summer.
The spacecraft includes a sunshade that [19459008schützt] JWST 's scientific instruments and a spacecraft bus that will carry its flight avionics, solar panels and power system.
Within the next year, the spacecraft will be combined with the 21.3-foot (6.5-meter) telescope and science payload, both last year at the Johnson Space Center of NASA in Houston , Texas were successfully tested.
At the launch, the sun-shield in origami style is folded into the disguise of a Ariane 5 rocket that will carry the observatory into space.
The sunscreen test started longer than initially expected. While the mission scientists planned to test them for two weeks, they folded and stowed for a month, the actual development took a month, and the folding and stowing took two months.
Because the cables that hold the sunscreen also developed the membrane of the shield seven small cracks during the test phase, two of them were four inches wide.
JWST will be placed in the Earth-Sun Lagrange point a million miles from Earth, meaning that there will be no way to repair any part of it should a problem develop after launch. Any cracks in the sunshade would render the telescope unusable, as its instruments must be kept cold to protect them from the heat, light, and infrared rays of the sun, the earth, and the moon.
Also on Schedule JWST Propulsion System
"An incorrect solvent was passed through the propulsion system, as a result we had to replace the valves in this system and a catalyst bed heater was inadvertently overstressed and had to be replaced", Andrucyk said at the press conference. "These [issues] are avoidable mistakes, but things like that happen in the development of very complex systems."
Spacecraft environmental testing, which will expose it to the conditions it will experience during takeoff and orbit, will be completed over the next few months. This is followed by the integration of the entire Observatory and tests to ensure that all components work together properly.
The primary mirror of the infrared telescope consists of 18 hexagonal segments and was assembled between November 2015 and February 2016. It will have the sevenfold light-gathering force of Hubble .
After the launch, JWST will observe the earliest stars and galaxies of the universe in infrared light. The scientists also intend to investigate the atmospheres of exoplanets while traveling in front of their parent stars. It is expected that the telescope will be operated for a period of five to ten years.
"Webb is the highest priority for the Science Mission Directorate agency and the largest international space exploration project in US history," Lightfoot said. "The observatory's hardware is now complete, but the problems encountered with the spacecraft element prompt us to take the necessary steps to focus our efforts on completing this ambitious and complex observatory."
Investment by NASA and our international partners will systematically go through these latest tests, with the extra time needed to get ready for launch in May 2020, "said Zurbuchen.
Video courtesy of Northrop Grumman
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who loves to write about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University and earned a Graduate Certificate of Science from Swinburne University's Astronomy Online Program. Her writings have been published online in the Atlantic, Astronomy Magazine Guest Blog section, the UK Space Conference, the IAU's 2009 Annual General Meeting, The Space Reporter, and newsletters from various astronomy clubs. She is a member of Cranford, NJ-based Amateur Astronomers, Inc. Laurel, who is particularly interested in the outer solar system, gave a brief presentation at the Great Planet Debate 2008 at the Applied Physics Lab of Johns Hopkins University in Laurel, MD. 19659060]