James Webb launch slips another year to 2021 after Independent Review Board report

by Chris Gebhardt

Following an Independent Review Board report on the James Webb Space Telescope project, NASA has announced a further delay to the telescope’s anticipated launch.  Coming just three months after a year-long delay to 2020, NASA now says the telescope will not be ready to launch until 2021 at the earliest and that the project will breach its $8.8 billion USD cost cap.

James Webb goals and mission:

While the delays currently form the conversation surrounding the James Webb Space Telescope (JWST), it is important to remember the benefits to science and astronomy the telescope will offer.  At 100 times the power of the Hubble Space Telescope, JWST will provide unprecedented resolution and sensitivity of the farthest and oldest objects of the universe and will enable a broad range of investigations across the fields of astronomy and cosmology.

One of the telescope’s major goals is observing some of the most distant events and objects in the universe, like the formation of the first galaxies – targets that are beyond the reach of current ground- and space-based observatories.  Other goals include understanding the formation of stars and planets as well as direct imaging of exoplanets and novas.

Unlike Hubble, which observes in the near ultraviolet, visible, and near infrared spectra, JWST will observe the long-wavelength (orange to red) spectrum in the mid-infrared (0.6 to 27 μm) range – allowing JWST to see high redshift objects too old and distant for Hubble and other telescopes to observe.  Observations conducted via mid-infrared better penetrate dust and gas and will allow JWST to see dimmer, cooler objects than Hubble and the Spitzer Space Telescope can.

NASA’s James Webb Space Telescope, set for launch NET 2021

JWST is also far better suited to observe the cosmological redshift.  The more distant an object is from Earth, the younger it appears because its light takes a very long time to reach our observatories.  This, coupled with the fact that the universe is expanding, means that light from the earliest stars and galaxies becomes red-shifted as it travels toward Earth.

Because of this, these early-universe objects are easier to observe if viewed in the mid-infrared – as JWST will do.  In fact, JWST’s infrared capabilities are expected to allow scientists and observers to see back in time to the formation of the first galaxies just a few hundred million years after the Big Bang.

JWST is planned for launch on a Arianespace Ariane 5 rocket from the Guiana Space Centre in Kourou, French Guiana in South America.

New delay:

Providing an update on the results of the Independent Review Board (IRB) and ongoing schedule for the James Webb Space Telescope – the agency’s much heralded follow-on observatory of the Hubble Space Telescope – NASA today confirmed that:

  1. The telescope’s launch is slipping at least another year to NET 2021
  2. The project will breach its $8.8 billion cost cap and require additional funds to be authorized by Congress.


Above all, though, the IRB stressed the need to continue and see JWST through to launch and operation.  “Webb should continue based on its extraordinary scientific potential and critical role in maintaining U.S. leadership in astronomy and astrophysics,” said Tom Young, the chair of the review board.  “Ensuring every element of Webb functions properly before it gets to space is critical to its success.”

The board also reaffirmed Webb’s significant complexity, incredible scientific potential, and importance to astrophysics.  The report includes several recommendations for moving forward, some of which NASA has already initiated. The agency agrees with the review board’s expert guidance on decisive steps necessary to safeguard and complete the telescope’s development.

“The more we learn more about our universe, the more we realize that Webb is critical to answering questions we didn’t even know how to ask when the spacecraft was first designed,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate.  “Webb is poised to answer those questions, and is worth the wait. The valuable recommendations of the IRB support our efforts towards mission success; we expect spectacular scientific advances from NASA’s highest science priority.”

However, because the project will breach its cost cap, the U.S. Congress will have to authorize additional funds to complete the telescope – something Congress will likely have no appetite to do until at least December of this year or more likely January of 2019 when the new Congress is sworn in following the Congressional campaigns and mid-term elections in November.

Protected from the Sun’s rays by its multi-layer sunshield, the James Webb Space telescope opens its mirrors to observe the universe. (Credit: Nathan Koga for L2/NSF)

And even though discussions are likely in Congress, the possibility exists that the already high-cost (as viewed by Congress) project could result in Congress refusing to authorize more money.  If that happens, NASA would have to find the additional money in its already-allocated budget – meaning that other programs would have to be significantly scaled back or canceled outright so money could be shifted internally to complete and launch James Webb.

The program cost-cap is currently set at $8.8 billion USD.  The IRB report notes that the new projects cost total for lifecycle cost to support the revised launch date is estimated at $9.66 billion USD.

History of integration issues:

The delays and issues faced during Webb’s integration are not necessarily unexpected for a project of its magnitude, but they are certainly more worrisome for NASA, ESA (European Space Agency), and CSA (Canadian Space Agency) as JWST, once launched, is not serviceable like Hubble – meaning any issues missed pre-launch cannot be fixed by a human or robotic servicing mission.

Moreover, these are not the first issues to face the James Webb Space Telescope project in the last nine months.  Following NASA’s announcement in September that the telescopes launch was slipping from October 2018 to NET (No Earlier Than) March-June 2019, the Government Accountability Office (GAO) warned in February 2018 of dangers of additional slips beyond the realigned date due to ongoing issues with integration and testing operations and prime contractor [Northrop Grumman] optimism.

Northrop Grumman performs folding test on James Webb Space Telescope’s sunshield. (Credit: Northrop Grumman)

The report was particularly scathing toward Northrop Grumman, highlighting the company’s work on JWST as the project’s critical path toward being able to launch at the end of the window in June 2019 as well as Northrop’s continued “optimism” for schedules and underestimation of time needed to complete work.

Moreover, the GAO identified five specific areas that posed threats to the March-June 2019 launch schedule, including:

  • “resolving lingering technical issues from the OTIS (Optical Telescope & Integrated Science Instrument Module) cryovacuum test and preparing and shipping of OTIS to the Northrop Grumman facility in California for integration with the spacecraft,
  • Completing integration of spacecraft hardware, and conducting spacecraft element environmental tests and remaining deployments of the spacecraft and sunshield – activities which, to date, have taken considerably longer than planned,
  • Integrating the completed OTIS element with the spacecraft element and testing the full observatory in the fifth and final integration phase, which includes another set of challenging environmental tests,
  • Mitigating approximately 47 remaining tracked hardware and software risks to acceptable levels and continuing to address the project’s 300+ potential single point failures to the extent possible, and
  • Preparing and shipping the observatory to the launch site and completing final launch site processing, including installation of critical release mechanisms.”

As a result, the GAO warned that JWST was at risk of exceeding its $8 billion formulation and development cost cap prior to launch.


Before the announced slip last year to March-June 2019, JWST had been slated to launch in October 2018 – a date itself that was 11 years after the originally planned launch target of 2007 when the project was first conceived in 1997.

The $8 billion pre-launch spending cap and October 2018 launch date were established during a JWST program replan in September 2011.  This replan followed a 2010 report by NASA in which the agency highlighted how the original budget, schedule, and subsequent budget changes made the JWST project’s original plan and budget untenable.

The 2011 replan was a complete re-baselining of JWST with a new life cycle cost estimate of $8.835 billion (with a total cost not to exceed $8 billion prior to launch), including additional money for operations, a replanned launch in October 2018, and 13 months of funded schedule reserve.

That funded schedule reserve ran out in summer 2017, leading NASA to announce the five to eight month launch slip of James Webb from October 2018 to March-June 2019 – which provided four months of schedule reserve – double what Northrop Grumman said was necessary – into the schedule.

However, according to the February 2018 GAO report, “shortly after requesting the revised launch window from ESA (the European Space Agency), which will contribute the launch vehicle, the project learned from Northrop Grumman that up to another 3 months of schedule reserve use was expected, due to lessons learned from conducting deployment exercises of the spacecraft element and sunshield.”

NASA and Northrop Grumman looked at the remaining schedule for JWST at that point and implemented a few schedule efficiencies to buy back 14 days of reserve, leaving the agency with just 1.5 months of schedule reserve with over a year to go until launch.

However, this 1.5 months of remaining schedule reserve to meet the new launch window was “below the standards established by Goddard Space Flight Center for a project at this stage of development,” noted the GAO report.

Then, just one month after the GAO report was released, NASA announced a year-long slip to James Webb’s launch date — with a new target launch of NET May 2020.  During the teleconference, NASA officials stated the recent findings in March 2018 from James Webb’s Standing Review Board (SRB) indicated that more time was needed to test and integrate the telescope’s components and perform environmental testing at Northrop Grumman.

Specifically, Associate Administrator of the Science Mission Directorate (SMD) Thomas Zurbuchen, and Deputy Associate Administrator of SMD Dennis Andrucyk stated that esting of the telescope’s hardware and spacecraft elements has demonstrated that these systems individually meet their requirements.

An Ariane 5 ECA – the same variant that will launch James Webb – lifts off from its launch pad in Kourou, French Guiana. [Credit: ESA]

However, NASA did not elaborate on what the issues the SRB found were that led to a year long delay to the mission.  Instead, the agency cited sunshield tears and improper propulsion system cleaning by Northrop Grumman as the primary causes leading to the delay and increase in daily oversight for NASA’s Science Mission Directorate over Northrop Grumman.

But both of those issues – sunshield tears and improper thruster cleaning – were known and discussed at length in last month’s Government Accountability Office (GAO) report on James Webb, a report that said even with those known issues there was still 1.5 months of schedule reserve left to meet the March-June 2019 launch window.

Regardless, the year-long delay to May 2020 prompted NASA to establish an external Independent Review Board (IRB) that will be chaired by Thomas Young.  The IRB’s findings, are expected to bolster confidence in NASA’s approach to completing the final integration and test phase of the mission, the launch campaign, commissioning, as well as the entire deployment sequence.

Both boards’ findings and recommendations (due 25 June 2018), as well as the project’s input, will be considered by NASA as it defines a more specific launch date.  During the media teleconference, NASA admitted that there was currently only a 70% confidence level that JWST will be ready in time for its now May 2020 launch target.

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