Balancing astronomical visions with budgetary realities

The James Webb Space Telescope with its sunshield deployed during a test last fall at a Northrop Grumman facility in California. (credit: NASA/Chris Gunn)



In an alternate timeline, last week’s meeting of the American Astronomical Society (AAS) would have been filled with presentations involving data from the James Webb Space Telescope. In that timeline, JWST would have launched in October 2018 and completed its six-month commissioning phase in the spring of 2019—time for astronomers to start using the telescope and presenting the results, from observations of the solar system to distant galaxies, at one of the biggest astronomy conferences of the year.

Instead, in this reality JWST remains in a clean room at a Northrop Grumman facility in Southern California, still undergoing tests ahead of a launch now scheduled for late March 2021. Astronomers settled for sessions about how to prepare proposals for using JWST, with the first call for such proposals, known as Cycle 1, set to open later this month (or technically, reopen: the Cycle 1 call was opened in early 2018 but cancelled when it became clear that the telescope’s launch would be significantly delayed.)

At a JWST town hall at the conference, program officials emphasized that work on the telescope was now going well after a series of programs delayed its launch by two and a half years. “Although the schedule margin looks a little tight up there,” said NASA JWST program scientist Eric Smith, referring to a schedule chart for the mission, “we do remain within our budget and we are planning to the March 2021 launch readiness date.”

The amount of margin in JWST’s schedule has been a topic of interest, and concern, for months. Last spring, Tom Young, the retired aerospace executive who chaired the independent review board that studied JWST, warned that schedule reserves appeared to be consumed at a higher-than-expected rate, suggesting that they would be used up and force a delay in the launch to compensate. Project officials said last fall that they were down to two months of schedule reserves, the same figure Smith quoted at the town hall meeting.

However, project leaders at both NASA and Northrop Grumman, the JWST prime contractor, said in interviews during the AAS conference that they were optimistic that, despite that limited schedule reserve, the mission could remain on track for launch next March, based on the progress the project has made and the work ahead of it.

One reason for that optimism is that the consumption of schedule reserve has dropped significantly since Young sounded his warning last spring. “In the second half of 2019, schedule erosion has diminished significantly, and that’s what gives us a lot of confidence to still press to that March 2021 launch date,” said Greg Robinson, the JWST program director at NASA Headquarters.

“2019 was as successful of a year on this program as you probably could have imagined in the history of it,” claimed Scott Willoughby, vice president and program manager for JWST at Northrop Grumman. “I think that’s a great foretelling of 2020.”

Another reason for the optimism is the work remaining. Last fall workers connected the two units of JWST, the optics and instruments section with the spacecraft bus and sunshield, for the first time. That was followed by a deployment test of the sunshield, which technicians are now working to stow. They will also replace two electronics units on the spacecraft that failed last year.

After that, the complete spacecraft will go through a series of vibration and acoustics tests to simulate the launch environment it will experience on an Ariane 5. That will be followed by one more deployment test of the sunshield and final configuration of the spacecraft before it is stowed and the spacecraft packaged for shipment to Kourou, French Guiana.

Very little of that work, Willoughby said, is “first time” tasks. The sunshield had been deployed and stowed before (and, the first time they did it, the project underestimated how long it would take), and the two sections of JWST have previously undergone separate environmental testing. Moreover, both Willoughby and Robinson noted, the upcoming environmental tests will be at lower “acceptance” testing levels, and not the more rigorous “protoflight” tests the units previously undertook.

“All of the work that’s planned in front of us is very well understood,” Willoughby said. “If everything goes as planned, the schedule is very much sufficient to get us there.”

Robinson noted that the schedule remains a major concern for the mission, despite that optimism. The schedule will be reviewed in May prior to the start of environmental testing. Around that time NASA will also give formal notification to ESA of its plans so that ESA can start Ariane 5 launch preparations roughly, but not exactly, 12 months ahead of the launch.

“Hopefully by the end of the year we’ll take this baby over to Long Beach and put it on a boat and send it to Kourou,” Robinson said of JWST.

As JWST edges closer to launch, work is picking up on NASA’s next flagship astronomy mission, the Wide-Field Infrared Survey Telescope (WFIRST). The mission completed its preliminary design reviews last November and will early this year complete a confirmation review, which will set a formal cost and schedule estimate.

For the last two years, the administration’s budget request has proposed terminating WFIRST, in part to compensate for the cost and schedule overruns of JWST. Congress has rejected those proposals, including in the fiscal year 2020 appropriations bill enacted last month, which provided $510.7 million for WFIRST. While NASA officials said last year they needed $542 million in 2020 to keep the mission on schedule, Paul Hertz, director of NASA’s astrophysics program, said at the AAS meeting that the $510.7 million meant the mission was “fully funded” and would remain on schedule.

While that upcoming confirmation review will set formal cost and schedule targets for WFIRST, the project has been working towards a launch in the mid-2020s and a cost cap of $3.2 billion, a figure that has forced changes in the mission’s design, such as converting one of its instruments, a coronagraph, from a full-fledged science instrument to a technology demonstration.

However, WFIRST has avoided—for now, at least—the overruns that JWST has suffered over the years. “NASA had learned lessons from building Webb and the previous flagships,” Hertz said at one town hall session during the AAS meeting. “We’re demonstrating with WFIRST that we know how to build a flagship, that we know how to keep it within its cost box.”

That’s important not just for WFIRST but also for future programs. A committee of the National Academies is currently working on the next astrophysics decadal survey, known as Astro2020, that will conclude in about a year with recommendations on what missions to pursue in the next decade. That includes likely selecting one of four proposed flagship mission concepts—HabEx, LUVOIR, Lynx or Origins Space Telescope—as the flagship mission NASA should start development of later in the 2020s (see “Selecting the next great space observatory”, The Space Review, January 21, 2019).

The ability to complete WFIRST on cost and schedule, after the travails of JWST, would give NASA—and the administration and Congress—confidence that the flagship mission recommended by Astro2020 could be done on budget and schedule. Hertz, in presentations at the AAS meeting as well as other events last year, called on the decadal survey to be ambitious in its planning, arguing that, based on past budget trends and future projections, there would be at least $5 billion available for a flagship-class mission over the next decade.

At a session of the AAS conference about the Astro2020 decadal, the study’s two co-chairs didn’t go into details about their deliberations, but made it clear they got the message from Hertz. “They’re encouraging us, despite the multitude of uncertainties that are always on the horizon, to really be bold,” said Rob Kennicutt, one of the co-chairs. He added, though, that budget profiles provided by agencies is “the governor that prevents us from being too expansive” and that any set of recommendations that emerge from Astro2020 will also include “decision rules” that offer guidance if funding doesn’t meet those profiles.

“I have nothing to add,” the other Astro2020 co-chair, Fiona Harrison, said, “other than to applaud the agencies for making our job more fun by saying, ‘be visionary.’”


Note: we are temporarily moderating all comments submitted to deal with a surge in spam.


Source