Another decision involves an instrument called a coronagraph, which would directly image and study the chemical compositions of exoplanets. At first, the WFIRST team planned to treat the coronagraph as a technology demonstration. This meant that it would do enough science to show its usefulness for future generations of space observatories, but not enough to classify as a full-fledged science instrument. Somewhere along the way, the scientists decided to push the boundaries a little bit—imagine the potential findings of such advanced technology!—and added to its capabilities. That move set the mission up for more planning and testing and eventually got too expensive.
And so the WFIRST team has followed the report’s recommendation to reduce the scope of the coronagraph’s capabilities. “When the gun’s at your head, you realize maybe we could do this a simpler way,” said David Spergel, a Princeton University astrophysicist and cochair of the WFRIST science team. “This pressure, while painful, is actually good.”
Removing the coronagraph altogether would chop $400 million from the total mission cost, but NASA headquarters is intent on keeping it. WFIRST’s main science instrument, a wide-field imager that will investigate dark energy, can’t do detailed analysis of the exoplanets it finds. “The nice thing about the coronagraph is it makes the entire package much more palatable to the public and to congresspeople that are interested in exoplanets,” Boss said. “Getting an image of a nearby planet, to many people, is a lot more interesting than seeing some strange number about dark energy.”
Kruk said most of the cost-cutting this month has come from constant reshuffling of the design, development, and testing schedules. The more things they can do at the same time, the less money they spend. The project is also nearing agreements with other nations, like Canada and Japan, to participate and contribute hardware—$50 million here, another $50 million there, Spergel said.
The WFIRST mission has a busy few months ahead. Next week the House Committee on Science, Space, and Technology will hold a hearing on NASA’s next generation of large telescopes, including Webb and WFIRST, and the recent report on the latter will surely come up. In 2011, Congress placed an $8 billion cap on development costs for Webb. The mission has faced frequent delays, and its launch date has slipped steadily, from the proposed 2014 to 2019. Jeremy Kasdin, a Princeton professor who is leading the coronagraph’s development on WFIRST, is wary of the public making comparisons between the financial histories of the telescopes. “It’s important that people understand it’s not a runaway cost problem like the [Webb telescope] was, he said.”
In February, WFIRST scientists will present to headquarters their latest designs and science objectives, and, if approved, will move the project onto the next phase of development. By that time, they need to hit the $3.2 billion target, too. So far, the scientists I spoke with seem confident about cutting enough costs. They just know it’s going to hurt.
“The problem is astronomers always want to make the best possible instrument they can and engineers are happy to oblige them because engineers get their jollies making something work really well in space,” Boss said. “But unfortunately, they also charge you for it.”