America’s next big space telescope has been delayed at least a year to May 2020, NASA said on Tuesday, throwing the nation’s plan and budget for space astrophysics into potential turmoil.

It now seems likely the cost of the James Webb Space Telescope, the agency’s long-planned successor to the Hubble Space Telescope, will exceed an $8 billion limit that was imposed by Congress, meaning that the project will have to be reauthorized and other NASA missions could be jeopardized.

NASA is beefing up management overview of the program and has appointed an independent review board, chaired by Thomas Young, a former agency manager and a retired aerospace executive. The board is expected to report later this summer what exactly needs to be done and how much it will cost.