The Decision to Cancel the Hubble Space Telescope Servicing Mission 4 (SM4) and Its Reversal

Abstract

On January 16, 2004, NASA Administrator Sean O’Keefe announced his decision to cancel the Hubble Space Telescope (HST) Servicing Mission (SM4) by the Space Shuttle. SM4 was to have inserted two new instruments, the Wide Field Camera 3 and the Cosmic Origins Spectrograph, at the same time replacing the batteries and gyroscopes, extending Hubble’s lifetime to 2010. The decision resulted in a strong reaction among some members of Congress, the HST science community, and the general public, because it would likely leave the telescope inoperable by 2007, years before its full lifetime and well before the James Webb Space Telescope (JWST) would be launched. In the immediate aftermath of his decision to cancel the final servicing mission, Administrator O’Keefe requested an independent study be undertaken by the author in his role as NASA Chief Historian, in order to document in detail the events that led to the cancellation decision. What follows is a history of that decision and its aftermath, completed December 17, 2004, as well as an Epilogue added in 2012 describing the reversal of O’Keefe’s decision by NASA Administrator Michael Griffin.