In a speech yesterday, NASA Administrator O’Keefe stood by his much criticized decision to cancel Hubble Servicing Mission 4, saying, “it would not be responsible to prepare for a servicing mission, only to find that the required actions identified by the [Columbia Accident Investigation] Board could not be implemented.”

While news accounts (and his audience) have struck on his partial support for a robotic servicing mission, as O’Keefe announced a forthcoming Request for Proposals following up on a February request, O’Keefe also gave one of his most rigorous defenses yet of his decision to cancel SM4, saying in part,

“A mission to the Hubble would require the development of a unique set of procedures, technologies and tools different from any other mission we’ll fly before the Shuttle fleet retires. Many of these capabilities which provide safety redundancy for ISS missions are primary or singular for a Hubble mission. Moreover, these Hubble unique methods must be developed and tested promptly before Hubble’s batteries and other critical systems give out.

We are making steady progress in our efforts to meet the safety requirements for the Shuttle return to flight next year. But based on where we are today, prospects are even more challenging than six months ago for our being able to develop in time all required safety and return-to-flight elements for a servicing mission before Hubble ceases to be operational.”

The whole of O’Keefe’s speech is here.

In addition to this speech, O’Keefe has made a case for his decision here, here, and here, all based on the CAIB recommendations and his concern for human life. Meanwhile, critics of his decision have continually suggested that Hubble is too important to science to lose, thus setting up an age-old conflict of the relative importance of manned flight and science at NASA. Is this another example of the Excess of Objectivity that Prometheus has commented on elsewhere? Both sides continue to argue over the “facts” of mission risk and ignore the fundamental value conflict between the “Hubble Huggers” and Administrator O’Keefe.