Back in May, Roger noted some similarities between the situations of Hubble and the Tropical Rainfall Measurement Mission (TRMM) in determining how risk, cost, and scientific value balance out. Today, Guy Gugliotta, in the Washington Post reports a NASA decision to perform a controlled de-orbit of TRMM, thus dashing hopes of significantly extending the satellite’s mission. And the similarities are growing as, like Hubble’s case, the scientific community has vociferously attacked the decision.

Among the charges lies a suggestion that the cancellation of Hubble and TRMM serve as cost saving measures to support President Bush’s space initiative to the moon and Mars. That arguement has never rung true to me. To begin, in the TRMM case, Mr. Gugliotta reports:

“[Ghassem] Asrar [NASA's associate administrator for earth science] said it was “absolutely incorrect” that NASA decided to begin the de-orbit now to save money for the Bush initiative, noting that “we started looking at this issue two years ago,” long before the moon-Mars plan arose.”

In the case of Hubble, Administrator O’Keefe has stated several times that he personally made the decision to cancel SM4 on the grounds of risk alone.

And more to the point, a savings of up to $37 million for TRMM doesn’t make much of a dent in the $12 billion over the next five years President Bush has proposed. Hubble does, however, have a larger footprint, with operating costs running at $250 million per year, and the cost of the servicing mission itself running at about $140 million (SM3A). But even this larger amount occurs early in the Initiative before any serious moon or Mars missions begin and at the end of construction of ISS.

This arguement just doesn’t do enough work to wholly explain these cancellations. However, the cost savings critique is just one of manyand both decisions remain open to a number of different and probably more convincing arguements.