I think Goldin actually pushed it up to 8 m at one point but it was later descoped to 6.5 m. Incidentally, Lockheed proposed doing a 6 m monolithic telescope by enlarging the Atlas fairing to 7 m but they lost out to TRW (now NG) who proposed a folding design. In hindsight, that probably would have been a better alternative.

My understanding is that the Webb started getting tangled — geddit? — when Dan Goldin was the boss. Yes, the Webb gies back a ways.

The Euro. Space Agency agreed to launch the thing on Ariane V, which can accommodate a four meter diameter shroud. The original JWST design called for a four m. nominal diameter main telescope mirror.

Goldin allowed the mirror size to be increased to 6.5 m, which motivated the fancy folder design. Why the French haven’t tried during the past fifteen or so years to enlarge Ariane to handle a larger diameter shroud, I can’t say.

The question is, is a 6.5 m. main mirror really necessary? Yes, I agree that bigger telescopes are better as a general principle. But would infrared astronomy keel over and die if the Webb main mirror were, say, 5 m. in diameter? ( 5 m. — OK for Delta IV or Shuttle or upsized Ariane. )

If past experience is any guide, you’ll continue to make meaningless references to “neocons” without explaining what “neocons” are, or what they have to do with space policy.

That’s a splendid idea. Double up and double down on the “fancy folder” WEbb Telescope design. Just great.

Why not re-start manufacture of Space Shuttles? Following your logic, Shuttle costs will be cheaper with each iteration, correct?

Hey, we could save money by re-starting Saturn V production. Wait, NASA’s already trying to do that. Except they’ve changed the name.

Or they’ll label JWST as pork for Mikulsky.

In the meantime, Ed Weiler will go off somewhere and work as a mouthpiece, as did Griffin.

And of course, the neocons will blame Obama.

It’s time to start talking up a service mission to L2. … Astronauts Curly, Larry and Moe equipped with pry bars and hammers.

Testing is the right way to retire risk in a complex system but it still does not excuse the cost over runs. We knew this was a complex system from the beginning and the testing should have been included in the original estimates. We just didn’t discover that JWST was complex ten years into the project. If the full costs had been fully described upfront, a lower risk alternative may have been selected instead.

Testing also only gets you so far. Aside from the Rumsfeldian unknown unknowns, launch vehicles fail and so do satellite buses that have been built in significant numbers. That is the nature of the business and nothing we can do will change it in the foreseeable future. Replacing a JWST failure would take the better part of a decade and cost several billion dollars. It would likely suck the life out of our space sciences community for an entire generation. Putting that many eggs in an uncertain basket is unwise.

Gary Anderson
New England Reg Coordinator
TPIS