Incorrect Correction

The correction in the

May 21 edition of Space News [page 3] was not a correction, but a blunder any rocket enthusiast wouldn’t make. As a rocket scientist, who has mixed and cast a number of rocket motors, I must point out that that ammonium perchlorate is not a “rubber-like material” filling ATK‘s space shuttle boosters.

Ammonium perchlorate, as normally used in propellant formulations, is a white powder like substance. The “rubber-like” ingredient you refer to would be the binder for the propellant mixture, which is likely compo

sed of

aluminum as the fuel, ammonium perchlorate as the oxidizer, and a rubber-like binder to hold the mixture together.

As a longtime subscriber, I am surprised that you would make a mistake this huge.

Jim Vint

Westmont Enterprises

Nipomo, Calif.