"Fire in the spacecraft!" is a distress call the National Aeronautics and Space Administration hopes never to hear again. In the aftermath of last January's Apollo fire, NASA is spending more than $100 million to that end. By the time Astronauts Wally Schirra, Bonn Eisele and Walter Cunningham lift off a launch pad for the first manned Apollo flight next year, their spacecraft should be virtually fireproof.
Engineers and technicians began working on fireproofing soon after the tragedy. Since then, just about every conceivable combustible has been removed from the moon-bound spacecraft. Flammable components that could not be replaced have been isolated by fire-confining barriers. "It's been an extremely difficult job," says George Low, 41, who was appointed Apollo program manager in April. "But we'll have a spacecraft in which we probably won't be able to even start a fire when we try to this winter."
Critical Changes. Strapped into the conical command module, trapped by hatches impossible to open, Virgil Grissom, Edward White and Roger Chaffee scarcely had a chance. Now Apollo has only one hatch, and it can be opened with a ratchet from inside in about five seconds. The mechanism of the new, 70-lb. hatch, which Low says can be opened "with your little finger," is assisted by a cylinder of compressed nitrogen gas. Better for escape during ground tests, the quick-opening hatch also provides easier exit and re-entry during operations outside the spacecraft in flight. Moreover, it assures astronauts of a simpler solution to docking or passageway problems when they return to the command module in the spacecraft designed to carry them to and from the lunar surface.
While the hatch problem was being solved, NASA and North American Aviation engineers went to work on combustible materials that had cluttered Apollo's spacecraft before the January fire. Aluminum plumbing which melted at 1080° F. has been replaced by stainless steel. Brazed joints that withstand temperatures approaching 1,600° F. have been substituted for soldered joints that melt at 360° F. Coolant pipelines, which service electronic components and can release flammable glycol when ruptured, have been "armor-plated" at joints with high-strength epoxy. Should the joints come open, the epoxy serves as a back-up seal. Along Apollo's 15 miles of electrical wiring, circuit-breaker panels have been fireproofed with twelve coats of Ladicote paint, newly developed by North American. Bundles of wire, previously exposed to dangerous scuffing and wear during assembly, maintenance, tests and flight, are now encased in protective metal panels that double as fire walls. In addition, such flammables as nylon nets and plastic containers have been replaced by nonflammable or fire-resistant materials like Teflon.