NASA's Atlantis Ready For June 8 Launch

lifuchi writes "The guys and girls at NASA are at it again with Atlantis. The newly repaired space shuttle is set launch on June 8. The hail-damaged fuel tank has been repaired and is said to be a bit of an eyesore. Zee News is quoted as saying, 'Instead of being a uniform orange, it has a patchwork of white spots where technicians sprayed, scraped and filled fresh foam into the more than 4200 areas that were damaged during a freak hailstorm in February.'"

Re:So a can of orange paint was out of the budget

[Professor_UNIX]

The external fuel tank isn't painted orange, that's the natural color of the foam. Apparently the replacement foam for patch jobs is just naturally white so they can easily tell where they've added it.

Re:So a can of orange paint was out of the budget

[Anonymous Coward]

From TFA: "The tank`s deep orange colour is caused by ultraviolet light from the Sun striking the foam insulation over time."

Re:So a can of orange paint was out of the budget

[topical_surfactant]

The only shuttle launch that ever had the external fuel tank painted was the first - Columbia (RIP), April 12th 1981, where the tank was painted white to match the rest of the vehicle.

http://apod.nasa.gov/apod/ap010412.html [nasa.gov]

Re:So a can of orange paint was out of the budget

[Ellis D. Tripp]

Actually, the first TWO launches had white painted tanks. Then NASA realized that the paint added a lot of additional weight for zero benefit...

Re:So a can of orange paint was out of the budget

[arielCo]

From TFA:

The tank`s deep orange colour is caused by ultraviolet light from the Sun striking the foam insulation over time. The fresh foam on Atlantis` tank is however, light-coloured, some of it bright white and some off-white, indicating different repair techniques were used in separate areas.

So it's more like new foam on top of old foam. Apparently it happens very quickly, since every tank I've seen after STS-1/2 is orange.

Now for the obligatory Wikipedia [wikipedia.org] quote:

The external tanks of the first two missions were painted white, which added an extra 600 pounds (273 kg) of weight to each ET. Subsequent missions have had unpainted tanks showing the natural orange-brown color of the spray-on foam insulation. The orange-brown color results from ultraviolet light from the sun striking the foam insulation over time.[1] The lighter, unpainted tanks have increased the payload capacity by almost the entire weight savings of 600 pounds.