Question: The Space Shuttles have tiles that can resist the terrific heat that is generated during re-entry through the earth’s atmosphere, but what CAN’T they stand up to? (More than one may apply.)
- cold: They contract and de-bond at temperatures below -15 degrees C.
- impact: They are very sensitive to touch and can actually crumble if subjected to any frictional forces.
- rain: Unlike the Wicked Witch of the West, while they wouldn’t shrivel up if someone tossed a bucket of water on them, the impact of rain drops in transit atop the Shuttle Carrier Aircraft traveling at between 300 and 400 knots would also cause structural damage to the tiles.
- night: Darkness damages the tiles.
Answer: B, and C. NASA uses two specially modified Boeing 747s to ferry Space Shuttle orbiters back to the Kennedy Space Center from remote landing sites. These two billion dollar aircraft can withstand the searing heat of re-entry over and over again, but their tiles are sensitive to touch and debris–and that includes being pelted by rain drops. Once mated to the carrier aircraft, they more than double the normal 300,000+ pound gross weight of the 747, double the fuel burn, and cut its speed by a third. And instead of a 5000 nmi range, they typically fly 1000 nmi legs. They can’t fly through rain, or even thick clouds, and incidentally, they also don’t fly at night, presumably to avoid inadvertent flight into a cloud. (Darkness itself of course has no effect.)
Subject: High Lows and Low Highs
Question: Which unexpected coincidental relationship exists between Alaska and Hawaii regarding extremes of weather?
- The highest temperature ever recorded in Alaska is not less than the highest temperature ever recorded in Hawaii.
- The lowest temperature ever recorded in Hawaii is greater than the highest temperature on record for Alaska.
- The highest wind speeds ever recorded in both states are identical.
- Both states hold records for the highest barometer reading in the 20th century, and the barometric pressures were equal.
Answer: A. Alaska’s record high temperature was 100 degrees in Fort Yukon, on June 27 1915. (Its record low of -80F on January 23, 1971, is equally amazing.) Strangely enough, the record high temperature for Hawaii is also 100F (at Pahala, on April 27, 1931). And Hawaii’s lowest temperature was atop Mauna Kea (elevation 13,770 feet) on May 17, 1979, in case you’re wondering.
Subject: ‘When You’re A Jet…’
Question: What is the minimum altitude for the jet stream?
- 30,000 feet
- by definition, 18,000 feet
- 3000 feet
- the earth’s surface
Answer: D: The jet stream usually exists at altitudes between 30 to 40 thousand feet, but it can also reach as low as three to five thousand feet. (The official cut off’ point at which such a river of upper level wind can be called a jet is if it is greater than 57 mph.) Jet streams approaching and even exceeding 250 mph are possible. The altitude of the jet stream depends on the vertical and horizontal temperature distribution in the atmosphere. During the winter when the temperature disparity between the equator and the poles is at its greatest, the jet stream generally reaches its maximum velocity. Low level jet streams are believed to be responsible for frequent high winds atop Mount Washington in New Hampshire, a site known for the ‘world’s worst weather’. (It also lies in the path of the principal storm tracks and air mass routes affecting the northeast United States.) The average winter wind speed at its summit is about 40 knots, and on April 12, 1934, a wind of 231 mph was recorded there. All that said however, even lower streams have occurred; in these cases they are referred to as ground level jets.