| What happened to gravity? Doesn't it operate in | | | | tile volume, with a covering of thin glass. The |
| space? | | | | fabrication process - double vacuum, pressurized, is |
| The answer to the above questions is the same as | | | | extremely complex. Tile surfaces are relatively easily |
| for, "Why doesn't the moon fall onto Earth", or ".. the | | | | damaged, the inside appearance likened to white |
| Earth into the Sun". Gravity - the attractive force | | | | styrofoam - however, when the outside temperature |
| between two masses (or bodies - the product of | | | | is 3000 degrees F, the backside (attached to the |
| their masses divided by the square of the distance | | | | aluminum structure of the Orbiter by ordinary RTV |
| between the two centers) - does act continually and | | | | Room Temperature Vulcanizer) - is only 80 degrees |
| everywhere; the answer, therefore, is that the | | | | F. |
| Shuttle, Space Station and Moon are each traveling at | | | | - The highest reentry temperatures are on the |
| high speeds and (corresponding) heights, circling Earth, | | | | bottom of wing and body, and at the trailing edges |
| as does the Earth in its orbit around the Sun - and | | | | of the control surfaces; there are 30,000 black tiles; |
| that all are always "falling around" the curvature, e.g. | | | | NASA has reported the cost at $2500 each. |
| of the Earth. Although the flight path of the orbiting | | | | However, because of the tremendous insulating |
| vehicle (or moon, or planet) attempts to be a | | | | capability of the tiles, a greatly simplified and reliable |
| "straight" line - it is continually being pulled down by | | | | Space Shuttle concept has been achievable: |
| gravity - so that as "satellites" they continually travel | | | | - The Orbiter vehicle itself was essentially designed |
| in stable orbits, circular or elliptical. The same is true | | | | and constructed much as a conventional aircraft - its |
| throughout the universe, and while attractive forces | | | | only flight function, landing after reentry, uses |
| exist between all bodies in the Universe, each to | | | | conventional flight controls, tires and brakes (the |
| each other, the factor of distance-squared in the | | | | landing speed is similar to a commercial jet aircraft, |
| denominator effectively eliminates the significance of | | | | about 160 mph). |
| all other bodies in comparison to the two involved in | | | | - There is no propulsive capability for orbiting or |
| satellite orbiting. | | | | landing, the speed and momentum of the vehicle |
| To put a numerical perspective upon what has | | | | after reentry, permitting the astronaut-pilot to |
| become a casual acceptance of space activities, to | | | | maneuver the craft into the pre-selected NASA |
| achieve a stable orbit, the Shuttle Orbiter vehicle - | | | | airport and runway for landing. |
| which does not have propulsive power while orbiting - | | | | - The most powerful and efficient rocketry |
| must rise to a sufficient height above the Earth's air | | | | arrangement is therefore designed for the lift-off |
| layer, where the vacuum of space produces no | | | | sequence: two solid rockets (approximately twelve |
| "drag" resistance (generally about 125 miles altitude) - | | | | feet in diameter), plus the three Orbiter engines |
| to achieve this, the lift-off propulsion system must | | | | (fueled by the large center fuel-oxidizer tank); all five |
| propel the orbiting vehicle to approximately 18,000 | | | | are fired simultaneously for maximum thrust at lift-off |
| miles per hour (note: traveling in the easterly direction | | | | (approximately seven million pounds thrust required) - |
| gains the Earth-surface rotational speed of about | | | | along with the giant ground-retention explosive bolts |
| 1000 mph). | | | | at the base of the solid rockets (only attachment of |
| At the completion of the mission, to return to Earth, | | | | the entire assemblage to the launch platform). |
| the Orbiter is slowed slightly - dropping closer to | | | | - After twelve minutes of flight, the exhausted solid |
| Earth - smashing into individual air molecules, which | | | | rockets are depleted and dropped (parachuted and |
| are "vaporized" by the impact - a tiny pulse of both | | | | recovered in the ocean); the three on-board engines |
| "drag" (causing further slowing and lowering of the | | | | continue until the center tank is empty, when it is |
| Shuttle) and also of "heat". As the Shuttle is slowed | | | | separated; afterwards, the Orbiter, traveling at |
| and lowered for the reentry mode, the heat build-up | | | | orbiting altitude and speed, has no more propulsive |
| develops tremendous temperatures of up to 3000 | | | | capability. |
| degrees Fahrenheit - requiring the insulating "tiles", | | | | A human-interest worry about mankind's 21st century |
| which cover the lower wing and body surfaces. | | | | "Space adventures" is space debris - the remains of |
| The concept of the Space Shuttle is remarkably and | | | | space-hardware rocketry that have not, as yet, |
| functionally (and beautifully) simple and reliable - as a | | | | returned to Earth. Varying in size from complete |
| result of reliance upon this function of insulation - in | | | | rocket stages to tiny particles, they are true hazards |
| an absolutely hostile, unforgiving space environment | | | | because of their thousands of mph travel speeds. |
| of cryogenic iciness plus vacuum. The rentry insulation | | | | The larger ones are monitored - just recently, March |
| tiles, invented and developed by NASA and Lockheed | | | | 5, 2009, warnings about a possible strike of the |
| Aircraft, shield the Orbiter Spacecraft (fabricated of | | | | International Space Station forced the US astronauts |
| conventional light, aluminum-alloy thin skin-stringer | | | | to take shelter in the parked Russian Soyuz capsule. |
| construction, similar to most sub-sonic aircraft of that | | | | Two months ago, two satellites collided in orbit, |
| era) from re-entry heat - temperatures which would | | | | adding several hundred new pieces of "junk" to the |
| melt the strongest alloy steel. | | | | space debris litter-belt circling Earth. The NASA Orbital |
| - The tiles are individually designed for the anticipated | | | | Debris Program Office is at Johnson Space Center, |
| reentry temperatures, 6x6 inches in size and average | | | | reporting that about 13,000 such threats are |
| about 1 inch in depth; | | | | constantly tracked, of about 600,000 total debris |
| - Inside, they are comprised of extremely long, fine | | | | items. |
| filaments of quartz, compressed into the vacuumized | | | | |