xkcd’s Randall Munroe on How to Mail a Package (From Space)

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Light-weight objects that have extra drag begin slowing down at a better altitude, the place the air density is decrease. For the reason that air is so skinny, it doesn’t warmth the article as effectively, and though the reentry takes longer, peak temperatures might be a lot decrease. The truth is, calculations by Justin Atchison and Mason Peck have proven that an object formed like a sheet of paper, curved to fall flat facet first, may in concept enter the ambiance “softly” with out ever reaching particularly excessive temperatures.

When you print your message on a sheet of baking parchment paper, aluminum foil, or another skinny and light-weight materials that may survive being warmed up, you may simply have the ability to toss it out the door as is. So long as it’s formed proper, it may make it to the bottom intact. The truth is, a workforce of Japanese researchers deliberate to do this by launching paper airplanes from the ISS. They designed the planes to outlive the warmth and stress of reentry, however, sadly, the venture by no means went by.

A package deal tossed by hand from the ISS will descend step by step over the course of many orbits, with little management over the eventual touchdown level. Controlling the place the package deal will land is far tougher than merely delivering it to Earth.

Returning spacecraft usually attempt to management the place they land. Some do that with extra precision than others. SpaceX’s spent rocket boosters can information themselves exactly sufficient to land instantly on a goal on the deck of a ship, whereas the older Apollo and Soyuz spacecraft have usually missed their targets by just a few miles.4 Spacecraft present process uncontrolled reentry—like your package deal—can miss their meant touchdown web site by a whole lot or 1000’s of miles.

You may enhance the precision of your package deal supply by throwing the package deal actually exhausting. A quick throw can get the package deal down into the ambiance extra instantly, with out a lengthy delay as atmospheric drag causes its orbit to slowly decay in a hard-to-predict approach. Surprisingly, the way in which to do that isn’t to throw the package deal downward, towards Earth. As an alternative, it is best to throw it backward. When you throw it downward, it should nonetheless have sufficient ahead pace to remain in orbit—it should simply be a barely totally different orbit. You need it to lose pace as a substitute.

The sooner you throw the package deal, the extra exact its touchdown. The ISS is touring at nearly 8 kilometers per second, however fortunately, you don’t have to throw your package deal that quick. Shaving off simply 100 meters per second from the orbital pace on the ISS’s altitude is sufficient to ship your package deal to the ambiance. Sadly, throwing one thing at 100 m/s is troublesome. Even the quickest pitchers don’t break 50 m/s. Golf balls, then again, journey quick sufficient. A golfer floating subsequent to the ISS may conceivably hit a golf ball out of orbit in a single stroke. In case your package deal is the scale of a golf ball, you’ll be able to attempt that supply methodology.

When you launch the package deal at 100 m/s, it should enter the ambiance touring at a downward angle of about 1°, which will provide you with a particles footprint—the realm the place your package deal may land—over 2,000 miles lengthy. When you’re aiming for St. Louis, it may land anyplace between Montana and South Carolina. When you can throw it tougher—250 or 300 m/s—you’ll be able to enter the ambiance at a proportionally steeper angle and reduce the particles footprint down to some hundred miles. Nonetheless, regardless of how briskly and exact your throw, the randomness of turbulence and wind will maintain you from hitting a goal with a precision of higher than just a few miles.

MIR

In March of 2001, the area station Mir was about to reenter the ambiance. Most of it was anticipated to fritter away, however among the bigger modules had an opportunity of constructing it to the floor. The Russian Mission Management planners tried to time its reentry so it might come down over an uninhabited area of the Pacific, however nobody knew precisely the place it might land.

Capitalizing on this, Taco Bell got here up with a singular promotion: they floated a large sheet on the Pacific with a bull’s-eye painted on it, and supplied a free taco to everybody in America if any piece of Mir hit the goal.

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