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chyna's avatar

Why will the satellite that is re-entering the earth's atmosphere going to burn into pieces, but the manned spaceships didn't?

Asked by chyna (34519 points ) September 23rd, 2011

I’m a big conspiracy theorist when it comes to believing man went to the moon, thus this question. Keep the answers light and fun, no name calling on my thread or I’ll flag you.

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17 Answers

rebbel's avatar

As far as I know it has to do with the angle an object enters the atmosphere with.
A manned spaceship uses an angle, calculated to get the least friction.
The satellite probably has an angle that gives more friction (when entering) thus it will desintegrate (although not totally I have heard…, parts of it apparently will make it through and will fall on Earth).
That is my lay men’s knowledge of it.

And I will do it anyway…., your name is @chyna.
Flag me! ;-)

Seelix's avatar

I don’t know anything about space stuff, but I always thought that satellites were designed to burn up on reentry.

lillycoyote's avatar

Because manned spaceships have human beings in them?

Manned spaceships are designed so that they and the people who are in them will survive reentry. Satellites aren’t. No conspiracy, just common sense.

FutureMemory's avatar

I believe it lies in the hardiness of their construction.

If you drop a safe onto concrete, it will behave quite differently than a box constructed of pure glass would.

JilltheTooth's avatar

The shuttles and capsules also have involved and sophisticated heat shielding, the regular satellites don’t. And if they fall at night they make really cool looking shooting stars which expedites wishing. Which is, I am sure, a major factor in their design.

Adirondackwannabe's avatar

@JilltheTooth Friggin mensa weenies.
It’s the specially designed heat shields made of materials that can take the temps. Satellites aren’t shielded. They’re still figuring a few chunks will make it to the ground, since it’s a big satellite.

robdamel's avatar

@lillycoyote This. Manned spaceships have people in them. They need to survive and therefore the same ships are prepared to handle the heat upon entry. Definitely no conspiracy :)

Cruiser's avatar

It’s a combo of @rebbel‘s and @JilltheTooth‘s answers. The manned craft have thick ceramic heat shield tiles that can withstand the tremendous heat from the friction of re-entering the upper atmosphere. But those tiles are not enough to withstand entering any old place of the atmosphere and as @rebbel pointed out the angle as well of the location is everything as well. Speed of re-entry is also an issue as humans can only endure so much G force and going too fast will also generate higher friction and higher temps which would roast the passengers. Re-entry is a precise and harrowing endeavor. Read about it here

filmfann's avatar

The manned flights had heat shields, which were aimed to take all the heat of reentry.
When Columbia was destroyed, part of the heat shield had unknowingly fallen off (during take-off). That’s why we lost those 7 astronauts.
When John Glenn’s Mercury Capsule returned, it was feared his heat shield had been dislodged, and it was very tense till his flight splashed down.

marinelife's avatar

The capsules were designed for re-entry and the satellites were not.

“The TPS (Thermal Protection System) covers essentially the entire orbiter surface, and consists of seven different materials in varying locations based on amount of required heat protection:

* Reinforced carbon-carbon (RCC), used in the nose cap and wing leading edges. Used where reentry temperature exceeds 1,260 °C (2,300 °F).
* High-temperature reusable surface insulation (HRSI) tiles, used on the orbiter underside. Made of coated LI-900 Silica ceramics. Used where reentry temperature is below 1260 °C.
* Fibrous refractory composite insulation (FRCI) tiles, used to provide improved strength, durability, resistance to coating cracking and weight reduction. Some HRSI tiles were replaced by this type.
* Flexible Insulation Blankets (FIB), a quilted, flexible blanket-like surface insulation. Used where reentry temperature is below 649 °C (1,200 °F).
* Low-temperature Reusable Surface Insulation (LRSI) tiles, formerly used on the upper fuselage, but now mostly replaced by FIB. Used in temperature ranges roughly similar to FIB.
* Toughened unipiece fibrous insulation (TUFI) tiles, a stronger, tougher tile which came into use in 1996. Used in high and low temperature areas.
* Felt reusable surface insulation (FRSI). White Nomex felt blankets on the upper payload bay doors, portions of the midfuselage and aft fuselage sides, portions of the upper wing surface and a portion of the OMS/RCS pods. Used where temperatures stay below 371 °C (700 °F).

Each type of TPS has specific heat protection, impact resistance, and weight characteristics, which determine the locations where it is used and the amount used.

The shuttle TPS has three key characteristics that distinguish it from the TPS used on previous spacecraft:

* Reusable. Previous spacecraft generally used ablative heat shields which burned off during reentry and so couldn’t be reused. This insulation was robust and reliable, and the single-use nature was appropriate for a single-use vehicle. By contrast, the reusable shuttle required a reusable thermal protection system.
* Lightweight. Previous ablative heat shields were very heavy. For example the ablative heat shield on the Apollo Command Module comprised about ⅓ of the vehicle weight. The winged shuttle had much more surface area than previous spacecraft, so a lightweight TPS was crucial.
* Fragile. The only known technology in the early 1970s with the required thermal and weight characteristics was also so fragile, due to the very low density, that one could easily crush a TPS tile by hand.”

Wikipedia

LuckyGuy's avatar

Heat shields, airfoil like shapes, angle of attack, and a skipping return path..

Communication satellites are weak, spindly things with very little structural rigidity . There is no reason to spend mass on structure when the device is only used in a weightless environment.

For the same mass-to-orbit mission a manned, return mission costs 5 to 10x (or more) a unmanned no return.
At $10,000 per pound to orbit, you want to make the satellite as light as possible to keep the cost down.

There are technologies to launch small (paint can sized) satellites from military aircraft. They are very cheap but burn up on reentry.

blueiiznh's avatar

You are assuming that there really are manned spacecrafts.
hmmmmmmmmmmmmmm are you really a “big conspiracy theorist”?

I wanted to be an astronaut as a kid till I discovered it was all a farce.

CWOTUS's avatar

Manned spaceships were designed with heat shielding because of the known dangers of re-entry. Unmanned satellites, Skylab and other human satellites in low-Earth orbit are not designed for re-entry… or ‘survivable’ re-entry. In fact, when those re-enter Earth’s atmosphere we definitely want them to burn up, so that “chunks” won’t be falling on populated parts of the planet.

… And all of the things that @worriedguy said. (Maybe others, too, but I haven’t read the entire thread.)

augustlan's avatar

[mod says] This is our Question of the Day!

rebbel's avatar

By the way, it has slowed down…..

Good choice, @augustlan !

chyna's avatar

All good answers. Thanks for the enlightenment!

lillycoyote's avatar

Don’t get too comfy though. There’s another one coming in a month or so and it’s bigger and badder. “The German “rogue satellite ROSAT is headed our way too.. DLR, the company who built, it has some information on its website.

Duck and cover kids.

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