Naked Science Forum

Non Life Sciences => Technology => Topic started by: iacopo.russo on 06/10/2021 14:12:01

Title: Why do rockets smell and make a noise when they are nearby?
Post by: iacopo.russo on 06/10/2021 14:12:01
Elizabeth wrote to us from Scotland to ask a few questions about rockets:

Why do rockets smell and make a noise when they are nearby? How can rockets/space junks suddenly move if they see a rocket they don't like when they are meant to be a bit of junk/rocket that can't do anything? How can a rocket almost park on top of a house without setting on fire the contents of it? What material is the safest to have on a house roof to block microwaves from rockets?

Can you answer any or all of them?
Title: Re: Why do rockets smell and make a noise when they are nearby?
Post by: Origin on 06/10/2021 16:20:59
Why do rockets smell and make a noise when they are nearby?
They only make noise when they are launched.  When a rocket is launched gases are ignited which of course makes a lot of noise and the burnt gases have an odor.
 
How can rockets/space junks suddenly move if they see a rocket they don't like when they are meant to be a bit of junk/rocket that can't do anything?
They can't.  Rockets and space junk don't have feelings and they can't see.
How can a rocket almost park on top of a house without setting on fire the contents of it?
It can't, unless it is a very small hobby rocket over a tile roof.  If we are talking about a large NASA type rocket then the house will be obliterated.
What material is the safest to have on a house roof to block microwaves from rockets?
Rockets don't emit microwaves.

Is the OP some sort of joke post?
Title: Re: Why do rockets smell and make a noise when they are nearby?
Post by: LigiaOzimek on 20/01/2022 10:56:44
When launched, rockets always make a loud noise. They are very powerful.
Title: Re: Why do rockets smell and make a noise when they are nearby?
Post by: evan_au on 20/01/2022 20:34:11
Quote from: OP
How can a rocket almost park on top of a house without setting on fire the contents of it?
There is an orbit about 35,786 km from Earth's surface called geostationary orbit, where a satellite appears to "park" over a particular spot on the equator.
- In reality, the satellite is orbiting the Earth, but the orbital period of 24 hours exactly matches the Earth's rotation period of 24 hours, so it appears to sit at a fixed position in the sky, relative to Earth's surface.
- This is used for satellite TV, so your satellite TV dish can sit pointing in a fixed direction to pick up signals from the satellite.

If your house were on the equator, the satellite would appear to be "parked" directly over your house.
- But it would not damage your house, because the satellite can stay in this orbit for millions of years without firing any rockets
- ...although they do need to sometimes fire small rockets to cancel gravitational disturbances from the Moon & Sun
- but you will not hear or see these rockets because the satellite is far away, and there is no air to carry the sound of the rocket to your house.
https://en.wikipedia.org/wiki/Geostationary_orbit

PS: With advances in electronics, satellite antennas are now electronically steerable, so a fixed antenna can stay pointed at satellites in Low-Earth Orbit, even though they appear to move across the sky.
In cold weather, there is a de-icing heater, but this might suffer some unfortunate interference, as in this Starlink antenna...
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This satellite antenna was described as equivalent to a Cat5 connection.
Title: Re: Why do rockets smell and make a noise when they are nearby?
Post by: HannahC on 25/02/2022 08:28:31
How can flying rockets not make any noise? How do you suppose it?
Title: Re: Why do rockets smell and make a noise when they are nearby?
Post by: evan_au on 25/02/2022 09:26:54
Quote from: HannaC
How can flying rockets not make any noise?
If the rocket is flying at a supersonic speed, it will pass you (or hit you) before the sound reaches you.

if a jet aeroplane is flying very high, the sound will be attenuated before it reaches the ground, so it might not be audible over motor vehicle traffic noise.
Title: Re: Why do rockets smell and make a noise when they are nearby?
Post by: Colin2B on 25/02/2022 10:02:47
How can flying rockets not make any noise?
Be assured, up close they make a phenomenal amount of noise.
Title: Re: Why do rockets smell and make a noise when they are nearby?
Post by: Bored chemist on 25/02/2022 11:26:04
In space nobody can hear you ... whatever.