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Author Topic: Is NASA's New Horizons the fastest ever man made object?  (Read 1951 times)

Offline Pseudoscience-is-malarkey

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NASA, with their New Horizons robotic spacecraft mission has been on route to the dwarf planet Pluto for over nine years now. It will reach Pluto on July 14 this year, taking the first ever photographic pictures of the dwarf planet. My question is this: is New Horizons the fastest ever man made object? Someone said NASA's Helios 2 takes that record, but how can it be so? That probe was built in the early 1970s when men such as Richard Nixon and Edward Heath were running governments. Long time ago.


 

Offline PmbPhy

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Re: Is NASA's New Horizons the fastest ever man made object?
« Reply #1 on: 25/02/2015 12:51:54 »
NASA, with their New Horizons robotic spacecraft mission has been on route to the dwarf planet Pluto for over nine years now. It will reach Pluto on July 14 this year, taking the first ever photographic pictures of the dwarf planet. My question is this: is New Horizons the fastest ever man made object? Someone said NASA's Helios 2 takes that record, but how can it be so? That probe was built in the early 1970s when men such as Richard Nixon and Edward Heath were running governments. Long time ago.
When it was built does not determine how fast it is. That's determine by how much fuel it burns.
 

Offline CliffordK

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Re: Is NASA's New Horizons the fastest ever man made object?
« Reply #2 on: 26/02/2015 12:04:57 »
The biggest determination of the speed of spacecraft beyond Earth's orbit is which direction you point them.

All of our current rockets have relatively short bursts of power followed by long periods of "coasting". 

During these coasting periods, the velocity is affected by the gravity of the sun, and the planets, either slowing them down if going away from the object, speeding them up if going towards it, or changing the direction if in orbit.

The Helios probes were fired towards the sun, and thus gained velocity as tehy approached the sun.

New Horizons, and the Voyager probes were fired heading away from Earth and the sun, and thus lost velocity as they traveled further from the sun.

The Voyager probes would not have ever gotten to solar system escape velocity had they not done several planetary flybys and gained energy from those planets, but are still traveling slower than when they were launched.

I believe New Horizons has the current distinction of the fastest launch velocity disregarding the direction of travel.
 

Offline Ophiolite

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Re: Is NASA's New Horizons the fastest ever man made object?
« Reply #3 on: 28/02/2015 07:20:59 »
The Helios probes were fired towards the sun, and thus gained velocity as tehy approached the sun.

New Horizons, and the Voyager probes were fired heading away from Earth and the sun, and thus lost velocity as they traveled further from the sun.
This is potentially misleading. It requires more energy to fire a rocket to the sun than to fire one to Pluto. Have you ignored the velocities inherent in orbiting?

To reach Pluto from Low Earth Object requires substantially less delta-V than to reach the sun. See this diagram. Although Pluto is not included, the delta-V between passing Neptune and escaping the system is less than 1km/second and can be ignored.
 

Online jeffreyH

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Re: Is NASA's New Horizons the fastest ever man made object?
« Reply #4 on: 28/02/2015 18:38:25 »

 

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