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Red Tesla Roadster mounted on PLA



 
 
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  #11  
Old December 25th 17, 12:28 AM posted to sci.space.policy
David Spain
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Default Red Tesla Roadster mounted on PLA

On 12/24/2017 11:30 AM, Greg (Strider) Moore wrote:
"Alain Fournier"Â* wrote in message news

I hope they will have a copy of the Hitchhiker's Guide to the Galaxy
and a towel in that car.


Damn it. I wish I had thought of that first. I love it!


Life imitates art (sort of). Opening sequence to the movie Heavy Metal:
(1981) Who knew way back then?

Radar Rider....

https://www.youtube.com/watch?v=t_KXgFpguE0

Dave
  #12  
Old December 25th 17, 03:24 PM posted to sci.space.policy
Jeff Findley[_6_]
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Default Red Tesla Roadster mounted on PLA

In article ,
says...

On 2017-12-24 10:29, David Spain wrote:

How do car tires deal with space vacuum? Is it launched with them
largely under-inflated? I'd expect they'd "go flat" anyway eventually.


Add 14.7psi to the pressure the tires must sustain when environment
around them is 0psi.

The cold and heat may have greater effect on the rubber though.


Since the wheels are off the ground, you could inflate them to just a
few psi and they'll look nice and round in those pictures.

Also, note that the X-37B's tires don't explode in vacuum. The longest
mission so far has been 717 days and 20 hours, which is just shy of two
years.

Looks like a convertible, so no need to worry about keeping the windows
rolled down.


I would have hoped he would have had a "closed" car with air vents
plugged up to see how long any pressure can be maintained in the car.


That would be pointless and counter productive. My guess is that they
specifically DO NOT want the top on it because they don't want any
chance of anything holding air in or the top coming off during launch.
Either of which might damage the payload fairing. Why is that
important? Because this test is being closely watched by US Air Force,
who is certifying Falcon Heavy for launches using that type of payload
fairing. There is serious money to be made by taking the biggest of
launches away from ULA.

Also, Musk can do whatever he wants since it's his car. Also, this
isn't actually going anywhere near Mars. Reports to the contrary are
inaccurate. This is about as good as it gets:

https://www.space.com/39164-elon-mus...-heavy-rocket-
photos.html

From above:

"Musk has said that Falcon Heavy's first payload will be his
own midnight-cherry-red Tesla Roadster, launched on a
trajectory aimed for Mars orbit."

In other words, this sounds to me like a transfer orbit between earth
orbit and Mars orbit. My guess it will be chosen so that there is zero
chance of it actually hitting Mars or earth. So, it's just going into a
solar orbit.

I'm also guessing that the car won't separate from the payload adapter.
Keeping it mounted to the upper stage would make it easier to track.
Obtaining an accurate reading of its final orbit will help engineers
verify the performance of Falcon Heavy.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #14  
Old December 25th 17, 03:42 PM posted to sci.space.policy
Niklas Holsti
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Default Red Tesla Roadster mounted on PLA

On 17-12-25 16:27 , Jeff Findley wrote:
In article ,
says...

Say a car were well built, and air intakes/exhaust from passenger cabin
welded shut.

(you can lookup Colin Furze's videos of turning a BMW into a mobile hot
tub on Youtube for example).


You launch the car with windows closed. (and a roof).

Obviously, the car won't hold 14.7 psi. But wouldn't air stop exiting
car at some point leaving a very thin atmopsphere inside the car?


No. Air will keep leaking out of every tiny little hole and gap.

Can a gas still fill a compartment but be at 0 PSI or do gas laws
require the gas always exert a pressure no matter how small it might be?


LOL, no. 0 PSI is called vacuum and it contains no gas.


Getting a bit silly, but what if the temperature is (almost) zero
Kelvin? There could be lots of gas there, but the pressure could be
lowered indefinitely by lowering the temperature, until the gas
liquefies. In the silly limit, if the gas were to be very quickly cooled
to make the thermal motion very slow, it could take considerable time
for the gas molecules to collide with other gas molecules and so form a
liquid or solid.

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
  #15  
Old December 25th 17, 04:54 PM posted to sci.space.policy
David Spain
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Posts: 2,901
Default Red Tesla Roadster mounted on PLA

On 12/25/2017 9:24 AM, Jeff Findley wrote:

Since the wheels are off the ground, you could inflate them to just a
few psi and they'll look nice and round in those pictures.

Also, note that the X-37B's tires don't explode in vacuum. The longest
mission so far has been 717 days and 20 hours, which is just shy of two
years.


Jeff,

Do you know if the X-37B and the Space Shuttle for that matter used
specially rated tires for space? I only know the history of the tires
used for the SR-71, and they were far from ordinary.

Also, Musk can do whatever he wants since it's his car. Also, this
isn't actually going anywhere near Mars. Reports to the contrary are
inaccurate. This is about as good as it gets:

https://www.space.com/39164-elon-mus...-heavy-rocket-
photos.html

From above:

"Musk has said that Falcon Heavy's first payload will be his
own midnight-cherry-red Tesla Roadster, launched on a
trajectory aimed for Mars orbit."

In other words, this sounds to me like a transfer orbit between earth
orbit and Mars orbit. My guess it will be chosen so that there is zero
chance of it actually hitting Mars or earth. So, it's just going into a
solar orbit.


That sounds very reasonable to me. Far easier to obtain with the given
hardware.

Dave

  #16  
Old December 25th 17, 05:11 PM posted to sci.space.policy
David Spain
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Posts: 2,901
Default Red Tesla Roadster mounted on PLA

On 12/22/2017 5:55 AM, Jeff Findley wrote:
It's looking like Musk is seriously launching an actual car into space.
Well, that'll be a first for the record books.

Jeff


You know when space salvage becomes routine, this is also it's own
X-prize. First company to bring it back intact could auction it for a
fortune.

Yeah and like most X-prizes the money spent getting it back will far
exceed the (monetary) value of the prize itself....

Dave
  #17  
Old December 25th 17, 05:43 PM posted to sci.space.policy
David Spain
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Posts: 2,901
Default Red Tesla Roadster mounted on PLA

On 12/24/2017 11:23 PM, JF Mezei wrote:
Say a car were well built, and air intakes/exhaust from passenger cabin
welded shut.

(you can lookup Colin Furze's videos of turning a BMW into a mobile hot
tub on Youtube for example).


You launch the car with windows closed. (and a roof).

Obviously, the car won't hold 14.7 psi. But wouldn't air stop exiting
car at some point leaving a very thin atmopsphere inside the car?

Can a gas still fill a compartment but be at 0 PSI or do gas laws
require the gas always exert a pressure no matter how small it might be?

For instance say you threw dust up in the car and started a fan,
wouldn't the fan push the thin air and keep the dust moving with the
thin air?


Jeff and Alain have already addressed the issue of a car interior being
able to maintain air pressure.

And in terms of the CD player playing "Space Oddity". Would there remain
enough air inside (at 0 or near 0 PSI to provode some cooling of
components in the CD player?


No. You'd be solely depending upon radiant cooling and whatever
conductive cooling you'd get through the metal component to PC board
connections. For the "ground (GND)" connections they "might" transfer
heat to the car chassis. Depends on how those connections are made.

Same for the audio. Unless your helmet is in direct physical contact
with the "speaker", there is nothing to hear.

Even if all that endures, eventually the battery would expire. Not
owning a Tesla myself (ahem) I can't actually speak if the (presumed 12v
audio) system is derived from a separate electrical system or is
regulated from the Li-ion pack. Which I suspect won't be present.

Or will the sun striking the car be "no contest" in terms of melting
everything inside despite some thin air remaining ?



Unlikely. First there is no air. Second solar radiance isn't high enough
at this distance. Third don't assume the Telsa is stable relative to any
given x,y,z planes. Unless the PLA remains mated to the 2nd stage. Which
Jeff thinks is likely for tracking and performance purposes. If true, it
would be possible to put the Tesla, PLA and 2nd stage into a rotation to
provide more even solar radiance distribution. Why or if that is done
depends upon what SpaceX desires to know about this "dummy payload", as
a dead mass, is handled by the 2nd stage in space.

However exposure to temperature extremes, and the rad hard environment
of interplanetary space, will over time, probably play havoc on any and
all vinyl & plastic components (or even for a Tesla Roadster all that
.... rich Corinthian leather. lol)

Personally, I'd be interested to know how well the paint job holds up!

Dave


  #18  
Old December 25th 17, 05:59 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 2,307
Default Red Tesla Roadster mounted on PLA

In article , says...

On 12/25/2017 9:24 AM, Jeff Findley wrote:

Since the wheels are off the ground, you could inflate them to just a
few psi and they'll look nice and round in those pictures.

Also, note that the X-37B's tires don't explode in vacuum. The longest
mission so far has been 717 days and 20 hours, which is just shy of two
years.


Jeff,

Do you know if the X-37B and the Space Shuttle for that matter used
specially rated tires for space? I only know the history of the tires
used for the SR-71, and they were far from ordinary.


I know, but we're talking about tires that will almost surely be filled
such that they won't come close to exceeding their maximum recommended
pressure when in vacuum (SpaceX engineers have surely thought of this).
Yes ultraviolet radiation and vacuum will surely take their toll on the
rubber that make up these tires, But, I would think that they will hold
pressure long after the launch is done and the upper stage has been used
for the last time (the batteries will die and the LOX will boil away
long before the tires ever burst).

Also, Musk can do whatever he wants since it's his car. Also, this
isn't actually going anywhere near Mars. Reports to the contrary are
inaccurate. This is about as good as it gets:

https://www.space.com/39164-elon-mus...-heavy-rocket-
photos.html

From above:

"Musk has said that Falcon Heavy's first payload will be his
own midnight-cherry-red Tesla Roadster, launched on a
trajectory aimed for Mars orbit."

In other words, this sounds to me like a transfer orbit between earth
orbit and Mars orbit. My guess it will be chosen so that there is zero
chance of it actually hitting Mars or earth. So, it's just going into a
solar orbit.


That sounds very reasonable to me. Far easier to obtain with the given
hardware.


There is no way the Falcon upper stage has enough battery and thermal
control over the LOX to perform a "burn" anywhere near Mars.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #19  
Old December 26th 17, 02:22 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Red Tesla Roadster mounted on PLA

JF Mezei wrote:

Say a car were well built, and air intakes/exhaust from passenger cabin
welded shut.

(you can lookup Colin Furze's videos of turning a BMW into a mobile hot
tub on Youtube for example).


You launch the car with windows closed. (and a roof).

Obviously, the car won't hold 14.7 psi. But wouldn't air stop exiting
car at some point leaving a very thin atmopsphere inside the car?

Can a gas still fill a compartment but be at 0 PSI or do gas laws
require the gas always exert a pressure no matter how small it might be?


There is either gas (and pressure) or there is no gas (and no
pressure). You don't get gas with no pressure or pressure with no
gas.


For instance say you threw dust up in the car and started a fan,
wouldn't the fan push the thin air and keep the dust moving with the
thin air?


What thin air?


And in terms of the CD player playing "Space Oddity". Would there remain
enough air inside (at 0 or near 0 PSI to provode some cooling of
components in the CD player?


No.


Or will the sun striking the car be "no contest" in terms of melting
everything inside despite some thin air remaining ?


The fairing is opaque.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #20  
Old December 26th 17, 02:29 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Red Tesla Roadster mounted on PLA

JF Mezei wrote:

On 2017-12-25 09:27, Jeff Findley wrote:

LOL, no. 0 PSI is called vacuum and it contains no gas.



Say I have a totally airtight car and going on a weekend camping trip to
the moon. Halfway there, someone farts in the car and I open the window,
air goees out.

So, halfway between Earth and Moon, there is a "blob" of smelly air that
was let out of the car. Since there is nothing to contain it, no gravity
to pull it down and give it weight, Can't that gas exist at 0 PSI,
taking whatever volume it wants ?


No, and in point of fact 'space' is generally not at 'zero pressure';
it is just very, very, very low pressure. There is typically 1 atom
of gas per cubic meter in space. Your 'blob of gas' is going to
dissipate to that level.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
 




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