On 21/04/2023 03:33, Paul wrote:
> On 4/20/2023 5:56 PM, Davey wrote:
>> On Thu, 20 Apr 2023 14:44:27 -0400
>> Paul <nospam@needed.invalid> wrote:
>>
>>> On 4/20/2023 2:32 PM, Andy Burns wrote:
>>>> Davey wrote:
>>>>> "A SpaceX engineering manager, said the rocket had suffered a
>>>>> 'rapid unscheduled disassembly' ".
>>>>>
>>>>> Or, in other words, it blew itself to smithereens. I suppose that
>>>>> it's good to look on the bright side, though, even though it's in
>>>>> thousands of pieces.
>>>>>
>>>>> Ah, the power of words.
>>>>
>>>> I think they were pretty much expecting that, Musk said a few weeks
>>>> back that the criteria for success was clearing the tower.
>>>>
>>>> The spaceX people all booed when the countdown was paused at about
>>>> T-40s and cheered wildly when it eventually blew up having spun
>>>> round a few times after not separating.
>>>
>>> Apparently the thrust left a crater, so if they launch
>>> from the same facility for the next one, some construction
>>> work is in order.
>>>
>>> It's a good thing it cleared the pad. That's the "achievement".
>>>
>>> It might have been blown by range-safety.
>>
>> Yes, it was some kind of auto self-destruct mechanism. At least that
>> worked!
>>
>
> It's a good way to get rid of old engine parts,
> without paying a tipping fee.
>
>    "as many as eight engines appeared to have gone out"
>
> Something was gnawing at the vitals as the ship was rising.
> There may not have been enough redundancy left for the next
> maneuver.
>
> The gimbal system used to be hydraulic, but it switched to
> electric. This version of ship may well have had the old
> hydraulic gimbal, and there was a hydraulic problem, It's
> quite possible something was on fire on the way up, burned
> through some hydraulic kit, and so on.
>
> I consider the whole thing a success, because now they have
> proof they need a flame trench. And none of the infrastructure
> got ruined by a giant explosion. The whole thing is a "time saver" :-)
>
>    Paul

Action = Reaction. Does a NASA-style flame trench (cooled with
tonnes of water) reduce the effective thrust compared to taking off
from terra not-so-firma ?

On Fri, 21 Apr 2023 20:09:56 +0100, Andrew wrote:

> On 21/04/2023 03:33, Paul wrote:
>> On 4/20/2023 5:56 PM, Davey wrote:
>>> On Thu, 20 Apr 2023 14:44:27 -0400 Paul <nospam@needed.invalid> wrote:
>>>
>>>> On 4/20/2023 2:32 PM, Andy Burns wrote:
>>>>> Davey wrote:
>>>>>> "A SpaceX engineering manager, said the rocket had suffered a
>>>>>> 'rapid unscheduled disassembly' ".
>>>>>>
>>>>>> Or, in other words, it blew itself to smithereens. I suppose that
>>>>>> it's good to look on the bright side, though, even though it's in
>>>>>> thousands of pieces.
>>>>>>
>>>>>> Ah, the power of words.
>>>>>
>>>>> I think they were pretty much expecting that, Musk said a few weeks
>>>>> back that the criteria for success was clearing the tower.
>>>>>
>>>>> The spaceX people all booed when the countdown was paused at about
>>>>> T-40s and cheered wildly when it eventually blew up having spun
>>>>> round a few times after not separating.
>>>>
>>>> Apparently the thrust left a crater, so if they launch from the same
>>>> facility for the next one, some construction work is in order.
>>>>
>>>> It's a good thing it cleared the pad. That's the "achievement".
>>>>
>>>> It might have been blown by range-safety.
>>>
>>> Yes, it was some kind of auto self-destruct mechanism. At least that
>>> worked!
>>>
>>>
>> It's a good way to get rid of old engine parts,
>> without paying a tipping fee.
>>
>>    "as many as eight engines appeared to have gone out"
>>
>> Something was gnawing at the vitals as the ship was rising.
>> There may not have been enough redundancy left for the next maneuver.
>>
>> The gimbal system used to be hydraulic, but it switched to electric.
>> This version of ship may well have had the old hydraulic gimbal, and
>> there was a hydraulic problem, It's quite possible something was on
>> fire on the way up, burned through some hydraulic kit, and so on.
>>
>> I consider the whole thing a success, because now they have proof they
>> need a flame trench. And none of the infrastructure got ruined by a
>> giant explosion. The whole thing is a "time saver" :-)
>>
>>    Paul
>
> Action = Reaction. Does a NASA-style flame trench (cooled with tonnes of
> water) reduce the effective thrust compared to taking off from terra
> not-so-firma ?

You would imagine a burst of steam, with some going upwards.

On Fri, 21 Apr 2023 20:09:56 +0100, Andrew <Andrew97d@btinternet.com>
wrote:

>
>Action = Reaction. Does a NASA-style flame trench (cooled with
>tonnes of water) reduce the effective thrust compared to taking off
>from terra not-so-firma ?

I doubt it makes a scrap of difference. The tons* of cooling water
would protect the concrete to some degree, meaning that repairs for
the next launch would be less extensive, but the engine thrust would
be no different whether there was water, desert sand or vacuum beneath
them.

*do they do 'tonnes' over there?

--
Chris

On 21/04/2023 23:03, Chris Hogg wrote:

> I doubt it makes a scrap of difference. The tons* of cooling water
> would protect the concrete to some degree, meaning that repairs for
> the next launch would be less extensive, but the engine thrust would
> be no different whether there was water, desert sand or vacuum beneath
> them.
>
> *do they do 'tonnes' over there?
>
Not that I've noticed.

S Viemeister wrote:

> Chris Hogg wrote:
>
>> I doubt it makes a scrap of difference. The tons* of cooling water
>> would protect the concrete to some degree, meaning that repairs for
>> the next launch would be less extensive, but the engine thrust would
>> be no different whether there was water, desert sand or vacuum beneath
>> them.
>>
>> *do they do 'tonnes' over there?
>>
> Not that I've noticed.

More likely to use tens or hundreds of thousands of pounds ...

On 4/22/2023 2:21 AM, Andy Burns wrote:
> S Viemeister wrote:
>
>> Chris Hogg wrote:
>>
>>> I doubt it makes a scrap of difference. The tons* of cooling water
>>> would protect the concrete to some degree, meaning that repairs for
>>> the next launch would be less extensive, but the engine thrust would
>>> be no different whether there was water, desert sand or vacuum beneath
>>> them.
>>>
>>> *do they do 'tonnes' over there?
>>>
>> Not that I've noticed.
>
> More likely to use tens or hundreds of thousands of pounds ...
>

Gallons or liters of water, would work as a unit of measure.

News reports would use "Olympic swimming pools" as a unit.
2.5 million liters of water. 660 thousand gallons. Per pool.

A flame trench uses 1.1 million gallons per minute, or
"two Olympic pools per minute". The water likely needs to be switched
on, some number of seconds before T=0, so there is laminar flow
at some depth.

You might not need a minutes worth, unless some cool water is
needed to dilute the hot water. And make the wild life feel
better about themselves.

Makes about a hundred thousand servings of fish chowder.

Paul

On Sat, 22 Apr 2023 03:55:09 -0400
Paul <nospam@needed.invalid> wrote:

> Gallons or liters of water, would work as a unit of measure.

Remembering to specify whose gallons you are talking about. UK
full-bodied ones, or the puny little US versions.
Something not always taken into account when quoting car mileage
figures.
--
Davey.

On 21/04/2023 18:52, Theo wrote:
> mm0fmf <none@invalid.com> wrote:
>> On 21/04/2023 14:14, RDS wrote:
>>> On 20/04/2023 19:15, Davey wrote:
>>>> "A SpaceX engineering manager, said the rocket had suffered a 'rapid
>>>> unscheduled disassembly' ".
>>>>
>>> Is that a posh term for pingfuckit?
>>>
>>
>> He's taking piss out of NASA who are famous for such expressions.
>
> That is the official term, along with others like 'lithobraking'.

Suffering a massive entropic increase.

--
In todays liberal progressive conflict-free education system, everyone
gets full Marx.

On 22/04/2023 07:21, Andy Burns wrote:
> S Viemeister wrote:
>
>> Chris Hogg wrote:
>>
>>> I doubt it makes a scrap of difference. The tons* of cooling water
>>> would protect the concrete to some degree, meaning that repairs for
>>> the next launch would be less extensive, but the engine thrust would
>>> be no different whether there was water, desert sand or vacuum beneath
>>> them.
>>>
>>> *do they do 'tonnes' over there?
>>>
>> Not that I've noticed.
>
> More likely to use tens or hundreds of thousands of pounds ...
>
a metric tonne is very close to am imperial ton

--
In todays liberal progressive conflict-free education system, everyone
gets full Marx.

The Natural Philosopher wrote:

> Andy Burns wrote:
>
>> More likely to use tens or hundreds of thousands of pounds ...
>>
> a metric tonne is very close to am imperial ton

But they don't seem to switch to tons at the scale where we would switch
to tonnes; it's not a 50 tonne excavator, it's a 120,000 pound excavator.

There are numerous stories about this. Firstly, Eye Witnesses seem to be
suggesting that some engines failed a split second after launch, which put
stresses on things that should not have been stressed. as to whether the
unpland rapid disassembly referred to inside the booster, or the fact it
blew up is mute.

As it seems to have been over Texas at the time one does wonder whether it
might have been policy to let it go to a relatively unpopulated area before
it was blown up.
Unfortunately, making rockets safe does often end in a lot of failed
attempts, but often you have to test them under realistic conditions. I did
sort of feel like the huge sound reflections from the ground at lift off
might have shaken something loose and at least it did not blow up on the
pad. Redesign the flame trench and spray more water?

Brian

--

--:
This newsgroup posting comes to you directly from...
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Note this Signature is meaningless.!
"mm0fmf" <none@invalid.com> wrote in message
news:u1uhpl$2r8lu$1@dont-email.me...
> On 21/04/2023 14:09, Davey wrote:
>> On Fri, 21 Apr 2023 13:43:55 +0100
>> mm0fmf <none@invalid.com> wrote:
>>
>>> On 21/04/2023 11:33, Davey wrote:
>>>> Oh, ok. One of the reports says that it was an automatic
>>>> sensing system that caused it to self-destruct
>>>
>>> I've been in the software business for 41 years. I'd want there to be
>>> something manual still in the automatic self-destruct loop. Just
>>> saying....
>>>
>>>
>>
>> Well, there could easily be a manual parallel operator, ie if the auto.
>> system doesn't fire, then the man on the ground could do it instead.
>> Or do you want a manual 'Don't Fire!' option, to prevent auto action?
>> and if so, how fast would the man's reactions need to be?
>> 'Discuss', as they used to say in school.
>>
>
> You're in the spaceship... so do you want a fully automatic destruct
> system based on your experiences with computers over the last decades?
>
> There you've answered your own question.

Brian Gaff wrote:

> As it seems to have been over Texas at the time one does wonder whether it
> might have been policy to let it go to a relatively unpopulated area before
> it was blown up.

It started off at the coast and went across the gulf of mexico, the
first stage should have only travelled a few miles offshore and the
stage should have passed over the Caribbean, done its orbit and landed
off Hawaii.

Given that it didn't survive more than a few seconds past the supposed
separation point, I doubt it got further than a few miles out to sea, so
not over any land, let alone populated land.

On 4/22/2023 4:11 AM, Davey wrote:
> On Sat, 22 Apr 2023 03:55:09 -0400
> Paul <nospam@needed.invalid> wrote:
>
>> Gallons or liters of water, would work as a unit of measure.
>
> Remembering to specify whose gallons you are talking about. UK
> full-bodied ones, or the puny little US versions.
> Something not always taken into account when quoting car mileage
> figures.
>

That's where the standardized unit of the "Olympic Pool" comes in :-)

Presumably everyone here has had a swim in an Olympic pool.

Paul

On Sat, 22 Apr 2023 10:27:19 -0400
Paul <nospam@needed.invalid> wrote:

> On 4/22/2023 4:11 AM, Davey wrote:
> > On Sat, 22 Apr 2023 03:55:09 -0400
> > Paul <nospam@needed.invalid> wrote:
> >
> >> Gallons or liters of water, would work as a unit of measure.
> >
> > Remembering to specify whose gallons you are talking about. UK
> > full-bodied ones, or the puny little US versions.
> > Something not always taken into account when quoting car mileage
> > figures.
> >
>
> That's where the standardized unit of the "Olympic Pool" comes in :-)
>
> Presumably everyone here has had a swim in an Olympic pool.
>

But not necessarily measured the depth...

--
Joe

On 22/04/2023 08:55, Paul wrote:
> On 4/22/2023 2:21 AM, Andy Burns wrote:
>> S Viemeister wrote:
>>
>>> Chris Hogg wrote:
>>>
>>>> I doubt it makes a scrap of difference. The tons* of cooling water
>>>> would protect the concrete to some degree, meaning that repairs for
>>>> the next launch would be less extensive, but the engine thrust would
>>>> be no different whether there was water, desert sand or vacuum beneath
>>>> them.
>>>>
>>>> *do they do 'tonnes' over there?
>>>>
>>> Not that I've noticed.
>>
>> More likely to use tens or hundreds of thousands of pounds ...
>>
>
> Gallons or liters of water, would work as a unit of measure.
>
> News reports would use "Olympic swimming pools" as a unit.
> 2.5 million liters of water. 660 thousand gallons. Per pool.
>
> A flame trench uses 1.1 million gallons per minute, or
> "two Olympic pools per minute". The water likely needs to be switched
> on, some number of seconds before T=0, so there is laminar flow
> at some depth.
>
> You might not need a minutes worth, unless some cool water is
> needed to dilute the hot water. And make the wild life feel
> better about themselves.
>
> Makes about a hundred thousand servings of fish chowder.
>
>    Paul

I thought the whole Saturn V tower was drenched with water
to protect it.

On 22/04/2023 15:27, Paul wrote:
> On 4/22/2023 4:11 AM, Davey wrote:
>> On Sat, 22 Apr 2023 03:55:09 -0400
>> Paul <nospam@needed.invalid> wrote:
>>
>>> Gallons or liters of water, would work as a unit of measure.
>>
>> Remembering to specify whose gallons you are talking about. UK
>> full-bodied ones, or the puny little US versions.
>> Something not always taken into account when quoting car mileage
>> figures.
>>
>
> That's where the standardized unit of the "Olympic Pool" comes in :-)
>
> Presumably everyone here has had a swim in an Olympic pool.
>
>    Paul

Many public swimming pools seem to be only half length
in the UK.

Andrew wrote:

> Many public swimming pools seem to be only half length
> in the UK.

I think we only have about a dozen that are 50mx25m

On 22 Apr 2023 at 15:27:19 BST, "Paul" <nospam@needed.invalid> wrote:

> On 4/22/2023 4:11 AM, Davey wrote:
>> On Sat, 22 Apr 2023 03:55:09 -0400
>> Paul <nospam@needed.invalid> wrote:
>>
>>> Gallons or liters of water, would work as a unit of measure.

or possibly litres.

>> Remembering to specify whose gallons you are talking about. UK
>> full-bodied ones, or the puny little US versions.
>> Something not always taken into account when quoting car mileage
>> figures.
>
> That's where the standardized unit of the "Olympic Pool" comes in :-)
>
> Presumably everyone here has had a swim in an Olympic pool.

Had a swim in one? We all have our *own* Olympic pools, don't you know!

--
The reason you think government is the solution is because you think freedom is the problem. But the truth is that government ensures that the most evil, ruthless people end up in control, because the state is a single point of failure, and a high-value target of corruption.

Alan Lovejoy

In message <u20ufu$3aool$2@dont-email.me>, Andrew
<Andrew97d@btinternet.com> writes
>On 22/04/2023 15:27, Paul wrote:
>> On 4/22/2023 4:11 AM, Davey wrote:
>>> On Sat, 22 Apr 2023 03:55:09 -0400
>>> Paul <nospam@needed.invalid> wrote:
>>>
>>>> Gallons or liters of water, would work as a unit of measure.
>>>
>>> Remembering to specify whose gallons you are talking about. UK
>>> full-bodied ones, or the puny little US versions.
>>> Something not always taken into account when quoting car mileage
>>> figures.
>>>
>> That's where the standardized unit of the "Olympic Pool" comes in
>>:-)
>> Presumably everyone here has had a swim in an Olympic pool.
>>    Paul
>
>Many public swimming pools seem to be only half length
>in the UK.
>

And there have been one or two that were full size, until they put the
tiles on.

Adrian
--
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On 20/04/2023 19:44, Paul wrote:
> On 4/20/2023 2:32 PM, Andy Burns wrote:
>> Davey wrote:
>>
>>> "A SpaceX engineering manager, said the rocket had suffered a 'rapid
>>> unscheduled disassembly' ".
>>>
>>> Or, in other words, it blew itself to smithereens. I suppose that it's
>>> good to look on the bright side, though, even though it's in thousands
>>> of pieces.
>>>
>>> Ah, the power of words.
>>
>> I think they were pretty much expecting that, Musk said a few weeks
>> back that the criteria for success was clearing the tower.
>>
>> The spaceX people all booed when the countdown was paused at about
>> T-40s and cheered wildly when it eventually blew up having spun round
>> a few times after not separating.
>>
>
> Apparently the thrust left a crater, so if they launch
> from the same facility for the next one, some construction
> work is in order.
>
> It's a good thing it cleared the pad. That's the "achievement".
>
> It might have been blown by range-safety.
>
>    Paul

Looks like some changes may be in store

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

On 4/22/2023 6:00 AM, Andy Burns wrote:
> The Natural Philosopher wrote:
>
>> Andy Burns wrote:
>>
>>> More likely to use tens or hundreds of thousands of pounds ...
>>>
>> a metric tonne is very close to am imperial ton
>
> But they don't seem to switch to tons at the scale where we would switch to tonnes;  it's not a 50 tonne excavator, it's a 120,000 pound excavator.
>

If you're doing an advert for a Pickup Truck, the unit is the "ton".

If there is a productivity report in the Business section of the
newspaper, then a baffling array of near-equivalents is given.
To make all sorts of weirdos happy :-)

The purpose of all these definitions, is to cheat people.
The more definitions there are, the more likely it is
that someone is getting shafted (miners).

https://en.wikipedia.org/wiki/Ton

Paul

On Sun, 23 Apr 2023 22:33:25 +1000, Paul <nospam@needed.invalid> wrote:

> On 4/22/2023 12:49 PM, Tim Streater wrote:
>> On 22 Apr 2023 at 15:27:19 BST, "Paul" <nospam@needed.invalid> wrote:
>>
>>> On 4/22/2023 4:11 AM, Davey wrote:
>>>> On Sat, 22 Apr 2023 03:55:09 -0400
>>>> Paul <nospam@needed.invalid> wrote:
>>>>
>>>>> Gallons or liters of water, would work as a unit of measure.
>> or possibly litres.
>>
>>>> Remembering to specify whose gallons you are talking about. UK
>>>> full-bodied ones, or the puny little US versions.
>>>> Something not always taken into account when quoting car mileage
>>>> figures.
>>>
>>> That's where the standardized unit of the "Olympic Pool" comes in :-)
>>>
>>> Presumably everyone here has had a swim in an Olympic pool.
>> Had a swim in one? We all have our *own* Olympic pools, don't you know!
>
> They're easy to dig.
>
> All you need is a shovel, and... determination.
>
> The deep end, it's been a while since I've been to one, but
> I believe it's on the order of 16 feet or so. Swimming down to the
> bottom "manually", without using a dive board, is a bit of effort.

Not if you breath out first.

> (It's hard on the ear drums too.) The lifeguards don't like you
> doing that either, because it's hard to see whether you're OK or
> in trouble, down there. Like, some fool will swim down there on
> purpose, and then "stop moving" :-)

> My sister used to be a lifeguard at that pool. You need multiple
> guards for a pool that big, and especially, around the diving
> area (too many idiots, during public swims). That would take
> about three guards, one just for the diving area, one in the chair,
> one covering the shallow end (where the "incautious" live).

We never did ours that stupidly and didnt have any at all in the
big pools in Singapore.

> You would think it would be impossible, for a non-swimmer to
> get in trouble in the shallow end of that pool. Yet, they do it.
> You're just as likely to have someone floating face down in the
> shallow end, as in the deep end. If you're guarding the shallow
> end, you can't be asleep, because the people will always
> find a way to get in trouble. Maybe that person is practicing
> the "jelly fish float" or maybe... they've passed out.

On 4/22/2023 12:49 PM, Tim Streater wrote:
> On 22 Apr 2023 at 15:27:19 BST, "Paul" <nospam@needed.invalid> wrote:
>
>> On 4/22/2023 4:11 AM, Davey wrote:
>>> On Sat, 22 Apr 2023 03:55:09 -0400
>>> Paul <nospam@needed.invalid> wrote:
>>>
>>>> Gallons or liters of water, would work as a unit of measure.
>
> or possibly litres.
>
>>> Remembering to specify whose gallons you are talking about. UK
>>> full-bodied ones, or the puny little US versions.
>>> Something not always taken into account when quoting car mileage
>>> figures.
>>
>> That's where the standardized unit of the "Olympic Pool" comes in :-)
>>
>> Presumably everyone here has had a swim in an Olympic pool.
>
> Had a swim in one? We all have our *own* Olympic pools, don't you know!

They're easy to dig.

All you need is a shovel, and... determination.

The deep end, it's been a while since I've been to one, but
I believe it's on the order of 16 feet or so. Swimming down to the
bottom "manually", without using a dive board, is a bit of effort.
(It's hard on the ear drums too.) The lifeguards don't like you
doing that either, because it's hard to see whether you're OK or
in trouble, down there. Like, some fool will swim down there on
purpose, and then "stop moving" :-)

My sister used to be a lifeguard at that pool. You need multiple
guards for a pool that big, and especially, around the diving
area (too many idiots, during public swims). That would take
about three guards, one just for the diving area, one in the chair,
one covering the shallow end (where the "incautious" live).

You would think it would be impossible, for a non-swimmer to
get in trouble in the shallow end of that pool. Yet, they do it.
You're just as likely to have someone floating face down in the
shallow end, as in the deep end. If you're guarding the shallow
end, you can't be asleep, because the people will always
find a way to get in trouble. Maybe that person is practicing
the "jelly fish float" or maybe... they've passed out.

Paul