Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

wrote in message
...
Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Looks like an angle grinder, doesn't it. You need a reliable ignition source
before you turn the hydrogen on! I guess the oxygen goes on first, but
someone will be along in a minute with all the details.

newshound wrote:
wrote in message
...
Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Looks like an angle grinder, doesn't it. You need a reliable ignition source
before you turn the hydrogen on! I guess the oxygen goes on first, but
someone will be along in a minute with all the details.



Yes, I always understood that those sparks were used to ignite the
liquid fuel engines. I'm sure there are folks here that can answer in
far more detail.
AL A.

wrote:
Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Those are Hydrogen Burn Off Initiators.

They are meant to keep leaking or unburned hydrogen fuel from a failed
engine start from accumulating to explosive levels.

Good Video:

http://www.youtube.com/watch?v=IFXVxc6ms1U

Stuart

On Sun, 29 Jun 2008 18:08:04 GMT, with neither quill nor qualm,
quickly quoth:

Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?

That's the NASA version of a Bic lighter. It causes the volatile fuel
to ignite.

Remember hearing the countdown? Three, two, one, ignition, liftoff.

--
Such is the irresistible nature of truth that all it asks, and all it wants,
is the liberty of appearing. -- Thomas Paine

Larry Jaques wrote:
On Sun, 29 Jun 2008 18:08:04 GMT, with neither quill nor qualm,
quickly quoth:

Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?

That's the NASA version of a Bic lighter. It causes the volatile fuel
to ignite.

Remember hearing the countdown? Three, two, one, ignition, liftoff.

--
Such is the irresistible nature of truth that all it asks, and all it wants,
is the liberty of appearing. -- Thomas Paine

Made that up all by yourself, eh?

t-15 suppression water start
t-10 secs, free hydrogen burn off initiators fire, run 9 secs (+5/-0)
t-6.6 sec Main engine 3 start
t-6.48 sec Main engine 2 start
t-6.36 sec Main engine 1 start
t-0 SRB ignition, release hold downs

Liftoff

And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?

These are hot beads, ceramic I believe. They make for smooth ignition
instead of a fuel-air or fuel-oxidizer explosion. The principle is not
unlike lighting a welding torch, where you get a bang if you relight
without turning off the O2.

On Sun, 29 Jun 2008 17:47:58 -0400, Stuart Wheaton
wrote:

wrote:
Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Those are Hydrogen Burn Off Initiators.

They are meant to keep leaking or unburned hydrogen fuel from a failed
engine start from accumulating to explosive levels.

Good Video:

http://www.youtube.com/watch?v=IFXVxc6ms1U

Stuart
Thanks Stuart. I always figured that they couldn't possibly be for
lighting the engines. If they were, then they would need to be
blasting off with the shuttle. Either that, or some astronaut would
need to go on an EVA with a striker. I can just see this poor
spacesuited figure holding a striker around the edge of a rocket
nozzle.
Eric

wrote:
Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric


If you find out, let the rest of us know. I wrote to NASA a few years
ago with the same question and never received an answer. I have to
assume that the shower of sparks is to ignite any gathering fuel before
is can collect into a dangerous amount, but that's just my opinion.

Jim

SteveB wrote:
wrote in message
...

On Sun, 29 Jun 2008 17:47:58 -0400, Stuart Wheaton
wrote:


wrote:

Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Those are Hydrogen Burn Off Initiators.

They are meant to keep leaking or unburned hydrogen fuel from a failed
engine start from accumulating to explosive levels.

Good Video:

http://www.youtube.com/watch?v=IFXVxc6ms1U

Stuart

Thanks Stuart. I always figured that they couldn't possibly be for
lighting the engines. If they were, then they would need to be
blasting off with the shuttle. Either that, or some astronaut would
need to go on an EVA with a striker. I can just see this poor
spacesuited figure holding a striker around the edge of a rocket
nozzle.
Eric


I'm late on this, but I saw a program a long long time ago that said they
were to ignite gases around the base. I thought that plausible, but then
looking at that huge friggin solid propellant blowtorch going off, I
wondered what extra gas could be hanging around and not ignited. I guess
that's why they're sitting there in Mission Control and I'm sitting here in
Buck Snort.

As an aside, I nominate Cliff Culprick (sp?) for the job.

Steve




The solid boosters don't ignite until AFTER the main engines are running.

Jim Chandler wrote:
wrote:
Whenever the launch is shown there is a shot of the exhaust coming
out of the rockets. And there is always in the shot a device that
shoots out sparks horizontally. What is the spark shower for?
Eric


If you find out, let the rest of us know. I wrote to NASA a few years
ago with the same question and never received an answer. I have to
assume that the shower of sparks is to ignite any gathering fuel
before is can collect into a dangerous amount, but that's just my
opinion.


I build these for engines for a living.
I can't imagine why NASA didn't reply. They are pretty good at PR.

The main engines in any launch platform that is liquid fueled mix fuel and
oxidizer in the motor section.
A coaxial motor has one section for each with a difuser in between. They
sections are joined with metering ports.
Typically, these systems run at three hundred pounds and, as an example, the
third stage set I'm building now feeds the oxidized through a two inch OD
..065 wall Stainless inlet port and the fuel is similar but an inch and a
half in diameter.

That is a LOT of stuff.

The problem, as you might have realised, is getting from zero to 300 lbs
with that much flow and without tearing the internals apart. Balancing the
pressure on both sides of the system is important.
It doesn't take long but you still "spill" a lot of volume and that has to
be ignited in a controlled manner.

The engines are actually fired electrically by an igniter that runs directly
through the center of the engine and isn't unlike the spark plug in you car.
Well, except for the price.

LOL

Rocketdyne has an engine the size of the shuttle Main on a concrete pad in
front of their Chatsworth, California plant. Stop and look it over if you
ever have the chance.

--

John R. Carroll
www.machiningsolution.com

wrote in message
...
On Sun, 29 Jun 2008 17:47:58 -0400, Stuart Wheaton
wrote:

wrote:
Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Those are Hydrogen Burn Off Initiators.

They are meant to keep leaking or unburned hydrogen fuel from a failed
engine start from accumulating to explosive levels.

Good Video:

http://www.youtube.com/watch?v=IFXVxc6ms1U

Stuart
Thanks Stuart. I always figured that they couldn't possibly be for
lighting the engines. If they were, then they would need to be
blasting off with the shuttle. Either that, or some astronaut would
need to go on an EVA with a striker. I can just see this poor
spacesuited figure holding a striker around the edge of a rocket
nozzle.
Eric

I'm late on this, but I saw a program a long long time ago that said they
were to ignite gases around the base. I thought that plausible, but then
looking at that huge friggin solid propellant blowtorch going off, I
wondered what extra gas could be hanging around and not ignited. I guess
that's why they're sitting there in Mission Control and I'm sitting here in
Buck Snort.

As an aside, I nominate Cliff Culprick (sp?) for the job.

Steve

On Mon, 30 Jun 2008 11:01:48 -0800, "SteveB" toquerville@zionvistas
wrote:


wrote in message
...
On Sun, 29 Jun 2008 17:47:58 -0400, Stuart Wheaton
wrote:

wrote:
Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Those are Hydrogen Burn Off Initiators.

They are meant to keep leaking or unburned hydrogen fuel from a failed
engine start from accumulating to explosive levels.

Good Video:

http://www.youtube.com/watch?v=IFXVxc6ms1U

Stuart
Thanks Stuart. I always figured that they couldn't possibly be for
lighting the engines. If they were, then they would need to be
blasting off with the shuttle. Either that, or some astronaut would
need to go on an EVA with a striker. I can just see this poor
spacesuited figure holding a striker around the edge of a rocket
nozzle.
Eric

I'm late on this, but I saw a program a long long time ago that said they
were to ignite gases around the base. I thought that plausible, but then
looking at that huge friggin solid propellant blowtorch going off, I
wondered what extra gas could be hanging around and not ignited. I guess
that's why they're sitting there in Mission Control and I'm sitting here in
Buck Snort.

As an aside, I nominate Cliff Culprick (sp?) for the job.

Steve


Id be happy to donate a box of Blue Diamond "strike anywhere" kitchen
matches and an umbrella to him for the job.

Gunner


"The American people will never knowingly adopt socialism, but under the
name of liberalism they will adopt every fragment of the socialist program
until one day America will be a socialist nation without ever knowing how it
happened." -- Norman Thomas, American socialist

Gunner Asch wrote:

Id be happy to donate a box of Blue Diamond "strike anywhere" kitchen
matches and an umbrella to him for the job.


What, no Acme® anvil? ;-)



--
http://improve-usenet.org/index.html

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

Sporadic E is the Earth's aluminum foil beanie for the 'global warming'
sheep.

wrote:
Whenever the launch is shown there is a shot of the exhaust coming
out of the rockets. And there is always in the shot a device that
shoots out sparks horizontally. What is the spark shower for?
Eric

Others have said "why", but from my standpoint, the "what" is just as
fascinating. Those are zirconium gerbs (fountains by any other name).

Zirconium is so damned expensive because of its military/aerospace
igniter uses, that we cannot use it in civilian fireworks. But it makes
some beautiful, white, and very hot sparks.

LLoyd

SteveB wrote:
"cavelamb himself" wrote in message
m...
SteveB wrote:
wrote in message
...

On Sun, 29 Jun 2008 17:47:58 -0400, Stuart Wheaton
wrote:


wrote:

Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric
Those are Hydrogen Burn Off Initiators.

They are meant to keep leaking or unburned hydrogen fuel from a failed
engine start from accumulating to explosive levels.

Good Video:

http://www.youtube.com/watch?v=IFXVxc6ms1U

Stuart
Thanks Stuart. I always figured that they couldn't possibly be for
lighting the engines. If they were, then they would need to be
blasting off with the shuttle. Either that, or some astronaut would
need to go on an EVA with a striker. I can just see this poor
spacesuited figure holding a striker around the edge of a rocket
nozzle.
Eric

I'm late on this, but I saw a program a long long time ago that said they
were to ignite gases around the base. I thought that plausible, but then
looking at that huge friggin solid propellant blowtorch going off, I
wondered what extra gas could be hanging around and not ignited. I guess
that's why they're sitting there in Mission Control and I'm sitting here
in Buck Snort.

As an aside, I nominate Cliff Culprick (sp?) for the job.

Steve

The solid boosters don't ignite until AFTER the main engines are running.

Don't know what starts when, or the exact sequence, but in every launch I
have seen, I cannot imagine anything burnable under that rocket not finding
an ignition source.

Steve


That's actually the reason they are there. If the SSME's don't fire
properly, there's a bunch of hydrogen pouring out of them, the
initiators will ignite it before it has a chance to accumulate to
dangerous levels and blow the ass end off the spacecraft. They only
burn a few seconds until the engines are running full on. Those SSME's
get to 90% or better thrust in about 4 seconds, which is the trigger
that fires the solids.

Remember this is NASA, suspenders and belt. Especially when you think
about the fact that they don't add weight to the ship.

Stuart

"cavelamb himself" wrote in message
m...
SteveB wrote:
wrote in message
...

On Sun, 29 Jun 2008 17:47:58 -0400, Stuart Wheaton
wrote:


wrote:

Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?
Eric

Those are Hydrogen Burn Off Initiators.

They are meant to keep leaking or unburned hydrogen fuel from a failed
engine start from accumulating to explosive levels.

Good Video:

http://www.youtube.com/watch?v=IFXVxc6ms1U

Stuart

Thanks Stuart. I always figured that they couldn't possibly be for
lighting the engines. If they were, then they would need to be
blasting off with the shuttle. Either that, or some astronaut would
need to go on an EVA with a striker. I can just see this poor
spacesuited figure holding a striker around the edge of a rocket
nozzle.
Eric


I'm late on this, but I saw a program a long long time ago that said they
were to ignite gases around the base. I thought that plausible, but then
looking at that huge friggin solid propellant blowtorch going off, I
wondered what extra gas could be hanging around and not ignited. I guess
that's why they're sitting there in Mission Control and I'm sitting here
in Buck Snort.

As an aside, I nominate Cliff Culprick (sp?) for the job.

Steve


The solid boosters don't ignite until AFTER the main engines are running.

Don't know what starts when, or the exact sequence, but in every launch I
have seen, I cannot imagine anything burnable under that rocket not finding
an ignition source.

Steve

On Sun, 29 Jun 2008 22:10:23 -0400, Stuart Wheaton wrote:
Larry Jaques wrote:
On Sun, 29 Jun 2008 18:08:04 GMT, quickly quoth:

Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?

That's the NASA version of a Bic lighter. It causes the volatile fuel
to ignite.

Remember hearing the countdown? Three, two, one, ignition, liftoff.

Made that up all by yourself, eh?

t-15 suppression water start
t-10 secs, free hydrogen burn off initiators fire, run 9 secs (+5/-0)
t-6.6 sec Main engine 3 start
t-6.48 sec Main engine 2 start
t-6.36 sec Main engine 1 start
t-0 SRB ignition, release hold downs

Liftoff

And more important, if by around t-1 if the computers don't see
three engines running properly at programmed outputs and steering
gimbals responding and aimed straight, with correct pressures and
temperatures everywhere, NO solids and NO liftoff.

The Main Engines can be shut down and the launch aborted easily
enough if something isn't right. But when they light off the Solids
they'd better blow the hold-down bolts within a few milliseconds,
because that ship is leaving, period.

You don't want to make a Lawn Dart or a Daisy Cutter out of a
spacecraft if there are people aboard. That kind of wild ride tends
to be immediately deleterious to life and health.

(Ain't that an understatement...)

-- Bruce --

On Tue, 01 Jul 2008 09:27:27 -0700, Bruce L. Bergman
wrote:

On Sun, 29 Jun 2008 22:10:23 -0400, Stuart Wheaton wrote:
Larry Jaques wrote:
On Sun, 29 Jun 2008 18:08:04 GMT, quickly quoth:

Whenever the launch is shown there is a shot of the exhaust coming out
of the rockets. And there is always in the shot a device that shoots
out sparks horizontally. What is the spark shower for?

That's the NASA version of a Bic lighter. It causes the volatile fuel
to ignite.

Remember hearing the countdown? Three, two, one, ignition, liftoff.

Made that up all by yourself, eh?

t-15 suppression water start
t-10 secs, free hydrogen burn off initiators fire, run 9 secs (+5/-0)
t-6.6 sec Main engine 3 start
t-6.48 sec Main engine 2 start
t-6.36 sec Main engine 1 start
t-0 SRB ignition, release hold downs

Liftoff

And more important, if by around t-1 if the computers don't see
three engines running properly at programmed outputs and steering
gimbals responding and aimed straight, with correct pressures and
temperatures everywhere, NO solids and NO liftoff.

The Main Engines can be shut down and the launch aborted easily
enough if something isn't right. But when they light off the Solids
they'd better blow the hold-down bolts within a few milliseconds,
because that ship is leaving, period.

You don't want to make a Lawn Dart or a Daisy Cutter out of a
spacecraft if there are people aboard. That kind of wild ride tends
to be immediately deleterious to life and health.

(Ain't that an understatement...)

-- Bruce --


and makes nasa look bad when approriations time comes around.....

"The American people will never knowingly adopt socialism, but under the
name of liberalism they will adopt every fragment of the socialist program
until one day America will be a socialist nation without ever knowing how it
happened." -- Norman Thomas, American socialist

In article ,
Bruce L. Bergman wrote:

You don't want to make a Lawn Dart or a Daisy Cutter out of a
spacecraft if there are people aboard. That kind of wild ride tends
to be immediately deleterious to life and health.

(Ain't that an understatement...)

NASA has never made a Lawn Dart or a Daisy Cutter out of a spacecraft.
NASA has, however, shown very bad stringing when shotgunning a couple of
shuttles and egregious CYA the like of which has never been heard on any
trap range when explaining them both.

John Husvar wrote:
In article ,
Bruce L. Bergman wrote:

You don't want to make a Lawn Dart or a Daisy Cutter out of a
spacecraft if there are people aboard. That kind of wild ride tends
to be immediately deleterious to life and health.

(Ain't that an understatement...)

NASA has never made a Lawn Dart or a Daisy Cutter out of a spacecraft.
NASA has, however, shown very bad stringing when shotgunning a couple of
shuttles and egregious CYA the like of which has never been heard on any
trap range when explaining them both.

Go back and look at the tests done using the Atlas rockets... More than
a few went TU just off the pad, when they made it off the pad at all....

I'll say one thing for ANY of the crews, it takes MAJOR LEAGUE guts to
willingly strap your ass to the top of a multi billion dollar machine
that was built out of parts procured through the lowest bidder program...
--
Steve W.

In article , "Steve W."
wrote:

John Husvar wrote:
In article ,
Bruce L. Bergman wrote:

You don't want to make a Lawn Dart or a Daisy Cutter out of a
spacecraft if there are people aboard. That kind of wild ride tends
to be immediately deleterious to life and health.

(Ain't that an understatement...)

NASA has never made a Lawn Dart or a Daisy Cutter out of a spacecraft.
NASA has, however, shown very bad stringing when shotgunning a couple of
shuttles and egregious CYA the like of which has never been heard on any
trap range when explaining them both.

Go back and look at the tests done using the Atlas rockets... More than
a few went TU just off the pad, when they made it off the pad at all....

I'll say one thing for ANY of the crews, it takes MAJOR LEAGUE guts to
willingly strap your ass to the top of a multi billion dollar machine
that was built out of parts procured through the lowest bidder program...

Those weren't spacecraft. Those were attempts to catch up with Russian
rockets which had made it into orbit and, thus, were spacecraft.

Fireworks displays, mere fireworks displays.

I wonder what the reactions would have been if the USSR's space teams
had conducted their tries, tests, and failures as openly as the USA did.
The USSR could sit back in Baikal and smash ever so much hardware into
lawn darts and nobody the wiser. Not us, oh, no! As usual, we had to
hang all our dirty laundry out for the whole neighborhood to see! Still
doing it, too.

Hello all
I work on these engines. They are started with spark plugs that can
take a little heat, just way over priced. The sparks are sprayed to
ignite any leaking hydrogen. If to much hydrogen leaks into any space
it will detonate. The greater amount of gas the greater the
detonation. At Mississippi test site they use glow plugs all over the
engine for the same reason.
Hope this helped.

wrote in message
...
Hello all
I work on these engines. They are started with spark plugs that can
take a little heat, just way over priced. The sparks are sprayed to
ignite any leaking hydrogen. If to much hydrogen leaks into any space
it will detonate. The greater amount of gas the greater the
detonation. At Mississippi test site they use glow plugs all over the
engine for the same reason.
Hope this helped.

Damn. I recall getting flamed in a conversation here when I said hydrogen
was flammable.

Steve