Successful flight by Blue Origin

In article ,
says...
All of that added complexity and added mass would cost money compared to
using "leftover" fuel and oxidizer and an engine that is already there
for launch.

The complexity from an operational point of view is nil.

That is absolute bull****.

Added engines, tanks, plumbing, and etc. *is* adding complexity to the
design. Costs scale with complexity. Especially since we're talking
about *toxic* hypergolic propellants to a stage which has been proven to
not need them. And toxicity is just one of the reasons that processing
costs go *up* for a vehicle which uses hypergolics.

LOX and kerosene are both super cheap and are relatively non-toxic
compared to hypergolics.

They're already building super dracos and flying them to land
capsules. A self contained module plugged into the landing
struts and tied to the avionics of a booster would be child's
play and easily adapted to any stage. This would let the
booster engines be optimised for their mission and let ALL
the propellant be used as well.

And would drive up the costs of the first stage versus carrying along
extra LOX and kerosene.

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.

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
Rick Jones wrote:

In sci.space.policy Jeff Findley wrote:
They're reasonable if they work. SpaceX is trying to avoid adding
other engines to the Falcon 9 first stage. The stage could hover
and land, for example, if it added Super Draco engines to the first
stage. But, they require different fuel and oxidizer than the first
stage carries. This would mean adding completely different tanks,
plumbing, and etc. for those engines. Also, if Super Dracos were
used, it would be advantageous to deplete the kerosene and then vent
any remaining LOX in the tanks before landing. So, any "leftover"
fuel and oxidizer would be "wasted". In my book, this would not be
a good trade to make.

If one wanted to give the Falcon 9 first stage the ability to hover,
wouldn't the most straightforward way to do that be create a
deeply-throttled Merlin?


Straightforward, perhaps, but it's a very big design change so you
start with having to requalify as if it's a whole new engine.

Yet you were just saying in another thread space stuff doesn't have
bureaucrat bull****.


Cite?


Sure, it was by someone called Fred J. McCall talking about nuclear
reactors on Mars being cheap for lack of bureaucrat bull****.


Wow, you REALLY don't comprehend English, do you? Either that or
you're just so intellectually dishonest everything sounds different to
you. Note that even if you interpret that one instance the way you do
(which is twisted) it doesn't say what you claim I've said.

Stop making up lies, Chimp.

Stop taking mind altering drugs, space cadet.


Stop begging to suck my dick, Chimp.

Sounds like someone would really like being in an all male isolated
environment.

Go have your fun, I'm not prejudiced against the LGBT community.


--
Jim Pennino

On Sunday, April 10, 2016 at 8:31:25 AM UTC+12, Jeff Findley wrote:
In article ,
says...
All of that added complexity and added mass would cost money compared to
using "leftover" fuel and oxidizer and an engine that is already there
for launch.

The complexity from an operational point of view is nil.

That is absolute bull****.

No its not.

Added engines, tanks, plumbing, and etc. *is* adding complexity to the
design. Costs scale with complexity.

You are favouring ill conceived generic statements about products which have provable flight statistics.

Especially since we're talking
about *toxic* hypergolic propellants

SuperDraco engines utilize a storable propellant mixture of monomethylhydrazine fuel and dinitrogen tetroxide oxidizer. They are capable of being restarted many times, and have the capability to deeply reduce their thrust providing precise control during propulsive landing.

to a stage which has been proven to
not need them.

Four self contained modular systems based on those developed for the Dragon V2 capsule, each massing 1500 kg and carrying 1388 kg of propellant - built into a module and each attached to the landing strut, reduces complexity and weight of the booster to which it is attached, and given the statistics of NTO/MMH hypergolic engines to date, improves reliability.

And toxicity is just one of the reasons that processing
costs go *up* for a vehicle which uses hypergolics.

Hypergolic fuels have well defined material safety and data regarding their routine use. The

LOX and kerosene are both super cheap and are relatively non-toxic
compared to hypergolics.

While exposure risk to MMH and NTO vapours is greater than that of LOX and kerosene, you seem to ignore that in combination LOX Kerosene can be quite deadly in certain circumstances, forming explosive solids that are easily detonated. Spilled kerosene have caused significant fires in actual use, and have consequently been responsible for more deaths in rocket operations throughout history. So, in light of this actual experience, your attempts to denigrate MMH and NTO, which already being used by SpaceX on their MANNED CAPSULE, it rather foolish.

They're already building super dracos and flying them to land
capsules. A self contained module plugged into the landing
struts and tied to the avionics of a booster would be child's
play and easily adapted to any stage. This would let the
booster engines be optimised for their mission and let ALL
the propellant be used as well.

And would drive up the costs of the first stage versus carrying along
extra LOX and kerosene.

No it wouldn't. Because a more precise and controlled application of thrust reduces total delta vee requirements to a minimum during recovery. Furthermore, deeply throttable main booster engines have greater fire and explosion risks, and are not so precisely controlled. Further, operating at reduced thrust at sea level, causes design choices to be made that alter the efficiency of the engine reducing its efficiency relative to a pure boost engine. Finally, containing a small quantity of landing propellant in a separate container improves fuel utilisation efficiency when compared to taking the remnants from a larger tank that is undergoing maneuvers and is shaking.


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.

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
Rick Jones wrote:

In sci.space.policy Jeff Findley wrote:
They're reasonable if they work. SpaceX is trying to avoid adding
other engines to the Falcon 9 first stage. The stage could hover
and land, for example, if it added Super Draco engines to the first
stage. But, they require different fuel and oxidizer than the first
stage carries. This would mean adding completely different tanks,
plumbing, and etc. for those engines. Also, if Super Dracos were
used, it would be advantageous to deplete the kerosene and then vent
any remaining LOX in the tanks before landing. So, any "leftover"
fuel and oxidizer would be "wasted". In my book, this would not be
a good trade to make.

If one wanted to give the Falcon 9 first stage the ability to hover,
wouldn't the most straightforward way to do that be create a
deeply-throttled Merlin?


Straightforward, perhaps, but it's a very big design change so you
start with having to requalify as if it's a whole new engine.

Yet you were just saying in another thread space stuff doesn't have
bureaucrat bull****.


Cite?


Sure, it was by someone called Fred J. McCall talking about nuclear
reactors on Mars being cheap for lack of bureaucrat bull****.


Wow, you REALLY don't comprehend English, do you? Either that or
you're just so intellectually dishonest everything sounds different to
you. Note that even if you interpret that one instance the way you do
(which is twisted) it doesn't say what you claim I've said.

Stop making up lies, Chimp.

Stop taking mind altering drugs, space cadet.


Stop begging to suck my dick, Chimp.

Sounds like someone would really like being in an all male isolated
environment.


Yeah, but it doesn't matter how much you beg. You're not my type. I
prefer them female, smart, cute, and human. You miss on all four.

Yet you seem to know nothing about them such as they have been putting
diapers on their babies since antiquity.


--
Jim Pennino

If they can do this 4 or 5 times in a row even if they have 1 failure after
that, then might be adequate for an unmanned booster. More likely though
they'll have couple of successes then a failure. Suicide-burn is inherently
less reliable than a hovering approach.

Bob Clark



----------------------------------------------------------------------------------------------------------------------------------
Finally, nanotechnology can now fulfill its potential to revolutionize
21st-century technology, from the space elevator, to private, orbital
launchers, to 'flying cars'.
This crowdfunding campaign is to prove it:

Nanotech: from air to space.
https://www.indiegogo.com/projects/n...ce/x/13319568/
----------------------------------------------------------------------------------------------------------------------------------
"Jeff Findley" wrote in message
...

In article ,
says...

Rick Jones wrote:

In sci.space.policy Jeff Findley wrote:
They're reasonable if they work. SpaceX is trying to avoid adding
other engines to the Falcon 9 first stage. The stage could hover
and land, for example, if it added Super Draco engines to the first
stage. But, they require different fuel and oxidizer than the first
stage carries. This would mean adding completely different tanks,
plumbing, and etc. for those engines. Also, if Super Dracos were
used, it would be advantageous to deplete the kerosene and then vent
any remaining LOX in the tanks before landing. So, any "leftover"
fuel and oxidizer would be "wasted". In my book, this would not be
a good trade to make.

If one wanted to give the Falcon 9 first stage the ability to hover,
wouldn't the most straightforward way to do that be create a
deeply-throttled Merlin?


Straightforward, perhaps, but it's a very big design change so you
start with having to requalify as if it's a whole new engine.

And today's successful barge landing proves they don't *need* to hover!

http://www.theverge.com/2016/4/8/113...uccess-falcon-
9-rocket-barge-at-sea

I watched it live and it looked like a very nice landing.

Jeff
--

In article ,
says...

On Sunday, April 10, 2016 at 8:31:25 AM UTC+12, Jeff Findley wrote:
In article ,
says...
All of that added complexity and added mass would cost money compared to
using "leftover" fuel and oxidizer and an engine that is already there
for launch.

The complexity from an operational point of view is nil.

That is absolute bull****.

No its not.

It is clear you do not understand complexity as it applies to systems
engineering.

Added engines, tanks, plumbing, and etc. *is* adding complexity to the
design. Costs scale with complexity.

You are favouring ill conceived generic statements about products which have provable flight statistics.

You are engaging in hand-waving. You need the Merlin engine(s) and fuel
to perform first the burn to bleed off horizontal velocity and then to
reduce the speed during reentry. Adding a landing burn to this adds
zero additional hardware to the system and has been proven to work (once
on land and once on a barge).

Especially since we're talking
about *toxic* hypergolic propellants

SuperDraco engines utilize a storable propellant mixture of
monomethylhydrazine fuel and dinitrogen tetroxide oxidizer. They
are capable of being restarted many times, and have the capability
to deeply reduce their thrust providing precise control during
propulsive landing.

True, but they're also toxic as hell. This introduces all sorts of
added processing costs (and time) both before launch and after landing.
You're ignoring that completely.

to a stage which has been proven to
not need them.

Four self contained modular systems based on those developed for
the Dragon V2 capsule, each massing 1500 kg and carrying 1388 kg
of propellant - built into a module and each attached to the
landing strut, reduces complexity and weight of the booster to
which it is attached, and given the statistics of NTO/MMH
hypergolic engines to date, improves reliability.

Possibly, but with increased complexity and added processing costs that
you completely ignore.

And toxicity is just one of the reasons that processing
costs go *up* for a vehicle which uses hypergolics.

Hypergolic fuels have well defined material safety and data
regarding their routine use.

Of course they're well defined. They're so well defined that NASA
studied replacing toxic hypergolics on the shuttle due to the added
cost, schedule, and safety hazards they introduce. That's a fact you
ignore.

LOX and kerosene are both super cheap and are relatively non-toxic
compared to hypergolics.

While exposure risk to MMH and NTO vapours is greater than that of
LOX and kerosene, you seem to ignore that in combination LOX
Kerosene can be quite deadly in certain circumstances, forming
explosive solids that are easily detonated. Spilled kerosene have
caused significant fires in actual use, and have consequently been
responsible for more deaths in rocket operations throughout history.
So, in light of this actual experience, your attempts to denigrate
MMH and NTO, which already being used by SpaceX on their MANNED
CAPSULE, it rather foolish.

You *need* the LOX and kerosene during launch *anyway*, so using the
excess for landing does *not* add any complexity to launch operations.
As for landing operations, if you don't use the remaining LOX and
kerosene for landing, you're still going to have to deal with it post-
landing.

Adding toxic hypergolics *does* add additional "safing" and handling
complexities post landing.

They're already building super dracos and flying them to land
capsules. A self contained module plugged into the landing
struts and tied to the avionics of a booster would be child's
play and easily adapted to any stage. This would let the
booster engines be optimised for their mission and let ALL
the propellant be used as well.

And would drive up the costs of the first stage versus carrying along
extra LOX and kerosene.

No it wouldn't. Because a more precise and controlled application
of thrust reduces total delta vee requirements to a minimum during
recovery. Furthermore, deeply throttable main booster engines have
greater fire and explosion risks, and are not so precisely
controlled. Further, operating at reduced thrust at sea level,
causes design choices to be made that alter the efficiency of the
engine reducing its efficiency relative to a pure boost engine.
Finally, containing a small quantity of landing propellant in a
separate container improves fuel utilisation efficiency when
compared to taking the remnants from a larger tank that is
undergoing maneuvers and is shaking.

You're quite wrong. Adding complexity (especially toxic hypergolics)
adds costs.

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.

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
Rick Jones wrote:

In sci.space.policy Jeff Findley wrote:
They're reasonable if they work. SpaceX is trying to avoid adding
other engines to the Falcon 9 first stage. The stage could hover
and land, for example, if it added Super Draco engines to the first
stage. But, they require different fuel and oxidizer than the first
stage carries. This would mean adding completely different tanks,
plumbing, and etc. for those engines. Also, if Super Dracos were
used, it would be advantageous to deplete the kerosene and then vent
any remaining LOX in the tanks before landing. So, any "leftover"
fuel and oxidizer would be "wasted". In my book, this would not be
a good trade to make.

If one wanted to give the Falcon 9 first stage the ability to hover,
wouldn't the most straightforward way to do that be create a
deeply-throttled Merlin?


Straightforward, perhaps, but it's a very big design change so you
start with having to requalify as if it's a whole new engine.

Yet you were just saying in another thread space stuff doesn't have
bureaucrat bull****.


Cite?


Sure, it was by someone called Fred J. McCall talking about nuclear
reactors on Mars being cheap for lack of bureaucrat bull****.


Wow, you REALLY don't comprehend English, do you? Either that or
you're just so intellectually dishonest everything sounds different to
you. Note that even if you interpret that one instance the way you do
(which is twisted) it doesn't say what you claim I've said.

Stop making up lies, Chimp.

Stop taking mind altering drugs, space cadet.


Stop begging to suck my dick, Chimp.

Sounds like someone would really like being in an all male isolated
environment.


Yeah, but it doesn't matter how much you beg. You're not my type. I
prefer them female, smart, cute, and human. You miss on all four.

Yet you seem to know nothing about them such as they have been putting
diapers on their babies since antiquity.


It's called 'cloth', not 'diapers', you stupid ****.

Cloth is raw stock.

Diapers, shirts, pants, sheets, etc. are finished goods, you stupid ****.


--
Jim Pennino

In article ,
says...

If they can do this 4 or 5 times in a row even if they have 1 failure after
that, then might be adequate for an unmanned booster. More likely though
they'll have couple of successes then a failure. Suicide-burn is inherently
less reliable than a hovering approach.

Agreed. But that said, space shuttle glide landings were inherently
less reliable than powered landings, yet it was "safe enough" that we
did not see a landing failure during that program.

SpaceX is gaining experience with this mode of recovery even if a thrust
to weight greater than one is not ideal. On their next reusable launch
vehicle design, they should have the opportunity to make improvements.
Exactly what improvements may very well depend on how the rest of the
Falcon 9/Falcon Heavy program pans out.

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.

"Jeff Findley" wrote in message
...

In article ,
says...

If they can do this 4 or 5 times in a row even if they have 1 failure
after
that, then might be adequate for an unmanned booster. More likely though
they'll have couple of successes then a failure. Suicide-burn is
inherently
less reliable than a hovering approach.

Agreed. But that said, space shuttle glide landings were inherently
less reliable than powered landings, yet it was "safe enough" that we
did not see a landing failure during that program.

To fair we'd had over 8 decades of experience of gliding/horizontal landings
and we had the Mark I eyeball in the cockpit to respond to unknowns.


SpaceX is gaining experience with this mode of recovery even if a thrust
to weight greater than one is not ideal. On their next reusable launch
vehicle design, they should have the opportunity to make improvements.
Exactly what improvements may very well depend on how the rest of the
Falcon 9/Falcon Heavy program pans out.


Ayup.

Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
wrote:

In sci.physics Fred J. McCall wrote:
Rick Jones wrote:

In sci.space.policy Jeff Findley wrote:
They're reasonable if they work. SpaceX is trying to avoid adding
other engines to the Falcon 9 first stage. The stage could hover
and land, for example, if it added Super Draco engines to the first
stage. But, they require different fuel and oxidizer than the first
stage carries. This would mean adding completely different tanks,
plumbing, and etc. for those engines. Also, if Super Dracos were
used, it would be advantageous to deplete the kerosene and then vent
any remaining LOX in the tanks before landing. So, any "leftover"
fuel and oxidizer would be "wasted". In my book, this would not be
a good trade to make.

If one wanted to give the Falcon 9 first stage the ability to hover,
wouldn't the most straightforward way to do that be create a
deeply-throttled Merlin?


Straightforward, perhaps, but it's a very big design change so you
start with having to requalify as if it's a whole new engine.

Yet you were just saying in another thread space stuff doesn't have
bureaucrat bull****.


Cite?


Sure, it was by someone called Fred J. McCall talking about nuclear
reactors on Mars being cheap for lack of bureaucrat bull****.


Wow, you REALLY don't comprehend English, do you? Either that or
you're just so intellectually dishonest everything sounds different to
you. Note that even if you interpret that one instance the way you do
(which is twisted) it doesn't say what you claim I've said.

Stop making up lies, Chimp.

Stop taking mind altering drugs, space cadet.


Stop begging to suck my dick, Chimp.

Sounds like someone would really like being in an all male isolated
environment.


Yeah, but it doesn't matter how much you beg. You're not my type. I
prefer them female, smart, cute, and human. You miss on all four.

Yet you seem to know nothing about them such as they have been putting
diapers on their babies since antiquity.


It's called 'cloth', not 'diapers', you stupid ****.

Cloth is raw stock.

Diapers, shirts, pants, sheets, etc. are finished goods, you stupid ****.


And BOTH cloth and finished goods were IMPORTED to the Colonies, you
dumb ****.

So what, space cadet?

Both cloth and finished goods are imported to the US from Sri Lanka.

Does that mean you can not survive in the US without imports from
Sri Lanka, space cadet?



--
Jim Pennino