A noteworthy 'amatuer' technology.

I think this is reasonable for this group.
Below (++++) is a report recieved via email on a project SS2S.
It uses an unusual staging technology known as phasing.
The motor uses a 'sugar+saltpeter' propellant, with the 1st phase
burning followed by a delay and then the 2nd (upper phase) ignites
driving gas into the empty 1st phase to reuse it's nozzle.
I think that's original, has anyone seen that approach before?

An encountered difficultly during testing has been numerous
failures of the 1st Combustion Chamber thermally stressed by
the 2nd phase exhaust input to the point of rupture.
Conventionally, solid rockets have an inhibitor and the hot gas
contact with the wall is limited in time. Liquid fuel CC had
thermal problems that were solved by 'regenerative cooling' by
the propellant circulation around the nozzle and CC.

The SS2S team has done (IMHO) some advanced research
in creating an inhibitor for the 1st phase capable of surviving
the 2nd phase burn as demo'd in testing, in effect a restartable
solid rocket.
Hot stuff.
Regards ======~~~~~~~~~
Ken S. Tucker






+++++++++++++++++++++++++++++++++++++++++++++++
Highlights of recent developments on the MiniSShot Project
-------------------------------------------------------------

- The MiniSShot rocket motor, officially deemed "ProtoSShot-M Mark
III", was successfully static fired at the FAR test facility in the
Mojave Desert on July 25th at 2:15 PDT. Although results are
preliminary at this point in time, the motor appears to have fared
well without apparent damage.
This successful test marks a key milestone in the Sugar Shot to Space
Program.

Some basic information on the ProtoSShot-M Mark III motor:
- Diameter: 3.5" (89 mm)
- Length: 79.5" (2019 mm)
- Dual phase (2 burns separated by a delay)
- Design burn time: 2.54 + 10 s.delay + 2.60 s.
- Design impulse: 13132 N-s. ("N-Class")
- Propellant Type: KNSB (potassium nitrate / sorbitol)
- Propellant load: 23.12 lbs. (10.485 kg.)


- A huge thank-you goes out to those Team members and collaborators
who braved 110F desert temperatures to participate in this important
test. Success would have eluded us without the dedication of the Team
members, and we are grateful for the assistance of the collaborators
at this event:
Matt Campbell (Propulsion Team member)
Chris King (Propulsion/Avionics Team member)
Rick Maschek (Propulsion Team member)
Paul Avery (Propulsion Team member)
Mark Holthouse (FAR secretary and Calif Pyro Op)
Bruce Pitt (helped Chris with Data Acquisition)
Matt Delcastillo (general helping out)
Ben Brockert (high speed video footage)
Jeff Jacobs (lent badly needed tools)


Setting up the rocket motor on the test rig:
http://sugarshot.org/downloads/dscn0667a.jpg
Video of the test firing:
http://www.youtube.com/watch?v=3kysK-TTKYw
Lo-res version of this video (1.3 Meg):
http://sugarshot.org/downloads/minisshot_july25_09.wmv
View from tower cam:
http://www.youtube.com/watch?v=_oQyrMX-yqc
(photo & videos courtesy Rick Maschek)

Motor firing, HD:
http://www.youtube.com/watch?v=2Exe2rwEwic&fmt=22

Motor firing, 1/20th speed:
http://www.youtube.com/watch?v=k2bbo2XIwSI
(both videos courtesy Ben Brockert)

- Over the next several days, the motor will be taken apart, cleaned
and carefully examined for signs of damage. If no significant damage
or sign of anomalous behaviour is uncovered, the motor will be deemed
"flight-worthy" and refurbished for launch later this year.
Motor partly disassembled after firing:
http://sugarshot.org/downloads/dsc07956a.jpg

- Good data was collected of the thrust and chamber pressure. The data
will be processed and analyzed over the next few days. Screen capture
of raw results:
First phase burn:
http://sugarshot.org/downloads/proto3thrust1.gif
Second phase burn:
http://sugarshot.org/downloads/proto3thrust2.gif
(courtesy Chris King)

- Dan Pollino (inverseengineering.com) was invited to attend and video-
document the event, in conjunction with a flight of his own Coyote
Rocket. Dan's unique documentary style captured both the essence and
excitement that filled the air that day.
http://www.youtube.com/watch?v=JdNiE9n9-fU
Congratulations to Dan on his highly successful flight!

- On Sunday, a post-firing Skype debriefing session was held between
members of the Propulsion Team. Excellent information about the event
was documented on what went well, what did not go well, and what
lessons were learned to improve things next time around.

- Peter Kocalka continues to make good progress with the MiniSShot
telemetry system. Peter has begun testing of the transmitter and GPS
unit, and reports:

GPS needs 40mA current and 45mA peak [9V]
Tiny_Track needs 43mA current and 48mA peak [9V]
GPS with original cable is 102g mass
Tiny Track is 34g mass

http://sugarshot.org/downloads/tiny_track.jpg
http://sugarshot.org/downloads/tiny_track2.jpg
http://sugarshot.org/downloads/null_modem.jpg
http://sugarshot.org/downloads/display.jpg
http://sugarshot.org/downloads/gps011.jpg
(photos courtesy Peter Kocalka)


------
Be a part of our success, celebrate, and show that you, too, are a
believer in our dream by making a financial donation:
http://www.sugarshot.org/sponsors.html#Donors

Ken S. Tucker wrote:
I think this is reasonable for this group.
Below (++++) is a report recieved via email on a project SS2S.
It uses an unusual staging technology known as phasing.
The motor uses a 'sugar+saltpeter' propellant, with the 1st phase
burning followed by a delay and then the 2nd (upper phase) ignites
driving gas into the empty 1st phase to reuse it's nozzle.
I think that's original, has anyone seen that approach before?


It's similar to the way that some dual thrust solid motors work, like
used on the Hawk missile for instance.
Rather than dividing it into upper and lower sections, in which case the
empty lower section of the motor casing gets exposed to wall heating as
the upper part burns (as you pointed out), it would make more sense to
put a faster-burning propellant combination on the inside walls of the
central bore of the grain, which burns first to generate high initial
thrust, and as it burns away exposes the slower burning outer propellant
grain for the sustainer burn. One problem here is motor nozzle throat
diameter; the throat diameter that is optimal for the high-thrust
segment of the burn will be too large for the lower thrust secondary
burn and decrease overall efficiency. There would be other ways of doing
this, but they would involve some really complex grain designs, and
might pose problems keeping the grain in place in the motor casing as it
burned.
A really complex solution to this would be to use something similar to
the rocket/solid fuel ramjet like used on the Russian SA-6 "Gainful"
SAM: http://www.ausairpower.net/APA-2K12-Kvadrat.html
That's done by firing a solid fuel booster inside of a ramjet casing,
which is then fed propellant gas by burning a solid charge that is low
in oxygen so that it achieves secondary combustion when it is exposed to
external air fed to it by four ram inlets.
Although I'd hate to have to come up with a design for this in detail,
you might be able to sheath the inside of the bottom part of the casing
wall with some sort of a propellant that burns at fairly low temperature
due to a deficit of oxygen, which is then made up by a oxygen-rich
forward fuel segment to achieve the optimal fuel-oxygen mix.
The concept would be somewhat similar to the "veil cooling" developed by
Dr. Thiel to keep the V-2 engine's combustion chamber and nozzle from
melting via injecting alcohol along its inside walls which combusted at
a fairly low temperatu
http://abyss.uoregon.edu/~js/images/V-2_thrust.jpg

Pat

Hi Pat and all.
On Aug 1, 7:45 am, Pat Flannery wrote:
Ken S. Tucker wrote:
I think this is reasonable for this group.
Below (++++) is a report recieved via email on a project SS2S.
It uses an unusual staging technology known as phasing.
The motor uses a 'sugar+saltpeter' propellant, with the 1st phase
burning followed by a delay and then the 2nd (upper phase) ignites
driving gas into the empty 1st phase to reuse it's nozzle.
I think that's original, has anyone seen that approach before?

It's similar to the way that some dual thrust solid motors work, like
used on the Hawk missile for instance.
Rather than dividing it into upper and lower sections, in which case the
empty lower section of the motor casing gets exposed to wall heating as
the upper part burns (as you pointed out), it would make more sense to
put a faster-burning propellant combination on the inside walls of the
central bore of the grain, which burns first to generate high initial
thrust, and as it burns away exposes the slower burning outer propellant
grain for the sustainer burn. One problem here is motor nozzle throat
diameter; the throat diameter that is optimal for the high-thrust
segment of the burn will be too large for the lower thrust secondary
burn and decrease overall efficiency. There would be other ways of doing
this, but they would involve some really complex grain designs, and
might pose problems keeping the grain in place in the motor casing as it
burned.

Yes, it would be complex. The SS2S philosophy is mainly Rich Nakka's
a friend of ours btw, he has a good site here,
http://www.nakka-rocketry.net/

The SS2S philosophy is difficult.
The 1st phase pushes the rocket through the thickest atmosphere,
coasts upward then the delayed 2nd phase burns in thin atmosphere
to provide the impulse (speed) to obtain 100km altitude.

A really complex solution to this would be to use something similar to
the rocket/solid fuel ramjet like used on the Russian SA-6 "Gainful"
SAM:http://www.ausairpower.net/APA-2K12-Kvadrat.html
That's done by firing a solid fuel booster inside of a ramjet casing,
which is then fed propellant gas by burning a solid charge that is low
in oxygen so that it achieves secondary combustion when it is exposed to
external air fed to it by four ram inlets.
Although I'd hate to have to come up with a design for this in detail,
you might be able to sheath the inside of the bottom part of the casing
wall with some sort of a propellant that burns at fairly low temperature
due to a deficit of oxygen, which is then made up by a oxygen-rich
forward fuel segment to achieve the optimal fuel-oxygen mix.
The concept would be somewhat similar to the "veil cooling" developed by
Dr. Thiel to keep the V-2 engine's combustion chamber and nozzle from
melting via injecting alcohol along its inside walls which combusted at
a fairly low temperatuhttp://abyss.uoregon.edu/~js/images/V-2_thrust.jpg
Pat

The SS2S team has pretty much locked on to the dual-phase burn idea,
and with any rocketry project many different options were available,
none
are perfect, that's their decision.
Ken

In article ,
"Ken S. Tucker" writes:
Yes, it would be complex. The SS2S philosophy is mainly Rich Nakka's
a friend of ours btw, he has a good site here,
http://www.nakka-rocketry.net/

The 1st phase pushes the rocket through the thickest atmosphere,
coasts upward then the delayed 2nd phase burns in thin atmosphere
to provide the impulse (speed) to obtain 100km altitude.

Why the delay? To stay within the dynamic pressure limit? Burning
all the propellant as fast as possible would be more efficient. (You
don't want to carry that mass to high altitude if you can avoid it.)

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

Steve Willner wrote:

Why the delay? To stay within the dynamic pressure limit? Burning
all the propellant as fast as possible would be more efficient. (You
don't want to carry that mass to high altitude if you can avoid it.)


The engine will generate more thrust in the thinner upper atmosphere?
The concept seems counter-intuitive to me also.

Pat

On Aug 5, 4:13 am, Pat Flannery wrote:
Steve Willner wrote:

Why the delay? To stay within the dynamic pressure limit? Burning
all the propellant as fast as possible would be more efficient. (You
don't want to carry that mass to high altitude if you can avoid it.)

The engine will generate more thrust in the thinner upper atmosphere?
The concept seems counter-intuitive to me also.
Pat

I did a post to Steve a few days ago about that, it went to cyber-
heaven,
(I hardly think it was rejected, if so, moderators, please advise the
group).
Check the documentation on Oct 1 2005 here,
http://sugarshot.org/
(Report on Project "Phase One" Findings)

I'm sure you've all heard "go for throttle up" during a Shuttle
launch,
well - as I understand - that's a tough calculus, balancing between
aerodynamic stress that uses fuel to go through the denser low
altitude air and fuel wasted by doing something akin to cruising.
It's a maxima-minima problem that's ultimately tweeked via sims.
Regards
Ken

"Ken S. Tucker" wrote:

(I hardly think it was rejected, if so, moderators, please advise the
group).

You would have been notified if it was.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

"Ken S. Tucker" wrote:

I did a post to Steve a few days ago about that, it went to cyber-
heaven, I hardly think it was rejected, if so, moderators, please advise the
group).

After investigation, it appears it was accidentally marked as spam and
rejected - probably caused by me moderating with insuficient caffiene
in my system.

Mea Culpa.

Please repost.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Ken S. Tucker wrote:
I did a post to Steve a few days ago about that, it went to cyber-
heaven,
(I hardly think it was rejected, if so, moderators, please advise the
group).
Check the documentation on Oct 1 2005 here,
http://sugarshot.org/
(Report on Project "Phase One" Findings)


If this works it will really surprise me, as I played around with
"carmel candy" rocket propellant, and I don't think it has anywhere near
the specific impulse to get a rocket into space, particularly a
single-stage rocket (it is single stage, isn't it?) You know,
sulfer-zinc is a amauter propellant also, and it's got a lot better
specific impulse than "carmel candy".
For that matter, even black powder might be better.
Then they are going to try to recover the vehicle, with all the added
weight and complexity that that concept entails.
To give you some idea of the mismatch of fuel and expected performance I
foresee, they are trying to achieve superior altitude to the WAC
Corporal sounding rocket of around the same size with its booster (which
topped out at around 50 miles). And it used liquid fuel and a
solid-fueled booster to get even _that_ high.

Pat

On Aug 6, 4:55 pm, (Derek Lyons) wrote:
"Ken S. Tucker" wrote:

I did a post to Steve a few days ago about that, it went to cyber-
heaven, I hardly think it was rejected, if so, moderators, please advise the
group).

After investigation, it appears it was accidentally marked as spam and
rejected - probably caused by me moderating with insuficient caffiene
in my system.
Mea Culpa.
Please repost.

LOL, it may have appeared I was 'selling' the Sugar Shot to Space,
which is of course inappropriate, but my motive is a light discussion
about the technical approach the SS2S team is using, that others
may find interesting.
Generally any unique rocket technology that is successfully tested
gets me excited.

D.
Touch-twice life. Eat. Drink. Laugh.
http://derekl1963.livejournal.com/

Cheers
Ken


======================================= MODERATOR'S COMMENT:
JDL