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General Discussion => Advanced Concepts => Topic started by: fatjohn1408 on 07/25/2013 08:44 am

Title: New "Green" Monopropellants as potential first stage propellants
Post by: fatjohn1408 on 07/25/2013 08:44 am
Hello,

In this thread I would like to open up the discussion of usage of recent developments in monopropellants.
As you may or may not know Hydrazine is no longer the top dog of the monopropellant arena.
Both in Europe as in the States research is ongoing regarding high performance monopropellants.

These reach theoretical Isp values of 252s and 266s in vacuum with densities of 1.25 and 1.46 respectively.

I have a lot of questions about this.
How available are these propellants?
How easy are they to work with?
How simple is a monopropellant stage compared to a bipropellant/solid?
Are there any other monopropellants that I missed?

Join me in this great quest for more answers and more questions!
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: john smith 19 on 07/25/2013 09:10 am
Hello,

In this thread I would like to open up the discussion of usage of recent developments in monopropellants.
As you may or may not know Hydrazine is no longer the top dog of the monopropellant arena.
Both in Europe as in the States research is ongoing regarding high performance monopropellants.

These reach theoretical Isp values of 252s and 266s in vacuum with densities of 1.25 and 1.46 respectively.

I have a lot of questions about this.
How available are these propellants?
How easy are they to work with?
How simple is a monopropellant stage compared to a bipropellant/solid?
Are there any other monopropellants that I missed?

Join me in this great quest for more answers and more questions!
Before starting a thread on this you might like to use this sites search box. May I suggest "green propellant" as a thread topic?

You can also search the usenet groups sci.space.tech and others using Google.

They can also tell you all you want to know about the other questions you have asked.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: fatjohn1408 on 07/25/2013 09:52 am
Well you are partially right.
I did search a little bit, but all applications were for satellite systems and Attitude control systems.

However after researching I found this post:

No. HAN propellants require a catalyst bed, meaning that the design is totally different from existing bipropellant hypergol thrusters like Draco. It is also very different from a hydrazine thruster because the reaction temperature is 2-3 times higher. Hydrazine thrusters are typically made of nickel alloys. HAN thrusters use ceramics and expensive refractory metals like rhenium.

HAN propellants have some shelf-life stability issues that have been one of the major points of focus for developing this propellant type. The understanding of how to stabilize them has improved steadily over the years however, and would probably be fine for any depot with a reasonable throughput. If you're thinking for large scale main propulsion though, HAN would not be a great fuel, as the catalyst bed will result in low T/W for a larger engine. and there's not really any major benefits it would bring to the table over something like Methane/LOX. For refueling satellites, maybe, but the business case is probably weak. I'm not a satellite guy, but I don't think propellant is usually the life-limiting factor.

So appearantly for launch vehicles HAN propellants are not a really good way to go. Is the same true for ADN propellants?
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: R7 on 07/25/2013 10:27 am
So appearantly for launch vehicles HAN propellants are not a really good way to go. Is the same true for ADN propellants?

It appears to have same problems. From http://www.intechopen.com/books/advances-in-spacecraft-technologies/green-propellants-based-on-ammonium-dinitramide-adn-

Quote
One important aspect in the development of a new monopropellant is the ignition. State of
the art hydrazine thrusters use catalytic ignition, which is simple and reliable. To replace hydrazine,
ADN-based monopropellants must be as easy to ignite. However, a
disadvantage of the ADN-based monopropellants is the high combustion temperature,
which is approximately 800°C higher than hydrazine, as seen in Table 10. The combustion
temperature is in the same range as for HAN-based monopropellants, and it has been
reported that the current state of the art hydrazine catalyst (Shell 405) cannot withstand such
high temperatures (Reed, 2003; Zube et al., 2003). This and the fact that hydrazine and ADNbased
liquid propellants are very different, both physically and chemically, require
development of new ignition methods, or new catalysts. When dripping the FLP-106 on a
hot plate, with a temperature in the range of 200 to 250°C, it ignite and burn fast. This
clearly shows that thermal ignition is possible and thermal ignition might thus be a feasible
ignition method. Three different methods of heating the propellant to the ignition
temperature have been identified:
• Pyrotechnic (by forming hot gases using a solid energetic material which in turn will
heat the propellant)
• Thermal conduction (by spraying the propellant on a hot object which in turn is heated
by electric means)
• Resistive (ADN is a salt and the propellants thereby possess a relatively high electric
conductivity. This means that an ADN-based monopropellant can be resistively heated)
Development of catalytic (Scharlemann, 2010), thermal (Wingborg et al., 2006), and resistive
(Wingborg et al., 2005) ignition methods is ongoing.

See also the other green thread http://forum.nasaspaceflight.com/index.php?topic=32165.0 (maybe these two should be joined?)
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: MP99 on 07/25/2013 11:35 am
Doesn't that suggest that in a big engine, once you get ADN burning, and the thrust chamber hot, that combustion would be self-sustaining? (I gueess that means the heat de-composes it, and then it immediately burns.)

Problem may be more in stopping the heat soaking into the feed pipe? Also, potential for solid-like explosion if a bulk of liquid happens to get heated?

Cheers, Martin

Edit: and not great for regen-cooling of the engine.  :o
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: A_M_Swallow on 07/25/2013 06:02 pm
Hydrogen Peroxide is an alternative green monopropellant.  The NASA Mighty Eagle mini-lander uses it.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: fatjohn1408 on 08/01/2013 12:40 pm
Hydrogen Peroxide is an alternative green monopropellant.  The NASA Mighty Eagle mini-lander uses it.

Yes but the Isp and other performance issues makes it a non-viable alternative for most applications including first stages.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: douglas100 on 08/01/2013 01:33 pm
It's already been used on two stages of a vehicle that has successfully launched a satellite.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: R7 on 08/01/2013 01:58 pm
It's already been used on two stages of a vehicle that has successfully launched a satellite.

Not as monopropellant.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Port on 08/01/2013 02:59 pm
Quote
It is typically bonded with glycidyl azide polymer (GAP), Hydroxyl-terminated polybutadiene (HTPB), or carboxy-terminated polybutadiene (CTPB) and requires preheating to 200-300 °C to decompose. The catalyst is a noble metal, similar to the other monopropellants that use silver or palladium.

I've read somewhere that rhuthenium or iridium works best.. cant quiet remember where
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: douglas100 on 08/01/2013 04:47 pm
It's already been used on two stages of a vehicle that has successfully launched a satellite.

Not as monopropellant.

True.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Oli on 09/02/2013 03:44 am

Apparently NASA was considering Ammonium dinitramide (ADN) as an oxidizer for Ares I.

http://www.flightglobal.com/blogs/hyperbola/2008/12/nasa_denies_ares_i_crew_launch/

A 4% increase in ISP and 8% decrease in density compared to AP. Maybe solids will switch to ADN when its ready, but green (i.e. non-toxic) propellants are definitely more interesting for replacing hydrazine in thrusters.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: cordwainer on 09/03/2013 08:37 pm
MON propellants might work, but they aren't exactly "green". Hydrogen peroxide might be used as an "oxidizer" with a solid or paste like "green" propellant to make a hybrid rocket engine.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: RanulfC on 09/03/2013 09:02 pm
MON propellants might work, but they aren't exactly "green". Hydrogen peroxide might be used as an "oxidizer" with a solid or paste like "green" propellant to make a hybrid rocket engine.

H2O2 and Paraffin Wax :)

NOT a "mono-propellant" though...

Randy
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: cordwainer on 09/04/2013 07:00 pm
Well. the question was how simple a monopropellant rocket compared to a bipropellant rocket would be, and that isn't always a straightforward comparison. Monopropellants usually require intense heat or expensive catalysts which do not make them ideal for a lift off stage. Like monopropellants, mixed propellants and hybrid propellant rockets don't necessarily need the complicated plumbing, storage and turbo-pumping that bipropellant rockets do. Of course pressure fed bipropellants don't need turbopumps, offering higher thrust than a monopropellant and less weight than a bipropellant. Downside is that they aren't very fuel efficient but that doesn't matter so much for a lift-off stage or SSTO. Big dumb thrusters like OTRAG don't give up anything in payload once built beyond a certain size.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 10/02/2013 09:51 am
Doesn't that suggest that in a big engine, once you get ADN burning, and the thrust chamber hot, that combustion would be self-sustaining? (I gueess that means the heat de-composes it, and then it immediately burns.)

Problem may be more in stopping the heat soaking into the feed pipe? Also, potential for solid-like explosion if a bulk of liquid happens to get heated?

Cheers, Martin

Edit: and not great for regen-cooling of the engine.  :o



Page 2 "AF-M315E offers higher performance than hydrazine, yields 12% higher Isp (257 vs. 235 sec), and is 45% more dense (1.47 vs. 1.00 g/cc), affecting both reduced propellant and tank mass."

Page 2 "Aerojet Rocketdyne estimates that an AF-M315E-based descent stage on the Mars Science Laboratory would have enabled 58 kg increased landed mass for the 930-kg rover compared to the hydrazine system that was flown."

Page 4 "A key, albeit by no means exclusive, contributor to the rapid acceleration in maturation of AF-M315E thruster technology seen in recent times has been the advent of Aerojet’s patent-pending LCH-240 high-temperature long-life catalyst, demonstrating sufficient endurance within the propellant’s decomposition/combustion environment to extend thruster life over 15× compared to the prior state-of-the-art."

Page 9 "The culmination of this program will be high-performance, green AF-M315E propulsion system technology at TRL 7+ that is ready for direct infusion to a wide range of applications for the space user community."

From: GPIM AF-M315E Propulsion System  By Ronald A. Spores, Robert Masse, Scott Kimbrel, and Chris McLean  July 2013   49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit



Perhaps someone somewhere is running water in an open cycle through a cooling jacket around the mono-propellant feed line and then into the cooling channels around a large rocket engine and making use of the produced steam to power a turbo-pump for the AF-M315E mono-propellant before releasing the low pressure vapor into the propellant tank or atmosphere.  Pretty simple technology for a first stage, right?

Propellant density is very useful and may offer some "Green" Mono-propellants as potential first stage propellants.

 
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: betaking12 on 10/02/2013 12:49 pm
This would allow for fuel cross feeding right? (or at least easier fuel cross feeding).

now if they only had a non-toxic bipropellant/oxidizer :D
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 10/02/2013 01:24 pm
More food for thought:


HIGH-PERFORMANCE GREEN PROPULSION (HPGP) FOR IMPROVED PERFORMANCE, RESPONSIVENESS AND REDUCED LIFECYCLE COST  By Steve Beckel and Aaron Dinardi  Space Tech Expo Satellite & Space Summit      May 22, 2013

Page 4
"LMP-103S monopropellant: ADN 60-65 % Methanol 15-20 % Ammonia 3-6 % Water balance (by weight)"

Page 5
"NASA GSFC analyzed the mass savings which would have been achieved on the Lunar Reconnaissance Orbiter (1,882 kg) if it had implemented HPGP instead of hydrazine, and concluded that: • A 39% smaller tank (volume) and 26% less propellant (mass) could have been used, resulting in “waterfall” mass savings of 18.7% of the entire spacecraft’s mass"

Page 7
"HPGP has been flight-proven to outperform hydrazine on the PRISMA mission"

Page 15
"ATK is Building the Foundation for US High Performance Green Propulsion (HPGP) Technology"



Note: On page 18 is a 220 N thruster that is noted to be at TRL 4/5 and have an Isp of (~ 255 - 285 sec).


Is anyone besides me wondering, "Is ATK eventually going to build a large and 'green' rocket?"
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: savuporo on 10/02/2013 02:41 pm
http://www.sscspace.com/about-the-ssc-group/ssc-companies/ecaps/success-stories-1

They have a very very small thruster however, scaling that for first stage propulsion is no small feat.

http://www.spaceref.com/news/viewpr.html?pid=39789
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 10/02/2013 03:59 pm
This would allow for fuel cross feeding right? (or at least easier fuel cross feeding).

now if they only had a non-toxic bipropellant/oxidizer :D



Ammonium dinitramide    From Wikipedia
At: http://en.wikipedia.org/wiki/Ammonium_dinitramide

"Molecular formula    H4N4O4    Molar mass 124.06 g mol−1       Density 1.81 g/cm3"
   
And, "Ammonium dinitramide (ADN) is the ammonium salt of dinitraminic acid. ADN decomposes under heat to leave only nitrogen, oxygen, and water."

And, "It makes an excellent solid rocket oxidizer with a slightly higher specific impulse than ammonium perchlorate and more importantly, does not leave hydrogen chloride fumes. It decomposes into low molecular mass gases so it contributes to higher performance without creating excessive temperatures if used in gun or rocket propellants."



As for a high energy fuel to burn with the solid ADN oxidizer, how about pressurized propane tanks feeding a hybrid rocket?

With the tank pressurized propane "fuel cross feeding" into the large and mostly solid ADN hybrid motor, you simply 'drop' opposite pairs of the six exterior mounted propane tanks as they empty.

That might be a pretty simple first stage.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Former SSC employee on 10/21/2013 04:29 pm
For information about ATK , ECAPS (SSC Space), Skybox and ECAPS ADN propellant (LMP-103S) and thrusters, see this AIAA paper from 12:th of September 2013:

Implementation and Continued Development of High Performance Green Propulsion (HPGP) in the United States

written by A. Dinardi 1) - Ecological Advanced Propulsion Systems, Inc. S. Beckel 2) - Alliant Techsystems, Inc.
and J. Dyer 3) - Skybox Imaging, Inc.

Link to 1st page: http://arc.aiaa.org/doi/abs/10.2514/6.2013-5441 (http://arc.aiaa.org/doi/abs/10.2514/6.2013-5441)

Approximately 5 years ago, ATK entered into an agreement with ECAPS to serve as the U.S. agent for
the import of HPGP technologies. Since that time, with the support of some key customers, ATK has
invested to bring the propellant blending capabilities to its Elkton facility, performed hazard
classification testing to obtain a Department of Transportation (DOT) certification to ship the propellant
and has now set up a vacuum chamber test stand to perform hot-fire testing of HPGP thrusters. Most
importantly, ATK has also established the capability to develop HPGP rocket engines for a variety of
applications of interest to NASA, DoD and Commercial customers. To date, customer response has
been excellent, with needs for thrusters ranging from mN up to about 2kN of force for applications
ranging from spacecraft, launch vehicle and missile interceptor attitude control systems to apogee kick
motors for orbit adjustment.

Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 10/29/2013 03:00 pm
Maybe the New "Green" Monopropellants as potential first stage propellants should consider:


"Nitrous Oxide Fuel Blend propellants are a class of liquid rocket propellants. The fuel and oxidizer are blended and stored, and are sometimes referred to as 'mixed monopropellants'. Upon use, the propellant is heated or passed over a catalyst bed and the Nitrous oxide decompose into oxygen-rich gasses."

And, "NOFBX is the trademarked name for a proprietary nitrous oxide/fuel/emulsifer blended mono-propellant developed by Firestar Technologies LLC.[6] NOFBX has a higher ISP and is less toxic than other monopropellants currently used in space applicatons, such as hydrazine."

And, "The patent claims a mixture of nitrous oxide (oxidizer) with ethane, ethene or ethyne as the fuel; as an example, the mixed gases are condensed into a liquid at –70 °C."

From: Nitrous oxide fuel blend   Wikipedia
At: http://en.wikipedia.org/wiki/NOFBX#NOFBX


Anyone have any ideas about the various Isp possibilities of various mixtures of ethane, ethene or ethyne burned with nitrous oxide?


See also:
As announced in March this year, a NOFBX monopropulsion demonstration will be performed on ISS in 2012.
....
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Former SSC employee on 10/29/2013 04:14 pm
Abour NOFBX: http://www.aiaa.org/uploadedFiles/About-AIAA/Press_Room/Key_Speeches-Reports-and-Presentations/Greg_Mungas.pdf (http://www.aiaa.org/uploadedFiles/About-AIAA/Press_Room/Key_Speeches-Reports-and-Presentations/Greg_Mungas.pdf)

SSC ECAPS has a new propellant in the pipe which will use less expensive thruster materials i.e. the propellant has a lower burning temperature: http://congress.cimne.com/eucass2013/admin/files/fileabstract/a625.pdf (http://congress.cimne.com/eucass2013/admin/files/fileabstract/a625.pdf)

I think the key is the burning temperature.

With burning temp about 1600C or higher the thruster will be too expensive to fabricate.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Former SSC employee on 10/30/2013 03:23 pm
About the interest NASA shows about SSC ECAPS green propellant and thrusters.

NASA and Swedish National Space Board (SNSB) establish a cooperative agreement to test ECAPS' High Performance Green Propulsion technology in the U.S.

Link: http://www.spaceref.com/news/viewpr.html?pid=41843 (http://www.spaceref.com/news/viewpr.html?pid=41843)


In furtherance of the recently signed cooperative agreement, ECAPS will - under contract to SNSB - mature both the 5N and 22N thrusters to Technology Readiness Level (TRL) 6.  Flight-like thrusters will then be delivered to NASA for testing and evaluation in the United States.  LMP-103S propellant will also be delivered to NASA, for use in hot-fire ground testing and U.S. Range Safety analyses.

"We are seeking propulsion alternatives to hydrazine in order to decrease environmental and operational hazards and pollutants, reduce spacecraft processing costs and increase on-orbit performance," said Dr. Christyl Johnson, Deputy Center Director for Science and Technology at NASA's Goddard Space Flight Center. "We are happy to be working with SNSB under this cooperative agreement, and we look forward to collaborating with both SNSB and ECAPS on the testing, evaluation, and comparison of this technology to hydrazine."
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 11/11/2013 02:03 pm
"ALICE is a rocket propellant which consists of nanoaluminium powder and water. After mixing, the material is frozen to keep it stable. Hence, the name ALICE, for ALuminium ICE rocket propellant."

From: ALICE (propellant)    Wikipedia
At: http://en.wikipedia.org/wiki/ALICE_%28propellant%29


Various other solid propellants or liquid slurry based monopropellants might be dense and have useful amounts of chemical energy.

Add a liquid, or a binder, to lots of fullerenes with acetylene molecules trapped inside of them and mix with other fullerenes with oxygen molecules trapped inside of them.   

Or just add a liquid, or a binder, to fullerenes with oxygen molecules trapped inside of them.


Note:

"A fullerene is any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, tube, and many other shapes. Spherical fullerenes are also called buckyballs, and they resemble the balls used in football (soccer)."

From: Fullerene    Wikipedia
At: http://en.wikipedia.org/wiki/Fullerene#Other_buckyballs


And:

"Endohedral fullerenes (co-called endofullerenes) are fullerenes that have additional atoms, ions, or clusters enclosed within their inner spheres."

From: Endohedral fullerene    Wikipedia
At: http://en.wikipedia.org/wiki/Endohedral_fullerenes
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Former SSC employee on 11/11/2013 08:23 pm
It is not easy to space qualify a new propellant.

Look here what ESA says about qualification:

LMP-103S SYSTEM/COMPONENT QUALIFICATION NEEDS EVALUATION (CLEAN SPACE)

http://emits.sso.esa.int/emits/owa/emits_online.showao?typ1=5976&user=Anonymous (http://emits.sso.esa.int/emits/owa/emits_online.showao?typ1=5976&user=Anonymous)

A short cut from the above link:

Note: based on development activity to date, it is expected that LMP-103S is materially and functionally compatible with most propulsion equipment. Thus, the development needs are thought to be minimal; however, this must be verified in the proposed activity. The primary tasks of this activity include the following:
-Identify materials and equipment used in propellant systems.
-Verify that LMP-103S compatibility has been demonstrated for all materials or ensure that this will be addressed in the LMP-103S qualification activity.
-Analyse LMP-103S functional/performance compatibility with the propulsion system/equipment. This may include math models and validation testing.
-Determine the detailed approaches required to achieve qualification of propulsion system/equipment for use with LMP-103S.
-Coordinate with equipment/system suppliers to get concurrence on development, qualification or EQSR activity foreseen for the equipment/system.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: simonbp on 11/12/2013 03:47 pm
"ALICE is a rocket propellant which consists of nanoaluminium powder and water. After mixing, the material is frozen to keep it stable. Hence, the name ALICE, for ALuminium ICE rocket propellant."

From: ALICE (propellant)    Wikipedia
At: http://en.wikipedia.org/wiki/ALICE_%28propellant%29

That's pretty cool. Sounds ideal for the asteroid miners...
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 11/14/2013 03:22 pm
"ALICE is a rocket propellant which consists of nanoaluminium powder and water. After mixing, the material is frozen to keep it stable. Hence, the name ALICE, for ALuminium ICE rocket propellant."

From: ALICE (propellant)    Wikipedia
At: http://en.wikipedia.org/wiki/ALICE_%28propellant%29

That's pretty cool. Sounds ideal for the asteroid miners...


Yep! And maybe useful for the Lunar miners too!
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 11/16/2013 05:41 pm
As was noted previously,

Ammonium dinitramide    From Wikipedia
At: http://en.wikipedia.org/wiki/Ammonium_dinitramide

"Molecular formula    H4N4O4    Molar mass 124.06 g mol−1       Density 1.81 g/cm3"
   
And, "Ammonium dinitramide (ADN) is the ammonium salt of dinitraminic acid. ADN decomposes under heat to leave only nitrogen, oxygen, and water."

And, "It makes an excellent solid rocket oxidizer with a slightly higher specific impulse than ammonium perchlorate and more importantly, does not leave hydrogen chloride fumes. It decomposes into low molecular mass gases so it contributes to higher performance without creating excessive temperatures if used in gun or rocket propellants."




Apparently NASA was considering Ammonium dinitramide (ADN) as an oxidizer for Ares I.

http://www.flightglobal.com/blogs/hyperbola/2008/12/nasa_denies_ares_i_crew_launch/

A 4% increase in ISP and 8% decrease in density compared to AP. Maybe solids will switch to ADN when its ready, but green (i.e. non-toxic) propellants are definitely more interesting for replacing hydrazine in thrusters.


So if the "excellent solid rocket oxidizer" ADN is mixed with nanoaluminium powder, a binder, and possibly a catalyst, would the mix form a very useful high performance solid propellant for the first stage for an ATK Dark Knight/Ares I type of launcher?

Would it burn clean and green enough?

If the second stage also used the same solid propellant and lofted an easy to store 'green' liquid propellant third stage, we might have the basis for launching a kinetic energy/chemical explosive quick response interceptor for shattering a small incoming NEO.


This would allow for fuel cross feeding right? (or at least easier fuel cross feeding).

now if they only had a non-toxic bipropellant/oxidizer :D



Or all the interceptor's stages could burn an easy to store ADN slurry monopropellant that contained nanoaluminium particles that were carefully 'tailored' to have the appropriate neutral buoyancy.

Three such ADN and nanoaluminum slurry propelled launchers could have a Delta IV Heavy type of configuration with propellant cross-feed.

Edited.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 11/21/2013 10:02 pm

Apparently NASA was considering Ammonium dinitramide (ADN) as an oxidizer for Ares I.

http://www.flightglobal.com/blogs/hyperbola/2008/12/nasa_denies_ares_i_crew_launch/

A 4% increase in ISP and 8% decrease in density compared to AP. Maybe solids will switch to ADN when its ready, but green (i.e. non-toxic) propellants are definitely more interesting for replacing hydrazine in thrusters.


Mix in Endohedral hydrogen fullerenes with the ADN.

How much hydrogen would be inside the average Endohedral hydrogen fullerene?

What would be the theoretical Isp of such a monopropellant?


"Endohedral hydrogen fullerene (H2@C60) is an endohedral fullerene containing molecular hydrogen. This chemical compound has a potential application in molecular electronics and was synthesized in 2005 at Kyoto University by the group of Koichi Komatsu.[1][2] Ordinarily the payload of endohedral fullerenes are inserted at the time of the synthesis of the fullerene itself or is introduced to the fullerene at very low yields at high temperatures and high pressure."

And, "H2@C60 is found to be a stable molecule. it survives 10 minutes at 500 °C and shows the same chemical reactivity as empty C60."

Endohedral hydrogen fullerene    Wikipedia
At: http://en.wikipedia.org/wiki/Endohedral_hydrogen_fullerene
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 11/21/2013 10:24 pm
"Selective hydrogenation method exists. Reaction of C60 with 9,9',10,10'-dihydroanthracene under the same conditions, depending on the time of reaction, gives C60H32 and C60H18 respectively and selectively.[54]

C60 can be hydrogenated,[55] suggesting that a modified buckminsterfullerenes called organometallic buckyballs (OBBs) could become a vehicle for 'high density, room temperature, ambient pressure storage of hydrogen'. These OBBs are created by binding atoms of a transition metal (TM) to C60 or C48B12 and then binding many hydrogen atoms to this TM atom, dispersing them evenly throughout the inside of the organometallic buckyball. The study found that the theoretical amount of H2 that can be retrieved from the OBB at ambient pressure approaches 9 wt %, a mass fraction that has been designated as optimal for hydrogen fuel by the U.S. Department of Energy."

From: Buckminsterfullerene
At: http://en.wikipedia.org/wiki/C60_fullerene#Hydrogenation


"Yakobson and his team determined that the maximum number of hydrogen atoms inside C60, which can form a metastable structure, i.e. corresponds to an energy minimum, is 58. Their model allows to calculate the maximum number of hydrogen that can be encapsulated in a stable fullerene of any given radius. For instance, a giant fullerene cage C720 could contain over 800 hydrogen atoms."

From: Fullerenes for hydrogen storage      By Michael Berger   Oct 19, 2007     nanowerk   
At: http://www.nanowerk.com/spotlight/spotid=2999.php

Edited.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 11/23/2013 01:51 pm
And a very simple rocket engine that might be especially suitable for New "Green" Monopropellants as potential first stage propellants is being considered.


"In this case, thrusters based on the PulCheR concept are likely to be used also in all the missions for which continuous thrust is required (lift-off, landing), thus extending its intrinsic advantages (smaller weight, good performance even with 'green' propellants, components reduction) to these missions." 

From: "Pulsed Chemical Rocket With Green High Performance Propellants" By Pasini A., Torre L., Pace G., Valentini D., d'Agostino L.,  49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, San Jose, California, USA, July 2013.
At: http://www.alta-space.com/index.php?page=green_publications
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 12/05/2013 04:46 pm
And a very simple rocket engine that might be especially suitable for New "Green" Monopropellants as potential first stage propellants is being considered.


"In this case, thrusters based on the PulCheR concept are likely to be used also in all the missions for which continuous thrust is required (lift-off, landing), thus extending its intrinsic advantages (smaller weight, good performance even with 'green' propellants, components reduction) to these missions." 

From: "Pulsed Chemical Rocket With Green High Performance Propellants" By Pasini A., Torre L., Pace G., Valentini D., d'Agostino L.,  49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, San Jose, California, USA, July 2013.
At: http://www.alta-space.com/index.php?page=green_publications


Ammonium dinitramide (ADN) or NH4N(NO2)2 - dissolved in a solution such as used for the LMP-103S mono-propellant with 'ADN 60-65 %, methanol 15-20 %, ammonia 3-6 %, and "water for the balance (by weight)".

 When used as a mono-propellant the LMP-103S exhaust gases are Exhaust Gases are "H20 (50%), N2 (23%), H2 (16%), CO (6%), CO2 (5%)" with an Isp of "(~ 255 - 285 sec)".  Operating temperature of "-5°C to 60°C."

Quotes and information from: HIGH-PERFORMANCE GREEN PROPULSION (HPGP) FOR IMPROVED PERFORMANCE, RESPONSIVENESS AND REDUCED LIFECYCLE COST  By Steve Beckel and Aaron Dinardi  May 22, 2013.


It would seem that an aluminum or acetylene additive to LMP-103S might boost its Isp.

Note also:

"Additions of dense, solid metallic powders to neat fuels increase fuel densities and generally increase propellant densities. The major advantage of these metallized propellants is the reduction of vehicle dry mass due to smaller propellant tankage required or an increase in delivered payload at a fixed vehicle dry mass.

And, "Low aluminum additions (5 wt%) to hydrocarbon fuels increase fuel densities by 3 to 4.5%. Large aluminum additions, however, dramatically increase fuel density. Sixty-weight percent aluminum increases the neat fuel density of liquid hydrogen by 141%. Such high metal loadings may be stably suspended in neat fuels."   

From: High Energy-Density Liquid Rocket Fuel Performance   By Douglas C. Rapp   July 1990


A very large PulCheR engine with very high combustion chamber pressure pulses might offer an even higher Isp than the above noted 285 for burning the LMP-103S mono-propellant.

Even the 285 Isp noted above for the LMP-103S green mono-propellant combined with low pressure in a very lightweight single mono-propellant tank structure and the simple, high efficiency, high pressure, and lightweight pulsed rocket engines that are possible under the above noted PulCheR concept offers a significant and useful option for a first stage or SLS boosters with large conformal tanks.

 
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Former SSC employee on 12/06/2013 09:06 am
"Green Propellants" a Doctoral Thesis by Martin Rahm

Link to a fulltext copy (in English):

http://www.diva-portal.org/smash/get/diva2:360054/FULLTEXT01.pdf (http://www.diva-portal.org/smash/get/diva2:360054/FULLTEXT01.pdf)

Abstract
To enable future environmentally friendly access to space by means of solid rocket
propulsion a viable replacement to the hazardous ammonium perchlorate oxidizer is
needed. Ammonium dinitramide (ADN) is one of few such compounds currently
known. Unfortunately compatibility issues with many polymer binder systems and
unexplained solid-state behavior have thus far hampered the development of ADNbased
propellants.


HISP

Link: http://www.foi.se/en/Customer--Partners/Projects/HISP/HISP/ (http://www.foi.se/en/Customer--Partners/Projects/HISP/HISP/)

HISP stands for High performance solid propellants for In-Space Propulsion, or solid propellant with High Isp (specific impulse). As the name indicates, the objective of the project is to develop high performance solid rocket propellant for spacecrafts.

Propulsion and propellants are key technologies for all space missions. The HISP project will advance the chemical propulsion technology by linking together some of the key players in Europe to develop an advanced high performance solid propellant by using the new high energy density oxidizer ammonium dinitramide, ADN, an energetic binder based on glycidyl azide polymer, GAP, and high energy density fuels such as aluminium hydride (AlH3), nano-aluminium or activated aluminium.

This will strengthen the competitiveness of the European space propulsion industry and increase its competitiveness, and will increase the effectiveness of future European space exploration missions

HISP has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 262099.

Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 12/06/2013 03:06 pm
"Green Propellants" a Doctoral Thesis by Martin Rahm

Link to a fulltext copy (in English):

http://www.diva-portal.org/smash/get/diva2:360054/FULLTEXT01.pdf (http://www.diva-portal.org/smash/get/diva2:360054/FULLTEXT01.pdf)

Abstract
To enable future environmentally friendly access to space by means of solid rocket
propulsion a viable replacement to the hazardous ammonium perchlorate oxidizer is
needed. Ammonium dinitramide (ADN) is one of few such compounds currently
known. Unfortunately compatibility issues with many polymer binder systems and
unexplained solid-state behavior have thus far hampered the development of ADNbased
propellants.


HISP

Link: http://www.foi.se/en/Customer--Partners/Projects/HISP/HISP/ (http://www.foi.se/en/Customer--Partners/Projects/HISP/HISP/)

HISP stands for High performance solid propellants for In-Space Propulsion, or solid propellant with High Isp (specific impulse). As the name indicates, the objective of the project is to develop high performance solid rocket propellant for spacecrafts.

Propulsion and propellants are key technologies for all space missions. The HISP project will advance the chemical propulsion technology by linking together some of the key players in Europe to develop an advanced high performance solid propellant by using the new high energy density oxidizer ammonium dinitramide, ADN, an energetic binder based on glycidyl azide polymer, GAP, and high energy density fuels such as aluminium hydride (AlH3), nano-aluminium or activated aluminium.

This will strengthen the competitiveness of the European space propulsion industry and increase its competitiveness, and will increase the effectiveness of future European space exploration missions

HISP has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 262099.


From the above noted "Green Propellants" a Doctoral Thesis by Martin Rahm:

"It has been estimated that if a propellant formulation based on ADN were to replace today’s AP-based propellants the lift capacity of space launchers would increase by approximately 8%."


From the above noted: http://www.foi.se/en/Customer--Partners/Projects/HISP/HISP/ (http://www.foi.se/en/Customer--Partners/Projects/HISP/HISP/)

"Objectives
The objective of the project will be met by developing a high performance solid rocket propellant. Its performance will be similar or higher compared to state of the art liquid bi-propellants and about 10% higher compared to the current state of the art solid propellant based on AP/HTPB/Al. This will be achieved using the new high energy density oxidizer ammonium dinitramide, ADN, an energetic binder based on glycidyl azide polymer, GAP, and high energy density fuels such as aluminium hydride (AlH3), nano-aluminium or activated aluminium."



Note: ATK Star 27   "Isp=288s." "Propellant mass fraction 0.924" "Charge: 338 kg pf AP/HTPB/Al propellant"
"Gross mass: 361 kg (795 lb).  Unfuelled mass: 27 kg (59 lb)"  From: http://www.astronautix.com/engines/star27.htm



Green propellant options derived from modern chemistry can significantly improve the Isp performance and density of both mono-propellants and solid propellants.

Many potential green mono-propellants can be stored at near sea level pressures and room temperatures and this can significantly reduce the structural weight dedicated to the tank since only one large and uninsulated tank is needed. Heavy and insulated bulkheads to separate the oxidizer from the fuel are not needed.

In general, both propellant density and Isp seem to be very significant variables for reducing the size, mass, and costs of the first stage.


"The payload performances of the reusable kerosene and methane booster are therefore almost identical with some edge for kerosene. In view of the increased size and dry mass of a reusable methane booster stage, one can expect a cost disadvantage for CH4 from a launch vehicle system level point of view."

From: Comparative Study of Kerosene and Methane Propellant Engines for Reusable Liquid Booster Stages    By Holger Burkhardt, Martin Sippel, Armin Herbertz, and Josef Klevanski               
4th International Conference on Launcher Technology "Space Launcher Liquid Propulsion" 3-6 December 2002 – Ličge (Belgium)



"5. Based on historically-proven launch vehicle hardware, liquid oxygen and kerosene appear to be a preferred propellant combination for SSTO. Of all the propellants considered, these require the smallest fraction of orbiting mass for major propulsion components."

From: Single stage to orbit mass budgets derived from propellant density and specific impulse  By John C. Whitehead   Lawrence Livermore National Laboratory   
This paper was prepared for submittal to 32nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference Lake Buena Vista, FL July 1-3, 1996
Available at: http://www.osti.gov/scitech/biblio/379977


Could the use of a new and dense green mono-propellant significantly simplify, reduce costs, and lower the risks of rocket propulsion system preparations for missions staged from Earth, LEO, low Lunar orbit, and the Moon?

Could the use of a new and dense green mono-propellant combined with the lightweight simplicity and robustness offered by the 'pulsed chemical rocket engine' significantly simplify maintenance costs for reusable first stages and boosters for the SLS, a future Russian HLV, Japan's H-IIA, the Ariane 5 ME, and other large launchers?

Could the use of a new, dense, and easy to store green mono-propellant in a low pressure and lightweight tank and fed to a 'pulsed chemical rocket engine' enable the reuse of a smaller, cheaper, and less massive single stage Lunar Lander than would be the case with conventional bi-propellants?


See:

Pulsed Chemical Rocket With Green High Performance Propellants  By Pasini A., Torre L., Pace G., Valentini D., d'Agostino L.,  49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, San Jose, California, USA, July 2013.
At: http://www.alta-space.com/index.php?page=green_publications


Edited.
 
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: a_langwich on 12/06/2013 05:28 pm
Green propellant options derived from modern chemistry can significantly improve the Isp performance and density of both mono-propellants and solid propellants.

Many potential green mono-propellants can be stored at near sea level pressures and room temperatures and this can significantly reduce the structural weight dedicated to the tank. Since only one large and uninsulated tank is needed, and heavy and insulated bulkheads to separate the oxidizer from the fuel are not needed.

In general, both propellant density and Isp seem to be very significant variables for reducing the size, mass, and costs of the first stage.

...

Could the use of a new and dense green mono-propellant significantly simplify, reduce costs, and lower the risks of rocket propulsion system preparations for missions staged from Earth, LEO, low Lunar orbit, and the Moon?

Could the use of a new and dense green mono-propellant combined with the lightweight simplicity and robustness offered by the 'pulsed chemical rocket engine' significantly simplify maintenance costs for reusable first stages and boosters for the SLS, a future Russian HLV, Japan's H-IIA, the Ariane 5 ME, and other large launchers?


No.

You compare the green monopropellants to (very low Isp) non-green monopropellants, and find they can have better Isp.  Then you ask if they can replace (much much higher Isp) first-stage bipropellants?  No, they perform far worse than these, and in fact they are far less "green" and more toxic than Delta 4's hydrogen and oxygen combo, and not really any better than kerosene.

Yes, they would be denser than liquid hydrogen, but not much different from kerosene, and far worse in performance.  The poor performance will greatly outweigh the difference in tank weights.  Remember that first stage engines are not pressure-fed, so the tank pressures would likely be the same for your green props.

These monoprop systems are meant to compete against existing hydrazine monoprop and hypergol biprop systems, and they do match up well there.  They don't match up well against first-stage alternatives.

However, against solid rocket formulations, green formulations _may_ have promise.  Don't know enough to say.

Pulse rocket theory is much, much further from practical than solid rocket formulations.  The promises are being made by very heavily simplified theoretical models, while practical results are far from competitive.  It is just as likely that the promising theoretical results are unreachable due to ignored, unavoidable, real-world inefficiencies (eg realistic heat transfer models) as it is that the existing designs simply haven't gotten it right.  It doesn't seem likely that a pulse-detonation combustion chamber, and valves cycling at 500 Hz withstanding combustion chamber temps and pressures up to 100 MPa and back down to atmospheric, will simplify maintenance.

Even so, the pulse rocket's main advantage is avoiding pressurized tanks.  Again, there likely aren't much savings to be had compared to pump-fed first stages, so your pulse rocket engine will have to compete on Isp, T/W, and robustness against traditional engines.  So far, they've got a long way to go.

Quote
Could the use of a new, dense, and easy to store green mono-propellant in a low pressure and lightweight tank and fed to a 'pulsed chemical rocket engine' enable the reuse of a smaller, cheaper, and less massive single stage Lunar Lander than would be the case with conventional bi-propellants?

Now here the case is probably much stronger, and green fuels are worth competing in trade studies against the large array of existing alternatives.  The pulsed engine, maybe in a few decades, if somebody can make it work.  That's not going to be easy, until the theoretical models get a lot more work.  Perfect for academic interest:  professors can get grants for their entire academic career, refining one or more aspects of modeling pulse rocket engines, and really not caring whether it could ever be useful except in the "motivation" section of their publications.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 12/07/2013 02:02 pm
Green propellant options derived from modern chemistry can significantly improve the Isp performance and density of both mono-propellants and solid propellants.

Many potential green mono-propellants can be stored at near sea level pressures and room temperatures and this can significantly reduce the structural weight dedicated to the tank. Since only one large and uninsulated tank is needed, and heavy and insulated bulkheads to separate the oxidizer from the fuel are not needed.

In general, both propellant density and Isp seem to be very significant variables for reducing the size, mass, and costs of the first stage.

...

Could the use of a new and dense green mono-propellant significantly simplify, reduce costs, and lower the risks of rocket propulsion system preparations for missions staged from Earth, LEO, low Lunar orbit, and the Moon?

Could the use of a new and dense green mono-propellant combined with the lightweight simplicity and robustness offered by the 'pulsed chemical rocket engine' significantly simplify maintenance costs for reusable first stages and boosters for the SLS, a future Russian HLV, Japan's H-IIA, the Ariane 5 ME, and other large launchers?


No.

You compare the green monopropellants to (very low Isp) non-green monopropellants, and find they can have better Isp.  Then you ask if they can replace (much much higher Isp) first-stage bipropellants?  No, they perform far worse than these, and in fact they are far less "green" and more toxic than Delta 4's hydrogen and oxygen combo, and not really any better than kerosene.

Yes, they would be denser than liquid hydrogen, but not much different from kerosene, and far worse in performance.  The poor performance will greatly outweigh the difference in tank weights.  Remember that first stage engines are not pressure-fed, so the tank pressures would likely be the same for your green props.

These monoprop systems are meant to compete against existing hydrazine monoprop and hypergol biprop systems, and they do match up well there.  They don't match up well against first-stage alternatives.

However, against solid rocket formulations, green formulations _may_ have promise.  Don't know enough to say.

Pulse rocket theory is much, much further from practical than solid rocket formulations.  The promises are being made by very heavily simplified theoretical models, while practical results are far from competitive.  It is just as likely that the promising theoretical results are unreachable due to ignored, unavoidable, real-world inefficiencies (eg realistic heat transfer models) as it is that the existing designs simply haven't gotten it right.  It doesn't seem likely that a pulse-detonation combustion chamber, and valves cycling at 500 Hz withstanding combustion chamber temps and pressures up to 100 MPa and back down to atmospheric, will simplify maintenance.

Even so, the pulse rocket's main advantage is avoiding pressurized tanks.  Again, there likely aren't much savings to be had compared to pump-fed first stages, so your pulse rocket engine will have to compete on Isp, T/W, and robustness against traditional engines.  So far, they've got a long way to go.

Quote
Could the use of a new, dense, and easy to store green mono-propellant in a low pressure and lightweight tank and fed to a 'pulsed chemical rocket engine' enable the reuse of a smaller, cheaper, and less massive single stage Lunar Lander than would be the case with conventional bi-propellants?

Now here the case is probably much stronger, and green fuels are worth competing in trade studies against the large array of existing alternatives.  The pulsed engine, maybe in a few decades, if somebody can make it work.  That's not going to be easy, until the theoretical models get a lot more work.  Perfect for academic interest:  professors can get grants for their entire academic career, refining one or more aspects of modeling pulse rocket engines, and really not caring whether it could ever be useful except in the "motivation" section of their publications.


Well, we are posting in the Advanced Concepts section.

Perhaps we should not be dismissive of "professors" and what they are thinking or "caring" about. Some "professors", such as Albert Einstein,  have had a great influence far beyond the "academic" world.

And the work of another "professor" is also quite germane.

"Robert Hutchings Goddard (October 5, 1882 – August 10, 1945) was an American professor, physicist, and inventor who is credited with creating and building the world's first liquid-fueled rocket,[1][2] which he successfully launched on March 16, 1926. Goddard and his team launched 34 rockets[3] between 1926 and 1941, achieving altitudes as high as 2.6 km (1.6 mi) and speeds as high as 885 km/h (550 mph).[3]

Goddard's work as both theorist and engineer anticipated many of the developments that were to make spaceflight possible.[4] He has been called the man who ushered in the Space Age."

From: Robert H. Goddard    Wikipedia
At: http://en.wikipedia.org/wiki/Robert_H._Goddard


And I did suggest one green, and obviously non-toxic, mono-propellant additive that in theory could contain lots of hydrogen. I do like the idea of using hydrogen as a propellant.


"Yakobson and his team determined that the maximum number of hydrogen atoms inside C60, which can form a metastable structure, i.e. corresponds to an energy minimum, is 58. Their model allows to calculate the maximum number of hydrogen that can be encapsulated in a stable fullerene of any given radius. For instance, a giant fullerene cage C720 could contain over 800 hydrogen atoms."

And, "'Just imagine' says Pupysheva, 'they can keep so much hydrogen inside themselves, that the pressure is comparable with that inside the giant planets Jupiter or Saturn!'"

From: Fullerenes for hydrogen storage      By Michael Berger   Oct 19, 2007     nanowerk   
At: http://www.nanowerk.com/spotlight/spotid=2999.php

And large fullerenes might also be able to contain oxygen or oxygen containing molecules such as ADN. Perhaps fullerenes that contain a fuel like Alane (AlH3)n, propane (C3H8), Methylacetylene (propyne) (CH3C≡CH), or methane (CH4) may eventually be feasible to use in a mono-propellant.


"5. Based on historically-proven launch vehicle hardware, liquid oxygen and kerosene appear to be a preferred propellant combination for SSTO. Of all the propellants considered, these require the smallest fraction of orbiting mass for major propulsion components."

From: Single stage to orbit mass budgets derived from propellant density and specific impulse  By John C. Whitehead   Lawrence Livermore National Laboratory    June 6, 1996


Currently, the key issue is the very high cost of access to LEO. Isp does not reign supreme in first stages and boosters. And as was noted above, kerosene and LOX seem to be quite efficient in a systemic sense despite the obvious fact that many propellants, including liquid hydrogen and LOX, have a higher Isp.

A high Isp is just one variable to be considered. Trading a high Isp propellant for the reduced launcher costs and benefits offered by a dense propellant combination like kerosene and LOX makes good engineering sense for the Atlas V.

Launcher systemic complexity, including launch preparation, drives up risks and costs.

For liquid rocket boosters as substitutes for SRBs for the SLS, Japan's H-IIA, and the Ariane 5 ME, it might be beneficial to use a dense green mono-propellant in lightweight conformal tanks.


Note:

"Methylacetylene (propyne) is an alkyne with the chemical formula CH3C≡CH."

And, "Their research showed[citation needed] that propyne would be highly advantageous as a rocket fuel for craft intended for low Earth orbital operations."

And, "They reached this conclusion based upon a specific impulse expected to reach 370 s with oxygen as the oxidizer, a high density and power density—and the moderate boiling point, which makes the chemical easier to store than fuels that must be kept at extremely low temperatures." 

From: Methylacetylene    Wikipedia
At: http://en.wikipedia.org/wiki/Methylacetylene


Can ADN be used with propyne to form a dense and high Isp mono-propellant?

Engine, tank, and propellant choices that minimize risk, mass, and mission preparation costs while delivering a high delta-v to the rocket should be the goal.

For beyond LEO spaceflight missions, ammonia, or NH3, as a mono-propellant for nuclear thermal and Arc-Jet electrothermal rocket engines seems quite useful, especially for launches from the Moon and Mars.
 

"Arc-Jet Electrothermal Thrusters
Pros: Second only to resistojets for spacecraft flight use experience. Uses storable fluids that can
be serviced off line without the use of a facilitated ground system"  "Isp ~ 800 sec with NH3 at 30 kWe."

From: Page 12 of Propulsion System Choices and Their Implications  By Claude R. Joyner II, Daniel J. H. Levack, Russel E. Rhodes, John W. Robinson   July 2010

Edited.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Former SSC employee on 12/14/2013 08:51 am
Although the title includes the term "mircopropellant" the attached patent registration may be of interest.

"Novel Ionic Micropropellants Based on N2O for Space Propulsion"

SUMMARY OF THE INVENTION
[0010] An object of the present invention may be therefore
a monopropellant based on nitrous oxide not having the dis
advantages stated hereinbefore, and notably the instability.
Firstly, the problem related to the sensitivity of the mixture
has been solved by generating a monopropellant in Which the
fuel in its isolated form is an energetic salt. Its putting into
solution in nitrous oxide generates an ionic liquid phase.
Because of its reduced saturation vapor pressure, the fuel is
bound in the liquid phase, so that the vapor phase co-existing
With the liquid exclusively contains nitrous oxide. Secondly,
the speci?c gravity of the thereby formed monopropellants is
high by providing the salt, thereby guaranteeing high energy
density. The applied salts have formation enthalpies and
structures such that their association With nitrous oxide pro
vides theoretical ISPs comprised betWeen 300 s and 350 s
depending on the candidates.



Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 12/14/2013 11:10 am
Although the title includes the term "mircopropellant" the attached patent registration may be of interest.

"Novel Ionic Micropropellants Based on N2O for Space Propulsion"

SUMMARY OF THE INVENTION
[0010] An object of the present invention may be therefore
a monopropellant based on nitrous oxide not having the dis
advantages stated hereinbefore, and notably the instability.
Firstly, the problem related to the sensitivity of the mixture
has been solved by generating a monopropellant in Which the
fuel in its isolated form is an energetic salt. Its putting into
solution in nitrous oxide generates an ionic liquid phase.
Because of its reduced saturation vapor pressure, the fuel is
bound in the liquid phase, so that the vapor phase co-existing
With the liquid exclusively contains nitrous oxide. Secondly,
the speci?c gravity of the thereby formed monopropellants is
high by providing the salt, thereby guaranteeing high energy
density. The applied salts have formation enthalpies and
structures such that their association With nitrous oxide pro
vides theoretical ISPs comprised betWeen 300 s and 350 s
depending on the candidates.



I wonder if the "salt" or some other similar salt fuel would work in NYTROX?


"SPG engineers have recently conceived a new class of oxidizers based on refrigerated mixtures of nitrous oxide and oxygen, that we call Nytrox. Specifically, the goal is to formulate a high density, self-pressurizing oxidizer that does not have to operate at deep cryogenic temperatures. Note that in the mixture the oxygen is the volatile component which serves as the pressurizing agent whereas the N2O is the less volatile one with the primary function of densifying the mixture."

From: Propellants   NYTROX
At: http://www.spg-corp.com/nytrox-propellants.html
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 12/15/2013 08:48 am
Green propellant options derived from modern chemistry can significantly improve the Isp performance and density of both mono-propellants and solid propellants.

Many potential green mono-propellants can be stored at near sea level pressures and room temperatures and this can significantly reduce the structural weight dedicated to the tank. Since only one large and uninsulated tank is needed, and heavy and insulated bulkheads to separate the oxidizer from the fuel are not needed.

In general, both propellant density and Isp seem to be very significant variables for reducing the size, mass, and costs of the first stage.

...

Could the use of a new and dense green mono-propellant significantly simplify, reduce costs, and lower the risks of rocket propulsion system preparations for missions staged from Earth, LEO, low Lunar orbit, and the Moon?

Could the use of a new and dense green mono-propellant combined with the lightweight simplicity and robustness offered by the 'pulsed chemical rocket engine' significantly simplify maintenance costs for reusable first stages and boosters for the SLS, a future Russian HLV, Japan's H-IIA, the Ariane 5 ME, and other large launchers?


No.

You compare the green monopropellants to (very low Isp) non-green monopropellants, and find they can have better Isp.  Then you ask if they can replace (much much higher Isp) first-stage bipropellants?  No, they perform far worse than these, and in fact they are far less "green" and more toxic than Delta 4's hydrogen and oxygen combo, and not really any better than kerosene.

Yes, they would be denser than liquid hydrogen, but not much different from kerosene, and far worse in performance.  The poor performance will greatly outweigh the difference in tank weights.  Remember that first stage engines are not pressure-fed, so the tank pressures would likely be the same for your green props.

These monoprop systems are meant to compete against existing hydrazine monoprop and hypergol biprop systems, and they do match up well there.  They don't match up well against first-stage alternatives.
....



"Nitrous oxide is said to deflagrate somewhere around 600 °C (1,112 °F) at a pressure of 21 atm. It can also easily be ignited using a combination of the two. At 600 psi for example, the required ignition energy is only 6 J, whereas N2O at 130 psi would not react even with a 2500 J ignition energy input.[23][24][25][26]

Specific impulse (Isp) can be improved by blending a hydrocarbon fuel with the nitrous oxide inside the same storage tank, becoming a nitrous oxide fuel blend (NOFB) monopropellant. This storage mixture does not incur the danger of spontaneous ignition, since N2O is chemically stable. When the nitrous oxide decomposes by a heated catalyst, high temperature oxygen is released and rapidly ignites the hydrocarbon fuel-blend. NOFB monopropellants are capable of Isp greater than 300 seconds, while avoiding the toxicity associated with hypergolic propulsion systems.[27][28] The low freezing point of NOFB eases thermal management compared to hydrazine and dinitrogen tetroxide—a valuable property for space storable propellants."

From: Nitrous oxide   Wikipedia
At: http://en.wikipedia.org/wiki/Laughing_gas

I wonder about the Isp and density of the various hydrocarbon/NYTROX, NFOB, NYTROX/aluminum additive, NFOB/aluminum additive blended mono-propellants.

"NOFB monopropellants are capable of Isp greater than 300 seconds" is a clear hint that a mono-propellant doesn't have to feature a low Isp.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Former SSC employee on 12/24/2013 10:15 pm
Initial Evaluation of ADN as Oxidizer in Solid Propellants for Large Space Launcher Boosters. Final Report.

http://www.comspacewatch.com/news/viewsr.rss.html?pid=30020 (http://www.comspacewatch.com/news/viewsr.rss.html?pid=30020)

http://www.foi.se/rapport?rNo=FOI-R--2988--SE (http://www.foi.se/rapport?rNo=FOI-R--2988--SE)

http://books.google.se/books/about/Initial_Evaluation_of_ADN_as_Oxidizer_in.html?id=feSEYgEACAAJ&redir_esc=y (http://books.google.se/books/about/Initial_Evaluation_of_ADN_as_Oxidizer_in.html?id=feSEYgEACAAJ&redir_esc=y)

Abstract: The aim of this work is to perform an initial evaluation of ammonium dinitramide, ADN, as substitute for ammonium perchlorate, AP, in solid rocket propellants for large space launch boosters.

This final report includes performance evaluation, compatibility and curing assessments, propellants formulation and determination of ballistic properties.

The results show that the theoretical specific impulse increases from 262 s to 270 s by replacing AP with the same volume ADN in a typical HTPB/Al-based formulation.

ADN is found to be chemically compatible with HTPB. However, ADN seems to accelerate the oxidative degradation of HTPB and thus a suitable antioxidant is required.

ADN/HTPB/Al-based propellants have been formulated and cured successfully using isocyanates. The formulations were found to be thermally stable.

Ballistic properties were determined using a strand burner.

ADN/Al/HTPB propellant with a solid loading of 80 % had a burn rate of 12.8 mm/s at 6 MPa and a pressure exponent of 0.9. The pressure exponent is high. However, no burn rate modifiers or ballistic additives were used.

This encourages continued evaluation. The report also includes information on how to handle ADN with respect to transportation, toxicity and hazard properties.

This work was performed on NASA contract NNC09CA11C.



See alse the "old" report:

Elimination of Toxic Materials and Solvents from Solid Propellant Components
Final Report
January 2001
Sponsored by: Strategic Environmental Research and Development Program

http://www.serdp.org/content/download/6143/82970/file/PP-1058-FR-01.pdf (http://www.serdp.org/content/download/6143/82970/file/PP-1058-FR-01.pdf)
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 12/27/2013 01:44 pm
Green Satellite Propulsion Nears Industry Breakthrough   By Caleb Henry   December 23, 2013
At: http://www.satellitetoday.com/technology/2013/12/23/green-satellite-propulsion-nears-industry-breakthrough/


"[Via Satellite 12-23-13] After decades of uncontested use, hydrazine is being challenged by a new upcoming fuel in the spacecraft propulsion market. Together with Aerojet Rocketdyne, NASA and the U.S. Air Force, Ball Aerospace’s Green Propellant Infusion Mission (GPIM) is using 15 years of work to create a competitive satellite propellant called Hydroxyl Ammonium Nitrate (HAN) fuel/oxidizer blend, or AF-M315E."

And, "'When your look at a mature bus that has a hydrazine system, the odds are the rebuild of the next system wouldn’t employ this, but some of our studies show that when you employ AF-M315E, you can step down a launch vehicle for some LEO type missions,' said McLean. 'There’s $20-30 million off your launch price tag right there.'"


Nifty! Some large mono-propellant rocket engines might be useful, too! 
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: Archibald on 12/27/2013 05:42 pm
N2O is third best oxidiser behind LOX and H2O2, specific impulse with kerosene is around 310 seconds.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: HappyMartian on 01/11/2014 04:14 am
N2O is third best oxidiser behind LOX and H2O2, specific impulse with kerosene is around 310 seconds.


There are many possibilities for stable and efficient additives to H2O2 that would make it into a useful mono-propellant for rocket engines. Some of the additives are noted here:

THERMODYNAMIC DESIGN OF AN ALTERNATIVE MONOPROPELLANT FOR EMERGENCY POWER UNITS  By Shin Matsumura, John J. Rusek Department of Aeronautics and Astronautic  Purdue University   2002

"A monopropellant to replace hydrazine in emergency power units used in military aircraft has been formulated from a thermodynamic design approach. The combustion products from a combined mixture of hydrogen peroxide and a miscible organic fuel have shown that the energy available far exceeds that of pure hydrogen peroxide or of hydrazine. The propellant mixture was analyzed and formulated using a thermochemistry code and the simplex downhill method for the optimization of a design objective function. The results have shown that even with the most common fuels such as methanol, acetaldehyde, acetonitrile, acetone, and methyl ethyl ketone, a decrease of about a factor of two in the propellant volume, or an increase of about a factor two in the total operation time is possible."



Note also:

"Hydrazine is also used as a low-power monopropellant for the maneuvering thrusters of spacecraft, and the Space Shuttle's auxiliary power units (APUs). In addition, monopropellant hydrazine-fueled rocket engines are often used in terminal descent of spacecraft. Such engines were used on the Viking program landers in the 1970s as well as the Phoenix lander and Curiosity rover which landed on Mars in May 2008 and August 2012, respectively."

From: Hydrazine    Wikipedia
At: http://en.wikipedia.org/wiki/Hydrazine


It would seem that H2O2 and an additive, such as noted in "hydrogen peroxide and a miscible organic fuel", has the stability and energy density needed to be carefully considered in the search for various new 'green' mono-propellants for potential new reusable first stages or LRBs".

Perhaps the upcoming SLS booster competition will include at least one green mono-propellant LRB design.


Edited.
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: savuporo on 08/23/2015 04:28 pm
Just remembered we had this thread
http://spacenews.com/aerojet-rocketdyne-wraps-green-propulsion-system/

Quote
The propulsion system consists of a propellant tank and five thrusters that each produce 0.22 pounds of force. It uses AF-M315E, a nontoxic fuel developed by the U.S. Air Force Research Laboratory that provides higher performance than conventional propellants like hydrazine that are also hazardous to handle.

“This propulsion system delivery marks the success of more than 10 years of research and development,” Julie Van Kleeck, vice president of advanced space and launch programs at Aerojet Rocketdyne, said in a prepared statement. “Following extensive testing, we ended up with a propulsion design using a new, green monopropellant, which will fly into orbit in 2016.”

Second, older thread specifically on GPM early announcement:
http://forum.nasaspaceflight.com/index.php?topic=31821.0
Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: savuporo on 11/06/2015 12:22 am
http://www.nasa.gov/centers/marshall/news/news/releases/2015/new-green-propellants-complete-milestones.html

Quote
NASA recently completed several hot-fire tests with thrusters powered by two different green propellants with the potential to replace hydrazine. Both are ionic liquid-based blends that are less toxic and less flammable than hydrazine, which makes them easier and less costly to store, to handle and to fuel up spacecraft before launch. Additionally, the new propellants offer higher performance, delivering more thrust for a given quantity of propellant than hydrazine.

..For this project, the GPIM team tested two different sized thrusters (1 and 22 Newton) with AF-M315E. Five of the 1-Newton thrusters will fly on GPIM...

..A team at NASA’s Marshall Space Flight Center in Huntsville, Alabama, recently completed tests with both 5 Newton and 22 Newton thruster built by ECAPS and powered by LMP-103S. Engineers fired the 22 Newton thruster 35 times under varying conditions and monitored results with infrared cameras...

Both alternatives are making progress, GPIM is slated to fly next year, with ECAPS of course already with flight heritage.

Title: Re: New "Green" Monopropellants as potential first stage propellants
Post by: savuporo on 10/26/2017 02:56 am
http://digitalcommons.usu.edu/cgi/viewcontent.cgi?filename=0&article=3670&context=smallsat&type=additional


Quote
SkySat-3 was the first commercial S/C to fly a HPGP system
ECAPS’ next generation 1N ‘GP’ thruster will be incorporated into future SkySat platforms
Progress on bringing both smaller and larger HPGP thrusters to market continues