Author Topic: New "Green" Monopropellants as potential first stage propellants  (Read 29627 times)

Offline fatjohn1408

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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!

Offline john smith 19

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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.
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline fatjohn1408

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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?

Offline R7

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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?)
AD·ASTRA·ASTRORVM·GRATIA

Offline MP99

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
« Last Edit: 07/25/2013 11:36 AM by MP99 »

Offline A_M_Swallow

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Hydrogen Peroxide is an alternative green monopropellant.  The NASA Mighty Eagle mini-lander uses it.

Offline fatjohn1408

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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.

Offline douglas100

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It's already been used on two stages of a vehicle that has successfully launched a satellite.
Douglas Clark

Offline R7

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It's already been used on two stages of a vehicle that has successfully launched a satellite.

Not as monopropellant.
AD·ASTRA·ASTRORVM·GRATIA

Offline Port

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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

Offline douglas100

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It's already been used on two stages of a vehicle that has successfully launched a satellite.

Not as monopropellant.

True.
Douglas Clark

Offline Oli

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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.

Offline cordwainer

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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.

Offline RanulfC

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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
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline cordwainer

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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.

Offline HappyMartian

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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.

 
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Offline betaking12

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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

Offline HappyMartian

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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?"
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Offline savuporo

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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
« Last Edit: 10/02/2013 02:45 PM by savuporo »
Orion - the first and only manned not-too-deep-space craft

Offline HappyMartian

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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.
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