Author Topic: Aerojetís confidence in Next Generation Engine and green propellants  (Read 17083 times)

Online Chris Bergin

http://www.nasaspaceflight.com/2012/02/aerojets-confidence-next-generation-engine-green-propellants/

Mainly let the quotes do the talking in the second half, as it heady stuff ;D

All quotes to NSF via the good folks at Aerojet.

Offline deltaV

  • Full Member
  • ****
  • Posts: 1538
  • Change in velocity
  • Liked: 165
  • Likes Given: 480
From the article:
Quote
For interplanetary missions to Mars, NASA has chosen Aerojetís monopropellant hydrazine thrusters for both cruise and landing for all Mars landers to date for the simple reason that hydrazine (N2H4) does not contain carbon.

What's wrong with carbon?
« Last Edit: 02/07/2012 03:35 AM by deltaV »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 27993
  • Minnesota
  • Liked: 7808
  • Likes Given: 5202
From the article:
Quote
For interplanetary missions to Mars, NASA has chosen Aerojetís monopropellant hydrazine thrusters for both cruise and landing for all Mars landers to date for the simple reason that hydrazine (N2H4) does not contain carbon.

What's wrong with carbon?
Maybe it has to do with lack of (instrument or soil) contamination when looking for organic chemical life signs or precursors?


Anyway, does aerojet have any FIRM customers that have bought on to any of their new thrusters or engines for flight?
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Jason Sole

  • Full Member
  • **
  • Posts: 225
  • Chicago
  • Liked: 4
  • Likes Given: 3
Interesting article! The green prop part was all new to me.

Offline Jason Sole

  • Full Member
  • **
  • Posts: 225
  • Chicago
  • Liked: 4
  • Likes Given: 3

Anyway, does aerojet have any FIRM customers that have bought on to any of their new thrusters or engines for flight?

They'd need to make them first, right. And then companies don't go into sales and allow competitors know.

Strange question.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 27993
  • Minnesota
  • Liked: 7808
  • Likes Given: 5202

Anyway, does aerojet have any FIRM customers that have bought on to any of their new thrusters or engines for flight?

They'd need to make them first, right. And then companies don't go into sales and allow competitors know.

Strange question.
I'm just wondering if any of their newer engines (Aerojet has tested lots of engines in the past that haven't flown) have a new firm order for flight instead of just more development contracts (i.e. paper and test-firing but no flights).
« Last Edit: 02/07/2012 02:27 PM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline 93143

  • Senior Member
  • *****
  • Posts: 3038
  • Liked: 292
  • Likes Given: 1
Nitrous/ethanol, eh?  I tried it in CEA, with a 30 bar chamber and a 100:1 nozzle, and I got a vacuum Isp of around 295-300 s, Ī10 or so, with several seconds difference between room-temperature gaseous N2O and cryogenic liquid N2O.  Chamber temperature is a bit shy of 3100 K.  The optimum O/F ratio seems to be around 5...

Overall performance might be 30-50 seconds short of optimum LOX/ethanol (>3300 K, less nitrogen).

Does this sound wrong to anybody?

The reason the optimum O/F is so high is probably the relatively small oxygen fraction - the nitrogen doesn't really care much about the alcohol, and there's a lot of N2 in the exhaust.  But while N2O may be a fairly unenthusiastic oxidizer, it has a high positive heat of formation; cryogenic liquid N2O is a monopropellant with an Isp of about 180 s at 100:1.  Room-temperature gaseous N2O does better:  200 s.  In fact the article mentions work on nitrous oxide as a monopropellant...
« Last Edit: 02/07/2012 08:59 AM by 93143 »

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 218
  • Likes Given: 12
Nitrous/ethanol, eh?  I tried it in CEA, with a 30 bar chamber and a 100:1 nozzle, and I got a vacuum Isp of around 295-300 s, Ī10 or so, with several seconds difference between room-temperature gaseous N2O and cryogenic liquid N2O.  Chamber temperature is a bit shy of 3100 K.  The optimum O/F ratio seems to be around 5...

Overall performance might be 30-50 seconds short of optimum LOX/ethanol (>3300 K, less nitrogen).

Does this sound wrong to anybody?

The reason the optimum O/F is so high is probably the relatively small oxygen fraction - the nitrogen doesn't really care much about the alcohol, and there's a lot of N2 in the exhaust.  But while N2O may be a fairly unenthusiastic oxidizer, it has a high positive heat of formation; cryogenic liquid N2O is a monopropellant with an Isp of about 180 s at 100:1.  Room-temperature gaseous N2O does better:  200 s.  In fact the article mentions work on nitrous oxide as a monopropellant...

It's about right. The thing with any propulsion using nitrous is that it's a little more instructive to think of it as an augmented monopropellant. You get a lot of your energy from the N2O. Yes it does talk about mono-N2O. Doable, but the density Isp isn't great (half of hydrazine). Someone would have to want it enough to pay for dev.

Interesting article! The green prop part was all new to me.

HAN is why people talking about NOFBX like it'll replace hydrazine rubs me the wrong way so much. There are so many other green monoprops out there, it's just some have better PR than others.
« Last Edit: 02/07/2012 04:10 PM by strangequark »

Offline robertross

  • Canadian Member
  • Senior Member
  • *****
  • Posts: 17797
  • Westphal, Nova Scotia
  • Liked: 462
  • Likes Given: 3939
http://www.nasaspaceflight.com/2012/02/aerojets-confidence-next-generation-engine-green-propellants/

Mainly let the quotes do the talking in the second half, as it heady stuff ;D

All quotes to NSF via the good folks at Aerojet.

Good stuff. I like the idea of 'trying' to move away from toxic chemicals on HSF missions, especially ones of long duration. The real benefit is reduced complexity (wrt safety) on the ground with processing & handling, but you never know: in the future we may need to perform orbital repairs, and the more benign the propellants the better. Obviously a long way from that, but you have to give it a chance.
Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 218
  • Likes Given: 12
Good stuff. I like the idea of 'trying' to move away from toxic chemicals on HSF missions, especially ones of long duration. The real benefit is reduced complexity (wrt safety) on the ground with processing & handling, but you never know: in the future we may need to perform orbital repairs, and the more benign the propellants the better. Obviously a long way from that, but you have to give it a chance.

Thereís a performance benefit too. The established players are pretty comfortable with N2H4, and theyíve already paid a lot of the costs associated with its handling. Therefore, low toxicity isnít as big a selling point as you might think. It just so happens that the green monoprops can give you biprop-like performance. That is the aspect that will really sell these systems once they are flight-ready.

Offline robertross

  • Canadian Member
  • Senior Member
  • *****
  • Posts: 17797
  • Westphal, Nova Scotia
  • Liked: 462
  • Likes Given: 3939
Good stuff. I like the idea of 'trying' to move away from toxic chemicals on HSF missions, especially ones of long duration. The real benefit is reduced complexity (wrt safety) on the ground with processing & handling, but you never know: in the future we may need to perform orbital repairs, and the more benign the propellants the better. Obviously a long way from that, but you have to give it a chance.

Thereís a performance benefit too. The established players are pretty comfortable with N2H4, and theyíve already paid a lot of the costs associated with its handling. Therefore, low toxicity isnít as big a selling point as you might think. It just so happens that the green monoprops can give you biprop-like performance. That is the aspect that will really sell these systems once they are flight-ready.


Granted the costs of handling Hydrazine & such are an aspect, but also the turn-around & ground ops. If we start having many commercial companies looking to use these 'green' propellants on their vehicles, it makes their job a whole lot simpler, faster, and safer.

Being able to 'land anywhere' for something like a Dreamchaser, for example (and it's non-hazardous return ferry flight).
Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

Offline baldusi

  • Senior Member
  • *****
  • Posts: 7437
  • Buenos Aires, Argentina
  • Liked: 1442
  • Likes Given: 4499
Good stuff. I like the idea of 'trying' to move away from toxic chemicals on HSF missions, especially ones of long duration. The real benefit is reduced complexity (wrt safety) on the ground with processing & handling, but you never know: in the future we may need to perform orbital repairs, and the more benign the propellants the better. Obviously a long way from that, but you have to give it a chance.

Thereís a performance benefit too. The established players are pretty comfortable with N2H4, and theyíve already paid a lot of the costs associated with its handling. Therefore, low toxicity isnít as big a selling point as you might think. It just so happens that the green monoprops can give you biprop-like performance. That is the aspect that will really sell these systems once they are flight-ready.

One of the big issues that I seldom see mention, but that would seem some of the most critical to me, are the simplicity of long term storage, and its density. Both critical issues that might more than compensate for a lower performance fuel. Specially when talking about thrusters or maneuver engines for GSO sats.
Toxicity isn't a problem to current users, but might be critical for new entrants. Let's use for example Argentina's space program. They are currently using a Navy base for launches, because they have a zone qualified for toxic substances and all the requires fire fighting and safety equipment. But when they tried to look for a place to put a base, there's just one point in the country that would allow 35 to 107 degrees launches without overflying a city or town. And guess what, it's a protected zone and the environmental impact was simply too much for an hypergolic rocket like Tronador.
I'm pretty sure that's a problem that not only my country is facing. The NOFBX people had stated that green fuels and it's technology can be exported without ITAR problems. I see there a possible market. I not only mean new entrants into the space program, but start ups that would need to make the extra investment if they where to chose hypergolics.

Offline beb

  • Full Member
  • **
  • Posts: 264
  • Liked: 3
  • Likes Given: 7
I'm curious what Aerojet hopes to achieve with their NGE replacement for the RL-10? The impression I have (as an armchair scientist) is that the RL-10 is about perfection when it comes to ISP, weight and thrust-to-weight ratio. How would the NGE improve on any of that?

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 218
  • Likes Given: 12
I'm curious what Aerojet hopes to achieve with their NGE replacement for the RL-10? The impression I have (as an armchair scientist) is that the RL-10 is about perfection when it comes to ISP, weight and thrust-to-weight ratio. How would the NGE improve on any of that?

It improves on all three, and is a much smaller engine. I know how it does so, but I don't think the information is public. Let's just say it's a pretty clever little engine.
« Last Edit: 02/08/2012 02:30 PM by strangequark »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 27993
  • Minnesota
  • Liked: 7808
  • Likes Given: 5202
I'm curious what Aerojet hopes to achieve with their NGE replacement for the RL-10? The impression I have (as an armchair scientist) is that the RL-10 is about perfection when it comes to ISP, weight and thrust-to-weight ratio. How would the NGE improve on any of that?

It improves on all three, and is a much smaller engine. I know how it does so, but I don't think the information is public. Let's just say it's a pretty clever little engine.
Interesting. I hope they get it to flight.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Proponent

  • Senior Member
  • *****
  • Posts: 5346
  • Liked: 924
  • Likes Given: 604
I'm curious what Aerojet hopes to achieve with their NGE replacement for the RL-10? The impression I have (as an armchair scientist) is that the RL-10 is about perfection when it comes to ISP, weight and thrust-to-weight ratio. How would the NGE improve on any of that?

It improves on all three, and is a much smaller engine. I know how it does so, but I don't think the information is public. Let's just say it's a pretty clever little engine.

If it's smaller, wouldn't it also likely be cheaper?

Online kevin-rf

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8639
  • Overlooking the path Mary's little Lamb took..
  • Liked: 1111
  • Likes Given: 241
If it's smaller, wouldn't it also likely be cheaper?

Overhead and engineering costs would probably more than offset those costs. The real question would be, are Aerojet's overhead costs lower? If yes, then they can offer the engine for less than an RL-10!
If you're happy and you know it,
It's your med's!

Online Chris Bergin

Good timing! ;D

Feb. 8, 2012

David E. Steitz
Headquarters, Washington
202-358-1730
[email protected]

Kimberly Newton
Marshall Space Flight Center, Huntsville, Ala
256-544-0034
[email protected]


RELEASE: 12-046

NASA SEEKS PROPOSALS FOR GREEN PROPELLANT TECHNOLOGY DEMONSTRATIONS

WASHINGTON -- NASA is seeking technology demonstration proposals for
green propellant alternatives to the highly toxic fuel hydrazine. As
NASA works with American companies to open a new era of access to
space, the agency seeks innovative and transformative fuels that are
less harmful to our environment.

Hydrazine is an efficient and ubiquitous propellant that can be stored
for long periods of time, but is also highly corrosive and toxic. It
is used extensively on commercial and defense department satellites
as well as for NASA science and exploration missions. NASA is looking
for an alternative that decreases environmental hazards and
pollutants, has fewer operational hazards and shortens rocket launch
processing times.

"High performance green propulsion has the potential to significantly
change how we travel in space," said Michael Gazarik, director of
NASA's Space Technology Program at the agency's headquarters in
Washington. "NASA's Space Technology Program seeks out these sort of
cross-cutting, innovative technologies to enable our future missions
while also providing benefit to the American space industry. By
reducing the hazards of handling fuel, we can reduce ground
processing time and lower costs for rocket launches, allowing a
greater community of researchers and technologists access to the high
frontier."

Beyond decreasing environmental hazards and pollutants, promising
aspects of green propellants also include reduced systems complexity,
fewer operational hazards, decreased launch processing times and
increased propellant performance.

Maturing a space technology, such as green propellants, to mission
readiness through relevant environment testing and demonstration is a
significant challenge from a cost, schedule and risk perspective.
NASA has established the Technology Demonstration Missions Program to
perform this function, bridging the gap between laboratory
confirmation of a technology and its initial use on an operational
mission.

NASA anticipates making one or more awards in response to this
solicitation, with no single award exceeding $50 million. Final
awards will be made based on the strength of proposals and
availability of funds. The deadline for submitting proposals is April
30.

The Technology Demonstration Missions Program is managed by NASA's
Marshall Space Flight Center in Huntsville, Ala. To view the
announcement and instructions for submissions, visit:

http://go.usa.gov/Qbx

For more information about NASA's Space Technology Program and
Technology Demonstration Missions, visit:

http://www.nasa.gov/oct


Offline simonbp

Maybe it has to do with lack of (instrument or soil) contamination when looking for organic chemical life signs or precursors?

Yes. While the Martian surface doesn't lack for CO2, the UV environment is so intense that almost any other carbon-bearing gas molecule has a very short lifetime (geologically). CH4, for example, has a mean atmospheric lifetime of about 100 years. Thus, any trace organic compounds are signs of an active, ongoing process, either geological or biological. This means it's quite important not to pollute your landing site with the exact chemicals you're looking for...

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7442
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 162
What's wrong with carbon?

Can't be used for monopropellant because of carbon deposits on the catalyst pack.
We will be vic-toooooo-ri-ous!!!

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 218
  • Likes Given: 12
What's wrong with carbon?

Can't be used for monopropellant because of carbon deposits on the catalyst pack.

Well yes, but it's also a contaminant if you're searching for life.

Offline deltaV

  • Full Member
  • ****
  • Posts: 1538
  • Change in velocity
  • Liked: 165
  • Likes Given: 480
Thanks, the theory of not wanting to contaminate the landing site with carbon compounds makes sense to me.

Offline robertross

  • Canadian Member
  • Senior Member
  • *****
  • Posts: 17797
  • Westphal, Nova Scotia
  • Liked: 462
  • Likes Given: 3939
Good timing! ;D

NASA SEEKS PROPOSALS FOR GREEN PROPELLANT TECHNOLOGY DEMONSTRATIONS

...
NASA anticipates making one or more awards in response to this
solicitation, with no single award exceeding $50 million. Final
awards will be made based on the strength of proposals and
availability of funds. The deadline for submitting proposals is April
30.
Indeed.
Nice to see Aerojet ahead of the curve on this. Never hurts to get funding for your work.
Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

Online Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 15145
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 4522
  • Likes Given: 589
I don't think N2O/C2H6O is a very good combination. Liquid N2O can detonate under shock, as Scaled Composites found out to its loss. Compared to liquid oxygen it does give better density, but much worse Isp. Here's some numbers. The impulse density (Id) is propellant density times exhaust speed, and gives an indication of the volumetric efficiency of the propellant. The higher the better.

Efficiency = 97.4%
Chamber Pressure = 20.7 MPa
Expansion Ratio = 77.5
HTP = 0.98*H2O2 + 0.02*H2O by mass

Propellants  MR   dp (kg/L)  ve (m/s) Id (Ns/L)
O2/RPĖ1      2.8   1.0307     3554     3663
N2O/RP-1     9.2   1.1626     3099     3603
N2O/C2H6O    5.7   1.1301     3042     3438
HTP/RPĖ1     7.3   1.3059     3223     4209


HTP has excellent Id which makes it a very good first stage propellant, better even than O2/RPĖ1. Modern HTP is stable and decomposes at less than 1% per year. It also does not detonate under shock, but cleanliness to the same levels as for O2 are required to prevent rapid decomposition.

For your amusement, attached is a list I've made up of various propellant combinations. Have a favourite that's not listed? Let me know and I'll run the numbers.
« Last Edit: 02/11/2012 06:48 AM by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Online Ronsmytheiii

  • Moderator
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 22446
  • Liked: 760
  • Likes Given: 277
Bumping as related to MSL, but also would be interested to know how Aerojet will handle the NGE competition now that their main competitor was purchased by their parent company.....
"Every vision is a joke until the first man accomplishes it; once realized, it becomes commonplace." - Robert Goddard

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 218
  • Likes Given: 12
Bumping as related to MSL, but also would be interested to know how Aerojet will handle the NGE competition now that their main competitor was purchased by their parent company.....

My understanding is that PWR's entry was essentially the RL-10C. It wouldn't surprise me if the RL-10C ends up being used in the near-term, with Aerojet's NGE coming online later on. The development on the former should be quick, whereas the latter offers a lot more performance for the longer term, but it's a completely novel engine cycle.

Offline baldusi

  • Senior Member
  • *****
  • Posts: 7437
  • Buenos Aires, Argentina
  • Liked: 1442
  • Likes Given: 4499
My understanding is that PWR's entry was essentially the RL-10C. It wouldn't surprise me if the RL-10C ends up being used in the near-term, with Aerojet's NGE coming online later on. The development on the former should be quick, whereas the latter offers a lot more performance for the longer term, but it's a completely novel engine cycle.
That means lots and lots of qual testing, thus expense and time?

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 218
  • Likes Given: 12
That means lots and lots of qual testing, thus expense and time?

Si, por supuesto.

Tags: