Ursa Major Technologies

[Solarsail]

At 9:48, he says their getting 340s isp on the test stand, from Hadley, which is an RP1/LOX engine. Wow.

EDIT: A bit later at the test stand, they say they have an error of up to 1% when calculating isp on the stand, so that could be as low as 337.6s Still not bad at all!

If that's test-stand performance and not projected-vacuum performance, then that's noticeably better than Raptor, and much better than the RD-171 or RD-180...  Both of those run at more than 250 bar chamber pressure.

Also interesting is that the Arroway is now full-flow staged combustion cycle, instead of fuel rich.  Also, apparently Stoke space is going to be flying a full-flow engine.

[JEF_300]

At 9:48, he says their getting 340s isp on the test stand, from Hadley, which is an RP1/LOX engine. Wow.

EDIT: A bit later at the test stand, they say they have an error of up to 1% when calculating isp on the stand, so that could be as low as 337.6s Still not bad at all!

If that's test-stand performance and not projected-vacuum performance, then that's noticeably better than Raptor, and much better than the RD-171 or RD-180...  Both of those run at more than 250 bar chamber pressure.

Yeah. For point of reference, the RS-25's sea-level isp is 366s. It almost has to be projected vacuum isp, but even still, wow.

[Robotbeat]

340s SL could be the case if they’re extremely high pressure, like above Raptor level. But yeah, probably vacuum.

EDIT: he is pointing to the vacuum engine when saying this, so I’m pretty sure it’s extrapolated vacuum Isp.

[catdlr]

Inside Ursa Major's State-Of-The-Art Rocket Engine Factory!

Sep 28, 2023
Today we check out Ursa Major and all the incredible different rocket engines they're working on. We talk to experts who will give us the nitty gritty details that I love, I get my hands on a rocket engine for the first time to help build one and we even get to catch an engine test from closer than I've ever been!

00:00 - Intro
01:30 - Overview of Engines
05:10 - Hadley Production
11:10 - Hadley On Test Stand
19:45 - Ripley On Test Stand

33:40 - Building Ripley
43:45 - Test Fire
49:00 - Explosion Compilation
50:15 - Outro

[DJPledger]

At 9:48, he says their getting 340s isp on the test stand, from Hadley, which is an RP1/LOX engine. Wow.

EDIT: A bit later at the test stand, they say they have an error of up to 1% when calculating isp on the stand, so that could be as low as 337.6s Still not bad at all!

If that's test-stand performance and not projected-vacuum performance, then that's noticeably better than Raptor, and much better than the RD-171 or RD-180...  Both of those run at more than 250 bar chamber pressure.

Also interesting is that the Arroway is now full-flow staged combustion cycle, instead of fuel rich.  Also, apparently Stoke space is going to be flying a full-flow engine.

So has Stoke done a deal with Ursa Major to supply Arroway engines for the 1st stage of their LV?

[niwax]

At 9:48, he says their getting 340s isp on the test stand, from Hadley, which is an RP1/LOX engine. Wow.

EDIT: A bit later at the test stand, they say they have an error of up to 1% when calculating isp on the stand, so that could be as low as 337.6s Still not bad at all!

If that's test-stand performance and not projected-vacuum performance, then that's noticeably better than Raptor, and much better than the RD-171 or RD-180...  Both of those run at more than 250 bar chamber pressure.

Yeah. For point of reference, the RS-25's sea-level isp is 366s. It almost has to be projected vacuum isp, but even still, wow.

They mentioned a 110 expansion ratio. Merlin gets 348s from a 165 expansion ratio with a gas generator, so they're very good but not exceptional considering the cycle. RD-0124 gets 360s in vacuum with a 82 expansion ratio but 160 bar ox-rich cycle.

The same goes for thrust-to-weight, just under 60 is decent but not amazing. Just goes to show how hard it is to reach big-engine numbers at this size.

Ironically, this is exactly the quickly developed medium performance version of a high performance architecture that Blue Origin has been claiming for years. Things bode well for their big 100-ton engine if they can keep up this kind of performance.

[edzieba]

Also of note is the claim that Ripley went from a napkin-spec to a first test fire in 24 months.

[ParabolicSnark]

Also of note is the claim that Ripley went from a napkin-spec to a first test fire in 24 months.

That seems an odd thing for them to claim and is demonstrably false by their own press and social media.

See my post from back in 2019:

While Ursa Major (@ursamajortech) is known for an active Instagram page, I have to wonder what they're actually accomplishing.

https://www.instagram.com/p/BqIxGzphAEP/
11/13/2018 (T+0): Ursa completes the first print of the Ripley combustion chamber. Note the print is in 2 pieces with a groove exposing the regen channels in the middle. (This is closed out in a later manufacturing step.) Ursa's website timeline indicates the first printed parts were actually in 9/2018, so this photo is 2 months behind (making the rest of this timeline even worse).

https://www.instagram.com/p/BwK3rW2BntC/
04/12/2019 (T+150 days): The first tease photo of Ripley showing the forward end of the combustion chamber. This suggest it took them about 5 months to weld the two chamber halves together and machine the interfaces shown in this photo.

https://www.instagram.com/p/BxyRCOPB1WQ/
05/22/2019 (T+190): The first full picture of Ripley with turbopump housings, aft half of the gimbal, and 2 feed lines.

https://www.instagram.com/p/ByiJYJhhUdZ/
06/10/2019 (T+209): Ripley is teased in the background, blurred with bokeh. It shows all the same items as the last photo.

https://www.instagram.com/p/B0TWxJkhO2r/
07/24/2019 (T+253): Detail of Ripley's LOx housing. This is either their 2nd housing, an old photo, or they took apart Ripley from older photos for this one.

https://www.instagram.com/p/B1oVFF9B6FE/
08/26/2019 (T+286): Bokeh blur close up of Ripley. Red cover plates aren't on it, but insides are darkened. No apparent difference in hardware.

https://www.instagram.com/p/B34ggnFhNJw/
10/21/2019 (T+342): The latest tease of Ripley in the background. Again, no difference.

That's almost 6 months (174 days) between the first complete photo and their most recent one and nothing has really changed. Ripley's only service to date has been to sit on a table in the background of photos. This appears to me like an oft-used trick where you assemble a few critical pieces to make a great photo that looks like a lot of progress was made when, in reality, there's a lot more to do. I speculate that those housings are empty: there's no rotor in it. If they had one, there'd be a push to get it on the test site and start running pump testing as soon as possible.

If they have had housings for 6 months and no rotor, that indicates one of two things:
1. They're running into manufacturing issues on the rotor itself (You'd never release the housings to manufacturing unless the design of the rotor was also already complete.)
2. They're not allocating resources to completing Ripley because they have no customers for it. Generation Orbit is only buying Hadley. ABL Space Systems went with in-house engines. Ursa announced the Samus engine, indicating they're chasing a specific customer.

They then announce they've completed the first hotfire tests for Ripley on March 9, 2023.

That makes first appearance of hardware (and its public announcement) to hotfire in 4 years, 3 months, and 26 days. Add on to that the time between napkin-sketch and first hardware and you're looking at 4.5-5.0 years, well over twice that claim. So either they're claiming that the Ripley they announced in 2018 wasn't actually Ripley and there's some Hollywood accounting on how they track project duration (admittedly it was sitting and doing nothing for a long time).

[TrevorMonty]

Also of note is the claim that Ripley went from a napkin-spec to a first test fire in 24 months.

That seems an odd thing for them to claim and is demonstrably false by their own press and social media.

See my post from back in 2019:

While Ursa Major (@ursamajortech) is known for an active Instagram page, I have to wonder what they're actually accomplishing.

https://www.instagram.com/p/BqIxGzphAEP/
11/13/2018 (T+0): Ursa completes the first print of the Ripley combustion chamber. Note the print is in 2 pieces with a groove exposing the regen channels in the middle. (This is closed out in a later manufacturing step.) Ursa's website timeline indicates the first printed parts were actually in 9/2018, so this photo is 2 months behind (making the rest of this timeline even worse).

https://www.instagram.com/p/BwK3rW2BntC/
04/12/2019 (T+150 days): The first tease photo of Ripley showing the forward end of the combustion chamber. This suggest it took them about 5 months to weld the two chamber halves together and machine the interfaces shown in this photo.

https://www.instagram.com/p/BxyRCOPB1WQ/
05/22/2019 (T+190): The first full picture of Ripley with turbopump housings, aft half of the gimbal, and 2 feed lines.

https://www.instagram.com/p/ByiJYJhhUdZ/
06/10/2019 (T+209): Ripley is teased in the background, blurred with bokeh. It shows all the same items as the last photo.

https://www.instagram.com/p/B0TWxJkhO2r/
07/24/2019 (T+253): Detail of Ripley's LOx housing. This is either their 2nd housing, an old photo, or they took apart Ripley from older photos for this one.

https://www.instagram.com/p/B1oVFF9B6FE/
08/26/2019 (T+286): Bokeh blur close up of Ripley. Red cover plates aren't on it, but insides are darkened. No apparent difference in hardware.

https://www.instagram.com/p/B34ggnFhNJw/
10/21/2019 (T+342): The latest tease of Ripley in the background. Again, no difference.

That's almost 6 months (174 days) between the first complete photo and their most recent one and nothing has really changed. Ripley's only service to date has been to sit on a table in the background of photos. This appears to me like an oft-used trick where you assemble a few critical pieces to make a great photo that looks like a lot of progress was made when, in reality, there's a lot more to do. I speculate that those housings are empty: there's no rotor in it. If they had one, there'd be a push to get it on the test site and start running pump testing as soon as possible.

If they have had housings for 6 months and no rotor, that indicates one of two things:
1. They're running into manufacturing issues on the rotor itself (You'd never release the housings to manufacturing unless the design of the rotor was also already complete.)
2. They're not allocating resources to completing Ripley because they have no customers for it. Generation Orbit is only buying Hadley. ABL Space Systems went with in-house engines. Ursa announced the Samus engine, indicating they're chasing a specific customer.

They then announce they've completed the first hotfire tests for Ripley on March 9, 2023.

That makes first appearance of hardware (and its public announcement) to hotfire in 4 years, 3 months, and 26 days. Add on to that the time between napkin-sketch and first hardware and you're looking at 4.5-5.0 years, well over twice that claim. So either they're claiming that the Ripley they announced in 2018 wasn't actually Ripley and there's some Hollywood accounting on how they track project duration (admittedly it was sitting and doing nothing for a long time).

Could be firing of a component eg thrust chamber.

[edzieba]

Also of note is the claim that Ripley went from a napkin-spec to a first test fire in 24 months.

That seems an odd thing for them to claim and is demonstrably false by their own press and social media.

See my post from back in 2019:

While Ursa Major (@ursamajortech) is known for an active Instagram page, I have to wonder what they're actually accomplishing.

https://www.instagram.com/p/BqIxGzphAEP/
11/13/2018 (T+0): Ursa completes the first print of the Ripley combustion chamber. Note the print is in 2 pieces with a groove exposing the regen channels in the middle. (This is closed out in a later manufacturing step.) Ursa's website timeline indicates the first printed parts were actually in 9/2018, so this photo is 2 months behind (making the rest of this timeline even worse).

https://www.instagram.com/p/BwK3rW2BntC/
04/12/2019 (T+150 days): The first tease photo of Ripley showing the forward end of the combustion chamber. This suggest it took them about 5 months to weld the two chamber halves together and machine the interfaces shown in this photo.

https://www.instagram.com/p/BxyRCOPB1WQ/
05/22/2019 (T+190): The first full picture of Ripley with turbopump housings, aft half of the gimbal, and 2 feed lines.

https://www.instagram.com/p/ByiJYJhhUdZ/
06/10/2019 (T+209): Ripley is teased in the background, blurred with bokeh. It shows all the same items as the last photo.

https://www.instagram.com/p/B0TWxJkhO2r/
07/24/2019 (T+253): Detail of Ripley's LOx housing. This is either their 2nd housing, an old photo, or they took apart Ripley from older photos for this one.

https://www.instagram.com/p/B1oVFF9B6FE/
08/26/2019 (T+286): Bokeh blur close up of Ripley. Red cover plates aren't on it, but insides are darkened. No apparent difference in hardware.

https://www.instagram.com/p/B34ggnFhNJw/
10/21/2019 (T+342): The latest tease of Ripley in the background. Again, no difference.

That's almost 6 months (174 days) between the first complete photo and their most recent one and nothing has really changed. Ripley's only service to date has been to sit on a table in the background of photos. This appears to me like an oft-used trick where you assemble a few critical pieces to make a great photo that looks like a lot of progress was made when, in reality, there's a lot more to do. I speculate that those housings are empty: there's no rotor in it. If they had one, there'd be a push to get it on the test site and start running pump testing as soon as possible.

If they have had housings for 6 months and no rotor, that indicates one of two things:
1. They're running into manufacturing issues on the rotor itself (You'd never release the housings to manufacturing unless the design of the rotor was also already complete.)
2. They're not allocating resources to completing Ripley because they have no customers for it. Generation Orbit is only buying Hadley. ABL Space Systems went with in-house engines. Ursa announced the Samus engine, indicating they're chasing a specific customer.

They then announce they've completed the first hotfire tests for Ripley on March 9, 2023.

That makes first appearance of hardware (and its public announcement) to hotfire in 4 years, 3 months, and 26 days. Add on to that the time between napkin-sketch and first hardware and you're looking at 4.5-5.0 years, well over twice that claim. So either they're claiming that the Ripley they announced in 2018 wasn't actually Ripley and there's some Hollywood accounting on how they track project duration (admittedly it was sitting and doing nothing for a long time).

The first Ripley test firing was not successful (interview video contains multiple clips from multiple angles of Ripley RUDs), so 'time to first firing' and 'time to completion of first successful test campaign' would not be the same.

[Gliderflyer]

Pretty sure the napkin time is referring to the current version. The old Ripley was 35k (I think) not 50, and had the pump on top of the chamber instead of on the side. It looks like they ditched the old one and reused the name on a completely new engine design.

[TrevorMonty]

Pretty sure the napkin time is referring to the current version. The old Ripley was 35k (I think) not 50, and had the pump on top of the chamber instead of on the side. It looks like they ditched the old one and reused the name on a completely new engine design.

Just watched and did sound like from napkin to firing of complete engine.

I can see lot of potential in Draper as high performance inspace engine which uses storable nontoxic fuels.

ULA is only customer I can think of for Arroway. They really do need a RLV to follow on from Vulcan. Arroway could be used to repower Vulcan booster which means it could use same pads without major modifications. Maybe case of operating both vehicles in parallel for a while. Arroway booster would make 3 core heavy lot more viable.

[Cheapchips]

So has Stoke done a deal with Ursa Major to supply Arroway engines for the 1st stage of their LV?

I'd expect a deal would be public by now if they had one. Assuming Stoke aren't buying Arroways in secret, then the question is why not?

Stoke's pace and aspirations for reuse might make it too risky to tie themselves to someone else development plan?  They've also bags of in-house knowledge on engine development.

[edzieba]

At 9:48, he says their getting 340s isp on the test stand, from Hadley, which is an RP1/LOX engine. Wow.

EDIT: A bit later at the test stand, they say they have an error of up to 1% when calculating isp on the stand, so that could be as low as 337.6s Still not bad at all!

 All the post graduate hoohaw in here and nobody caught this?

What's to catch? It's broadly comparable to other Kerolox ORSC engines (e.g. YF-115, RD-181) and to other Kerolox engines in that thrust class with different cycles (e.g. Rutherford). I'm pretty sure it's the smallest ORSC integrated engine* ever fired though, by quite some margin.

* Hedging my bets in case someone has demoed a tiny ORSC powerpack in a lab somewhere.

[Comga]

At 9:48, he says their getting 340s isp on the test stand, from Hadley, which is an RP1/LOX engine. Wow.

EDIT: A bit later at the test stand, they say they have an error of up to 1% when calculating isp on the stand, so that could be as low as 337.6s Still not bad at all!

 All the post graduate hoohaw in here and nobody caught this?

What's to catch? It's broadly comparable to other Kerolox ORSC engines (e.g. YF-115, RD-181) and to other Kerolox engines in that thrust class with different cycles (e.g. Rutherford). I'm pretty sure it's the smallest ORSC integrated engine* ever fired though, by quite some margin.

* Hedging my bets in case someone has demoed a tiny ORSC powerpack in a lab somewhere.

The 3rd grade math error.

No, oh venerable snarkmaster, it’s third grade listening comprehension.

He says: “..ISP is one of the hardest numbers to pin down inside of one to two percent uncertainty … we really try to drive to sub-one percent uncertainty in Isp and thrust”

Now Tim Dodds doesn’t ask for their ultimate uncertainty value, but their customers have heard it and it’s implied to be less than 1%. 
But as an engineer you know it isn’t proper to multiply Ursa’s value by 99.00%. If your 3rd grade teacher told you to do that it’s because he or she was a specialist in early education, not engineering, as it should be.  The Isp could be as low as 340*(100%-3*2%) (minus 3 sigma at the looser estimate) or as high as 360 (with the same faulty logic, but without the false precision of decimal points) but 340 seconds is the best estimated value as stated.

Question:  The Isp value is equivalent to the exhaust velocity divided by the acceleration of gravity.  Could the velocity in the supersonic flow be measured optically or with radar?

[JEF_300]

The 3rd grade math error.

No, oh venerable snarkmaster, it’s third grade listening comprehension.

He says: “..ISP is one of the hardest numbers to pin down inside of one to two percent uncertainty … we really try to drive to sub-one percent uncertainty in Isp and thrust”

I was referring to 12:51 in the video:
"And beyond that, we can get about 1% error in calculating isp."

I used that first statement rather than the one you quote from later in the video for 2 reasons. Firstly, because that first statement was the most direct, absolute, and clear. And second and much more importantly, because I hadn't actually gotten that far in the video yet when I made that edit to that post.

[deadman1204]

So question - who is buying all the 100+ engines they've made?

[gongora]

URSA MAJOR’S SOLUTION TO SOLID ROCKET MOTOR DESIGN AND MANUFACTURING IS A GAME CHANGER FOR AMERICA’S DEFENSE CAPABILITIES

DENVER, November 20, 2023 - Ursa Major is proud to introduce Lynx, a new approach to designing and manufacturing solid rocket motors (SRM). Lynx redefines a market plagued by a broken supply chain and an overextended industrial base. With Lynx, Ursa Major offers a revolutionary solution to America’s SRM shortage with a faster, more affordable process, leveraging 3D printing to manufacture multiple motors that promise to outperform legacy systems.

Traditional SRM providers rely on production lines that are difficult to re-tool, expensive to ramp up, and dependent on a significant workforce to operate. As a leader in advanced manufacturing, Ursa Major has taken a new approach. Lynx introduces flexible and scalable manufacturing to an industry currently constrained by outdated processes. Instead of inefficient, platform specific propellent requirements, Lynx offers a collaborative solution for energetics.

Flexible, adaptable production units are at the core of Ursa Major’s Lynx process. These units leverage additive manufacturing and a product-agnostic tooling system to rapidly produce multiple scalable SRM systems simultaneously without expensive and time-consuming re-tooling or retraining. That flexibility extends to propellants, where an agnostic approach to energetics allows Ursa Major to work directly with the Department of Defense, as well as incumbent SRM manufacturers and innovators.

“Ursa Major is offering a new way to scale production of SRMs,” said Ursa Major Founder and CEO Joe Laurienti. “Lynx meets the defense industry’s need for a faster, cheaper, scalable, and flexible SRM production process that results in better-performing solid rocket motors. We’ve adapted our extensive experience in additive manufacturing, materials development, and propulsion production to the most pressing problems facing the SRM industry. The result is an adaptable manufacturing process that is designed to mass produce multiple systems, rapidly switching from one model to another, producing reliable SRMs quickly and at scale, while leaving room to collaborate across the industry on energetics.”

According to data from the Center for Strategic and International Studies, depleted inventories of munitions like Javelins, Guided Multiple Launch Rocket Systems (GMLRS), and Stingers that rely on SRMs will take between five and 18 years to replace if the country continues to rely on slow, outdated production techniques. These production rates are insufficient to supply America’s allies while deterring adversaries like China.

Lynx will restore inventories with SRMs that are simpler and faster to produce, with higher anticipated performance for the warfighter.

Production capability and scalability: One additive machine can print over 1,650 man-portable motor casings in a year. In contrast, the current surge production rate for Javelin is only 2,100 per year.

Adaptability: “One-click” changeover to different casings with one additive machine.
Relevance: Ursa Major’s approach is applicable to many motors ranging from two to 22.5 inches in diameter. This size range includes many of the most commonly used missile systems, like Stingers, GMLRS, and air defense systems.

Common propellant: Ursa Major designed Lynx SRMs to carry more propellant using the same engine footprint, making it poised to outperform legacy motor systems. Additionally, the motor design is intended to allow for common propellants used across multiple applications. This approach could address supply chain challenges often associated with developing bespoke propellants for each individual motor application and could enable increased collaboration with other industry partners.

Lower costs and fewer parts: Ursa Major has reduced complex and labor-intensive manufacturing processes to significantly reduce part count and simplify and shorten the assembly process.

Ursa Major is currently developing the core technology with the intent to scale the product to multiple motor sizes and applications over the next year. Due to recent continued consolidation in the rocket motor industry, many defense contractors are looking for an alternative to relying on purchasing motor systems from competitors.

[trimeta]

Interesting, this puts them in direct competition with X-Bow Systems, which also claims to be the future of solid rocket motors.

[thespacecow]

This is a good move, why compete in the tiny launch market against super competitive new space companies, when you can compete in the much more lucrative defense market against old dinosaurs?