Barry Jenakuns
@jenakuns.bsky.social
New profile new Akin Law:
"Capabilities drive requirements, regardless of what the systems engineering textbooks say."
"Capabilities drive requirements, regardless of what the systems engineering textbooks say."
Past 3 days of Blue Origin if you even care.
I mean come on this is cool.
I mean come on this is cool.
November 22, 2025 at 1:53 AM
Past 3 days of Blue Origin if you even care.
I mean come on this is cool.
I mean come on this is cool.
:((((((((((((((((
Superheavy you were supposed to be the good part of Starship; not join the dark side of failing press tests. No more clean transition; all bets are off. (aside from betting against Elon I guess)
Superheavy you were supposed to be the good part of Starship; not join the dark side of failing press tests. No more clean transition; all bets are off. (aside from betting against Elon I guess)
November 21, 2025 at 10:53 PM
:((((((((((((((((
Superheavy you were supposed to be the good part of Starship; not join the dark side of failing press tests. No more clean transition; all bets are off. (aside from betting against Elon I guess)
Superheavy you were supposed to be the good part of Starship; not join the dark side of failing press tests. No more clean transition; all bets are off. (aside from betting against Elon I guess)
From the SpaceX side of things, Merlin 1D, ASDS VTVL, Raptor are genuine excellent and technical marvels. But it is the lean manufacturing, vertical integration and flat management that makes the capital/IP in their hands valuable.
October 26, 2025 at 4:03 AM
From the SpaceX side of things, Merlin 1D, ASDS VTVL, Raptor are genuine excellent and technical marvels. But it is the lean manufacturing, vertical integration and flat management that makes the capital/IP in their hands valuable.
This is great. NASA being able to drive government R&D/talent and milestone based funding through an efficient management structure which is then able to tap private capital/markets substantially increases the amount NASA achieves. SpaceX is not an antagonist to NASA; it is their greatest success.
October 26, 2025 at 4:03 AM
This is great. NASA being able to drive government R&D/talent and milestone based funding through an efficient management structure which is then able to tap private capital/markets substantially increases the amount NASA achieves. SpaceX is not an antagonist to NASA; it is their greatest success.
Multiple poor experiences with space vendors is what led to the drive for vertical integration.
With Merlin 1C, the pumps were brought in house, although still based on the initial Fastrac 1.
However over the course of Merlin dev, the pumps have 4x'd their original horsepower; think pump of Theseus.
With Merlin 1C, the pumps were brought in house, although still based on the initial Fastrac 1.
However over the course of Merlin dev, the pumps have 4x'd their original horsepower; think pump of Theseus.
![The Merlin engine itself has undergone a number of improvements, including reducing the number of parts and increasing its power and efficiency. According to Mueller, the 140,000-pound-thrust Merlin 1D, designated the production model for Falcon 9, has the highest thrust-to-weight ratio of any rocket engine ever made.
Significantly, the Merlin engines—like roughly 80 percent of the components for Falcon and Dragon, including even the flight computers—are made in-house. That’s something SpaceX didn’t originally set out to do, but was driven to by suppliers’ high prices. Mueller recalls asking a vendor for an estimate on a particular engine valve. “They came back [requesting] like a year and a half in development and hundreds of thousands of dollars. Just way out of whack. And we’re like, ‘No, we need it by this summer, for much, much less money.’ They go, ‘Good luck with that,’ and kind of smirked and left.” Mueller’s people made the valve themselves, and by summer they had qualified it for use with cryogenic propellants.
“That vendor, they iced us for a couple of months,” Mueller says, “and then they called us back: ‘Hey, we’re willing to do that valve. You guys want to talk about it?’ And we’re like, ‘No, we’re done.’ He goes, ‘What do you mean you’re done?’ ‘We qualified it. We’re done.’ And there was just silence at the end of the line. They were in shock.” That scenario has been repeated to the point where, Mueller says, “we passionately avoid space vendors.”](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:rgctb5bjolcv5ixg3rz6ajbo/bafkreid6vrnzs6xno7mkzrdvlzzcea57kzn6o7j344gts5vdlnhcaxydqq@jpeg)
October 26, 2025 at 4:03 AM
Multiple poor experiences with space vendors is what led to the drive for vertical integration.
With Merlin 1C, the pumps were brought in house, although still based on the initial Fastrac 1.
However over the course of Merlin dev, the pumps have 4x'd their original horsepower; think pump of Theseus.
With Merlin 1C, the pumps were brought in house, although still based on the initial Fastrac 1.
However over the course of Merlin dev, the pumps have 4x'd their original horsepower; think pump of Theseus.
Going back to the initial days of SpaceX, one of the initial ideas was horizontal integration. The Fastrac turbopumps made by Barbel Nichols were bought and used for the Merlin 1A. This did aid with development timelines and helped them get a vehicle to pad.
spacenews.com/web-entrepre...
spacenews.com/web-entrepre...
October 26, 2025 at 4:03 AM
Going back to the initial days of SpaceX, one of the initial ideas was horizontal integration. The Fastrac turbopumps made by Barbel Nichols were bought and used for the Merlin 1A. This did aid with development timelines and helped them get a vehicle to pad.
spacenews.com/web-entrepre...
spacenews.com/web-entrepre...
Is LOX ISRU architectures a thing? I want them to be a thing. Lunox from the 90s did a fair amount of work on it and it's certainly doable. However, going for full reuse with a re-entry vehicle lander might be a bit more dubious; those margins look tight.
October 26, 2025 at 12:48 AM
Is LOX ISRU architectures a thing? I want them to be a thing. Lunox from the 90s did a fair amount of work on it and it's certainly doable. However, going for full reuse with a re-entry vehicle lander might be a bit more dubious; those margins look tight.
... under expansion decreases performance compared to optimum, but the engine still works fine which is glaringly obvious by the footage.
It's over expansion which causes issues at sea level with vac engines nozzles failing (although R-Vac sorta gets away with it)
It's over expansion which causes issues at sea level with vac engines nozzles failing (although R-Vac sorta gets away with it)
October 15, 2025 at 3:05 AM
... under expansion decreases performance compared to optimum, but the engine still works fine which is glaringly obvious by the footage.
It's over expansion which causes issues at sea level with vac engines nozzles failing (although R-Vac sorta gets away with it)
It's over expansion which causes issues at sea level with vac engines nozzles failing (although R-Vac sorta gets away with it)
My god these views are so excellent. Moon 2028, Mars 2030, Idk I like the cut of that jib.
Now SpaceX lets do a clean transition to V3; none of this screwing around for 4 launches.
Now SpaceX lets do a clean transition to V3; none of this screwing around for 4 launches.
October 14, 2025 at 3:21 AM
My god these views are so excellent. Moon 2028, Mars 2030, Idk I like the cut of that jib.
Now SpaceX lets do a clean transition to V3; none of this screwing around for 4 launches.
Now SpaceX lets do a clean transition to V3; none of this screwing around for 4 launches.
Well, he only mentions science once in that piece to argue that the de-prioritizing it for exploration is a good outcome. So you get an idea of how.
September 16, 2025 at 12:43 AM
Well, he only mentions science once in that piece to argue that the de-prioritizing it for exploration is a good outcome. So you get an idea of how.
Are we back? I've been under a rock for 2 months and oh my that is an Orange Starship we are back. Sick imagery; more daytime re-entries please. Hope we can see 1 month turn around for next launch.
I'm content, but lets not have to do the same for 4 launches with V3.
I'm content, but lets not have to do the same for 4 launches with V3.
August 27, 2025 at 2:21 AM
Are we back? I've been under a rock for 2 months and oh my that is an Orange Starship we are back. Sick imagery; more daytime re-entries please. Hope we can see 1 month turn around for next launch.
I'm content, but lets not have to do the same for 4 launches with V3.
I'm content, but lets not have to do the same for 4 launches with V3.
The fundamental goal of NASA isn't to build rockets or other service contracts; it is to conduct fundamental space based scientific research and develop the capability of the state to do continue to expand into space. Both of those are best served by scaling systems with markets.
August 26, 2025 at 11:56 AM
The fundamental goal of NASA isn't to build rockets or other service contracts; it is to conduct fundamental space based scientific research and develop the capability of the state to do continue to expand into space. Both of those are best served by scaling systems with markets.
NASA tried owning the services it bought for 50 years. Then in the shadow of the retirement of the Shuttle, they set up a new model for the small fry of ISS cargo. They ended up with an incredible deal at a time and a dynamic system which has continued to scale.
August 26, 2025 at 11:56 AM
NASA tried owning the services it bought for 50 years. Then in the shadow of the retirement of the Shuttle, they set up a new model for the small fry of ISS cargo. They ended up with an incredible deal at a time and a dynamic system which has continued to scale.
For me, it's just that Lockheed was specifically calling out their ability to make 2030 happen a week before the 100kW was announced.
August 17, 2025 at 12:57 AM
For me, it's just that Lockheed was specifically calling out their ability to make 2030 happen a week before the 100kW was announced.
We'll see what industry puts out, put sodium heat pipes was the baseline for Krusty.
ntrs.nasa.gov/api/citation...
ntrs.nasa.gov/api/citation...
August 6, 2025 at 11:39 AM
We'll see what industry puts out, put sodium heat pipes was the baseline for Krusty.
ntrs.nasa.gov/api/citation...
ntrs.nasa.gov/api/citation...
If you complete 3 reworks and get a better product in the time it takes the competitor to get 1 regular work; that's a better outcome.
July 22, 2025 at 4:17 AM
If you complete 3 reworks and get a better product in the time it takes the competitor to get 1 regular work; that's a better outcome.
Payload on orbit. F9/H has launched 504 times with 3.5 failures, >99% reliability. Only Atlas V exceeds that. F9 cadence is cracked, launches more times in a year than Atlas V has in the past 20.
June 21, 2025 at 2:21 PM
Payload on orbit. F9/H has launched 504 times with 3.5 failures, >99% reliability. Only Atlas V exceeds that. F9 cadence is cracked, launches more times in a year than Atlas V has in the past 20.
The good ol days ay.
June 6, 2025 at 11:11 AM
The good ol days ay.
I can understand that the republican party is not the biggest Earth science supporters, but astrophysics getting slaughtered beats me.
May 30, 2025 at 11:34 PM
I can understand that the republican party is not the biggest Earth science supporters, but astrophysics getting slaughtered beats me.
I like chaos in my programs. At least a little. The permutations allow for new structures to form. This new budget is maybe too much chaos though.
nasawatch.com/trumpspace/c...
nasawatch.com/trumpspace/c...
May 25, 2025 at 6:32 AM
I like chaos in my programs. At least a little. The permutations allow for new structures to form. This new budget is maybe too much chaos though.
nasawatch.com/trumpspace/c...
nasawatch.com/trumpspace/c...
Don't, this is easily one of the most pleasant interactions I've had in this category of online interactions.
I'll summarise my feelings on Isar in an image.
bsky.app/profile/jena...
I'll summarise my feelings on Isar in an image.
bsky.app/profile/jena...
March 28, 2025 at 5:34 AM
Don't, this is easily one of the most pleasant interactions I've had in this category of online interactions.
I'll summarise my feelings on Isar in an image.
bsky.app/profile/jena...
I'll summarise my feelings on Isar in an image.
bsky.app/profile/jena...
There's nothing in that document stating the subsidy phrasing; where did you find this?
"milestone based R&D Subsidy » according to the filing"
Looking at the URL, I now have my suspicions that I'm talking to an AI generated summary which makes me sad.
"milestone based R&D Subsidy » according to the filing"
Looking at the URL, I now have my suspicions that I'm talking to an AI generated summary which makes me sad.
March 22, 2025 at 2:13 PM
There's nothing in that document stating the subsidy phrasing; where did you find this?
"milestone based R&D Subsidy » according to the filing"
Looking at the URL, I now have my suspicions that I'm talking to an AI generated summary which makes me sad.
"milestone based R&D Subsidy » according to the filing"
Looking at the URL, I now have my suspicions that I'm talking to an AI generated summary which makes me sad.
2 sides of the coin ay. We caught it for a second time; Yay. But we lost it for a second time for a same failure mode; Nay. It's so weird having the two extremes of SpaceX right next to each other.
It's annoying because we were set for 2025 and now this has to be dealt with.
It's annoying because we were set for 2025 and now this has to be dealt with.
January 18, 2025 at 2:30 AM
2 sides of the coin ay. We caught it for a second time; Yay. But we lost it for a second time for a same failure mode; Nay. It's so weird having the two extremes of SpaceX right next to each other.
It's annoying because we were set for 2025 and now this has to be dealt with.
It's annoying because we were set for 2025 and now this has to be dealt with.
Yeah the phrasing goes back ages, you can see a variation here in Ignition (published in 1972).
January 18, 2025 at 12:30 AM
Yeah the phrasing goes back ages, you can see a variation here in Ignition (published in 1972).