generuso

6 ms·

1.
by generuso 5d ago
The cone of Cherenkov radiation produces arcs of "bright pixels" in the detector. There are very good illustrations of this if you search for "Super-Kamiokande Cherenkov ring." That's a Japanese neutrino telescope w
2.
by generuso 6d ago
It was not just the VCs. There were also influential people in Pentagon who saw the inefficiency of the prime defense contractors, especially after having seen what SpaceX was able to do. One of the consequences of this was the meteoric ris
3.
by generuso 10d ago
Indeed. Here is another page about the same thing: https://cwandt.com/products/pocket-fiche "This project is a collaboration with Miles Segal (Gotham Silicon), whose mission is to make microchip fabrication more b
4.
by generuso 10d ago
Sounds great as a slogan, but there are no details. For comparison, Intel's 1 um process (Fab 3, 80386-era) required about 4 weeks of processing time, and if pushed, the samples could be processed in as little as two weeks. For a long
5.
by generuso 10d ago
If Isar will get a large scale commitment from the government(s) to launch the OneWeb 2.0 constellation, as the European alternative to US, Chinese and Russian systems, they may well become a major launch provider. And of course they are al
6.
by generuso 10d ago
Talking about the role of V2 in the development of rocketry in various countries is more or less relevant to the discussion of Isar, because it was a major milestone, and it did influence all rocketry worldwide, in many different ways. Rock
7.
by generuso 11d ago
Incidentally, the early investment for Isar came from Bülent Altan, the Turkish ex-SpaceX guy who was in charge of the guidance system for Falcon-1, Falcon-9 and Dragon.
8.
by generuso 11d ago
Most of the US space launch startups have failed. And in Europe it is harder to even try. There was a confluence of several factors which helped SpaceX to succeed, and not the least of these was the employee number one. For many years, Tom
9.
by generuso 11d ago
USA got the cream of the crop of the managers of the German missile program, while the USSR got the workers, who actually did the work with their hands and built the parts for the rockets. (One exception was Helmut Gröttrup, the head of the
10.
by generuso 3mo ago
They do not like to talk about it too much in public these days, but Rocket Lab had somewhat shady beginnings. Once they moved past the semi-amateur phase, their first real project was weapons development on a DARPA contract. They were work
11.
by generuso 3mo ago
It is uncontroversial among Dostoyevsky's scholars that his main focus is on Russian mysticism while the stories themselves are merely a setting for presenting author's theology. But that may be flying over the head of a typical W
12.
by generuso 3mo ago
Marc Raibert was a student of Ivan Sutherland. Sutherland had a lot of pull at DARPA. This facilitated the unique prototyping work done at Boston Dynamics to get noticed and supported by DARPA. But as a flip side of this, Boston Dynamics de
13.
by generuso 4mo ago
Maybe it was a bit too colloquial. I am not sure if this is very important. A formal term would have been "full propellant load." The phrase "fill level" is also used in NASA documents. The question was whether during th
14.
by generuso 4mo ago
Correction: The first stage of New Glenn carries only about 260 tons of methane. The 1150 tons is the full propellent load, liquid oxygen and liquid methane combined. The heat from combustion of this amount would be about 3.4 kt, which is r
15.
by generuso 4mo ago
The problem is that there is no standard meaning for the "full duration" in this context. Some reports say that this means "running all seven BE-4 engines at full thrust for up to 38 seconds". In flight the engines fire
16.
by generuso 4mo ago
The TNT is relevant, because the atomic bomb energy output was defined in terms of TNT equivalent. Not the energy of the blast, but the total output. For Trinity this was 20 kt, or 20*4.2 TJ. This serves as a basis of comparison for this de
17.
by generuso 4mo ago
You are talking about the energy of the blast. In my comment I was talking about the heat output. From the followup comments it seems I have not made it sufficiently clear. The energy of the detonation wave in rocket explosions is typically
18.
by generuso 4mo ago
It is not clear what "full duration static fire" means, but if the stage was fully fueled, the fuel tank would have contained 1000 tons of methane. The heat of combustion of methane is 55 MJ/kg. TNT equivalent is defined as 4
19.
by generuso 4mo ago
Both SpaceX and NASA use LabView. NASA has a relatively detailed description of the engine test stands at Stannis: https://scholar.google.com/scholar?q=NASA+Data+Acquisition+S... https://scholar.google.com/s
20.
by generuso 4mo ago
Five years ago SpaceX reported that they had 30000 seconds of test firing time on the Raptor, over 567 engine starts. Since them the program accelerated dramatically. Well over one thousand engines had been produced, and on an average day a
21.
by generuso 4mo ago
If we look at the venting from the propellant tank (around T+16:15) it looks thick white closer to the vent, becoming more transparent and blue as it expands. That's just sunlight scattering on the particles and density fluctuations in
22.
by generuso 4mo ago
The views from Ship's engine bay looked rather ominous -- with the red glow visible in multiple places, and something venting furiously from the broken engine. It was a pleasant surprise that the ship did not explode and not only that,
23.
by generuso 4mo ago
There is an excellent three part documentary from Sandia National Labs: "Always/Never: The Quest for Safety, Control, and Survivability." (part 1) https://www.youtube.com/watch?v=DQEB3LJ5psk They cover both
24.
by generuso 4mo ago
Cleve Moler was one of the big names in numerical methods, and participated in creation of canonical FORTRAN libraries for solving linear equations, and matrix algorithms more generally. To teach this more conveniently to his students, he w
25.
by generuso 4mo ago
They struggled with many things, often time the minutiae of accomplishing something conceptually rather simple. For example, making an explosive with a significantly slower detonation velocity turned out to be very tricky. The concept was s
26.
by generuso 4mo ago
There are different versions of the story. In one of them, somebody asked the question whether the atmosphere could ignite, and that was very quickly answered in the negative, but then Oppenheimer mentioned it to the people in Washington, a
27.
by generuso 4mo ago
Plutonium was compressed about two-fold by volume. There is a story about it. When they first brainstormed the ways to make the bomb, even before Los Alamos, in 1942, one of the several ideas was to use explosives to throw smaller pieces of
28.
by generuso 4mo ago
It is all true, but one needs to take into account that because of the different properties of the materials, the critical mass for uranium-235 is intrinsically much greater than that for plutonium-239. For a bare sphere, it is about 10 kg
29.
by generuso 4mo ago
99% of all diamonds by mass are industrial diamonds. But they are so inexpensive that they only account for 3% or the revenue. The jewelry is the remaining 0.8% by mass, and it is split roughly equally between the natural and synthetic ston
30.
by generuso 4mo ago
I think one can extrapolate further. There will be two things intertwined together: 1. Thought will be liberated from the confines of mortal bodies. 2. Technology will be able to create and modify things on the molecular level, limited only

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