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August 29, 2021 Archives
Sunday, August 29, 2021
CONTEXT: The Largest Black Holes in the Universe
Here is more information on the ultra-massive black hole TON 618, whose mass is estimated as at least 66 billion solar masses, greater than the mass of all stars in the Milky Way combined, with quasar emission 140 trillion times the luminosity of the Sun.
Posted at
13:40
CONTINUITY: M-1 Rocket Engine Evolutionary Plans
Evolution of @AerojetRdyne's M1 engine into a 170 bar design with an expansion deflection nozzle for 450s Isp, and then into a more advanced ducted rocket at 650s Isp and even an air-turborocket with up to 850s Isp!
— ToughSF (@ToughSf) August 27, 2021
It would have fit post-Saturn Nova.https://t.co/0BJrygSSx3 pic.twitter.com/sJpiTJAcDW
The Aerojet M-1 rocket engine was envisioned in the early 1960s as providing propulsion for heavy launch vehicles that would succeed the Saturn series as the U.S. developed a mature space program with a sustained presence in space. The original design was a gas generator cycle liquid hydrogen and liquid oxygen engine with a single combustion chamber and nozzle, generating 1.5 million pounds (6.67 meganewtons) of thrust with a vacuum specific impulse of 428 seconds. The thrust was the same as the LOX/kerosene F-1 engine used in the first stage of the Saturn V, and like that engine, it used the relatively cool turbopump exhaust to cool the lower part of the engine nozzle.
The initial design was seen as the starting point for further evolution of the engine, increasing its thrust to 1.8 to 2 million pounds, increasing its efficiency by adopting a staged combustion cycle and expansion deflection nozzle, and ducted rocket and air-turborocket designs. This Aerojet design study [PDF] from the early 1960s sketches the evolution of the engine, including the Sea Dragon concept.
The M-1 engine project was cancelled in 1965 before the first prototype was assembled.
Posted at
13:07
THE HAPPENING WORLD: Artificial Intelligence Art Machine
An amazing notebook,“AI Art Machine”, has been posted on Google Colaboratory by Hillel Wayne, based on an earlier notebook by Katherine Crowson. It uses the VQGAN+CLIP technique to generate images from text prompts, having been trained on a large sample of tagged pictures. The results are often surreal, and I wouldn't be surprised to see them popping up as the covers of science fiction novels before long.
To use the notebook, you must be logged in to a Google account. Then, follow the instructions to generate your images. You may experience “Cannot connect to GPU backend” errors when you try to run the notebook. If this happens, there's nothing for it but to try again later.
Here are results produced from some Fourmilab-related prompts. There are numerous parameters you can tweak which change the results, and you can even supply the URL of an image whose style the generator will try to mimic (I haven't tried this).
Retro Psychokinesis
Atomic Space Car
Ant Laboratory
Mad Scientist Laboratory
Neutrino Collider
Posted at
12:17
THE HAPPENING WORLD: A Smartphone Application that Sees for the Blind
Posted at
11:55
TRACKING WITH CLOSEUPS: SpaceX and SpaceY
Scott Manley wins the space Internet today for this clip from his in-depth analysis of the Astra LV0006 launch attempt, which literally “went sideways” after an engine failed immediately after liftoff. This reduced the rocket's thrust to weight ratio to almost exactly 1 and created asymmetric thrust that resulted in the horizontal translation which, by pure luck, did not collide with any part of the launch structure or surrounding objects. Eventually, as fuel was consumed and the rocket became lighter, it began to climb, but much slower than intended.
A few hours later, SpaceX successfully launched their CRS-23 cargo mission to the International Space Station (ISS), recovering the first stage booster on the new autonomous drone ship “A Shortfall of Gravitas”. I have cued this video to start at one minute before launch: scroll back if you'd like to see the preliminaries, including a description of the cargo, among which is an ant farm. This is the 23rd Commercial Resupply Services mission to the ISS conducted by SpaceX, the fourth flight of its first stage booster, the 21st SpaceX launch of 2021, and the 90th first stage booster landing.
Posted at
11:25