The RS-25 engine has a chamber pressure of 20.64 MPa and a nozzle expansion ratio of 78:1, delivering a vacuum Isp of 452s.
What if it got a proper vacuum-optimized nozzle, with an expansion ratio of 250? Isp would climb to nearly 470s.
Engineering and inboard cameras for the STS-4 launch:
youtu.be/o-LH8M6IgSI
In slow motion we can clearly see the boundary of flow separation moving down and out of the RS-25 nozzles.
Video
The Solar Cruiser, a NASA project for a 1672 m^2 solar sail that would visit the Sun's poles. It was supposed to launch last year.
#space #art by Lee Kolb.
www.artstation.com/artwork/QX11g4
Since the Concorde, these private companies failed to get a supersonic passenger jet flying:
-Aerion Corporation (AS2)
-Exosonic (Horizon)
-Virgin Galactic (SJP)
-Spike Aerospace (S-512)
Now it's Boom Supersonic's turn.
Everyone knows the Bell X-1 that first broke the sound barrier.
But the Douglas D-558-2 Skyrocket was developed practically in parallel, using the same XLR-11 rocket engine, getting dropped by a modified B-29 (a P2B-1S patrol bomber) to achieve Mach 2 for the first time.
Capillaries are smaller than the red blood cells passing through them, requiring them to deform significantly to pass through.
So, they appear like this under a microscope:
youtu.be/dO8P9Qzhv2s
HAMR heads can generate hotspots just 51 nanometers wide out of an 800 nm laser wavelength, which is sub-diffraction-limited performance, thanks to metallic surface plasmon waveguides, enabling Plasmonic Near Field Transducers to record 5 TB/in^2 of data:
www.degruyterbrill.com/document/doi...
The Concorde looks so futuristic for a plane that first flew in 1969! Its vortex-generating S-curve delta wing for low-speed lift and high-speed efficiency is still a marvel.
#art by Julien Lepelletier.
lepelletier.artstation.com/projects/aR0...
MBDA has been awared $422m to install 50 kW DragonFire lasers aboard 4 Royal Navy destroyers by 2027:
www.gov.uk/government/n...
These were recently tested against 650 km/h drones at sea.
It'll be the first European 'high power laser weapon' in service.
Combining JWST and ALMA observations to explore the early Universe:
arxiv.org/abs/2601.04314
For example, by uncovering that carbon emerged earlier than 350 million years after the Big Bang, making it the first metal (in the astronomical sense).
