« July 27, 2021 | Main | July 29, 2021 »
July 28, 2021 Archives
Wednesday, July 28, 2021
CONTINUITY: NASA: RS-25 Rocket Engine “Improved”
Forty years after it first flew as the Space Shuttle Main Engine, the Aerojet Rocketdyne RS-25 rocket engine, which was originally designed for a service life of 27,000 seconds and 55 starts, has been “improved”, delivering a service life of 1700 seconds (6.8% of the original) and 4 starts (7.3% of the original). Thrust has been increased by 6%, along with “some cost savings”—the cost for the 24 RS-25 engines intended for the Space Launch System (SLS) comes to around US$ 146 million per engine.
The engines, routinely refurbished and reused in the Space Shuttle program, will be discarded as twisted wreckage in the briny deep on each flight of the SLS.
Infographic from @NASASpaceflight on the de-evolution of the RS-25 engines and their transformation from 27000 second reusable engines into 1700s expendable ones.https://t.co/zxCRC4vyNN https://t.co/JG6tcdKpAv pic.twitter.com/546h9jYgWp
— ToughSF (@ToughSf) July 28, 2021
Elon Musk estimates the cost of the SpaceX Raptor engine, which has slightly more thrust (albeit less fuel efficiency) than the SL-25, and is intended to be reused numerous times, at less than US$ 1 million for current engines, and a quarter of that for improved versions in volume production.
Raptor cost is tracking to well under $1M for V1.0. Goal is <$250k for V2.0 is a 250 ton thrust-optimized engine, ie <$1000/ton
— Elon Musk (@elonmusk) October 1, 2019
Posted at
14:27
TRACKING WITH CLOSEUPS: Tiny Electronic Components
If you've done digital electronics, you may have used a standard 7404 hex inverter chip. Here's the tiny inverter sitting on top of a 7404, smaller than the "4". pic.twitter.com/QLR4Dp6VHx
— Ken Shirriff (@kenshirriff) July 26, 2021
These @latticesemi FPGAs that just arrived in the mail are smaller than 1mm x 1mm. I can hardly see them without a magnifying glass of some sort.
— 𝐷𝑟. 𝐼𝑎𝑛 𝐶𝑢𝑡𝑟𝑒𝑠𝑠 (@IanCutress) July 28, 2021
If I try and bite into these, they'll get consumed. Maybe I can use them as sprinkles. pic.twitter.com/BHbxrH0HbQ
Posted at
13:07
THE HAPPENING WORLD: Do It Yourself Challenge—CNC Mill to Automated Gun Turret
A CNC mill tilting rotary table is almost a ready made auto-turret -- extreme precision, high speed, very rugged, with built in accessory actuators. It seems like it is only a couple T-slot to picatinny rail adapters away from a rather exciting YouTube video.
— John Carmack (@ID_AA_Carmack) July 28, 2021
Posted at
12:08
THE HAPPENING WORLD: Who Is an “Astronaut”?
First, it was “What is space?”, now it's who deserves to be called an “astronaut”. (I don't know why Blue Origin's marketing department hasn't seized on my suggestion to call those who fly on Branson's ride below the Kármán line “asterisknauts”.)
As Scott Manley observes, those who fly on vehicles operated by coercive governments, or even those in their employ who do have not yet flown, have been called “astronauts”, including politicians, such as the current NASA administrator, “Ballast Bill”, who went on a taxpayer-funded junket into space. I think the answer is to make the term “astronaut” one of derision, applied to civil service space cadets who have appropriated a noble title rightly belonging to genuine pioneers of space exploration. There's a parallel to this: nobody calls airline pilots or passengers “intrepid aeronauts” these days.
As for those who travel above the Kármán line today, how about “spacers” or, for those who see it as a New Age experience, “space cases”?
Posted at
11:12
CONTEXT: A Banana a Day
In South Korea, some stores package their bananas together in various ripeness stages so you can eat them over several days without them going brown. They call them "one-a-day" bananas. pic.twitter.com/BL8hFxeS8a
— All Things Interesting (@mrstrangefact) July 19, 2021
Posted at
10:08