While stacking was going on, they removed and inspected one of the engines. At the end of the last static fire there was an odd sound again, though the engine inspection may have been for some other reason. It’s back on now.
SH1 is under construction and the Nerdle-cam watchers are keeping an eye out for an early look at Super Heavy’s thrust puck.
Earlier last week Elon mentioned that the thermal protection along the hinge lines for the flaps is a bit of a challenge.
That “odd sound” isn’t really all that odd and has been heard at the end of static fire tests many times – and for rocket engines other than Raptor. Rocket engines aren’t the only things that have bells – so do brass musical instruments. That sound is a “note” produced as the speed of the escaping combustion gas slows and stops.
The engine that was removed was SN39. SN39 is the engine that set that 330 bar chamber pressure record a few weeks ago during a previous static fire test on a stand at McGregor. There was, I’m sure, understandable curiosity about how it was looking, internally, following the SN8 static fire. I think it was designated as part of SN8’s engine set precisely for this reason – another of what will likely prove to be several quick opportunities to examine the state of Raptor engineering advancement in its “native habitat,” so to speak.
Yes, many engines go through a burst of instability during the shutdown, particularly if purges push residual propellants into the chamber at low Mdot, causing low injector delta-P. The 4K14 engine did the most embarrassing chirp on shutdown, almost a whoopee cushion.
An example here- some folks laughed out loud, alas.
Here, we present observations of the Moon at 6 µm using the NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA). Observations reveal a 6 µm emission feature at high lunar latitudes due to the presence of molecular water on the lunar surface. On the basis of the strength of the 6 µm band, we estimate abundances of about 100 to 400 µg g−1 H2O. We find that the distribution of water over the small latitude range is a result of local geology and is probably not a global phenomenon. Lastly, we suggest that a majority of the water we detect must be stored within glasses or in voids between grains sheltered from the harsh lunar environment, allowing the water to remain on the lunar surface.
That works out to 2.7 to 10.7 fluid ounces per cubic yard of regolith. (It’s important to convert lunar data to the measurement system used by countries that have been to the moon.)
George, love the parenthetical. Here’s something to go with it.
When I was 15, back in 1969, my grandmother took my sister, my eldest cousin, and me on a month long tour of Europe. I’ll never forget her haggling with a street vendor in Venice. He gave her a price on some knickknack in lira, and her response was: “What’s that in real money?”
(BTW, I graduated Purdue with a BS and MS in mechanical engineering, so my temperature units are Rankine. Just sayin’)
When I come against a metric bigot, I like to point out that if we had adopted the metric system in the ’70s like we were supposed to, it would have been the wrong metric system.
If metric bigots had their way, we’d all be speaking Volapuk…
SN8 is now free-standing, the crane was detached a few minutes ago. Those manlifts are scary high up in the air!
You get used to it. My most puckerworthy moment came as a sewer worker when I climbed down a manhole into an underground pipe gallery and lowered myself onto a slippery pipe. Peering into the darkness below, I realized the concrete floor was 90 feet down.
“I can’t swim!”
“Hell, the fall alone will probably kill ya!”
Paging cadets Corbett, Manning, and Astro! Your ride is ready!
I believe one is on order for a guy named E. S. Blofeld, to be shipped to a small volcano island in the Sea of Japan.
Better launch it before Queen Greta the All Knowing and Sleepy Joe completely outlaw combustion of hydrocarbons!
While stacking was going on, they removed and inspected one of the engines. At the end of the last static fire there was an odd sound again, though the engine inspection may have been for some other reason. It’s back on now.
SH1 is under construction and the Nerdle-cam watchers are keeping an eye out for an early look at Super Heavy’s thrust puck.
Earlier last week Elon mentioned that the thermal protection along the hinge lines for the flaps is a bit of a challenge.
That “odd sound” isn’t really all that odd and has been heard at the end of static fire tests many times – and for rocket engines other than Raptor. Rocket engines aren’t the only things that have bells – so do brass musical instruments. That sound is a “note” produced as the speed of the escaping combustion gas slows and stops.
The engine that was removed was SN39. SN39 is the engine that set that 330 bar chamber pressure record a few weeks ago during a previous static fire test on a stand at McGregor. There was, I’m sure, understandable curiosity about how it was looking, internally, following the SN8 static fire. I think it was designated as part of SN8’s engine set precisely for this reason – another of what will likely prove to be several quick opportunities to examine the state of Raptor engineering advancement in its “native habitat,” so to speak.
Yes, many engines go through a burst of instability during the shutdown, particularly if purges push residual propellants into the chamber at low Mdot, causing low injector delta-P. The 4K14 engine did the most embarrassing chirp on shutdown, almost a whoopee cushion.
An example here- some folks laughed out loud, alas.
https://www.youtube.com/watch?v=Yzd0Gs7a-4I&t=46s
Also coming out today was an important new paper on lunar water.
That works out to 2.7 to 10.7 fluid ounces per cubic yard of regolith. (It’s important to convert lunar data to the measurement system used by countries that have been to the moon.)
George, love the parenthetical. Here’s something to go with it.
https://metricviews.files.wordpress.com/2020/07/2bef6-twokindsofcountry_1024x528.jpg
When I was 15, back in 1969, my grandmother took my sister, my eldest cousin, and me on a month long tour of Europe. I’ll never forget her haggling with a street vendor in Venice. He gave her a price on some knickknack in lira, and her response was: “What’s that in real money?”
(BTW, I graduated Purdue with a BS and MS in mechanical engineering, so my temperature units are Rankine. Just sayin’)
Sorry, this is the correct link:
https://www.pinterest.com/pin/319755642267570954/
When I come against a metric bigot, I like to point out that if we had adopted the metric system in the ’70s like we were supposed to, it would have been the wrong metric system.
If metric bigots had their way, we’d all be speaking Volapuk…
SN8 is now free-standing, the crane was detached a few minutes ago. Those manlifts are scary high up in the air!
You get used to it. My most puckerworthy moment came as a sewer worker when I climbed down a manhole into an underground pipe gallery and lowered myself onto a slippery pipe. Peering into the darkness below, I realized the concrete floor was 90 feet down.
“I can’t swim!”
“Hell, the fall alone will probably kill ya!”
Paging cadets Corbett, Manning, and Astro! Your ride is ready!
I believe one is on order for a guy named E. S. Blofeld, to be shipped to a small volcano island in the Sea of Japan.
Better launch it before Queen Greta the All Knowing and Sleepy Joe completely outlaw combustion of hydrocarbons!