Ok, that aligns more closely with what is happening at work. Hopefully we/they can re-purpose equipment and any modules that have been manufactured.
NASA readies Artemis II for a manned launch
- Thread starter Snagglefoot
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We need to get a couple people from here into space. They could collect some of that old space junk including the old Russian stuff and weld up a lunar vessel. It’s already half way. Like a free mower on the curb.
Splashdown is scheduled for today, April 10 shortly after 8:00 PM EST off the coast from San Diego.
And they have less than 1 degree of angular tolerance to hit on that reentry corridor.
Yeah - we all know the Earth is flat, so, the moon landings must have been faked.
Just throwing it out there! LOL
Starship heavy booster makes 15 million pounds of thrust. Artemis makes just under 9 million.
4wd
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slo town
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RIP the mighty Saturn 5. It made "only" 7.6 million pounds of thrust. But when you consider that was 50 years ago.....Saturn 5 FTW!
Scott
I can't believe in today's day and age that still gets any traction.
People are gullible and easily fooled.
Of course the “moon landing conspiracy” and “round earth conspiracy” crowds think we are the ones who are easily fooled.
But hey, if some goofball says it on YouTube - no matter how stupid - it must be true!
I'm not surprised in the least. Quite the opposite.
Dunning-Krueger boldly displayed in public.
But they don’t realize in what quartile they actually exist…
I know I sound like a broken record, but we have to improve education. The cost to not do so is .... I don't know. This stuff scares me.
Owen Lucas
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A question I have asked people before when it comes to a technical topic, and it may be a little insulting is:
"What is your level of education?"
You can just stop the convo if you are debating space travel with a HS drop out.
There are folks, on this board, who claim to have advanced degrees, but don’t understand elementary chemistry, or simple physics.
Sometimes, you have to stop the convo after determining that the degree is as worthless as the paper on which it was printed.
Crewed v. Uncrewed.
It's interesting that the Artemis that is flying today (and the next two planned) used literally leftover used Shuttle engines in its first stage. The four liquid-fueled main engines are from the Shuttle program, most of them parted out from the three Shuttles that did not crash. The two solid fuel boosters are mostly Shuttle parts, except for one section being a new longer version for extra burn time.
For Artemis 5 and after, new engines will need to be built. There is a plan to do a modest redesign for higher performance in light of the fact that they do not need to be reusable.
For Artemis 5 and after, new engines will need to be built. There is a plan to do a modest redesign for higher performance in light of the fact that they do not need to be reusable.
Live reentry coverage starts at 4:00 PM Mountain Time today on the National Geographic Channel.
These people will never accept reality. And that's kind of scary.
The RS-25 (Space Shuttle Main Engine, RS-25D) was built to be re-useable. LH2/LOX burns very clean and the engines have a very long service history, over 1 million seconds (yes, rocket engine run times are measured in seconds) and they can be throttled between 65% and 100% (Space Shuttle missions) to limit Max Q (dynamic pressure on the airframe) during Shuttle ascent. “Go for throttle up” was called once the Shuttle was through Max Q, and you may remember that from the Challenger disaster, where the call was made once they were through max Q, and the SRB burn through happened seconds later.
The LH2/LOX combination gives an incredible specific impulse of 366 seconds sea level, 452 seconds vacuum. Specific impulse is a measure of rocket engine efficiency, it’s the impulse per kG of fuel, and when you reduce the numbers, you end up with a value in seconds. The Space-X Raptor engine is closer to 330-350 seconds. Specific impulse varies with altitude as well as engine design (nozzle shape, and other factors). Some engines are optimized for vacuum operation, and some for atmospheric operation and some, like the Raptor, are built to do reasonably well in both.
The mighty F-1 that powered the Apollo 1st stage ran on RP-1 (kerosene) and LOX and had a specific impulse of 265 seconds at sea level and closer to 300 seconds in vacuum. But it was built with different objectives - raw power and easily fueled. LH2 is difficult fuel to manage vs. RP-1. RP-1 is a liquid at normal temperatures, while LH2 has to be cooled to 20K, or roughly -253C, -423F to remain a liquid. Fuel considerations are part of why Space-X chose liquid Methane for the Raptor - burns clean (important for a re-usable engine) and the fuel is liquid at -161C/111K which is a lot easier to handle than LH2.
Because the Artemis engines won’t be recovered, they were run at 109% of rated output for the flight.
Once the RS-25D supply is used up, there is an RS-25E version - with some simplification because it won’t be recovered and inspected - which means a less expensive engine, but still with excellent efficiency and the proven track record.
The choice to use the RS-25 came down to a couple of factors - extensive service history, throttleable, very high specific impulse.
A reliable, efficient engine was sitting in storage after the cancellation of the Shuttle program, so, why not use it?
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