-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
What's interesting is that he's not wearing gloves. I suspect large rocket motors are a bit more forgiving, but for smaller motors you don't touch the bell without gloves on and depending on the coating of the chamber and throat, you don't touch them period. Oils from your fingers (or even just disturbing a special coating) creates hot spots, which can create blowouts...
And even more from SpaceX and Elon on the test:
"Completed a two-second test fire of the Starship Raptor engine that hit 170 bar and ~116 metric tons of force – the highest thrust ever from a SpaceX engine and Raptor was at ~60% power."
SpaceX on Instagram: “Completed a two-second test fire of the Starship Raptor engine that hit 170 bar and ~116 metric tons of force – the highest thrust ever…”
Someone on SpaceX Facebook did the math:
~60% Raptor = 116 metric tons of thrust = 255,000 lbs of thrust.
Merlin 1D at 100% = 190,000 lbs of thrust.
34% greater thrust than the Merlin.
"Completed a two-second test fire of the Starship Raptor engine that hit 170 bar and ~116 metric tons of force – the highest thrust ever from a SpaceX engine and Raptor was at ~60% power."
SpaceX on Instagram: “Completed a two-second test fire of the Starship Raptor engine that hit 170 bar and ~116 metric tons of force – the highest thrust ever…”
Someone on SpaceX Facebook did the math:
~60% Raptor = 116 metric tons of thrust = 255,000 lbs of thrust.
Merlin 1D at 100% = 190,000 lbs of thrust.
34% greater thrust than the Merlin.
Merlin held the record for thrust to weight ratio. It sure looks like Raptor will beat it. If you add in the added efficiency - Wow. Raptor will be the rocket engine to hopefully reach Elon's goal of making humanity multi-planetary.
Until we pull our heads out of our rear ends and develop proper nuclear rockets and higher power ion engines for vacuum operations. The ideal scenario is to use reusable chemical rockets for surface to a LEO station. And then use a nuclear/ion bus running back and forth to deep space destinations.
Oh, I'm quite sure he's aware of them. But I'm sure the investment required would be enormous. THIS is the proper role for NASA. They should be developing some of the more far-flung techs that truly enable far-flung operations.
JohnSnowNW
Active Member
At least initially, I'd wager cost and the amount of red tape that would be required to allow a private space company to put a nuclear "engine" into a rocket makes it infeasible.
Even at this base capability, the Starship equipped with 31 of them will already be 1.5X more powerful than the Saturn V, with it's five F1's.
If the Raptor design has some margin for thrust uprating like the Merlin did, than even a conservative 30% increase in thrust makes the Starship 2x more powerful than Saturn V. If they manage to nearly double the output over the eventual iterations (as happened with Merlin), then we are looking at a rocket 3x as powerful with ~23million lbs thrust.
Pretty incredible possibilities...
e-FTW
New electron smell
IIRC someone on Mars (the show) mentionned that Werner Von Braun had overbuilt the Saturn V because he wanted NASA to use it to go to Mars. He lost that bet, but this makes these figures quite interesting.
I would think SpaceX would really just reduce the number of engines, as the current Raptors give sufficient thrust.
Saturn V lifted off the pad at around 2 m/s^2, while the Super Heavy/Starship should lift off at around 3.5 m/s^2 (4400 tons gross, 5993 tons of thrust). Falcon 9 lifts off at around 4 m/s^2. If SpaceX could increase thrust to 250 tons per Raptor, which probably isn't too unrealistic, the Super Heavy/Starship would lift off the pad at closer to 7.5 m/s^2.
You take off more efficiently if you take off faster, but there are diminishing returns here. And reducing the number of engines is also a way of cutting down weight, increasing performance and reducing costs. If they were able to get to 250 tons per engine, and wanted the Super Heavy/Starship to take off at 4 m/s^2, they could remove ~6 Raptors. (And 1-2 Raptors on the Starship.)
Alternatively, they could of course stretch the Super Heavy a bit, like they've done with the Falcon 9. Stretching the Super Heavy by 20 meters would get you down to around 4 m/s^2, and would result in a significantly increased payload capacity. This would reduce the number of trips needed to refuel a Starship in orbit. (The Super Heavy/Starship would then be 138 meters tall, 28 meters more than the Saturn V...)
Here is approximation what it would look like:
Huh, had never heard that... interesting.
I've also subsequently read that Musk has mentioned that the current Raptor design is the "common" one they will initially use on both the first and second stages. They will eventually optimize them further (ostensibly beyond just the nozzle) for both atmospheric and vacuum use, with the target for the former being 250 metric tons of thrust... 25% greater than current.
That means a ~470K lb thrust Ratptor is certainly in the cards for the current architecture.
Good point... I suppose crushing occupants with a 6g liftoff might be overdoing it a bit... to say nothing of loading on the craft's structure.
I wonder what the practical payload limit/takeoff weight of something based on Starship's architecture might be....
"Raptor just achieved power level needed for Starship & Super Heavy Design requires at least 170 metric tons of force. Engine reached 172 mT & 257 bar chamber pressure with warm propellant, which means 10% to 20% more with deep cryo."
Elon Musk on Twitter
And no hint of green there, it was just residue...
Andre Infante @AndreTI
Replying to @elonmusk
- "Did you folks track down the source of the green hue?"
Elon Musk ✔ @elonmusk
- "Vaporized some copper"
DJPledger @NSF
- "Looks like film cooling with methane to me. They must have increased film cooling over the previous test to protect the thrust chamber. Excess film cooling will reduce Raptor's Isp so they will no doubt find out the optimum balance of film cooling over time."
Replying to @elonmusk
- "Did you folks track down the source of the green hue?"
Elon Musk ✔ @elonmusk
- "Vaporized some copper"
DJPledger @NSF
- "Looks like film cooling with methane to me. They must have increased film cooling over the previous test to protect the thrust chamber. Excess film cooling will reduce Raptor's Isp so they will no doubt find out the optimum balance of film cooling over time."
Similar threads
