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SpaceX Fires Mars-Bound Raptor Engine (extremetech.com)
Elon Musk took to Twitter Sunday evening to announce the "first firing of Starship Raptor flight engine." While SpaceX has fired individual components before and experimented with various designs, this is the first time the now-completed design has been assembled and fired in its intended spaceflight configuration. ExtremeTech reports: Raptor has gone through a number of design changes -- originally, SpaceX planned to mount it to the ITS launch vehicle back in 2016 (powered by 42 Raptor engines), before changing gears and unveiling its BFR rocket concept (officially known as "Super Heavy" for the first stage, and Starship for the second). The Super Heavy mounts 31 Raptor engines, while the Starship has seven. The engine has been designed with a priority on lowering overall wear and tear and removing failure points that could limit its reusability or increase long-term operating costs. Unlike SpaceX's Merlin engine, which runs on a mixture of RP-1 and LOX, the Raptor engine is fueled by cryogenic liquid methane and LOX. The Raptor uses subcooled methane (subcooling refers to keeping the temperature of the liquid well below its boiling point). Subcooling the methane allows SpaceX to increase the amount of propellant stored in the rocket. It increases specific impulse and reduces cavitation.
The actual test burn only goes on for a few seconds, but yields tremendously valuable information about the actual performance of the rocket and its ability to ignite in a controlled fashion. The green glow in the exhaust near the end of the firing indicates the copper liner in the engine chamber burned by accident. While this should not have happened, it's precisely to find these pain points that engineers conduct test firings in the first place. There is no substitute for this kind of test-firing and, as Ars Technica notes, "any 'first' test firing of a new, full-scale rocket engine that doesn't end in an uncontrolled explosion is a good thing." Ars also states that this specific engine may be deployed for "hopper" flights this year when SpaceX attempts to fly the Starship roughly 5km high, then land it again.
The actual test burn only goes on for a few seconds, but yields tremendously valuable information about the actual performance of the rocket and its ability to ignite in a controlled fashion. The green glow in the exhaust near the end of the firing indicates the copper liner in the engine chamber burned by accident. While this should not have happened, it's precisely to find these pain points that engineers conduct test firings in the first place. There is no substitute for this kind of test-firing and, as Ars Technica notes, "any 'first' test firing of a new, full-scale rocket engine that doesn't end in an uncontrolled explosion is a good thing." Ars also states that this specific engine may be deployed for "hopper" flights this year when SpaceX attempts to fly the Starship roughly 5km high, then land it again.
The green glow in the exhaust near the end of the firing indicates the copper liner in the engine chamber burned by accident
It's burning an engine-rich flame.
How are they going to get to Mars now? Re-hiring? H1-B's? Outsource in China?
we're now the only no-fly zone in the galaxy? after watching deliverance & year one films our alien allies are nervous about our motives?
The new plan is to send the BFR on trips to the moon, early on. Later, they'll send it to Mars; this may only happen after they build their next-gen Raptor engines.
There is some sense to this. If they can cram 100 space tourists into Starship, then send it to orbit the Moon for a day (7 day space vacation), they could make LOTS of money. $10 million per ticket x 100 seats = $1beeelion per launch (prior launch of fuel into orbit required, however), and they'd only pay the cost of fuel, probably less than $1million. After a few years, once they get more super heavies/starships built, they could bring the price down to $1 million for a ticket, still make massive profits, and it'd hugely increase the number of people who would pay to go to the moon. Only a few dedicated people would be willing to spend a few years of their life to go to Mars, wait a while for a launch window to arrive, then come back. Of course, they could also offer moon landings, maybe build a moon hotel. Maybe put some Starlink satellites in lunar orbit for lunar internet connectivity, although the 1,250ms latency would be killer.
Internet access on Mars would suck (due to the half-hour latency). Bet there's a business opportunity for an orbiting data center that'd host mirrors of various sites.
Corruption is convincing someone that the selfless ideal is the same as their selfish ideal.
... and Trump told the Raptor, "You're fired!"
S,cnr
âoerocket engine that doesn't end in an uncontrolled explosion is a good thing."
The industry thinks âoeexplosionâ is a unspoken word and prefers âoerapid unscheduled disassemblyâ
You do know this is all for show right?
No one is going to Mars any time soon....
Meanwhile let's get our crap together and moonbase.
You deploy a sat array around moon, then mars, then sat array junctions at locations along the way. This will need to be nexgen com sats as their function is to transmit as fast as possible in space to each other and then to the main relay and down to planet/moon.
that gets comms up, then you work out the rest.
They won't like Elon waking up their Martian sleeper cell. I hope a UFO full of little green terrorists doesnt land in New York City. Maybe we need random TSA butt searches at the space port... LOL
ae911truth dot org
First they fire their workers now they fire their hardware. Sweet.
In an unthinakbly rare mistake, particularly given the laser-accurate reporting on Musk's antics in the space buff community, there is a mistake in the summary.
Supercooling the methane don't increase the ISP, it increases the density, making the tanks slightly smaller for a given volume, slightly reducing the weight of the tanks. Technically, it increases the mass ratio (ratio of fueled to dry mass) very slightly. That's still good, as good as if it had increased the ISP, but the effect (which, as all things Musk "invents", has been used for about 60 years or more) is not to change the ISP.
Once you start burning it, you need exactly the same amount per unit oxygen and use the same mass of it per unit impulse you would have had anyway.
The rest of the concept is marginal, Methane is only slightly better than RP-1 (refined kerosene) in terms of ISP in an ideal situation for both, and even supercooled methane is still less dense than RP-1. So the effect is that the effect you are creating with supercooling is more effective if you went to RP-1 - still smaller tanks for a given amount of energy.
The same effect is why hydrogen makes a bad fuel, particularly for a first stage (or even worse, an airplane). Giant tanks for a given energy and the difficulty of handling outweigh the very large increase in ISP aside from special cases like upper stages.
If it's intended for going to Mars, shouldn't be called Planetship Raptor, instead of starship?
I saw that yesterday on Twitter and thought it was an especially impressive looking flame, so you should actually both to click on the link... the shape of the flame is really interesting.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
But how do raptors type with such long claws?
Weren't these also present in the Shuttles SSME on takeoff?
He will push the Earth into the Sun!