Musk wants to give up spark plugs in cars, but he is bringing more "spark plugs" into rockets.
3、2、1...... ignition?
Viewers of SpaceX's live broadcast were expected to see the company's Starhopper rocket launch 150 meters into Boca Chica Beach, Texas, on Monday (August 26). While this is only a small "jump" on the rocket, the launch could be part of a giant leap forward in the rocket's career. Starworm was the precursor to starships, a vehicle that sent humans to Mars on manned missions.
Just 0.8 seconds after launching at 6 p.m. Central Time, SpaceX put the brakes on the Star Bug. This water tower-like, stainless steel structure may have to be test flown another day.
"The igniter needs to be checked," SpaceX CEO Elon Musk explained to his 28 million Twitter followers afterwards, "and at the same time tomorrow we'll test fly again." ”
With this starship, Musk will soon realize his dream of exploring the future of space. Its Raptor engine uses liquid oxygen and liquid methane. Unlike rocket thrusters, they can theoretically be obtained from the atmospheres of Mars or other planets. Coupled with a reusable rocket design, the starship is about to launch a network of planetary-jumping bunkering points, and astronauts will be able to explore the solar system more deeply than ever before.
"BFR (the original name of this starship) is actually an interstellar transmission system capable of traveling from Earth to anywhere in the solar system, just like you've built many propellant depots along the way." Musk said in September 2018, "Mars, the Moon, and perhaps the moons of Venus, Jupiter, the entire solar system can be reached." ”
On Tuesday (August 27), this vision of the space age was temporarily hampered by what seemed to be a problem of low technical content: bad lines.
Illustration: SPACEX paused star bug testing.
SPACEX Star bugs: How to ignite an engine on Mars
For Starship, SpaceX is developing a completely different engine. The Raptor engine was not only powered by a different fuel, but also a completely different ignition mechanism. This is very different from the propellant fuel design of merlin engines used by the Falcon 9 and Falcon Heavy rockets.
Teslarati noted that the Merlin engine is a mixture of two materials called triethyl aluminum and triethylborane. They glow green and explode when they come into contact, providing the easiest way to ignite an engine. However, if ignition from this material were to mean that planet-hopping missions would require astronauts to somehow replace the fuel. This will become very difficult when far away from Earth.
Raptor used the methoxy-based flare igniter that Musk referred to in February as the equivalent of a "heavy spark plug." Similar to the method used by an internal combustion engine to ignite fuel with electricity, these spark plugs "ignite a double flare pre-igniter and main chamber"
It may be a bit ironic that Musk spent a lot of energy trying to get the car world out of the spark plug with Tesla electric cars, but found that he was still back in the rocket world. This is nothing new: NASA uses a similar design on the shuttle's RS-25 engine.
"Raptor uses dual redundant flare igniters," Muks explained on Twitter, "it's a better long-term development, but more difficult in the development process." ”
Raptor engine ignition test
Musk explains: "It seems like a wiring/connector issue. "Even Tesla's CEO can't get rid of the bad spark plug wiring. Musk called the experience "quite embarrassing."
SpaceX doesn't have to wait too long to determine if the line is ready, and it's expected to launch again later on Tuesday. If the launch is successful, Musk will hold a press conference in mid-September to describe his next plans. This will be done after the first version of the full-size Starship carries three Raptor engines, moving fuselage fins and a landing gear. The final Starship is expected to be combined with a Super Heavy propeller with more than 40 Raptor engines.
No wonder Musk announced in June 2019 that SpaceX aims to build a new engine every 12 hours by the end of the year.
Resources
1. WJ Encyclopedia
2. Astronomical terms
3. inverse- Andrew Ho， 球
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