“Exploded! Exploded!”
Once upon a time, this was the most commonly used headline format when American media reported on the American space exploration technology company SpaceX. In the past two years, SpaceX’s Starship (Starship) has undergone numerous tests, repeatedly encountering explosions and damage.
The more serious one was the explosion of the 12th interstellar spacecraft prototype test in March 2021. Countless debris was blown out of it, and it took SpaceX three months to clean it up.
2021 SN10 Starship Explosion
Chekhov once said: “Difficulties and tortures are like a hammer to the blank. What should be knocked out should be fragile iron filings, and what will be forged will be sharp steel.” Today’s SpaceX is Slowly get out of the haze and usher in a new milestone.
At 5 am on February 10, 2023, Beijing time, and on the evening of February 9, local time in the United States, SpaceX successfully conducted a static ignition test of the super-heavy rocket booster prototype Booster 7.Although there was no full engine ignition, and although the entire ignition process only lasted about 5 seconds, it has surpassed the record of simultaneous ignition of 30 NK-15 engines on the first stage of the Soviet N1 rocket.
SpaceX 31 engines static fire
SpaceX founder Elon Musk wrote on the social media platform: “The team shut down 1 engine before starting, and 1 engine stopped by itself, so a total of 31 engines ignited. But there are still enough engines to reach orbit! “
Many of our readers may not understand how dangerous this technical solution is to combine a large number of small engines in parallel into a manned moon landing rocket. Because, when a system becomes complex, its reliability will be greatly reduced. SpaceX can connect such a large number of rockets in parallel while ensuring the reliability of the system operation, which itself is a difficult task.
During the Cold War between the United States and the Soviet Union in the 1960s, the two sides engaged in a long space race around manned moon landings.
Due to inferior technology and lack of funds, the Soviet Union was unable to develop a high-thrust launch vehicle like the American Saturn 5 at the same time. However, with the successful launch of the Saturn 5 rocket of the United States many times during the same period, the top Soviet leaders could not sit still. In order to complete the manned mission to the moon before the American Apollo spacecraft, the Soviet high-level even skipped the independent test flight test of the N1 rocket, and carried the Soyuz 7K-L1 moon landing spacecraft on the rocket for the first time. .
30 parallel NK-33 engines: Does it look like a gas stove?
Time is tight and tasks are urgent, and the Soviet researchers can only hope that they will work hard to perform miracles. They connected 30 NK-33 engines in parallel to form the first-stage structure of the N1 rocket, and used “crowdfunding” to try to increase the rocket’s first-stage thrust. It stands to reason that the NK-33 engine is advanced enough that it was once the rocket engine with the highest thrust-to-weight ratio in human history until it was surpassed by SpaceX’s Merlin rocket engine in the 21st century.
But the problem is that at this point in time in January 1969, the 30 NK-33 engines that constitute the first-stage propulsion structure of the N1 rocket have just left the factory and have not passed the ignition test. The poor cause was weathered for four weeks on the launch pad. Finally, in the first test launch on February 21, 1969, the N1 rocket accidentally shut down one of the engines in the first-stage rocket, causing the system to shut down all 30 propulsion rockets. Three minutes after ignition, the N1 rocket lost power and crashed 52 kilometers from the launch tower.
In a total of more than 3 years, the N1 rocket has been launched 4 times, all of which ended in failure.In the second accident, due to the inhalation of foreign matter by one of the engines, all 30 engines responsible for the first-stage propulsion task were all turned off after the rocket was lifted 200 meters into the air, causing the N1 rocket to carry 2,300 tons of propellant on the launch pad. Crash and explode.
launch pad after explosion
It was not until half an hour after the explosion that the on-site personnel were allowed to come out of the bunker, while kerosene was still raining in the sky at that time. The destructive power of this explosion was equivalent to 7,000 tons of TNT equivalent, and it shattered the glass of all buildings within a radius of 10 kilometers. The flames were clearly visible in the city of Leninsk, 35 kilometers away from the launch site. Fortunately, despite the evacuation, the accident did not cause casualties. But the launch completely blew up the rocket pad, causing crews to spend 18 hours rebuilding it. After 4 consecutive failures, the Soviet Union was forced to abandon the manned moon landing project and gradually fell behind in the Cold War space race.
From this point of view, the difficulty of SpaceX connecting more than 30 engines in parallel is self-evident. Although this static ignition did not lift the spacecraft into space, it meant that the interstellar spacecraft had completed the last step before launching into orbit. In the next March or April, we are likely to see the first orbital flight test of the interstellar spacecraft-it is closer to Musk’s Mars immigration plan.
“One day, the starship will take us to Mars.” Musk said.
What does it mean to successfully ignite?
SpaceX’s Starship consists of two reusable parts, one is the first-stage booster Super Heavy about 70 meters high, and the other is the 50-meter-high spacecraft Starship. Collectively known as Starship, they represent a fully reusable transportation system designed to transport crew and cargo to Earth orbit, the Moon, Mars and beyond.
Starship
The first-generation prototype of the starship is Starhopper, and the second-generation prototype (Starship No.X) is called SNX for short, and X is the number. Super Heavy Booster No.X is called BX for short, and X is the serial number.
Since 2019, the interstellar spacecraft has gone through dozens of iterations and evolutions, some of which were blown up during testing. So far, the spacecraft Starship has been iterated to SN24, and the booster Super Heavy is Booster 7.
The spacecraft on top and the booster on the bottom, both powered by SpaceX’s Raptor engine, fueled by liquid methane and liquid oxygen (CH4/LOX). Among them, there are 33 Raptor rocket engines on the booster Super Heavy, and 6 on Starship. It is the bottom booster Super Heavy that successfully conducted the static ignition test this time.
It is worth noting that SpaceX does not use the Raptor on the Falcon 9 rocket, but the Merlin engine (Merlin rocket engine) with liquid oxygen kerosene. Although it can also last to Mars, the destination of Musk’s space immigrants, there is no supplementary energy on it. Moreover, liquid oxygen kerosene is prone to carbon deposition and coking, making it difficult to reuse.
Therefore, SpaceX developed the Raptor engine, and its power source is exactly what can be produced on Mars-methane.
Raptor rocket engine
The Raptor engine is the world’s first practical methane rocket engine, and it is also the world’s first practical full-flow staged combustion rocket engine.
The so-called full-flow staged combustion engine uses multiple combustion chambers. Part of the fuel first enters the pre-combustion chamber for combustion, and the thrust generated then drives the turbo pump to drive all the fuel into the main combustion chamber for combustion and generates thrust. The fuel is converted to thrust.
The diameter of the Raptor engine is only 1.3 meters, the chamber pressure is about 30 MPa, and the thrust of a single engine is not less than 200 tons, although the thrust is slightly smaller than the BE-4 of Blue Origin (the commercial space company of Amazon founder Bezos), But the volume and fuel utilization are far superior to the latter.
raptor rocket engine
But rather than saying that the Raptor engine burns methane, it is better to say that it “burns money”.
From 2009 to 2015, the Raptor engine has been developed by SpaceX with self-financing? By 2016, the U.S. Air Force decided to support SpaceX’s liquid oxygen/methane engine development project and provided $33.6 million in development funds, but at the same time required SpaceX itself has to invest $67.3 million in research and development funds?
Therefore, reusability is also one of the basic requirements for Raptor engine development. Musk previously stated that the Raptor engine installed on the interstellar spacecraft in the future can be used 100 times without maintenance, and can be reused 1,000 times after simple maintenance.
Theoretically, the more multiplexing times, the lower the cost of a single launch, and eventually the “spaceship ticket” will become cheaper and cheaper. But in the short term, space travel remains a rich man’s game.
Going to space is still a rich man’s game
Everything comes with a price tag, and space travel is no exception.
In April 2022, the US “SpaceX Crew Dragon” commercial spacecraft carrying the first all-civilian crew arrived at the International Space Station. In addition to former NASA astronaut Michael Lopez-Alegria, the passengers who took part in the space trip on the spacecraft also included American Larry Connor, Canadian Mark Passy and Israeli Irtan Irtan. Stieby. The three passengers each paid $55 million for the trip.
Bezos’s Blue Origin, the first suborbital flight cost as much as $20 million. With the help of reusable launch vehicles, the ticket price has now dropped to between $200,000 and $300,000 each.
blue origin
Virgin Galactic, led by Richard Branson, sold a space travel ticket last year for $450,000, but a deposit of $150,000 is required, and the travel time is 90 minutes. During the period, a few minutes of weightlessness experience and earth scenery viewing projects will be provided.
Unlike Blue Origin and Virgin Galactic sightseeing at the “edge of space,” SpaceX’s space travel is serious about sending the rich to the moon. All the seats of the SpaceX trip around the moon that Japanese billionaire Yusaku Maezawa paid for in 2018. In December 2022, he announced a crew of 10, which also includes TOP, a member of Korean star BIGBANG.
Yusaku Maezawa’s crew
This journey around the moon is to reach a place within 200 kilometers from the surface of the moon. It was originally planned to use a combination of Falcon Heavy and Dragon spacecraft, but it was later changed to Starship (Starship), which is the one that performed the engine static ignition test this time.
The earliest plan is to launch in the fourth quarter of 2023, but judging from the current progress,Although the static ignition test of the interstellar spacecraft is completed, it will still take time to actually go to the moon.
A day before the static ignition of the engine, SpaceX President and Chief Operating Officer Gwynne Shotwell publicly stated that the Starship needs to pass hundreds of unmanned flight verifications before it can be used for manned flights. Starship will be used for manned missions to the moon first, and then consider using Starship for missions to Mars. The target time for the first manned landing of the Starship on Mars may be in 2030.
Finally, let’s talk about whether we can go to the moon and Mars. At least now SpaceX has begun to show signs of profitability. Key lines of business for SpaceX are profitable, and one of the main rocket launch services that NASA relies on has become a source of profitability for the company, Shotwell said.
Musk’s Mars immigration plan
Last year, SpaceX hit several new milestones. The company has launched a total of 61 rockets in 2022, almost double the 31 launches in 2021. The Falcon 9 launch vehicle also became the rocket with the most launches of a single model in a year. In addition, SpaceX’s satellite internet service, Starlink, has more than 1 million users. She also said that in fiscal 2022, excluding launch-related expenses, Starlink will have a cash flow positive quarter.
write at the end
On SpaceX’s official website, there are words that Musk once said: “When you want to wake up in the morning and open your eyes, hope that our future will be better-this is what it means to be a space civilization. Just believe in the future, Thinking that the future will be better than the past. I can’t think of anything more exciting than going out into space and being there with the stars.”
But at present, it seems that the excitement of space travel is reserved for the rich to enjoy, and ordinary people are still arguing about the thousands of dollars that Tesla has gone up and down.
