This star is going to the moon

Chapter 515 The God of the Road Calls Out the Roll, Whoever He Calls Out Is Doomed!
Engineer: "Supervisor, the rocket is leaking liquid hydrogen again."

director:"……"

"Inspect immediately!"

The supervisor is numb.

Why is it always you?
hydrogen!

Hydrogen leaks are nothing new for NASA; many of the previous unpredictable space shuttle launches were caused by hydrogen leaks.

A ground team once spent six months trying to find the source of a hydrogen leak on the space shuttle, which led to the space shuttle being grounded for the entire year.

What a coincidence! The SLS rocket uses the same engines as the Space Shuttle!
Of course, it did not directly use the engines left over from the space shuttle; it was upgraded based on the original design.

Some performance was improved, but... some features were abandoned.

For example, the space shuttle engines were originally reusable, but after the upgrade, they were changed to disposable.

But no matter how it's modified, its foundation remains the space shuttle engine.

There's nothing we can do about that; there will definitely be issues related to hydrogen.

NASA had no choice; their insistence on using liquid hydrogen as a propellant on the SLS rocket was not for technical reasons.

Rather, it's because since NASA's founding in 1958, it has been using contractors across the federal government to maintain federal congressional policy and financial support for space exploration.

The first system to use liquid hydrogen was the Centaur rocket, developed in the 1950s and 60s.

Previously, the federal Congress had explicitly required NASA to use existing space shuttle technology in its authorization bill to fund the next generation of launch systems.

This decision was made to keep NASA contractors employed in key districts so they could benefit from federal funding and support for NASA.

After all, companies involved in the space shuttle program would face bankruptcy risks after its retirement, so the government had to do its best to maintain the aerospace industry chain and employment to stabilize the political "vote base," and thus the SLS rocket project was launched.

However, this decision also means that although the space shuttle is about to be retired, the RS-25 engine it carries and the liquid hydrogen and liquid oxygen fuel it uses will be transferred to the SLS rocket.

NASA collected a total of 16 engines from the retired space shuttle, four of which were upgraded and installed on the SLS rocket that now stands on the launch pad at the space center.

In other words, it's the engine that keeps leaking hydrogen, like the one that keeps leaking hydrogen.

As an official agency, NASA must prioritize securing the support of the federal Congress to sustain its space exploration program.

Therefore, the continued use of the RS-25 engine, a "relic" of the Space Shuttle, is a typical example.

This shows that even in the federal government, the choice of rocket fuel can be politicized, while the most direct and ideal solutions are often not feasible.

Ultimately, NASA did not choose propellants such as methane or kerosene for the SLS rocket, but instead opted to use a mixture of liquid hydrogen and liquid oxygen to power such a heavy-duty rocket.

And simply using it isn't enough; one must also praise this choice as excellent.

Therefore, in their preliminary project report, they wrote: "Based on current information and analysis, the design of the next-generation heavy-lift SLS launch vehicle represents the direction with the lowest short-to-medium-term cost, fastest availability, and least overall risk."

Choosing this architecture means that there is no need to develop new rocket engines in the short term, thus shortening the time to maiden flight and potentially minimizing the overall cost of the SLS rocket.

Ironically, the SLS rocket, originally scheduled for launch in 2017, has yet to take off.

Since the "Return to the Moon" program was initiated, the total research and development cost, including the Orion spacecraft, has exceeded $500 billion, not including the more than $40 billion required for each launch of the SLS rocket!
The rocket inherited components from the space shuttle, and NASA inherited the hydrogen leak problem.

Hydrogen is a very effective rocket fuel. This element is abundant on Earth, clean, lightweight, and burns extremely efficiently when combined with liquid oxygen.

However, hydrogen fuel has the disadvantage of being difficult to transport and control, and it also requires cooling to extremely low temperatures to maintain its liquid state.

Also, because hydrogen molecules are very small, they can easily leak through tiny pores in the weld.

More importantly, hydrogen is highly volatile in its liquid state, posing a risk of large-scale combustion.

When the SLS rocket is fueled, the sudden influx of cryogenic hydrogen causes a huge change in the rocket's physical structure.

A 40-meter-tall liquid hydrogen storage tank will shorten in length by 152 millimeters and shrink in diameter by 25.4 millimeters after being filled with supercooled liquid.

As a result, components connected to the storage tank, such as pipes, vent pipes, and supports, must compensate for this sudden contraction.

To address this issue, NASA used accordion-like bellows, slotted joints, expansion joints, and ball joint hinges in the connectors.

However, as the smallest molecule in the universe, hydrogen still often leaks out through tiny pores.

The problem of leaks in the fuel loading lines is particularly serious because they cannot be directly secured to the rocket with hard bolts.

As the name suggests, the quick disconnect device is designed to detach from the rocket quickly during launch, while also preventing hydrogen leakage under high pressure and ultra-low temperature conditions and ensuring a tight seal.

It was clearly not sealed properly and started leaking again.

As the audience watched the tentative countdown and the refueling progress, they all had a bad feeling.

[Damn, is there going to be another problem and it'll be postponed again?]

[Come again?]

[I'm getting old, and I rarely get to stay up all night, so please don't mess with me, NASA!]

I don't really care; I can just go to sleep anyway since it's postponed. I just feel sorry for the audience members who were there in person.

[That shouldn't be possible, right? Wasn't it supposed to be all fixed before the maiden flight?]

NASA's credibility score is a bit low these days; they've said it so many times.

[It just dawned on me, that wasn't a blessing from Lu Shen, it was clearly a curse!]

[Has our country gained another "strategic toxic milk"?]

[Haha, it's true! No wonder Lu Shen suddenly wished the Americans a successful spaceflight.]

[Ahem, perhaps the God of Road truly is offering a blessing; this is just our overinterpretation, don't take it seriously, don't take it seriously...]

This issue is not only being complained about by Chinese netizens, but also by netizens all over the world. After all, time is different in different parts of the world. Some people stay up all night like Chinese netizens, while others risk being caught slacking off during the day while at work.

So all you did was repay everyone with "continue to postpone"?
Fortunately, it wasn't "postponed," it was just "paused," so the audience's emotions remained relatively stable.

Since the president's convoy did not turn back but continued to head here, it means that it was just a technical adjustment.

It turned out to be a technical adjustment. NASA's previous repairs were not in vain. They replaced gaskets in areas prone to leakage and sealed areas where necessary. Although there was still a leak this time, it was much smaller than the previous large-scale leaks and was within a controllable range.

Next comes the classic mathematical problem of "a pool being filled and drained at the same time".

Engineer: "After inspection, the leak rate is very slow, so the fuel can still be refilled within the specified time. We believe we can continue refueling." Supervisor: "Then continue!"

When the countdown restarted, the audience at the scene breathed a sigh of relief, and the criticism in the live broadcast room also decreased.

In the coastal aerospace city, a group of young engineers stayed up all night with Lu Yun to watch the live broadcast. Someone couldn't help but ask, "Mr. Lu, is the Americans about to make it?"

Lu Yun, watching the live stream, stroked his stubble and said, "No, the countdown will probably have to be paused again in a bit. It's probably... a sensor problem."

"Sensor problem?"

Everyone was puzzled. What could be wrong with this?
There were problems with the launch pad and rocket during previous rehearsals.

The problems with the launch pad are basically due to the aging of the "Relics," such as fan malfunctions.

The main problem with rockets is fuel leakage, sometimes from the engine and sometimes from the fueling pipes.

These problems have now been largely resolved, and even those that haven't been 100% resolved haven't had much of an impact.

After so many rehearsals, the sensors are perfectly fine.

Lu Yun didn't say anything in response to everyone's questions, but instead gestured for everyone to just keep reading.

If an ordinary person said that, they would definitely refute it on the spot, but it was Lu Shen who said it...

Let's continue watching.

After waiting for a while, Old Deng's convoy arrived, and the next question arose!

Sensor alarm!
Supervisor: "What's going on?"

Engineer: "Six sensors issued abnormal data alerts, and the countdown immediately entered safe mode and stopped!"

Supervisor: "Shit!"

The manager originally planned to surprise James Harden when he arrived, but the Rockets surprised him instead.

And the news spread very quickly.

The maiden flight of the SLS rocket attracted worldwide attention, and the American media, being the most well-informed, quickly received information from "anonymous well-informed sources."

[Sensor Alert!]

Ignoring the string of question marks in the live stream chat, the young engineers watching the live stream with Lu Yun all had question marks on their faces.

And of course, there was shock!
Lu Yun secretly breathed a sigh of relief, then explained in a serious tone, "Actually, there's a big problem inside the other side..."

In fact, there have been many outward signs of this, such as SLS being called the "King of Pigeons".

Its development was plagued by delays, with the first launch date postponed from 2017 to 2022, a total of more than ten times, resulting in serious cost overruns.

NASA's Office of Inspector General also warned that "the launch cost of the SLS is too high and unsustainable."

In addition, there were also many problems with these wet rehearsals.

Not only did NASA discover the problems, but it also concealed many issues in order to save time. In fact, NASA never completely resolved the technical problems of the SLS rocket.

NASA previously resorted to "cheating" to check for problems in the latter part of the launch process. They chose to use computer programs to block out several issues and continue with subsequent tests.

In the end, none of the wet rehearsals were 100% successful. Instead, they managed to achieve the so-called "100% success" by combining several rehearsals with their own self-testing in the general assembly building.

The current sensor problem actually occurred during the first launch window at the end of August in the previous era, which NASA encountered only 40 minutes before launch.

In this life, they were in a rush to launch in June, and hadn't experienced what happened afterward, so now it can only be a total explosion.

The reason for the sensor malfunction is not complicated: the rocket's maiden flight was delayed for too long, causing the sophisticated sensors to age.

In fact, the Federation proposed the ambitious "Constellation" program in 2005, intending to use the newly developed "War God" series rockets to send the "Orion" spacecraft to the moon and Mars.

However, in 2010, when the new government came to power, they announced the cancellation of the "Constellation" project, citing reasons such as insufficient funding and slow progress.

Then, in order to maintain the federal government's manned spaceflight capabilities, NASA confirmed the development of the SLS rocket in 2011.

There has been much discussion in federal media about why the development of the SLS rocket is progressing so slowly.

The prevailing view is that this is related to factors such as NASA and traditional federal space companies' lack of innovation, serious bureaucracy, repeated changes to the White House space policy, and the decline of the federal space industry.

NASA has repeatedly stated that it needs to learn from the innovative spirit of federal private space companies such as SpaceFork, and has entrusted the development of a manned lunar lander to SpaceFork's "Moonhawk" project, an improvement on the "Super Falcon".

The SLS rocket has been delayed for so many years, and the batteries of the several "hitchhiking" CubeSats on board have all run out of power. How can such a sophisticated sensor be any better?

Lu Yun even knew that half of the CubeSats weighing a dozen kilograms that hitched a ride with him in his previous life were scrapped upon launch and never had a chance to carry out their missions.

Furthermore, the US Artemis program is not just a rocket problem; its other projects are also worrying.

The complete Artemis program consists of six major components: the SLS rocket, the Orion crew spacecraft, the exploration ground system, the crewed lunar landing system, the Gateway lunar orbital space station, and the Artemis Headquarters lunar base.

As the next-generation manned spacecraft of the Federation, the Orion spacecraft can accommodate four astronauts and can carry out deep space exploration missions to the International Space Station, the Moon, and even Mars.

However, the cramped living environment of the Orion spacecraft has drawn many complaints. One federal astronaut, when talking about his first impression of the Orion spacecraft, said: "It's really too small, it's really crowded for four people."

NASA maintains that, unlike the SpaceX Crew Dragon and Boeing Starliner spacecraft, which are primarily designed for low Earth orbit missions, Lockheed Martin's Orion spacecraft will be responsible for long-duration deep space exploration missions.

Therefore, safety and reliability must be the top priority, while comfort can only be considered later.

Unfortunately, Lu Yun knew that its security was also questionable.

The Orion spacecraft began development in 2006, had its first test flight in 2014, but only its second test flight was in 2022.

Judging from the current situation, it's even uncertain whether a test flight will be possible this year.

Moreover, even if it had been test-flown, Lu Yun knew about the major problems in its previous life.

That is, in its previous life, when it was operating in a "remote retrograde orbit" around the moon, communication with NASA mission control was interrupted for 47 minutes. The engineering team was able to restore the communication link between the spacecraft and the Deep Space Network by reconfiguring it.

During the high-speed reentry into Earth's atmosphere, charred material detached from the spacecraft's heat shield, a problem that had not been detected during previous low-orbit reentries.

Later, it was discovered that the spacecraft's life support system had a design flaw, and the batteries also had problems.

Lu Yun said, "Just wait and see, there's more to come!"

Everyone: "..."

(End of this chapter)