The Starship launch failed, but the next era of spaceflight is coming

Recently, an event that is amazing in the entire history of human spaceflight occurred: a test rocket carrying a spacecraft malfunctioned during its first launch. Several engines failed to ignite as soon as it was ignited, but it still took off tremblingly. After flying for a few minutes, it finally lost control and exploded, crashing into the sea. But whether the rocket ignited unsuccessfully or the takeoff posture was unstable, cheers from the staff on site could be heard, and the cheers continued until the rocket lost control and crashed into the sea. Some people even started to applaud and opened champagne to celebrate.

In the field of aerospace, people always celebrate successful launches. We have never seen a rocket launch fail, but the staff celebrated with a toast. Even Elon Musk, the boss of Space X, the company that built the rocket, congratulated the company after the rocket failed to launch. Such a result was surprising and confusing. But if you knew the significance of this rocket called "Starship" to the entire aerospace field, you would probably applaud the launch failure. This is the first launch of the largest rocket and spacecraft in the history of human aerospace. If the test is successful, it may reduce the cost of human space travel to 1/1,000~1/200 of the current level, thus completely bringing humans into the stage of cheap aerospace.

Starship on the launch pad

The rocket with the largest payload so far, coupled with the low transportation cost, has attracted great attention to this launch test. Therefore, the researchers set some "small goals", such as as long as the rocket ignites smoothly and does not blow up the launch pad, it will be a success; if it can take off smoothly and continue to fly, it will be a great success; if the first stage rocket separates smoothly and the spacecraft ignites smoothly, it will be a super success; if the spacecraft successfully enters orbit, it will be an unprecedented success.

It is not difficult to understand why the staff still opened champagne to celebrate even though the launch failed.

The dream of flying is no longer expensive

For today's human beings, flying into space is a dream that is neither big nor small. It is not big because, as long as you fly 100 kilometers into the sky and cross the Karman line, you are in space, and 100 kilometers is not a long distance, and a car can reach the destination in more than an hour on the highway; it is not small because it is easy to drive 100 kilometers on land, which does not burn 10 liters of gasoline and takes less than 2 hours, but it is very difficult to get rid of gravity and rise 100 kilometers vertically.

If you randomly pick 100 passers-by on the roadside and ask them if they want to travel to space without considering the cost, more than 90% of them may say yes. Since so many people want to go to space, why hasn't the space travel industry developed? First, although the success rate of rocket launches is high, once a danger occurs, the result is a rocket destroyed and people killed; second, it is expensive. If you want to take a rocket to space, buying a ticket costs 20 million to 40 million US dollars, which is 140 million to 280 million RMB.

If SpaceX's Starship is successfully tested, it will eventually be able to carry people or cargo into space, and the cost of transporting each kilogram can be reduced to $100, while traditional rockets will cost $20,000 to transport 1 kilogram of cargo into space. In this way, if a person weighs 70 kilograms, excluding space suits, he can be sent into space for only $7,000 (about 50,000 RMB). With the addition of a life support system and systematic training, it may cost less than 500,000 RMB to travel to space. In the future when the Starship is successfully launched and commercialized, the cost of traveling to space will be only 1/1,000 to 1/200 of the current cost.

This is still about transporting people into space, which requires a life support system, food and water, and the temperature inside the spacecraft must also be strictly controlled. If only some cargo is transported, the transportation cost can be reduced.

Starship, the pioneer of the next era of spaceflight

The human dream of flying may be traced back to the primitive humans in Africa. Millions of years ago, when the primitive humans finished a day of hunting and gathering and were about to fall asleep, they looked up and saw the starry sky, which may have aroused their strong interest in it. Therefore, the yearning for the sky or space may have been engraved in our genes.

Humans have been searching for ways to fly into space. It wasn’t until the end of the 19th century that a Russian named Tsiolkovsky proposed various theories of space travel and rocket thrust. Although the scientist, who lost his hearing at the age of 9 due to illness, ultimately failed to realize his design, his theory was right: multi-stage rockets using liquid oxygen and liquid hydrogen as fuel could reach space.

Tsiolkovsky

Since the first liquid rocket built by rocket scientist Robert Goddard, liquid rockets have remained the main force of rocket launches for nearly 100 years, and even the structure has hardly changed. Moreover, rockets have been facing a huge contradiction since their inception: rockets must carry a large amount of fuel, and the thrust generated by the combustion of the fuel will eventually push the rocket into space. The more cargo is transported, the heavier the rocket is, and the more fuel is needed. Due to this contradiction, rockets are unlikely to have too much load, but when we build space stations, lunar bases, and Mars bases, the amount of machinery and instruments transported is huge, and the demand for food and water is even greater. How to make rockets transport larger and heavier cargo and how to reduce freight costs are the main propositions of rocket launches.

Goddard and his liquid rocket

The two important advantages of Starship are almost entirely based on this main proposition. One is the specially designed engine, and the other is the repeated recycling of rockets.

Advances in rocket engines

The starship is mainly divided into two parts: the lower rocket booster part is called "superheavy", which is translated into Chinese as "super heavy"; the upper part that can carry cargo and spacecraft is called "starship", which is called "星舰" in Chinese. For the sake of easy memory, people combine superheavy and starship and call them "starship".

The two-part structure of a starship

When a rocket is ignited, it relies on the engine installed in the first stage rocket or booster to burn fuel, spray a large amount of flame and gas, and use the principle of action and reaction to take off. Therefore, whether the engine is reliable becomes the most important factor in the rocket's launch. With the advancement of materials science and engineering, the starship engine has been redesigned and iterated many times, and the current engine performance has surpassed all previous rocket engines.

Starship has 33 Raptor II engines installed in the super-heavy section and 6 in the Starship section, for a total of 39 engines. Each engine has a thrust of about 230 tons. Not counting the engines in the Starship section, the super-heavy section alone has a thrust of 7,590 tons. Is this thrust large enough? For example, before the construction of Starship, the most powerful rocket in human history was the Saturn V rocket used in the Apollo moon landing program, which had a thrust of 3,400 tons. A simple calculation shows that the thrust of Starship is more than twice that of Saturn V.

Starship has 33 engines installed in the super heavy section

With such a large thrust, it means that heavier cargo or spacecraft can be sent into space. If the return trip is not considered, Starship can send about 300 tons of spacecraft or cargo into space at a time. The carrying capacity of Saturn V is 140 tons, and the current strongest SLS BLOCK1B rocket can only send 95 tons of cargo or spacecraft into space.

What does a 300-ton spacecraft or cargo mean? A male African elephant weighs about 6 tons, and a starship can send 50 elephants into space at a time. Isn't such a terrifying thrust amazing?

Advances in Arrow Materials and Fuels

In terms of size, Starship is a little taller than his predecessors. But in terms of the material cost of the arrow body, Starship is quite cheap.

We should have used or seen a thermos cup with a 304 liner. Such a cup is durable and inexpensive. If such a material is used to make a rocket body, the cost is very low. 304 stainless steel costs only $3 per kilogram, while the carbon fiber composite material used to build modern main rockets is not so cheap. The cost of 1 kilogram of carbon fiber composite material is $100, which is more than 30 times that of 304 stainless steel. Moreover, 304 stainless steel is much easier to produce.

In addition to the improvement in the material of the rocket body, the choice of starship fuel is also special. It chooses liquid oxygen and methane.

At present, there are four main types of rocket fuels, namely solid fuel, nitrogen tetroxide/hydrazine (amine), liquid oxygen kerosene and liquid oxygen and liquid nitrogen. Among them, the manufacture of solid fuel engines is the simplest. Although the thrust is not large, solid fuel is relatively easy to preserve, so it is often used as the fuel of rockets' "brothers" - missiles. Nitrogen tetroxide/hydrazine (amine) is more convenient to ignite, ignites immediately upon contact, and can be stored at room temperature. However, since this fuel is highly toxic and extremely expensive, it is used less and less. Liquid oxygen kerosene is the first cost-effective at present, but the quality requirements of kerosene are extremely high, because its combustion is easy to accumulate carbon and coke, which is not conducive to the recycling of engines. Liquid oxygen and liquid hydrogen fuels are also the main fuels of today's rockets. Liquid oxygen and liquid hydrogen burn to produce water, which is very environmentally friendly, but the disadvantage is that such engines are too difficult to develop and fuel storage is also very difficult, because liquid hydrogen takes up a lot of space, the temperature difference with liquid oxygen is large, and insulation is also required.

The fuel used by Starship is liquid oxygen and methane. On the one hand, liquid oxygen and methane will not produce carbon deposits when burned like liquid oxygen and kerosene, and the engine is easy to clean and maintain, and easy to recycle and reuse; on the other hand, the storage temperature/boiling point of liquid oxygen and methane are very close, and the storage difficulty is much lower than that of liquid oxygen and liquid hydrogen, the storage of the latter in rockets is an extremely difficult problem.

At the same time, the construction difficulty of the liquid oxygen-methane engine is relatively low, and the structure is similar to that of the liquid oxygen-kerosene engine, and almost all related structures can be used. Moreover, liquid oxygen-methane is the lowest cost of all rocket fuels.

Rocket recovery screen

If we want to explore Mars, we will definitely have to return to Earth after arriving there. It is very expensive to produce liquid hydrogen on Mars, but it is relatively simple to use methane as fuel. Methane can be formed by combining carbon dioxide on Mars with water. Moreover, it is much easier to find methane than liquid hydrogen on the major planets in the solar system, especially on Jupiter, Saturn, Uranus and Neptune.

Reuse can significantly reduce costs

One of the dreams of mankind is to send a large number of manpower and machinery into space to build a space station, send them to Mars to build a base, and eventually migrate to Mars. This requires building rockets with larger payloads, which will result in extremely high costs. For example, the current 110-meter-high SLS rocket costs $2.2 billion to build and launch once.

Starship Mars Base concept art

In fact, the height of the Starship is also 120 meters, so the cost should not be too cheap, but its shell and engine can be reused 50 times, which is much cheaper when spread out over each launch. Therefore, one of the important reasons why the Starship is cheap is that it can be reused, which is something that most rockets in various countries cannot do.

Starships can now be mass-produced, and the factory can even build a Raptor engine every day. With the advancement of design, the price of a Raptor engine is only $2 million, and it only costs $1,000 to produce 1 kilonewton of thrust, while the RS-25 engine used in the space shuttle and SLS rocket costs $25,000 to produce 1 kilonewton of thrust, which is 25 times more expensive. Today, the more advanced Raptor II engine has a streamlined design, with a mass reduction of 400 kilograms and a price as low as $1 million. The thrust reaches 230 tons, and it can be reused 50 times, with a cost of only $8 per kilonewton of thrust.

In summary, the main advantages of Starship are its high thrust, easy production, and low cost. Therefore, even if the launch pad is not blown up, or even if it explodes after only a few minutes of flight, it will make people very excited, because this is the first step in the space travel of all people. Although it is only a small step, it may be a big step for human space travel.

Starship's future career plan

With cheap rockets, scientists can create scientific designs that were previously only imaginable but never possible, such as space-based solar energy.

Space-Based Solar Energy

On the ground, solar power generation is seriously affected by cloudy days and rain, but space-based solar power is different. It is not affected by weather at all in satellite orbit. With the development of telemetry technology, a large amount of electricity can be transmitted back to the earth's surface, which can be more environmentally friendly than any power generation device on the earth. What troubled scientists before was that launching so many solar panels and telemetry facilities would require a large number of rockets, and the cost would be much greater than the output. But with Starship, such a dream is no longer far away.

At the same time, the idea of ​​building a lunar base, a Mars base, or even launching a large number of devices to transform Mars is no longer out of reach.

Therefore, not only has Starship made great efforts in engine and recyclable technology, but China's aerospace industry is also catching up, and recyclable rocket technology has achieved some results. I believe that in the near future, China's own cheap rockets will also be launched, taking us into the next era of aerospace.