SpaceX lived up to expectations and fulfilled the promised time for the third flight of the Starship as scheduled. It chose the 22nd anniversary of the founding of SpaceX to launch the tallest and most powerful rocket in history and stage an epic third flight of the Starship. Bravely passing through many passes, the mission completion rate exceeded 80%, which was far more shocking and stunning than the first flight and the second flight - flying higher and farther.


He was not deterred by the thunderstorms in the weather forecast, nor was he knocked down by the naysayers of Starship. On the contrary, SpaceX firmly locked in the Π day, and the third flight of Starship arrived as scheduled: 8:25 a.m. on March 14, US-China time (Beijing time). At 21:25 pm on March 14), located at the orbital launch pad of the Starship Base in Boca Chica, Texas, the starship combination numbered B10+S28 began the starship’s third transatmospheric orbital test flight, rising majestically and shaking the earth. The future space transportation system that indicates that humans will become a cross-planetary species once again challenges the impossible and turns the impossible into a feasible task.

●What challenges did the Starship pass on its third flight?

On the eve of the launch, SpaceX's official website announced the established operating procedures for the third flight of the Starship. From the launch director's approval and the countdown to the Starship spacecraft flying half the world and finally completing the controlled sea splashdown, the entire process took 139 minutes as planned. Counting from the launch of the starship to the splashdown of the starship on the sea, the entire process lasted 64 minutes as planned, and was interlocking and progressive. By comparing the actual execution status with the established process one by one, it is not difficult for us to know: What hurdles did the third flight of Starship pass? Clear at a glance▼

The third flight of the starship can be said to be famous in one battle. The main tasks were completed more than 80%, and the main test objectives were successfully achieved: thermal separation was successfully completed again, the ability to deploy satellites was smoothly demonstrated, liquid oxygen transfer and refueling were smoothly achieved, and the spacecraft entered the re-entry stage... Only the super-heavy type performed poorly in the landing stage and the re-entry ignition stage of the spacecraft, losing 20%.


○The ignition and take-off time is 5 seconds, which is 3 seconds shorter than the first flight.

The third flight of the starship is set to take 5 seconds from ignition to takeoff, which is the same as the second flight, but 3 seconds shorter than the first flight. The first flight on April 20 last year was set to last 8 seconds from ignition to takeoff, which caused huge damage to the launch pad and its surroundings, even causing three Raptors to shut down the ignition process before takeoff; the second flight on November 18 was shortened to 5 seconds to avoid damage to the launch pad and the engine itself. The third flight this time will continue to last for 5 seconds. On the premise of ensuring that the 33 Raptors can reach the specified thrust value at full propulsion, damage should be avoided as much as possible.

The live broadcast after takeoff showed that all 33 Raptor engines of the B10 super-heavy rocket continued to exert force and passed the maximum air resistance point (Max-Q) in T+52 seconds. Until T+2 minutes and 42 seconds, two seconds before the separation of the first and second stages, the first stage B10 shuts down 30 Raptor engines, leaving only the three center engines to ignite and burn at 50% thrust. This operation is the same as the second flight.

○Thermal separation is delayed by 3 seconds

T+2 minutes and 44 seconds, the critical thermal separation is performed (Starship spacecraft S28 is ignited first and then separated from the interstage section). This is slightly delayed by 3 seconds from the thermal separation performed at T+2 minutes and 41 seconds on the second flight of the Starship. This is to generate greater superimposed thrust, further accelerate the second-stage starship spacecraft, and allow the S28 to minimize gravity loss, thus improving the efficiency of entering orbit.

○Successful return to home and ignition

At T+2 minutes and 55 seconds, the super-heavy rocket B10 successfully started the return ignition and started the three center engines to perform reverse thrust. This was the first time a super-heavy rocket passed this critical link, and was a big step ahead of the Starship's second flight, B9.

At that time, B9 experienced excessive acceleration after thermal classification, and the filter that provided liquid oxygen to the engine was clogged, causing the oxidizer inlet pressure to decrease, causing multiple engine failures. One of the engines suffered a violent failure, which ultimately caused B9 to trigger the AFTS automatic termination system and disintegrate in the air.

○Longer deceleration

At T+6 minutes and 36 seconds, the super-heavy B10 slowed down from supersonic speed to transonic speed, which was a full 18 seconds longer than the original plan of the Starship's second flight B9 to achieve transonic speed. The reason for this operation is to allow the super-heavy rocket to return in a more stable and slower flight attitude instead of faster and more violent flight attitude, thus helping to achieve the final operation-vertical sea splashdown.

○Failed to initiate landing ignition

At T+6 minutes and 46 seconds, the super-heavy B10 failed to start the landing ignition procedure as planned and did not start the three center engines again for reverse thrust. At this time, B10 was about 5 kilometers above sea level and flying at a speed of nearly 2,000 kilometers per hour. A few seconds later, the live broadcast showed that B10 tried to start three engines (two of which were non-center engines), but it was fleeting. The flight speed plummeted to nearly 1,000 kilometers per hour, and the live broadcast of the B10 was immediately interrupted. Obviously, the super-heavy B10 failed to perform landing and ignition as planned, let alone achieve a vertical sea descent in a controlled state, and gently embraced its destination - the Gulf of Mexico waters delineated about dozens of kilometers away from the starship launch site. As a result, the landing ignition could not be started, resulting in high-speed falling and violent splashing, until it disintegrated.

However, the series of previous operations of the super-heavy B10 have been unprecedented, and the test team has collected first-hand data. It should be said that the B10 could achieve a high score of more than 80 in this test flight mission. The only regret was that it failed to pass the last level - it failed to start the landing ignition and could not splash down vertically on the sea.

○S28 enters the taxiing stage

After passing through thermal separation, the second-stage S28 turned on the firepower of six Raptors at full power. At this time, the flight altitude reached 95 kilometers and the flight speed was 6342 kilometers per hour. It was not until 8 and a half minutes after liftoff, T+8 minutes and 35 seconds, when it almost reached orbital speed, that S28 shut down 6 engines as planned and entered the space taxiing stage.

Compared with the second flight of the starship, this third flight created another key breakthrough. You know, during the second flight, the S25 suddenly lost contact at this critical moment and then exploded. Later investigation and analysis revealed that the S25 leaked and caught fire when discharging excess liquid oxygen, causing damage to the flight computer and communication system. This caused the engine to receive a shutdown signal in advance, which ultimately triggered the AFTS system and caused the spacecraft to disintegrate in the air.

○First demonstration of satellite deployment capabilities

Starship spacecraft S28 opened the payload bay door at T+11 minutes and 56 seconds as planned, but it seemed to be defective and the opening and closing was not tight. The planned activation time is more than 16 minutes, which is exactly the time it will take to deploy Starlink satellites in orbit in the near future. During this period, not only the load hatch of the S28 was opened and closed, but the satellite distributor was also started to test the redesigned satellite distributor in the cabin. But this time no payload was deployed. The rack height of the satellite distributor carried by S28 this time is much higher than that of the previous starship distributor. This change means giving Starship the ability to carry and deploy more Starlink satellites. According to Musk's optimistic expectations, it is expected to be unveiled on the next Starship test flight at the earliest and put into use in the second half or the end of this year at the latest, in order to deploy the next generation of Starlink satellites in larger quantities.

○The starship flew to an apogee of 234 kilometers

At about T+25 minutes, Starship S28 arrived at the apogee of 234 kilometers. It is very close to the expected value of 235 kilometers. The third flight of the starship is a transatmospheric orbital flight. The planned flight orbit is 50×235 kilometers, and the actual flight orbit is 55×234 kilometers, which basically coincides with the expected value.

○First on-orbit demonstration of propellant transfer

T+24 points, a small amount of propellant transfer test is carried out as planned. Specifically, there are two small propellant tanks inside the starship's nose cone, one with a 10-ton reserve of liquid oxygen tank and the other with a 4-ton reserve of methane tank. According to a SpaceX live broadcast commentator, the liquid oxygen in the nose cone liquid oxygen tank has been successfully transferred and refilled to the main liquid oxygen tank.

This is the on-orbit demonstration of a small amount of cryogenic propellant transfer technology, which is the first step towards a two-ship on-orbit demonstration of propellant transfer in the near future. According to the plan, the propellant transfer of a dual starship in orbit will be demonstrated as early as this year. After one starship docks with another starship in orbit, one of them will refill propellant (liquid oxygen, liquid methane) for the other. This is starship in-orbit refueling (refilling propellant). The next technical demonstration is to refuel the refueling version of the starship, and then to refuel the manned version of the starship demonstration.

○Failed to perform re-ignition demonstration

According to the SpaceX live broadcast commentator, the S28 Raptor vacuum engine was originally planned to perform a space re-ignition demonstration 40 minutes after liftoff, but for some reason it failed to re-ignite. This also led to a series of subsequent unplanned situations: premature reentry into the atmosphere, inability to decelerate to allow the heat shield to withstand greater challenges, and the starship quickly lost over the Indian Ocean.

○Starship undergoes re-entry test for the first time

Starship's third flight began re-entering the atmosphere 46 minutes after launch, several minutes ahead of schedule. Beautiful plasma can be clearly seen in the live broadcast. This is the biggest test for the S28, which is covered with heat insulation sheets on the windward side. Starship S28 has demonstrated certain reentry capabilities.

However, when the spacecraft dropped to 115 kilometers at a flight speed of 7.4 kilometers per second, some debris could be observed falling off the hull from the live broadcast, most likely heat insulation sheets.


○Starship lost over the southern Indian Ocean

The live broadcast showed that the last message of S28 was fixed at T+49:05, with a flight altitude of 65 kilometers and a flight speed of 7.14 kilometers/second. After that, the signal was lost.

Fourteen minutes after the signal was lost, a SpaceX live broadcast commentator stated that the test team was highly confident that the spacecraft had been lost and had not survived re-entry. However, it still re-entered and disappeared over the established southern Indian Ocean.

One hour after launch according to the original plan, the spacecraft dropped from supersonic speed to transonic speed and then to subsonic speed. At approximately T+1 hour, 04 minutes and 39 seconds, S28 performed a self-destructive splashdown at sea. In the non-ignition and reverse thrust state, embracing the vast ocean with a death mentality - the inaccessible southern Indian Ocean, painted the final highlight of the starship's third flight.

But no matter how you look at it, the third flight of the starship is far higher and farther than the first flight and the second flight.

●How long is the whole flight?

The third flight of the Starship is planned to take 64 minutes, which is a significant reduction of 26 minutes from the 90 minutes planned in the previous two test flights. The reason for shortening the flight time is that SpaceX intends to reduce the difficulty of this test and improve mission completion and success rate by adjusting the orbital altitude and shortening the flight time.

The actual flight time of the third flight of the starship was 49 minutes, and the completion rate of the main tasks exceeded 80%. Facts have proved that the results of this test flight were remarkable and exceeded expectations.


●What are the special features of the two protagonists of Starship?

As the two protagonists of this third Starship flight: the super-heavy rocket B10 and the Starship spacecraft S28, after careful comparison with the Starship predecessors, we will find that there are many, many hardware upgrades. Let’s take a look at what evolutions there are? What are the highlights?


Compared with the first-stage super-heavy rocket B10, the second-stage starship spacecraft S28 has evolved more and changed even more.


Taking stock of the iterative highlights of the dual protagonists of Starship Flight 3


●What is the value of the third flight of the starship?

The dual protagonists of Starship's third flight, B10+S28, fulfilled their mission as pioneers with heroic gestures and provided the most valuable first-hand data and information for subsequent tests. In order to evolve into a mature starship as soon as possible, such sacrifices are a price that must be paid. Just like the previous starship martyrs who were buried in the sea of ​​fire, such as SN8, SN9, SN10, SN11, B7+S24, B9+S25, they all lined up in the glorious starship hall to welcome the final winner.

This is the rapid iterative development model that SpaceX leads in the aerospace industry. The spiritual core behind it is Musk's consistent philosophy of "fail fast, iterate fast": be willing to take risks, not afraid of failure, just blow up, reflect on corrections, and invest in the next test, so that you can quickly mature and approach success. According to Musk’s original words: “We don’t want to eliminate all risk in the design, otherwise we will get nowhere.”

On the other hand, other launchers, especially those national teams and established aerospace giants such as Boeing, Northrop Grumman, and ULA, all follow the more stable/more conservative linear development principle. They first spend several years designing each link, then spend several years building each hardware component, and then spend several years testing and modifying... Exchanging time and money for incremental stability is essentially risk aversion and fear of failure. After all, in any subject where bureaucracy prevails, everyone from top to bottom is afraid of failure, fear of making a fool of themselves, and worry about gains and losses.

This rapid iterative development method is the basis for all major innovations and progress of SpaceX, including Falcon series rockets, Dragon spacecraft, Starlink, etc., especially in building the epoch-making fully reusable super space transportation system-Starship, where recursive improvement is crucial.

The protagonists of the starship's first flight, second flight, and third flight are all pioneers and pathfinders, and the successors are already eager to try. It is expected to stage its fourth flight as soon as May this year. Next, it will challenge a higher goal - to upgrade from transatmospheric orbital launch to real orbital launch, and change the flight orbit from 50×235 kilometers to 200×200 kilometers. It may even be the first to try to deploy Starlink satellites. Since they all have the ability to enter orbit, why not go a step further and directly deploy their own starlink!

Once it enters the rapid testing period - a high-frequency rhythm of one launch every two months or even once a month, SpaceX is very hopeful to catch up with the original starship development progress: launch into orbit in 2024, deploy the first batch of Starlinks, and demonstrate on-orbit refueling technology; conduct orbit transfer capability demonstrations, unmanned lunar orbiting tests, unmanned lunar landing demonstrations, manned capability tests in 2025-2026... until it is capable of undertaking the Artemis 3 manned lunar landing mission.

All of this depends on multiple actual battles, continuous trial and error, and cumulative experience, so that the starship system can be quickly polished and iterated, and it will get closer and closer to the mature version of the starship. Based on my optimistic prediction, SpaceX will be able to achieve this goal after about ten or twenty test flights. From then on, a new starship era will rewrite human civilization and create a true new era of space roaming.

●The evolution of the main parameters of SpaceX’s starship development



●The most powerful space transportation system in history—a simplified evolution of starships