Starship is about to undergo its 5th test flight, can Musk's fantasy from 8 years ago become a reality?

At this moment, SpaceX's Starship's 5th test flight is on the verge of ignition and liftoff. The highlight of this flight is whether Elon Musk can fulfill the promise he made 8 years ago.

In September 2016, 8 years ago, during the closing speech at the International Astronautical Congress, Musk, under the gaze of the global aerospace community, unveiled for the first time the Mars colonization rocket planned by SpaceX—the Interplanetary Transport System (ITS). This is a giant rocket with a thrust of tens of thousands of tons, capable of shuttling between Earth and Mars. In an era when the heavy Falcon rocket had not yet made its maiden flight, few in the audience took this rocket of tens of thousands of tons seriously, and there were even sporadic chuckles during the Q&A session.

In the demonstration animation of this rocket of tens of thousands of tons at the conference in 2016, there was an even crazier idea—to achieve rapid and reliable reuse of this rocket, SpaceX planned for the first stage of the rocket after launch to not land at a recovery site or on a recovery ship, but to fly directly back to the launch pad where it took off, like a flying pencil returning to its original position. This would only require simple maintenance and refueling before it could be launched again. At a time when the concept of recovering the Falcon 9 rocket with a takeoff weight of less than a thousand tons was not yet fully mature, this idea was dismissed by many.

The Interplanetary Transport System animation at the 2016 conference | SpaceX

Time flies, and 8 years later today, the "Interplanetary Transport System" has officially been renamed "Starship".

In the upcoming 5th experimental launch of Starship, SpaceX is attempting the crazy idea from the animation 8 years ago of the rocket returning to the launch pad.

At this moment, if you tune into the live broadcast on Guokr Video, then around 7 minutes after Starship ignites and lifts off, you might just witness this historic moment.

Starship, with a diameter of 9 meters and a height of 121 meters, primarily uses stainless steel for its fuselage material.

The first stage of the rocket is called the "Super Heavy Booster", standing at 71 meters tall, capable of holding 3400 tons of propellant, with a total liftoff thrust of an astonishing 7590 tons, more than twice that of the Saturn V heavy rocket used in the Apollo program.

The second stage of Starship is actually a special spacecraft, about 50 meters tall, capable of holding around 1200 tons of propellant, with a thrust of about 1500 tons, providing a reusable payload capacity of no less than 100 tons to low Earth orbit. It is also equipped with heat-resistant tiles on its windward side, designed for recovery and reuse.

If all goes well, the 5th test flight of Starship will proceed as follows:

After liftoff, the rocket's first stage, codenamed B12, will fly normally, with all 33 Raptor engines successfully igniting and operating until separation. Subsequently, the "hot separation" system will successfully separate the first and second stages of the rocket, after which the first stage of the rocket will turn around, ignite, and fly back to the launch pad.

Approximately 7 minutes after liftoff, B12 will reach the launch tower, attempting for the first time to use the retractable and rotating recovery mechanism on the launch pad for hanging capture If successful, it will be the first time to realize Musk's concept of "where it comes from and where it goes" proposed in the PPT 8 years ago.

Compared to the mature Falcon 9 land landing site and sea recovery ship mode, this method will greatly shorten the time for rocket recovery and transportation.

The launch pad recovery mechanism captures the Starship first stage in a simulated animation |SpaceX.

At the same time, the Starship second stage with the codename S30 ignites normally and flies out of the atmosphere, gliding outside the atmosphere.

48 minutes after takeoff, the Starship second stage will re-enter the atmosphere, and the huge spacecraft, over 50 meters high and weighing over a hundred tons, will return to the embrace of the earth, experiencing intense friction with the thin upper atmosphere, streaking across the night sky like a meteor.

The improved heat shield structure will face the challenge of high temperatures of over a thousand degrees, and then the four wing surfaces of the second stage will perform a combined action to change the arrow's posture to a vertical position, start the engine for retrograde deceleration, and finally gently land in the sea.

If the Starship first stage can be successfully captured and recovered, and if the improvement of the heat shield system of the Starship second stage allows the second stage to withstand the re-entry into the atmosphere more completely, then the 5th test flight of the Starship will be considered as successfully completing all planned launch missions, and the goal of recovering and reusing both stages of the Starship will take a solid step forward.

Why use "chopsticks" to catch rockets

As we all know, SpaceX's Falcon 9 is a partially reusable launch vehicle, with the first stage of the rocket successfully recovered over 350 times to date.

With sufficient capacity, the Falcon 9, like the Starship, will turn around and fly back after separation, but it will land on the landing pad not far from the launch site using deployable landing legs.

However, with the goal of maximizing rocket capacity, in over 90% of launches, the first stage of the rocket will shut down and fly forward under inertia, ultimately landing on a recovery ship in the vast ocean.

In this case, after the first stage of the rocket lands, personnel need to board the ship to secure the rocket, and then it takes a few days to several weeks to transport it back to the port. Once the recovery ship docks, a crane is needed to lift and transport the rocket for storage, folding or disassembling the landing legs before returning to the factory for refurbishment.

This recovery and transportation process not only significantly lengthens the refurbishment cycle of the Falcon 9, but the landing legs on the rocket are also dead weight that is not needed during the launch phase.

To achieve faster rocket recovery and reuse, SpaceX proposed the idea of ​​the rocket first stage flying directly back to the launch pad after launch at the beginning of the Starship project.

This not only eliminates the time for rocket recovery and transportation, but also eliminates the need for landing legs on the rocket, making the rocket lighter and more streamlined. At the same time, the "big chopsticks" used for recovery are also tower cranes used for overall assembly before launch, serving dual purposes without the need for additional design and installation of dedicated recovery mechanisms.

Musk's ultimate ideal for the Starship has always been to achieve rocket reuse like commercial aircraft, where after landing, a simple inspection is all that is needed to refuel the propellant and launch again, even executing two or more launches in a single day Looking at the single-digit launch demand from most spacefaring countries each year, this goal can be said to be nothing short of a pipe dream. However, judging from SpaceX's current annual record of over a hundred launches, this goal seems quite realistic.

Of course, the plan for launch pad recovery is not without its drawbacks.

Similar to the Falcon 9's return-to-launch-site recovery, its primary drawback is inevitably reducing the rocket's payload capacity. Fortunately, the Starship itself has strong capabilities, leaving enough room for extravagance. Musk himself believes that if rapid and reliable reusability can be achieved, the loss of payload capacity from recovery can be compensated for.

The second significant drawback is the extremely high precision required for rocket landing, to the point of being abnormal. This is because the Starship's capture recovery attachment points are not four huge grid fins like the Falcon 9, but two inconspicuous inverted L-shaped attachment points on the rocket's tank sidewall, which are difficult to spot without careful observation.

Not only does the launch pad recovery require precise flying back to the launch pad, but it also involves accurately closing a 20-meter-long mechanism known as "Mechazilla," which cannot close too tightly to avoid damaging the fragile tank, while still being able to catch the small recovery attachment points on the rocket. The difficulty can be likened to threading a needle.

The first-stage rocket must be clamped by the 20-meter-long "Mechazilla," and the attachment points must be precisely hung on the "Mechazilla," which is no small feat | Ryan Hansen Space

The third drawback is related to the second one. If the Falcon 9 recovery fails, at most it will damage the recovery ship's deck, or leave debris all over the land-based recovery site, with no impact on subsequent launches. However, if the Starship's launch pad capture recovery mode fails, it could result in damaging the launch pad at best, or veering off course and hitting other launch support facilities at worst, directly causing economic losses and affecting the progress of subsequent launches.

Netizens have already started guessing the rocket's landing point again, with facilities surrounding the launch pad, and the consequences of even slight deviations are unimaginable.

To prevent the occurrence of a "lose-lose" situation where recovery fails and the launch pad is destroyed, during the first-stage return process of the Starship's 5th launch, the system will continuously check the status of the launch pad and the rocket.

Only when all statuses are good, and the launch personnel manually issue the command, will the first-stage rocket fly back to the launch pad for attempted capture recovery.

If there are abnormalities with the rocket, such as grid fin jamming, engine leaks, or even personnel entering the landing safety zone, the rocket will land at sea just like the 4th launch.

Starship, Raptors, upgrades without interruption

Although the upcoming launch will be the Starship's 5th, the S31 and B13 combination for the subsequent 6th Starship launch has already been manufactured and is undergoing a series of tests at the neighboring "Messi" test site.

Musk is relentlessly pushing forward with the subsequent test launches of the Starship, even going so far as to publicly criticize the regulatory agency FAA (Federal Aviation Administration) in the media for intentionally delaying progress with reviews, and even threatening that the FAA Administrator should resign. Because the Starship for the 5th launch was actually ready for launch in early September, but was held up by the FAA until mid-October, with FAA indicating that they would not clear it until November if NASA had not intervened to coordinate Regulations may be dragging their feet, but the follow-up improvement roadmap for the Starship is already clear. The Starships launched so far are all V1 versions, and SpaceX has outlined the roadmap for the subsequent V2 and V3 versions of the Starship. The physical first stage of the V2 version Starship with serial number S33 has also appeared, and it is expected to be used in the 7th Starship test flight.

From a physical perspective, the front wing surface of the V2 version second stage has been significantly adjusted to be smaller, more forward, and moved towards the leeward side, allowing the front wing surface to better hide behind the leeward side of the arrow body during reentry into the atmosphere, reducing the peak heat flux and preventing the occurrence of heat accumulation and burning through the wing surface as seen in the 4th launch. The distribution of the heat shield tiles has also been fine-tuned accordingly.

SpaceX claims that the payload capacity of the V2 version Starship in reusable condition is not less than 100 tons. The main change in the V2 version first stage is the interstage segment, with a fully integrated design for the heat separation structure, rather than the detachable structure of the V1 version. In the future, the first stage of the Starship will continue to increase the number of engines to 35 based on the current 33 engines.

The long-term improvements for the V3 version Starship are intuitive and exaggerated, with no change in rocket diameter, a slight lengthening of the first stage, and a significant lengthening of the second stage, requiring adaptability in the launch pad. Most importantly, as the engine thrust continues to increase, the liftoff thrust of the rocket's first stage will soar to over ten thousand tons.

For driving the massive arrow body, the current Starship first stage uses 33 sea-level "Raptor" liquid oxygen methane engines with a thrust of 230 tons, and the second stage has 6 Raptors, including 3 vacuum-optimized Raptors with a thrust of 285 tons. The second-generation Raptors are currently relatively stable, but to match the iterative nature of the Starship, the Raptor engines are continuously being upgraded.

The third-generation Raptor engines will be used starting from the V3 version Starship, with a highly simplified structure for the third-generation Raptors, making the engines lighter yet more powerful. However, there are bound to be drawbacks, namely manufacturing difficulties. But SpaceX currently claims that, thanks to advances in 3D printing technology, these manufacturing challenges have been largely resolved.

There is still room for upgrades for the third-generation Raptors, with Musk stating that the thrust can continue to climb from 280 tons to 300 tons, with a thrust-to-weight ratio exceeding 200. At that time, the liftoff thrust of the Starship will officially rise to over ten thousand tons.

Thinking back to 2016 when the ITS liftoff thrust reached over ten thousand tons, which was later reduced when it became the Starship, after various improvements and iterations, the Starship will once again realize the "ten thousand-ton rocket colonizing Mars" dream originally envisioned by the ITS Re-entry heat resistance remains a challenge, with manned missions facing dual challenges

Currently, Starship's second stage uses approximately 18,000 hexagonal heat tiles. The surface temperature of the second stage reaches up to about 1400 degrees Celsius, similar to the era of the space shuttle. Compared to the various shaped heat tiles used by the space shuttle, Starship uses uniformly sized hexagonal heat tiles, with three fixed points under each tile, sandwiched with adhesive in the middle, and a hanging net at the bottom. The uniform size of the heat tiles reduces production and maintenance pressure.

During the 4th launch, although the heat tiles as a whole withstood the test of the atmosphere, issues such as detachment and breakage were still difficult to avoid, especially the design at the wing hinge area clearly needing improvement.

Therefore, before the 5th launch, SpaceX conducted a comprehensive rework of the heat protection system for the S30. The launch team spent over 12,000 hours, replacing the entire second stage's heat protection system with a new generation of heat tiles and spare ablative layers. They also reinforced the heat protection and sealing at the wing hinge area, and placed experimental new heat tiles at certain special locations for testing.

The effectiveness of these improvement measures can only be verified by the actual situation when the second stage re-enters the Earth's atmosphere approximately 48 minutes after the 5th launch of Starship - this will also be the second major highlight of this test flight. However, whether maintenance-free re-launch can be achieved will require the comprehensive evaluation of the second stage recovery in subsequent launches.

In addition, SpaceX is steadfastly advancing the manned missions of Starship.

SpaceX has initiated a series of manned missions under the codename "Polaris", starting with the Crew Dragon spacecraft, gradually breaking through various deep space manned technologies, and ultimately achieving SpaceX's independent deep space manned capability.

In the first mission of the Polaris project in September this year, known as the "Polaris Dawn Mission", astronauts wearing SpaceX's newly developed spacesuits successfully carried out SpaceX's first-ever extravehicular activity.

The third mission of the Polaris project, which is also the final mission, will realize the first manned launch of Starship.

SpaceX also never forgets its grand vision of colonizing Mars.

In September this year, Musk declared that in 2 years, by 2026, an unmanned Starship will be launched to land on Mars. He had previously stated at the first Starship unveiling in 2016 that the first manned Starship landing on Mars would be achieved by 2024 - clearly, he did not meet that goal.

However, the 2026 mission is relatively practical. Based on Starship's current progress, preparing for an unmanned Mars mission in two years is feasible. Moreover, since it is highly likely to be a cargo-only landing, the number of orbital refueling may only need to be around 5 times, or even fewer. But the technical challenges of this mission are extremely daunting, requiring breakthroughs or validations in orbital refueling, long-term deep space orbit, Mars atmospheric entry, descent, and landing (EDL) technologies.

From all publicly available information at present, this mission is a self-funded mission by SpaceX, with no visible planned funding from NASA, as SpaceX simply does not want to miss the 2026 Earth-Mars transfer window However, if SpaceX is really ready to implement this mission in 2026, NASA is likely to come up with some payloads to "hitch a ride" on this journey, after all, this is the first opportunity for human tons-level payload delivery to Mars. But considering the high risks involved, the payloads are unlikely to be very advanced. At the same time, in terms of Mars reentry, landing, and landing, SpaceX will definitely seek help from NASA's Jet Propulsion Laboratory (JPL), as JPL has extremely rich experience in this area.

This Mars mission is not a sudden decision, but something SpaceX has been planning for a long time. Even before the Starship was officially announced, during the era when the Falcon Heavy had just completed its maiden flight, SpaceX had planned a "Red Dragon" mission, where a modified Dragon spacecraft would be launched to the surface of Mars at its own expense, and then land on the Martian surface using the Dragon spacecraft's retropropulsion landing capability. At that time, SpaceX submitted this plan to JPL as part of the MSR (Mars Sample Return) program. In the end, due to the rapid development of the Starship, and the cancellation of the Dragon spacecraft's retropropulsion landing, the project had to be canceled. Now, with the maturity of the Starship, this plan has resurfaced.

To achieve the Mars mission, the Starship must also break through the technology of large-scale propellant transfer in orbit, which will require a second orbital launch pad for turnover and alternate launches.

SpaceX's second launch tower has been basically completed, but interestingly, new improvements have been made to the supporting launch pad. On the second launch tower, the "water-cooled steel plate" may be replaced by the traditional "deflector" again, and the fixed ignition mechanism on the launch pad may be reintegrated into the rocket.

What is remarkable is that the two highly difficult, high-investment, and high-risk space missions of manned Starship flights and unmanned Mars landings are actually organized and completed by SpaceX based on its own corporate vision, independent of NASA funding and contract requirements.

If these two missions can eventually be carried out, it can be said that SpaceX is not only a space contractor focused on completing contracts and making profits, but also a company with poetic and distant ideals.

Whether the Starship can ultimately achieve Musk's ultimate goal of "colonizing Mars" is something we eagerly await.

But before that, at this moment, let's watch the live broadcast of the Starship's 5th test flight together, and see if its first-stage rocket will fly back to the launch pad today, and if it can be caught and recovered by the "big chopsticks"!