Raumfahrt - SpaceX’s Elon Musk: Starship Update-17


SpaceX Starship event expected this September, says Elon Musk


SpaceX CEO Elon Musk has implied that he will continue the tradition of annual Starship update events later this year, likely presenting on the progress the company has made over the last 12 months at its South Texas rocket factory.

Beginning in Guadalajara, Mexico at the September 2016 International Astronautical Congress (IAC), Musk has presented a detailed annual update on the status of SpaceX’s next-generation Starship launch vehicle in September or October for the last four years. Formerly known as the Interplanetary Transport System (ITS) and Big Falcon Rocket (BFR), Starship is effectively a continuation of the unprecedented progress SpaceX has made with Falcon 9 and Heavy reusability.

SpaceX has managed to reliably reuse Falcon boosters 5+ times and is on the way to replicating that with payload fairings, but Musk has concluded that the Falcon family – despite being some of the largest operational rockets in existence – is just too small to feasibly recover and reuse the orbital second stage. With Starship, SpaceX wants to take a slightly different approach.

While also a two-stage rocket, Starship will have a magnitude more thrust than Falcon 9 and twice the thrust of Saturn V, the largest liquid rocket ever successfully launched. More importantly, both Starship stages are designed to be easily and rapidly reusable, while also entirely getting rid of deployable payload fairings. In theory, once fully optimized, Starship and the Super Heavy booster should be capable of placing 150 metric tons (~330,000 lb) of payload into low Earth orbit (LEO) in a single launch.

Of course, that is going to be an immense challenge – arguably the single most ambitious project in the history of commercial spaceflight – and SpaceX has quite a ways to go before it can even come close. Aside from the huge publicity and excitement it generates, offering detailed explanations of how exactly SpaceX is progressing towards those goals and how Starship’s design is evolving is likely the primary reason Musk has chosen to continue doing annual presentations.

SpaceX may likely be years away from routine, fully-reusable Starship launches but that doesn’t mean that no progress has been made. In the last ~10 months, SpaceX has successfully flown Starhopper to 150 meters (500 ft), destroyed Starship Mk1; built, tested, and destroyed Starships SN1, SN3, SN4, and four standalone test tanks; and expanded its South Texas presence from almost nothing to a large, semi-permanent factory.

Aside from Starship production and testing, SpaceX has evolved the cutting-edge Raptor engine from a relatively rough prototype to an engine capable of operating at the fringes of what thermodynamics will allow. Per Musk, a vacuum-optimized variant of the existing Raptor engine may already be preparing for its first test fires in McGregor, Texas. Meanwhile, SpaceX won its first Starship contract from NASA a matter of weeks ago, solidifying the ambitious rocket’s stature relative to other more traditional next-generation rockets from Blue Origin and the United Launch Alliance (ULA).

All things considered, there is an extraordinary amount of tangible progress on tap for the Starship update Musk says is planned for September. With a little luck, the 2020 presentation will align with Starship’s test program much like the 2019 event did with Starhopper, coming just a few months after ambitious flight tests.



Update: 7.07.2020


SpaceX Starship prototype bears down on first Raptor engine tests

SpaceX’s fifth full-scale Starship prototype is fast approaching its first Raptor static fire tests after the company recently delivered one of the newest engines to the launch site.

Known as Starship SN5, the ship is the fifth SpaceX has built since full-scale prototype development began in early 2019, as well as the fourth full-scale ship the company has completed since it began producing upgraded hardware in January 2020. SN5 rolled from SpaceX’s Boca Chica, Texas rocket factory to nearby test and launch facilities on June 24th, less than a month after Starship SN4 was destroyed by operator error minutes after completing its fourth Raptor static fire in four weeks.

While Starship SN5 was already more or less complete, SN4’s explosive demise damaged the launch mount (used to secure and fuel prototypes) beyond repair, forcing SpaceX to rapidly build and outfit a replacement. SpaceX finished that replacement mount around June 20th, installed SN5 on it a few days later, and then spent about a week finalizing and inspecting both components.

After barely a month of downtime, Starship SN5 kicked off its first gauntlet of tests late on June 30th, carrying on into the early morning of July 1st. As usual, SpaceX began with an ambient-temperature pressure test, filling Starship’s tanks with neutral nitrogen gas to check for leaks. This time around, SN5 must have been put together with exceptional care, as the company was able to immediately proceed into the ship’s first cryogenic proof test just a few hours later.

CEO Elon Musk has yet to offer any confirmation but the implication is that SN5 performed beautifully during its first liquid nitrogen proof test. Notably, based on’s excellent unofficial coverage, SN5’s cryo proof was uniquely ambitious. It’s unclear what if the test infrastructure, SN5, general confidence in the vehicle, or some combination of the above components were upgraded, but SpaceX appeared to load Starship SN5 with liquid nitrogen incredibly quickly, taking just 20-30 minutes to fully fuel the rocket. Given that all of that liquid nitrogen (some 1000+ metric tons or ~3.2 million gallons) is being loaded through a single “quick disconnect” panel, it’s no mean feat and far outweighs SpaceX’s already speedy Falcon 9 and Heavy propellant loading.

SpaceX is famously the only current launch vehicle operator known to “sub-cool” its rockets’ propellant, effectively squeezing a performance boost of 5-10% out of the same rocket hardware by making said propellant colder – and thus denser. That performance increase comes with tradeoffs, though, adding significantly tighter operational constraints, lowering delay tolerances, and necessitating an extremely quick propellant load. Sub-cooled liquid oxygen and methane has always been part of SpaceX’s plans for Starship, so fast-load tests were inevitable, but it’s a great sign that the company is starting to seriously think about capabilities that will be necessary for efficient orbital launches.

Meanwhile, labeled “27”, the engine – logically assumed to be Raptor SN27 – SpaceX has just installed on Starship SN5 is also of interest. On top of Musk’s recent confirmation that SpaceX is already building Raptor SN30 (probably SN31 or SN32, now), SN27’s assignment to Starship SN5 confirms that the company has managed to complete (and test) at least one next-generation engines every other week since the first full-scale engine shipped to McGregor, Texas in February 2019.

Starship SN4 was tested with Raptor SN18 and SN20 just 1-2 months ago. (SPadre)
SN5 will kick off static fire testing with Raptor SN27. (NASASpaceflight – bocachicagal)

For a brand new engine as complex as Raptor, that’s an impressive production milestone. Per Musk, the end-goal is to produce at least one Raptor per day in the near term – a necessity given that each Starship and Super Heavy booster pair will require at least 37 engines. To feasibly build a fleet of tens – let alone hundreds or thousands – of Starships and boosters, one engine per day is arguably the bare minimum required just for early orbital launch attempts and initial operations.

According to published schedules, Starship SN5’s first live wet dress rehearsal (WDR) and static fire tests could happen as early July 8th, with backups on the 9th and 10th. Coincidentally, SpaceX’s next orbital Falcon 9 launch is also expected on the 8th, meaning that both Starship and Falcon 9 could fire up more or less simultaneously.



Update: 17.07.2020


SpaceX stacks Starship nose section for the first time in months


SpaceX has stacked a Starship nosecone section to its full height for the first time in almost a year, featuring an upgraded design that could soon support an ambitious series of flight tests.

Back in August 2019, SpaceX first began stacking the nose section of Starship Mk1 – the first full-scale prototype of any kind. It became clear a few months later that Starship Mk1 was more of a rough proof of concept than a full-fidelity test article, but it still became the first (and only, so far) Starship to reach its full ~50m (~160 ft) height. After serving as a centerpiece during CEO Elon Musk’s September 2019 Starship presentation, SpaceX removed the nose and attempted to test the Mk1 tank section itself, ultimately destroying the ship.

Now eight months distant from Mk1’s demise, SpaceX’s Starship R&D program has entered the prototype mass-production phase. Since January 2020, SpaceX has built five upgraded Starship tank sections (and tested three to destruction), built and tested four stout test tanks, and completed at least 4-5 new nosecone prototypes. For the first time since nosecone production began several months ago, one of the noses has finally been stacked to its full height atop five steel rings.

At the moment, SpaceX is hard at work preparing Starship SN5 for its first wet dress rehearsals (WDRs) with methane and oxygen propellant and either one or several Raptor engine static fire tests. If successful, SpaceX will quickly move to flight test preparations, readying SN5 for a nominal ~150m (~500 ft) hop, though the company is technically no longer restricted to that ceiling. For such a low-altitude test, aerodynamic features like a nosecone or flaps serve no functional purpose, meaning that SN5 is unlikely to ever receive those additions.

SpaceX’s fifth full-scale Starship prototype could become the first to take flight just a few days from now. (NASASpaceflight – bocachicagal)
Starship SN6 (left) and, possibly, the first two rings of Starship SN8. (NASASpaceflight – bocachicagal)

Roughly two miles west of the coastal launch and test site SN5 is stationed at, SpaceX has already more or less finished Starship SN6, although the newest ship’s fate is unclear. Pictured above on July 10th, the task of stacking an even newer ship (likely SN8) may already be underway. Last month, SpaceX tested a new ‘test tank’ built out of a different steel alloy said by CEO Elon Musk to be theoretically superior. Two cryogenic pressure tests seemingly confirmed that suspicion, proving that 304L stainless steel fails more gracefully than 301 while still offering similar strength at the pressures Starships operate at. The SN7 test tank was built and tested around the same time as SpaceX was finishing up SN6, implying that the ship was almost certainly built out of 301 steel.

If 304L really is the way forward for future Starship prototypes, the next step will be building an entire ship out of the steel alloy and performing a full cryogenic proof test and wet dress rehearsal. Given that SN5 and SN6 are likely identical (or nearly so), SN6 may have been made redundant before the ship even left the factory floor.

A swath of Starship rings are pictured in various states of assembly on July 13th. (NASASpaceflight – Nomadd)

This is all to say that it’s a bit of a mystery where the first upgraded nosecone will find itself in the coming weeks. Like SN6 or SN7, it could either be redundant on arrival, built as practice, or both. It could also be the first nosecone installed on a flightworthy Starship prototype. It’s unlikely but not impossible that SN5 survives its static fires and first hops and is modified to support three Raptors and aerodynamic control surfaces, while SN8 and SN9 are more probable candidates for the first high-altitude, high-velocity test flight(s). SpaceX has at least 3-5 more Starship nosecones strewn about its Boca Chica factory, though, so odds are good that the first new nose section to reach full height won’t be the first to take flight.

For now, Starship SN5 (sans nose) is scheduled to attempt its first wet dress rehearsal (WDR) no earlier than July 16th. If successful, a static fire could follow a few days after that and a hop test another few days later.