23.11.2021
SpaceX’s first two Super Heavy boosters making good progress towards test debuts
SpaceX is making good progress on Starship’s first two Super Heavy boosters, both of which could potentially be ready for their first major test campaigns before the end of the year.
On November 19th, some ten weeks after the process began, SpaceX craned Super Heavy B5’s methane (LCH4) tank on top of its oxygen (LOx) tank, marking the end of major structural assembly for the 69m (~225′) tall booster. A team of welders has since been working around the clock to weld the two tanks together and complete a transfer tube that routes methane propellant down through B5’s oxygen tank.
Two days prior, CEO Elon Musk shared a photo of SpaceX’s other Super Heavy booster (B4) which has been slowly progressing towards test readiness for more than three months. It’s unclear why SpaceX has been so sluggish to prepare Super Heavy B4 for testing but with B5 finally approaching the finish line, the company will soon find itself in a position where it will need to decide which booster to proceed with towards the program’s near-term end goal: the first orbital Starship test flight.
Once Booster 5’s two halves are welded together, only a few things will set it and Booster 4 apart. In recent weeks, SpaceX’s slow progress on Super Heavy B4 relented a bit as technicians began closing out the booster’s raceway (a conduit for plumbing, wiring, and avionics) with basic covers. More importantly, SpaceX also began reinstalling Raptor engines and installing heat shielding around those engines for the first time. In the photo Musk published on November 17th, that heat shield is easily visible and there are signs that it will ultimately enclose the entire outer ring of 20 Raptor Boost engines above their nozzles.
Once complete, that shield will theoretically protect each engine’s nest of sensitive plumbing and wiring during static fires; ascent, boostback, and landing burns; and – most importantly – reentry. Unlike Falcon boosters, which always perform a ~30-second, three-engine ‘reentry burn’ to slow down and cushion the blow of reentry heating, SpaceX plans to recover steel Super Heavy boosters without reentry burns. In theory, that should making booster recovery more efficient, allowing another dozen or so tons of propellant to go towards sending Starship to orbit instead of landing.
As of November 17th, SpaceX has reinstalled all 29 Raptor engines on Booster 4, partially finished the outer ring of Raptor heat shields, and set the stage for more heat shielding around its 9 center engines and the gap between those inner and outer Raptors. Shielding the Raptor Center engines in a way that still seals off Super Heavy’s aft will be even more challenging given that all nine need to be able to freely gimbal to vector their thrust, while the outer ring of 20 Raptor Boost (RB) engines are fixed in place. At pace of work established over the last few months, it will likely take SpaceX several more weeks to finish that heat shield and install seven ‘aerocovers’ over racks of sensitive equipment installed around Booster 4’s base.
Super Heavy Booster 5, on the other hand, has taken a slightly different path through assembly. Unlike Booster 4, which first rolled out as little more than a giant steel tank with Raptors half-installed, SpaceX appears to have installed most of Booster 5’s external plumbing, wiring, equipment racks, and maybe even the start of its Raptor heat shield during assembly instead of after. Perhaps as a result, SpaceX has taken more than ten weeks to stack Booster 5 versus 2.5 weeks for Booster 4. But given that Booster 4 still doesn’t appear to be complete some 18 weeks after its assembly began, there’s a chance that Booster 5 will ultimately take 4-6 weeks less to reach initial test readiness.
If SpaceX does complete Super Heavy B5 well ahead of B4’s schedule, it will soon find itself with two test-ready Starship boosters but only one orbital-class stand with which to test them, potentially forcing the company to make some interesting decisions.
Quelle: TESLARATI
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Update: 2.12.2021
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Starship engine 'crisis' poses possible bankruptcy risk for SpaceX, Elon Musk says: report
SpaceX "will need all hands on deck to recover from what is, quite frankly, a disaster," Musk wrote in an email recently.
A close-up of three SpaceX Raptor engines clustered together for the company's Starship SN8 prototype.(Image credit: SpaceX)
Elon Musk thinks SpaceX needs to ramp up production of its next-generation Raptor engine soon or face potentially dire consequences, according to media reports.
Raptors will power Starship, the huge, fully reusable vehicle that SpaceX is developing to take people and cargo to the moon, Mars and other distant destinations. Each Starship will need a lot of Raptors — 33 for the giant first-stage booster, called Super Heavy, and six for the upper-stage spacecraft, known as Starship.
SpaceX wants to operate a large fleet of Starships in the coming years. Indeed, perhaps 1,000 of the vehicles will be needed to colonize Mars, one of Musk's long-held dreams, the billionaire entrepreneur said earlier this month at the joint fall meeting of the Space Studies Board and the Board on Physics and Astronomy, both of which are part of the U.S. National Academies of Sciences, Engineering, and Medicine.
So SpaceX aims to manufacture a lot of Raptors in the relatively near future. And the company is apparently not on track to meet that challenge at the moment, according to an email Musk sent to SpaceX employees over the Thanksgiving weekend.
In the email, which was obtained by Space Explored, Musk describes the Raptor production situation as a "crisis" that is "much worse than it had seemed a few weeks ago." He says that he was foregoing a planned Thanksgiving weekend break to work on the Raptor production line and implores all SpaceX employees to pitch in if they can.
"Unless you have critical family matters or cannot physically return to Hawthorne, we will need all hands on deck to recover from what is, quite frankly, a disaster," reads the email, which Space.com has not seen directly. (SpaceX's headquarters are in Hawthorne, part of the Los Angeles metropolitan area.)
Musk explains that Starship is needed to launch Version 2 of SpaceX's Starlinkinternet satellites. The company has already lofted more than 1,600 V1 Starlink craft, and roughly 100 of the more-advanced V1.5 line, with its Falcon 9 rocket. But that workhorse launcher (which employs Merlin engines) cannot accommodate the bigger V2 satellites, which Musk sees as vital moneymakers for the company.
"Satellite V1, by itself, is financially weak, while V2 is strong," the email reads, according to Space Explored. "In addition, we are spooling up terminal production to several million units per year, which will consume massive capital, assuming that satellite V2 will be on orbit to handle the bandwidth demand. These terminals will be useless otherwise."
Time is of the essence to get the Raptor problem fixed, Musk stresses in the email.
"What it comes down to is that we face a genuine risk of bankruptcy if we can’t achieve a Starship flight rate of at least once every two weeks next year," the missive reads.
Given that Starship is designed to be completely and rapidly reusable, SpaceX should need just a few operational vehicles to be able to fly twice a month. But right now it doesn't have any, as Starship remains in the test-flight phase.
That could change relatively soon. SpaceX is gearing up to launch the program's first orbital test flight, which will involve a Starship prototype called SN20 and a Super Heavy known as Booster 4. That landmark mission could occur as soon as January or February, provided the U.S. Federal Aviation Administration wraps up its environmental review of Starship's orbital launch site in South Texas by the end of the year, Musk has said.
Space.com reached out to SpaceX for comment about Musk's email and the Raptor production situation but has not yet heard back from the company. Elon Musk did address the issue on Twitter, however.
"If a severe global recession were to dry up capital availability/liquidity while SpaceX was losing billions on Starlink & Starship, then bankruptcy, while still unlikely, is not impossible. GM & Chrysler went BK last recession. 'Only the paranoid survive.' — Grove," he tweeted on Tuesday, referring to a book by former Intel CEO Andrew Grove.
"It's getting fixed," Musk added in another Tuesday tweet, referring to the Raptor production problem.
You can read more about the email in the Space Explored story, which is full of interesting details.
This story was updated at 10:20 a.m. EST on Dec. 1 to include Musk's Twitter statements.
Quelle: SC
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SpaceX grapples with Raptor production problems
WASHINGTON — Problems increasing production of the Raptor engines that power SpaceX’s Starship vehicle have led to personnel shakeups at the company and a warning from founder Elon Musk that the company risked “bankruptcy” if the company could not resolve them.
The issue came to a head in a Nov. 26 email from Musk to SpaceX employees where Musk warned of a cascading effect of the “production crisis” of Raptor engines that could affect deployment of the next generation of its Starlink constellation and overall company finances. The email, obtained by SpaceNews, was first reported by SpaceExplored.com.
“Unfortunately, the Raptor production crisis is much worse than it seemed a few weeks ago,” he wrote. “As we have dug into the issues following exiting prior senior management, they have unfortunately turned out to be far more severe than was reported.”
Musk’s email did not go into the specifics of the issues, but his comments likely refer to the recent departure of Will Heltsley, vice president of propulsion at SpaceX. Heltsley, who had been at SpaceX since 2009 and in the role of vice president of propulsion since 2018, left amid problems scaling up production of Raptor.
In the email, sent the day after the Thanksgiving holiday, Musk said he had planned to take the holiday weekend off “but instead I will be on the Raptor line all night and through the weekend,” calling on company employees to do the same. “Unless you have critical family matters or cannot physically return to Hawthorne, we need all hands on deck to recover from what is, quite frankly, a disaster.”
SpaceX did not respond to a request for comment on Musk’s email. The company infrequently acknowledges media inquiries.
SpaceX needs to produce large numbers of Raptor engines for its Starship vehicle, whose first orbital flight could take place as soon as January. The Starship vehicle itself uses six Raptor engines, but its Super Heavy booster needed for orbital launches currently has 29 engines. Musk said in a Nov. 17 talk to two National Academies committees that Super Heavy will later use 33 Raptor engines, but did not give a schedule for that change.
The company is building a new factory at its McGregor, Texas, test site for large-scale production of Raptor engines, but for now is building the engines at its Hawthorne, California, headquarters. Musk said in July the McGregor facility will be able to produce two to four Raptor engines per day, but the company has not stated when that factory will begin operations.
That’s created a production crunch as SpaceX plans for a series of test flights of Starship in 2022. Musk said at the National Academies meeting that SpaceX is planning for as many as a dozen test flights of Starship in 2022 with the goal of enabling commercial operations to begin in 2023. “The engine build rate is currently the biggest constraint on how many vehicles we can make,” he said then.
Musk, though, appeared to be aiming for a much higher launch rate in his email. “What it comes down to is that we face genuine risk of bankruptcy if we cannot achieve a Starship flight rate of at least once every two weeks next year,” he wrote. That would be 26 launches next year, although one industry source, speaking on background, said Musk was likely referring to a launch rate to be achieved by the end of 2022, not an average for the full year.
The risk of bankruptcy is tied to the need to use Starship to deploy a second generation of Starlink satellites. “The consequences for SpaceX if we can’t get enough reliable Raptors made is that we then can’t fly Starship, which means we then can’t fly Starlink Satellite V2 (Falcon has neither the volume *nor* the mass to orbit needed for satellite V2),” he wrote. “Satellite V1 by itself is financially weak, whereas V2 is strong.”
SpaceX, he added, is investing “massive capital” on production of end-user terminals, with a goal of several million units per year. Those terminals, he wrote, depend on the additional bandwidth the second generation of Starlink satellites will provide. “These terminals will be useless otherwise,” he wrote.
In tweets Nov. 30, Musk appeared to back away from some of the more dire warnings in his earlier email. “If a severe global recession were to dry up capital availability / liquidity while SpaceX was losing billions on Starlink & Starship, then bankruptcy, while still unlikely, is not impossible,” he wrote, mentioning the bankruptcies of automakers Chrysler and General Motors in the 2008 recession. He then cited a quote attributed to Andy Grove, the late chief executive of Intel: “Only the paranoid survive.”
As for the Raptor production issues, he said in another tweet, “It’s getting fixed.”
Quelle: SN
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Update: 9.12.2021
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SpaceX stacking two Starships at once for the first time in ten months
As of late November, SpaceX has begun stacking two Starship prototypes simultaneously for the first time in ten months.
Known as Starship S21 and S22, SpaceX began stacking the latter prototype inside Starbase’s ‘midbay’ in mid-October – the first Starship assembly work seen in more than two and a half months. For about half a year, SpaceX has been significantly more focused on Super Heavy production as it works to thoroughly test a booster for the first time. In the interim, the assembly of Starships – which already have an impressive history of ground and flight tests – slowed to a halt, though the production of Starship parts did not.
Once that basic structure is complete, parts are cut out or welded on to create structural supports, pass-throughs, and mounts for avionics (batteries, wiring, power, comms) hardware, plumbing, mechanical systems, and more. In the case of ships, robotic arms also weld on thousand of studs that eventually become anchors for heat shield tiles. At some point, certain partially-finished ring sections are ‘sleeved’ around tank domes, of which Starship and Super Heavy both have three. Finally, at some point in the early ‘life’ of a Starship or Super Heavy, SpaceX begins assembling the actual vehicle out of that collection of different sections. While weeks or even months of work always precede that milestone, the first stack is still the point at which SpaceX decides to turn those parts into an actual vehicle – never a guarantee, no matter how far along those parts appear to be.
SpaceX installs Starship booster on orbital launch mount for the third time
After several signs of imminent activity on Sunday, SpaceX has installed Super Heavy Booster 4 (B4) on Starbase’s lone ‘orbital launch mount’ for the third time.
Around 10am CST (UTC-6), SpaceX began retracting more than a dozen clamps that hold the 69m (~225 ft) tall Super Heavy – the largest booster ever built – to its transport and work stand. By 11:30am, Booster 4 was safely extracted from the stand and hovering above it as the lift team crossed their Ts and dotted their Is before proceeding. SpaceX’s newest Starbase crane then spun around and crawled a short distance to the orbital launch mount, where it lifted Booster 4 above the mount.
In a process that this particular Super Heavy prototype is thoroughly familiar with, SpaceX then very carefully lowered B4 down into the center of the donut-shaped orbital launch mount, where 20 separate clamps – each capable of deploying and retracting – form a support ring and giant hold-down clamp.
It’s unclear how exactly that process of mount installation works but it could be quite the orchestration. By all appearances, Super Heavy hold-down clamps – mechanical devices designed to hold the booster to its work stand or keep it immobile on the launch mount during a variety of test – work by reaching inside the lip of the booster’s aft ‘skirt,’ which sports a very sturdy ring of steel that 20 Raptor Boost engines mount to and push against. The 20 clamps fit precisely between each of those 20 outer Raptors and grab onto Super Heavy from the inside.
Just before liftoff, all 20 hold-down clamps will rapidly retract back into the orbital launch mount. So will another 20 small quick-disconnect umbilical panels designed to supply every single Raptor Boost engine with the gases they need to ignite. The primary booster quick-disconnect – which connects Super Heavy to power, communications, and propellant supplies – will also retract into a hooded enclosure at some point during the process. Finally, a giant, swinging arm located about halfway up Starbase’s ‘launch tower’ will retract a similar quick-disconnect panel for Starship fueling, retract two claw-like support arms, and swing back for liftoff.
Altogether, while there are likely even more than just those described above, a single Starship launch will require at least 44 separate devices to successful actuate in rapid and precise succession – 41 for Super Heavy and at least 3 for Starship. That incredible complexity – probably making Starship’s the most mechanically complex launch mount in the history of rocketry – may partially explain why Super Heavy Booster 4 has yet to even attempt a single proof test more than four months after it first left the high bay it was built in.
Without a functioning orbital launch mount, it hasn’t been possible to fully test a Super Heavy booster. With any luck, on their third rendezvous, both Booster 4 and the orbital launch mount are finally close enough to completion to perform some serious testing. At the absolute minimum, everything appears to be in order for SpaceX to properly connect Super Heavy to the launch mount and pad for the first time – the process of which is already underway. Aside from connecting B4 to the mount’s hold-down clamps, which has been done twice before, SpaceX can now attach all 20 Raptor quick-disconnects and the main booster quick-disconnect to a Super Heavy for the first time. Further up the tower, SpaceX can also partially test out the Starship quick-disconnect arm, which is half-designed to grab onto and stabilize Super Heavy.
SpaceX currently has road closures (signifying plans for ship, booster, or pad testing) scheduled on Tuesday through Friday this week, hinting at the possibility that Super Heavy B4 could finally start proof testing in mid-December.
SpaceX to upgrade Starship with 50% more Raptor engines
SpaceX CEO Elon Musk says that future Starships – or at least certain Starship variants – are being upgraded with 50% more Raptor engines and stretched propellant tanks.
On December 17th, the CEO revealed the plans, confirming a tweet published three months prior stating that Starship was “begging for an extra 3 engines.” Musk was likely referring to the fact that a 9-engine Starship – combined with upcoming 33-engine Super Heavy boosters – would create a rocket with 42 engines, a number made famous as “the answer to the ultimate question of life [and everything]” in Hitchhiker’s Guide to the Galaxy – both of which the CEO vocally enjoys. As ever, it’s thus almost impossible to tell jokes from serious, consequential plans – as is the case with Starship.
Nonetheless, origination aside, adding another three Raptor engines to Starship – boosting the count from six to nine – and stretching its tanks could be a substantial upgrade.
According to amateur modelers, who are generally able to estimate rocket performance with enough information about its structures, shape, and engines; an optimal nine-engine Starship’s tanks would be stretched about 25% to store an additional 300 tons (650,000 lb) of cryogenic liquid oxygen and methane (LOx/LCH4). That upgraded Starship would have a liftoff mass close to 1600 tons (3.5M lb) and stand about 55 meters (~180 ft) tall – 10% taller than current ships.
At stage separation, close to vacuum, a stretched Starship with three sea-level-optimized Raptors (RCs) and six vacuum-optimized Raptors (RVacs) should produce at least 2000 tons (4.4M lbf) of thrust – and possibly more than 2250 tons (~5M lbf) depending on engine performance. At that upper level of thrust, Starship – an upper stage – would be just 10% less powerful than the first stage of Falcon Heavy, the most powerful operational rocket in the world.
Regardless of its thrust, dimensions, or weight, what matters most is how a stretched, nine-engine Starship would impact that overall rocket’s launch performance. If unofficial modelers are to be believed, the results are significant: compared to a ‘normal’ Starship with a six-engine upper stage and 33-engine booster, the stretched ship could theoretically boost the amount of payload the rocket can launch to low Earth orbit (LEO) from about 150 tons to 220 tons or more (330,000 to 485,000+ lb) – an almost 50% improvement. In fact, per another recent comment from Muskindicating that Starship – unlike almost all other rockets – won’t temporarily throttle down on ascent, the total payload performance could be a bit less than 230 tons (~500,000 lb) – more than 50% greater than a shorter six-engine Starship.
If those estimates are accurate, upgrading Starship with nine Raptors and stretching its tanks is a no-brainer. It might slow development and make all nine-engine ships cost a substantial fraction more but a 50% improvement in payload performance would significantly improve the efficiency of Starship’s more ambitious Moon and Mars launch profiles, which require numerous orbital refuelings.
In effect, a 50% payload increase would allow SpaceX to complete most refueling tasks more efficiently, quickly, and cheaply. Even if the upgrade plans mean that all Starships will be stretched and carry nine Raptors, fully refueling the new Starship variant in LEO could require 7 tanker launches instead of 8-10. If SpaceX doesn’t mind maintaining multiple distinct Starship variants, which appears to be the case, then ships that are exclusively dependent on refueling (Moon and Mars landers in particular) could stay at their current size, with ~1200 tons (~2.6M lb) of propellant storage and six Raptors. A fleet of upgraded Starships could thus refuel their smaller siblings with just 5-6 tanker launches.
However, there’s a good chance that the extra mass required to stretch Starship ~5.5m (~4 tons or ~9000 lb) is minor enough that SpaceX will instead stretch all Starship variants. In fact, for variants like NASA’s HLS Moon lander and future Marsbound Starships, which depend entirely on refueling to reach their destinations, stretched tanks and more propellant storage could increase the amount of payload they could send to the Moon, Mars, and other high-energy destinations by quite a bit. Ultimately, it will be fascinating to hear more details from SpaceX and Musk on how exactly the upgraded Starship design might benefit those operations in the coming weeks and months.
Quelle: TESLARATI