Connect with us

News

SpaceX’s Starship Raptor Vacuum engine plans laid out by CEO Elon Musk

A 2016 render of Raptor Vacuum. Much has changed about the engine's design in the three years since, but SpaceX is still pursuing a vacuum variant. (SpaceX)

Published

on

Elon Musk says that SpaceX Starship engine upgrades are on track to begin static fire tests of a Raptor Vacuum variant as few as a “couple months” from now.

Designed to enable more efficient performance in thin atmosphere or vacuum, Musk admitted that the first version(s) of Raptor Vacuum (RVac) will likely be a compromise between efficiency and speed of development. Nevertheless, the faster SpaceX can prepare Raptor Vacuum for flight, the easier it will be for Starship to begin serious (sub)orbital flight tests.

As it turns out, SpaceX’s first and only official render of Raptor – published in September 2016 – showed the engine’s vacuum-optimized variant. In the years since, CEO Elon Musk has vacillated between keeping the vacuum engines as a central Starship feature and simply replacing them with regular sea level Raptors to expedite the spacecraft’s debut. The 2016 and 2017 vehicles featured a mixture of vacuum and sea-level engines, whereas Musk revealed a vehicle with sea-level engines only in 2018.

Known as the Interplanetary Transport System in 2016, the ship featured six vacuum Raptors and 3 SL engines. (SpaceX)
In 2017, Big Falcon Spaceship shrunk and changed to 4 x RVac and 3x x Raptor SL engines. (SpaceX)
In 2018, Musk decided to sidestep vacuum engines entirely, moving to 7 SL Raptors. (SpaceX)

Perhaps less than a month after Musk’s September 2018 presentation, the SpaceX CEO made the decision to radically redesign the vehicle – newly christened Starship and Super Heavy – by moving from a carbon composite aerostructure to stainless steel. At first, the seven SL Raptors remained a part of the design, but Musk took to Twitter in 2019 to indicate that SpaceX had changed gears again and had reprioritized Raptor Vacuum development.

This came as a bit of surprise and it should go without saying that there’s a significant chance that Musk/SpaceX will oscillate in the opposite direction once again before Raptor Vacuum is actually ready for flight. This time, though, Musk has sketched out a development schedule and strategy that suggests SpaceX is much more serious this time.

Most notably, Musk claims that the first Raptor Vacuum prototype could be ready for static fire testing just a “couple months” from now, an immensely ambitious schedule for any large liquid rocket engine development program. Nevertheless, Musk did indicate that the “V1.0” Raptor Vacuum design would be significantly compromised and “suboptimal”, an intentional decision to prioritize the engine’s “speed of development”.

Even then, Musk believes that the first variant – featuring a shortened bell nozzle – could still be up to 12% more efficient than sea level Raptors and thus already 70-80% of the way to the physical limit of methane-oxygen rocket efficiency.

Advertisement
A sea-level Raptor engine is static-fired at SpaceX’s McGregor, TX test facilities. (SpaceX)

On a positive note, shrinking V1.0 Raptor Vacuum’s nozzle a bit from its nominal length will likely mean that SpaceX can static fire fully-integrated engines at its McGregor, TX test facilities, critical for speedy development. If not, the company has experience with alternatives through Merlin Vacuum, which can only be tested on the ground with its lengthy nozzle detached. This method just makes it dramatically harder to optimize a vacuum nozzle design, as full-scale, flight-like testing is nearly impossible if a given vacuum engine can’t be tested on the ground with said nozzle installed.

Vacuum engines need such large and unwieldy nozzles in order to make them as efficient as possible. In a very simplistic sense, a rocket engine nozzle directs the flow of superheated, ultrafast gases in order to squeeze as much momentum transfer as possible out of available propellant. The lower the pressure of the surrounding atmosphere is, the more those gases will expand immediately after leaving the nozzle – giant vacuum nozzles simply try to harness the additional momentum available from that extra expansion. This is why rocket exhausts appear to spread and thin out as launch vehicles reach higher and higher altitudes.

A Falcon 9 upper stage’s vacuum nozzle glows white hot during an orbital MVac burn. (SpaceX)

In this sense, the perfect theoretical vacuum nozzle is quite literally infinitely long. The job of vacuum rocket engineers is to find the perfect balance between that impractical theoretical perfection and the limits of real-world materials and dynamics. In theory, SpaceX’s sea-level Raptor engines have already been designed to operate in vacuum conditions, while the engine’s closed-cycle design and regeneratively (i.e. propellant) cooled nozzle should apply well to a vacuum design.

If SpaceX is lucky, there will be few roadblocks in the way of simply lengthening a SL Raptor-style nozzle and calling it a day, in which case it would be impressive but not all that surprising if SpaceX is actually able to begin RVac testing before the end of 2019. Once a rough V1.0 engine is in place, the process of optimizing efficiency can be done slowly and methodically, all while exploiting an unprecedented wealth of data from flight and orbit-tested Raptor Vacuum engines.

Check out Teslarati’s Marketplace! We offer Tesla accessories, including for the Tesla Cybertruck and Tesla Model 3.

Eric Ralph is Teslarati's senior spaceflight reporter and has been covering the industry in some capacity for almost half a decade, largely spurred in 2016 by a trip to Mexico to watch Elon Musk reveal SpaceX's plans for Mars in person. Aside from spreading interest and excitement about spaceflight far and wide, his primary goal is to cover humanity's ongoing efforts to expand beyond Earth to the Moon, Mars, and elsewhere.

Advertisement
Comments

News

Tesla adds a new feature to Navigation in preparation for a new vehicle

After CEO Elon Musk announced earlier this week that the Semi’s mass production processes were scheduled for later this year, the company has been making various preparations as it nears manufacturing.

Published

on

Credit: Uber

Tesla has added a new feature to its Navigation and Supercharger Map in preparation for a new vehicle to hit the road: the Semi.

After CEO Elon Musk announced earlier this week that the Semi’s mass production processes were scheduled for later this year, the company has been making various preparations as it nears manufacturing.

Elon Musk confirms Tesla Semi will enter high-volume production this year

One of those changes has been the newly-released information regarding trim levels, as well as reports that Tesla has started to reach out to customers regarding pricing information for those trims.

Now, Tesla has made an additional bit of information available to the public in the form of locations of Megachargers, the infrastructure that will be responsible for charging the Semi and other all-electric Class 8 vehicles that hit the road.

Tesla made the announcement on the social media platform X:

Although it is a minor development, it is a major indication that Tesla is preparing for the Semi to head toward mass production, something the company has been hinting at for several years.

Nevertheless, this, along with the other information that was released this week, points toward a significant stride in Tesla’s progress in the Semi project.

Now that the company has also worked toward completion of the dedicated manufacturing plant in Sparks, Nevada, there are more signs than ever that the vehicle is finally ready to be built and delivered to customers outside of the pilot program that has been in operation for several years.

For now, the Megachargers are going to be situated on the West Coast, with a heavy emphasis on routes like I-5 and I-10. This strategy prioritizes major highways and logistics hubs where freight traffic is heaviest, ensuring coverage for both cross-country and regional hauls.

California and Texas are slated to have the most initially, with 17 and 19 sites, respectively. As the program continues to grow, Florida, Georgia, Illinois, Washington, New York, and Nevada will have Megacharger locations as well.

For now, the Megachargers are available in Lathrop, California, and Sparks, Nevada, both of which have ties to Tesla. The former is the location of the Megafactory, and Sparks is where both the Tesla Gigafactory and Semifactory are located.

Continue Reading

Elon Musk

Tesla stock gets latest synopsis from Jim Cramer: ‘It’s actually a robotics company’

“Turns out it’s actually a robotics and Cybercab company, and I want to buy, buy, buy. Yes, Tesla’s the paper that turned into scissors in one session,” Cramer said.

Published

on

Credit: Tesla Optimus/X

Tesla stock (NASDAQ: TSLA) got its latest synopsis from Wall Street analyst Jim Cramer, who finally realized something that many fans of the company have known all along: it’s not a car company. Instead, it’s a robotics company.

In a recent note that was released after Tesla reported Earnings in late January, Cramer seemed to recognize that the underwhelming financials and overall performance of the automotive division were not representative of the current state of affairs.

Instead, we’re seeing a company transition itself away from its early identity, essentially evolving like a caterpillar into a butterfly.

The narrative of the Earnings Call was simple: We’re not a car company, at least not from a birds-eye view. We’re an AI and Robotics company, and we are transitioning to this quicker than most people realize.

Tesla stock gets another analysis from Jim Cramer, and investors will like it

Tesla’s Q4 Earnings Call featured plenty of analysis from CEO Elon Musk and others, and some of the more minor details of the call were even indicative of a company that is moving toward AI instead of its cars. For example, the Model S and Model X will be no more after Q2, as Musk said that they serve relatively no purpose for the future.

Instead, Tesla is shifting its focus to the vehicles catered for autonomy and its Robotaxi and self-driving efforts.

Cramer recognizes this:

“…we got results from Tesla, which actually beat numbers, but nobody cares about the numbers here, as electric vehicles are the past. And according to CEO Elon Musk, the future of this company comes down to Cybercabs and humanoid robots. Stock fell more than 3% the next day. That may be because their capital expenditures budget was higher than expected, or maybe people wanted more details from the new businesses. At this point, I think Musk acolytes might be more excited about SpaceX, which is planning to come public later this year.”

He continued, highlighting the company’s true transition away from vehicles to its Cybercab, Optimus, and AI ambitions:

“I know it’s hard to believe how quickly this market can change its attitude. Last night, I heard a disastrous car company speak. Turns out it’s actually a robotics and Cybercab company, and I want to buy, buy, buy. Yes, Tesla’s the paper that turned into scissors in one session. I didn’t like it as a car company. Boy, I love it as a Cybercab and humanoid robot juggernaut. Call me a buyer and give me five robots while I’m at it.”

Cramer’s narrative seems to fit that of the most bullish Tesla investors. Anyone who is labeled a “permabull” has been echoing a similar sentiment over the past several years: Tesla is not a car company any longer.

Instead, the true focus is on the future and the potential that AI and Robotics bring to the company. It is truly difficult to put Tesla shares in the same group as companies like Ford, General Motors, and others.

Tesla shares are down less than half a percent at the time of publishing, trading at $423.69.

Continue Reading

Elon Musk

SpaceX secures win as US labor board drops oversight case

The NLRB confirmed that it no longer has jurisdiction over SpaceX.

Published

on

Credit: SpaceX

SpaceX scored a legal victory after the National Labor Relations Board (NLRB) decided to dismiss a case which accused the company of terminating engineers who were involved in an open letter against founder Elon Musk. 

The NLRB confirmed that it no longer has jurisdiction over SpaceX. The update was initially shared by Bloomberg News, which cited a letter about the matter it reportedly reviewed.

In a letter to the former employees’ lawyers, the labor board stated that the affected employees were under the jurisdiction of the National Mediation Board (NMB), not the NLRB. As a result, the labor board stated that it was dismissing the case.

As per Danielle Pierce, a regional director of the agency, “the National Labor Relations Board lacks jurisdiction over the Employer and, therefore, I am dismissing your charge.”

Advertisement

The NMB typically oversees airlines and railroads. The NLRB, on the other hand, covers most private-sector employers, as well as manufacturers such as Boeing. 

The former SpaceX engineers have argued that the private space company did not belong under the NMB’s jurisdiction because SpaceX only offers services to “hand-picked customers.” 

In an opinion, however, the NMB stated that SpaceX was under its jurisdiction because “space transport includes air travel” to get to outer space. The mediation board also noted that anyone can contact SpaceX to secure its services.

SpaceX had previously challenged the NLRB’s authority in court, arguing that the agency’s structure was unconstitutional. Jennifer Abruzzo, the NLRB general counsel under former United States President Joe Biden, rejected SpaceX’s claims. Following Abruzzo’s termination under the Trump administration, however, SpaceX asked the labor board to reconsider its arguments. 

Advertisement

SpaceX is not the only company that has challenged the constitutionality of the NLRB. Since SpaceX filed its legal challenge against the agency in 2024, other high-profile companies have followed suit. These include Amazon, which has filed similar cases that are now pending.

Continue Reading