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.

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 starts testing its Starlink-integrated Cybercab on public roads

Published

on

Credit: lottherm | TikTok

Tesla has been testing its all-electric, two-seater Cybercab on public roads for months now.

Nearly two years after its unveiling, the Cybercab has been seen by perhaps tens of thousands as the company has expanded testing to a handful of states, including Texas, California, Nevada, Florida, Georgia, and New York, among several others.

However, nobody has seen one like this quite yet.

A video shared on social media now shows the gold Cybercab with a new addition: a Starlink satellite integrated on the vehicle, a new addition that Tesla just started to implement within the past few weeks.

@lottaherm More cybercabs being spotted now with Starlink integrated πŸ‘€ #cybercab #tesla #elonmusk #houston #htx ♬ original sound – π—™π—Όπ—Ώπ—”π—Ήπ—Ήπ—§π—΅π—²π—’π˜„π—Ήπ˜€|π“…“

Just a week ago, Tesla announced that it had built its first Cybercab with Starlink integration and showed it off at Gigafactory Texas. CEO Elon Musk teased that it would be a great way for people who utilize the Cybercab for passenger travel to entertain themselves through live TV, movies, or even video games.

Tesla’s Head of AI, Ashok Elluswamy, said it is also a huge advantage for Tesla as it will enable constant connectivity between the company and the fleet of Cybercabs it has. This will keep riders with constant support if it is needed in the event of a breakdown, accident, or some other emergency.

Tesla’s reason for Starlink integration on Cybercab might surprise you

It appears that this particular unit was spotted in Houston, Texas, a location where the company’s Robotaxi platform is already active. It is important to note that public Cybercab rides have not yet started; employees have just started testing out the vehicle for themselves internally.

Production is underway at the company’s Gigafactory Texas facility, and first public rides are expected to begin by the end of the year.

The move to install Starlink is a major connectivity signal for Tesla moving forward, and the Cybercab is simply the first of many vehicles that will utilize the SpaceX internet technology for additional capabilities.

Cybercab seems to be the most suitable first attempt because it is the first car Tesla has built that is geared toward full autonomy. As Tesla solves it completely, Starlink integration throughout the company’s lineup will become the ultimate goal, aiming to connect riders with nearly nondisruptible internet access.

Continue Reading

News

Tesla is building its largest Supercharger on the East Coast in New York City

Published

on

tesla store in New York City
Credit: Tesla

Tesla is building its largest East Coast Supercharger in New York City, planning to bring a 64- to 68-stall station to Queens, New York.

It will end up being tied for the largest Supercharger on the East Coast with this number of stalls. The largest on the Eastern Seaboard is located in Halifax, North Carolina, and is also 68 stalls.

The location is also set to be fitted with two pull-through stalls for EVs with trailers. We’ve seen Tesla implement these types of parking spots at newer locations as EV ownership continues to expand to those who do more than simply drive their cars.

There are plenty of Superchargers in the New York City metro, but they are mostly located in boroughs outside of Manhattan. There are five Superchargers in various neighborhoods of Manhattan, but there are limited plugs; usually only four per location. There are plenty of Destination Chargers in the Big Apple, though.

Queens, the Bronx, and Brooklyn have become popular locations for companies to build out charging infrastructure for those who live in the highly populated boroughs. There is simply much more real estate to build effective EV charging stations.

Tesla spends $18M to expand Supercharging in New York City

The Supercharger will be located in Maspeth, Queens, at 48-26 54th Road. Maspeth has I-495 running through it, so this will be a great location for Tesla owners to hop off the highway on their way to Long Island or to Manhattan to charge up before continuing their journey.

Tesla has done a really great job of expanding its charging footprint throughout the past several years, especially by building large-scale projects that cater to areas that have a high volume of traffic and are main routes of travel to major areas. Tesla is making an effort to make charging less stressful and more widely available in these concentrated regions.

Continue Reading

News

SpaceX just launched a secret payload from California

SpaceX launched a classified Space Force mission from Vandenberg, revealing almost nothing about its payload.

Published

on

By

Space Force officials say the Falcon 9 booster pictured here in SpaceX's rocket factory will have to wait a few months longer for its launch debut. (SpaceX)

SpaceX launched a classified Falcon 9 mission for the U.S. Space Force from Vandenberg Space Force Base on Saturday night, and the government released almost nothing about what was on board. The mission, designated USSF-366, lifted off from Space Launch Complex 4E with a window that opened at 9:52 p.m. ET and ran into the early hours of Sunday, according to SpaceX’s own mission page, which described the payload only as classified. SpaceX confirmed the launch on its X account and pointed viewers to a livestream that began roughly ten minutes before liftoff.


The lack of detail did not stop analysts from filling in the blanks. Independent tracking of the rocket’s stage drop zones matched the pattern SpaceX has used on previous Starlink Group 15 missions, according to reporting from Outer Space Today, which pointed to Starshield as the likely payload rather than a one off government satellite. Starshield is SpaceX’s national security product, a version of the Starlink satellite bus built to Pentagon specifications for earth observation, communications and hosted payloads. Unlike consumer Starlink, government agencies do not have to disclose what Starshield satellites are actually doing once they reach orbit.

USSF-366 is the latest entry in a steady flow of classified and semi classified work between SpaceX and the Space Force. The company picked up a $178.5 million task order in April to launch missile tracking satellites for the Space Development Agency, as Teslarati reported at the time, and followed that in July with a $1.6 billion award covering 18 more Falcon 9 missions from Vandenberg through the end of 2027, also detailed by Teslarati. Add those contracts up and SpaceX’s Pentagon business for 2026 alone tops $8 billion.

SpaceX scores another massive Pentagon deal to support military satellites

The Falcon 9 that flew Saturday landed back near the launch site, producing the sonic booms that have become routine for residents near Vandenberg. What is less routine is how little the public will likely ever learn about what the rocket carried. SpaceX and the Space Force have not confirmed the Starshield connection, and government satellite programs built on commercial buses rarely get identified beyond a mission number and a general orbit. For a company that live streams almost everything else it does, from Starship test flights to Optimus robot demos, USSF-366 is a reminder that some of SpaceX’s busiest work now happens entirely out of public view.

Continue Reading