News
Ex-SpaceX engineer leads Stratolaunch to major rocket engine test milestone
Led by rocket propulsion expert Jeff Thornburg, Stratolaunch – famous for owning the largest fixed-wing aircraft ever built – has completed the first hot-fire test of a full-scale rocket engine component known as the preburner, a major milestone in the development of any launch vehicle or propulsion system.
Despite the significant size and power of the component, destined to support an engine that will generate 200,000 pounds (~900 kN) of thrust, Thornburg and his team of engineers and technicians have managed to go from designing the preburner to successfully hot-firing a full-scale test article, an extraordinary achievement by any measure.
The team made amazing progress this week! Check out the #PGAEngine preburner’s first hot-fire test at @NASAStennis. #NewUSEngine pic.twitter.com/kKTnf0bj1S
— Stratolaunch (@Stratolaunch) November 6, 2018
Aside from SpaceX, Blue Origin, and Aerojet-Rocketdyne, Stratolaunch is the only private entity developing – let alone testing full-scale parts for – a liquid-fueled rocket engine as large as PGA. Shorthand for the Stratolaunch’s late founder and bankroller Paul G. Allen, PGA is a fuel-rich staged combustion cycle engine that uses liquid hydrogen and oxygen (hydrolox) fuel and oxidizer, typically resulting in high efficiency. In terms of scale and thrust, PGA is very closely comparable to SpaceX’s Merlin 1D engine, which uses kerosene instead of hydrogen but produces roughly 190,000 lbf (850 kN) of thrust and stands 4 feet (1.2m) wide and ~10 feet (~3m) tall.
Another major difference between PGA and Merlin 1D is the fact Merlin 1D’s nozzle is largely optimized for sea level while PGA is being built for a rocket that will be “launched” from a massive plane flying around 35,000 feet (~10.5 km), ultimately resulting in a nozzle that is much wider and longer, featuring nearly the same proportions as fully vacuum-optimized engines like SpaceX’s MVac. By widening the nozzle relative to the rest of the engine, rocket engines are able to operate far more efficiently at higher altitudes, where Earth’s atmosphere thins and exerts less pressure on the escaping exhaust gases. This is visualized well by the visible expansion of rocket exhausts during launches, morphing from a straight cylinder to a massive teardrop-shaped plume. At lower altitudes (and thus higher atmospheric pressures), wider nozzles can produce extreme turbulence and will ultimately shake themselves to destruction, preventing their usage on ground-launched rocket boosters.
Judging from official renders of the engine, PGA’s in-atmosphere variant appears to utilize a form of regenerative nozzle cooling very similar to that used on M1D, where liquid propellant flows through thin capillaries sandwiched between two or more layers of metal to cool the nozzle much like cold water chills the skin of an uninsulated water bottle.
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- A to-scale comparison of Falcon 1, Pegasus XL, MLV, and Falcon 9. (Teslarati/Stratolaunch/Wikipedia)
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- A render of Stratolaunch’s impressive PGA engine. Note the giant nozzle relative to the throat. (Stratolaunch)
Testing rocket engine preburners
In the case of staged combustion cycle hydrolox rocket engines, a small portion of liquid oxygen and all of the liquid hydrogen (hence “fuel-rich”) are mixed and combusted to generate hot gas that then spools up the engine’s primary turbopump(s), ultimately drawing fuel and oxidizer into the combustion quickly enough to ignite the engine and generate sustained thrust. The components that get those main turbopumps started are known collectively as the preburner, which is what Stratolaunch successfully tested – at full-scale – for the first time ever last week. For any liquid rocket engine that cannot solely rely on propellant tank pressure to deliver fuel to the combustion chamber, full-scale tests of preburners or gas-generators effectively mark the moment that engines truly become real.
“This is the first step in proving the performance and highly efficient design of the PGA engine. The hot-fire test is an incredible milestone for both the propulsion team and Stratolaunch.” – Jeff Thornburg, VP of Propulsion, Stratolaunch
Stratolaunch’s propulsion team will continue to test the preburner for longer durations and at higher power levels over the next several months, likely optimizing operations and tweaking or upgrading the preburner’s hardware as real tests produce valuable lessons-learned. Built entirely with additive manufacturing (3D printing), the team should be able to rapidly iterate on the physical design of the engine, a rarity in a field where traditional fabrication methods can take weeks or months to produce complex turbomachinery components with mercilessly strict tolerances.
According to Thornburg, the ultimate goal is to continue that additive-manufacturing-only strategy throughout the development of this rocket engine, theoretically enabling unprecedented design flexibility while also slashing production time throughout. PGA will ultimately power the creatively-named Medium Launch Vehicle (MLV), a small-ish air-launched rocket designed to place a respectable 3400 kg into low Earth orbit (LEO) as early as 2022, as well as a Heavy version of MLV and, potentially, a reusable spaceplane somewhere down the line.
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- PGA’s first full-scale preburner seen during assembly. (Stratolaunch)
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- PGA’s first full-scale preburner seen during assembly. (Stratolaunch)
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- Jeff Thornburg stands in front of Stratolaunch’s NASA Stennis Space Center test stand. (Stratolaunch)
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- The PGA preburner seen after installation at Stennis. (Stratolaunch)
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- The control center. (Stratolaunch)
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- MLV is released from Stratolauncher. (Stratolaunch)
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- A concept video produced by Stratolaunch shows the Roc launching a Kraken rocket. (Stratolaunch, via Wired)
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Elon Musk
SpaceX IPO could push Elon Musk’s net worth past $1 trillion: Polymarket
The estimates were shared by the official Polymarket Money account on social media platform X.
Recent projections have outlined how a potential $1.75 trillion SpaceX IPO could generate historic returns for early investors. The projections suggest the offering would not only become the largest IPO in history but could also result in unprecedented windfalls for some of the company’s key investors.
The estimates were shared by the official Polymarket Money account on social media platform X.
As noted in a Polymarket Money analysis, Elon Musk invested $100 million into SpaceX in 2002 and currently owns approximately 42% of the company. At a $1.75 trillion valuation following SpaceX’s potential $1.75 trillion IPO, that stake would be worth roughly $735 billion.
Such a figure would dramatically expand Musk’s net worth. When combined with his holdings in Tesla Inc. and other ventures, a public debut at that level could position him as the world’s first trillionaire, depending on market conditions at the time of listing.
The Bloomberg Billionaires Index currently lists Elon Musk with a net worth of $666 billion, though a notable portion of this is tied to his TSLA stock. Tesla currently holds a market cap of $1.51 trillion, and Elon Musk’s currently holds about 13% to 15% of the company’s outstanding common stock.
Founders Fund, co-founded by Peter Thiel, invested $20 million in SpaceX in 2008. Polymarket Money estimates the firm owns between 1.5% and 3% of the private space company. At a $1.75 trillion valuation, that range would translate to approximately $26.25 billion to $52.5 billion in value.
That return would represent one of the most significant venture capital outcomes in modern Silicon Valley history, with a growth of 131,150% to 262,400%.
Alphabet Inc., Google’s parent company, invested $900 million into SpaceX in 2015 and is estimated to hold between 6% and 7% of the private space firm. At the projected IPO valuation, that stake could be worth between $105 billion and $122.5 billion. That’s a growth of 11,566% to 14,455%.
Other major backers highlighted in the post include Fidelity Investments, Baillie Gifford, Valor Equity Partners, Bank of America, and Andreessen Horowitz, each potentially sitting on multibillion-dollar gains.
News
Tesla expands global FSD (Supervised) testing with Abu Dhabi trials
The program marks the emirate’s first formal testing framework for Tesla’s supervised autonomous driving technology.
Tesla has started its first Full Self-Driving (Supervised) road trials in Abu Dhabi under the oversight of the Integrated Transport Centre, also known as Abu Dhabi Mobility.
The program marks the emirate’s first formal testing framework for Tesla’s supervised autonomous driving technology.
FSD (Supervised) road trials are being conducted with the support of the Smart and Autonomous Systems Council and in coordination with the Legislation Lab at the General Secretariat of the UAE Cabinet.
Dr. Abdulla Hamad AlGhfeli, Acting Director General of the Integrated Transport Centre (Abu Dhabi Mobility), highlighted the agency’s regulatory role in overseeing the FSD (Supervised) tests in a press release.
“The supervision of the Integrated Transport Centre (Abu Dhabi Mobility) over the commencement of Tesla’s advanced autonomous driving technology tests reflects its regulatory and legislative role. These tests represent a qualitative step to evaluate the technology’s performance in a real-world operating environment and to collect the necessary data to verify its readiness before any future expansion in usage.
“Through this organized framework, and in cooperation with strategic partners, we seek to achieve a balance between supporting innovation and encouraging the adoption of smart solutions on one hand and ensuring the safety of road users on the other, in line with the emirate’s direction to develop an advanced, safe, and sustainable transport system,” he said.
Tesla is putting a lot of effort into expanding the rollout of FSD (Supervised) to territories outside in the United States. During a recent interview with Giga Berlin plant manager Andre Thierig, Musk stated that Tesla is looking to secure approval for FSD (Supervised) in the Netherlands this coming March.
“Tesla has the most advanced real-world AI, and hopefully, it will be approved soon in Europe. We’re told by the authorities that March 20th, it’ll be approved in the Netherlands,’ what I was told. Hopefully, that date remains the same. But I think people in Europe are going to be pretty blown away by how good the Tesla car AI is in being able to drive,” Musk stated.
Elon Musk
SpaceX considering confidential IPO filing this March: report
The filing could pave the way for a June listing at a valuation that may exceed $1.75 trillion.
SpaceX is reportedly preparing to confidentially file for an initial public offering (IPO) as soon as March. The filing could pave the way for a June listing at a valuation that may exceed $1.75 trillion, potentially making it the largest IPO in history.
The update was initially reported by Bloomberg News, which cited information shared by people reportedly familiar with the matter.
As per the publication, a confidential filing allows a company to receive regulatory feedback before publicly releasing its financials. Bloomberg’s source, however, noted that the timing of SpaceX’s IPO is still under discussion and plans could change.
SpaceX did not immediately respond to requests for comment.
A March submission would mark the clearest step yet toward bringing Elon Musk’s private space company into public markets. People familiar with the preparations said the offering could raise as much as $50 billion. That would surpass the $29 billion debut of Saudi Aramco in 2019, currently the largest IPO on record.
Major banks including Goldman Sachs Group Inc., JPMorgan Chase & Co., Morgan Stanley, and Bank of America Corp. are reportedly positioned for senior roles in the transaction. SpaceX is also said to be considering a dual-class structure that would allow insiders, including Musk, to retain enhanced voting control.
Satellite communications provider EchoStar Corp., which holds a stake in SpaceX, reportedly saw its shares rise following news of the potential filing.
At a valuation exceeding $1.75 trillion, SpaceX would immediately have a larger market cap than all but five of the companies traded in the S&P 500 index. That figure would place it ahead of Meta Platforms Inc. and Tesla Inc. by market capitalization, trailing only a small group of mega-cap firms such as Apple Inc. and Microsoft Corp.
The scale of the proposed valuation reflects SpaceX’s dominance in orbital launch services and its Starlink satellite network, which serves millions of users globally. The company has also outlined long-term expansion plans tied to higher Starship launch cadence, orbital infrastructure, and lunar development initiatives.
SpaceX IPO could push Elon Musk’s net worth past $1 trillion: Polymarket
Tesla expands global FSD (Supervised) testing with Abu Dhabi trials
