Tiberius bursts onto scene with 150 km-range, ramjet-powered precision 155 mm round

At a press briefing in London on 19 May 2025 new weapon technology company Tiberius Aerospace announced both its own arrival and that of its first flagship product: a liquid-fuelled, ramjet-powered, extended-range precision-guided 155 mm artillery round called Sceptre (TRBM 155HG).

Both the product and the company behind it are somewhat revolutionary: Sceptre is intended to facilitate precision artillery strikes on targets more than 150 km away at a fraction of the price of other precision-guided munitions, while Tiberius states that its defence-as-a-service (DAAS) model “decouples innovation from manufacturing – enabling rapid iteration, sovereign collaboration and continuous evolution of capability for the UK, the US and their closest allies”. The company was formed in 2022, in the wake of the Russian invasion of Ukraine in February of that year, by founders whose business DNA comes out of California’s Silicon Valley rather than the traditional defence market.

At the London press briefing Tiberius founder and CEO Chad Steelberg described how his first move in light of the Ukraine war, along with co-founder and chief strategy officer Andy Baynes, was to evacuate around 100 women and children from Ukraine to a farm in France.

“Then we really started brainstorming about how we can make a difference,” said Steelberg. “For me, it was about developing next-generation weapon systems, which led to the founding of Tiberius.”

The company initially focused on 155 mm rounds, Steelberg explained, because of the wide use of that calibre around the world and especially in Ukraine.

“We also realised, from an analytical standpoint, that if we could achieve a massive extension of range and accuracy in GPS-denied and RF (radio frequency)-denied regions, we would have one of the greatest impacts on ground warfare in decades,” he added.

The Sceptre round can be propelled by diesel, JP-4 or JP-8 fuel and potentially other fuel types that Tiberius has not yet tested. The round is fully compatible with NATO-standard 155 mm artillery platforms, although it is too long to be handled by current 155 mm autoloaders, with Steelberg noting that the company is currently in discussion with a number of 155 mm artillery manufacturers “in a number of both NATO and Indo-Pacific countries” to address this. When the round is fired its initial velocity of around Mach 2.4 is enough to initiate the ramjet, with the air pressure through the nozzle in its nose being used to control the flow of fuel through the ramjet. The round then reaches a speed of Mach 3.5 in six seconds and altitudes in excess of 65,000 ft (19,812 m) as it approaches its apogee, after which the round then glides to its target using canards that deploy from the round’s body. During flight the round’s onboard GPS and inertial measurement unit synchronise and leverage advanced artificial intelligence (AI) algorithms to error correct to desired confidence levels, allowing operation in GPS-degraded or -denied environments and offering a circular error probable (CEP) of less than 5 m compared to a CEP of more than 100 m for traditional artillery rounds.  If needed, multiple munitions can communicate in-flight to further refine the targeting solution.

While the Sceptre targeting system currently addresses high-value fixed targets at ranges out to 150 km, Steelberg said that future iterations of the weapon would look to address moving targets. The round has a launch mass of 47.5 kg, of which the payload is 5.2 kg, and is compatible with current 155 mm round fuzes.

Tiberius has been conducting trials of the Sceptre round every three to four weeks from a BAE Systems M777 lightweight howitzer, said Steelberg, who noted that Tiberius is also looking at the BAE Systems Archer 155 mm artillery system “and a few others that we’re going to certify against”.

He added, “Our expectation is that we will be delivering these in a production volume by the end of 2025 and we have some initial clients that are already on board.”

Just as innovative as the round itself is the company’s production model, under which Tiberius retains the intellectual property for Sceptre but licenses out production, allowing the round to be manufactured by multiple sources in multiple countries.

“A system like this normally is going to cost hundreds of millions of dollars to develop,” said Steelberg. “We’ve been able to do this in a fraction of the time at a fraction of the cost, (a) because we’ve taken a very agile development cycle … that we have been accustomed to in Silicon Valley. The second thing, though, is we took an MVP [minimum viable product] approach: let’s not try to build the guidance system that can track down to something day one; let’s build something that gives us the bus architecture and open it up to the community. Typically, one nation … would fund the entire programme and then we would go out there and license it and sell it to other nations. What we’ve taken instead is a democratised approach. We charge a fraction of that to each nation. We’re talking about a USD 5 million upfront fee, USD 2.5 million short-term, one-year contracts, that allows us to pull nations together that then have an egalitarian, equal opportunity to purchase and manufacture in country the weapon, given our reference specs. The way in which our economic model works then is depending on how many nations are a part of that programme for development, and NRE [on-recurring engineering cost] dictates the rate at which we can iterate and design, is directly proportional to the demand signal in the market, and we license the IP, not only to our own manufacturing partners but third parties, which then we have a flat royalty against, very similar to traditional technology models.”

With regard to unit cost, Baynes noted at the press conference that, while BAE Systems’ 50 km-range Excalibur 155 mm precision-guided round costs around USD 380,000, a Sceptre round will cost USD 52,000 without payload. Baynes further suggested that, with volume production, that unit cost for Sceptre could even come down to USD 40,000 to USD 42,000.

Sceptre does have a rival in the Ramjet 155 round, produced by a teaming of Nammo and Boeing, which is also stated to achieve a range of 150 km. The unit cost of this round, which is part of the US Army’s Extended Range Artillery Munitions Suite (ERAMS) programme, has not been overtly stated.

Steelberg was keen to point out, however, that price “is only equivalent to the accuracy modality of the weapon itself because price alone is indeterminate of the value in terms of the cost to destroy a target”. What is important, he explained, is a weapon system’s cost-effective lethality score.

“‘If I want to destroy a target at this range, at this distance, in this environment, what is the best weapon and the cheapest weapon I can use, both from a human and logistical overhead standpoint, from manufacturing cost standpoint, to guarantee a 95% kill rate?’ That’s the question we should be asking, said Steelberg. He noted that it would take more than 260 traditional unguided 155 mm rounds, which each cost only USD 3,300 but have a CEP of 100 m, to destroy a hardened target at 24 km because a direct hit would be required, whereas statistically two Sceptre rounds would do the job.

“So when you think about cost-effective lethality scores you’re talking about 267 times USD 3,300 versus two times the cost of ours,” said Steelberg, “and so we’re anywhere between nine and 10 times more cost efficient – even inside of traditional ranges that normal howitzers can reach.”

Meanwhile, Tiberius has multiple future developments in the pipeline. One of these involves taking the Sceptre technology and applying it to smaller calibres such as 120 mm and even beyond.

Another future product is Invictus: a ground-launched multi-mission strike missile that is 2.4 m long, 165 mm in diameter, weighs 190 kg and delivers an 8.5-24 kg payload to a maximum range of 200 km depending on payload configuration. The Invictus missile, Steelberg noted, is modular, “so the entire payload and solid-fuel booster can be variable sized and can be screwed together and reconfigured, giving you different payloads, different ranges, but mass manufacturing of components that are modularly compatible”.

Envisioned for launching Invictus missiles is the Vault system: an autonomous vertical launch system based on a 10×10 ft (3.05×3.05 m) shipping container that will loaded with up to 60 Invictus rounds. Steelberg noted that this system would be able to launch “at a peak rate of two per second, deploying almost 500 kg of payload to a 200 km range”, adding that the “price point on this is 10 cents on the dollar versus any other class missile in its in its category”.

Lastly, Tiberius is launching a product it calls Grail, which takes how the company uses AI to evaluate its own product roadmaps and packages this for other manufacturers and defence ministries to use.