It just doesn’t matter that much. If you look at the actual energy for gun launch and rocket launch, there’s no clear advantage to gun launch. Megajoules to Megajoules. And LOTS of drawbacks.
Cool announcement! Longshot just signed a lease with the City of Alameda for the use of an old Navy indoor cannon testing facility. It's like someone went back in time and tricked the Pentagon in building a space-gun development facility with a panoramic view of the SF Bay.Over the fall Longshot is going to be building the largest operational gun in the world (120' long 29" interior diameter. A tinker toy by my standards) at this facility before we move out the desert to build something not *embarrassingly insignificant*.If you want to see a quick walk though check out the video.
Progress continues on our space launch demonstrator, the K200! This is our first prototype designed to produce a sustained jet, at up to 10 MW for several seconds. Hydraulics for actuation, valve hydraulics, and fuel and probe lines have all been installed! This prototype is an essential stepping stone for determining jet scaling laws experimentally and for proving our kinetic launch concept.
[0:04:40] "Everytime you double the number of [gas] injections, the maximum pressure and temperature is cut by half." Max G-force applied to payload also cuts in half, so stretching the gun length makes launch gentler and cheaper materials can be used (steel/concrete).[0:05:20] Maximum pressure of the system is ~1,000 PSI.[0:13:20] 10-20 km gun will launch a payload at 150-250 Gs. Commercial electronics can survive 800-900 Gs.[0:14:30] Military electronics (e.g. guided weapons) can survive 40,000-60,000 Gs.[0:16:30] Starship is aiming for a "market price of $1,100 per kg" to orbit.[0:19:00] Minimal viable space gun would have a market price of ~$150/kg to orbit (500 kg payload). Aiming for "below $10" for future versions.[0:19:40] Most of the cost is electricity generation, so could go lower with cheaper solar panels or nuclear reactors.[0:20:20] 'Mama Bear' will fire a "20 ton bullet".[0:20:50] Currently building a 0.7 m diameter gun. [0:21:50] Existing gun hit Mach 4.2-4.5 using helium (built 2.5 years ago), could do Mach 6 if switching to hydrogen but not permitted at Oakland facility.[0:22:50] Material cost of gun is ~$40K, costs $5K per shot.[0:24:50] Big hypersonic market with DoD, $15 million rocket vs $150,000 using a gun (2 orders of magnitude).[0:26:10] Aiming for Mach 25, projectile heating is velocity3. Bigger projectiles are better (2 m diameter).[0:27:50] Needs to be over 150 kg projectile to reach orbit or will completely burn up from atmospheric friction.[0:28:40] A 2 ton projectile will lose ~50% mass from ablation. 20 ton vehicle needs 2 tons of ablative material to survive.[0:30:00] Mach 15 projectiles are well understood due to warhead heritage. Mach 25+ is unknown.[0:31:30] Sonic booms will be an issue, non elevated gun design was partly chosen for easier land procurement (and cheaper).[0:33:50] Air space issues are why Australia is a construction location vs USA (densest aircraft). Aiming for multiple launches per day. Alaska is also a possible location.[0:35:40] 'Papa Bear' gun is 7-8 m diameter, 70 km long and able to fire 100 ton projectiles (starship sized). Curvature of Earth becomes an issue.[0:38:40] The initial prototype gun was 12 m long, made of PVC, capable of Mach 1.8 and failed spectacularly.[0:40:10] Collecting telemetry is the current challenge (very short timeframes before it hits target).[0:41:10] Longshot have built 3 prototype barrel iterations.[0:43:50] New test location is an old Naval gun test facilty at Alameda Point with a 90 m long warehouse, been closed since the 1990s.[0:50:30] Competitor Spinlaunch has "blown through like $140 million" on a prototype to launch at Mach 1.6.[1:05:10] Air Force saved Longshot from bankruptcy.
An alternate approach... Wave Motion Launch Linkedin [Sep 2]
From $2,000/kg → $10/kg. Longshot’s accelerator gets material into space so much cheaper than traditional options, it’s redefining access to orbit.
We’ve been busy, but we secured our Alameda facility. A former Navy test hall now becoming home to Longshot’s next phase of hypersonic and space launch testing
Ever wonder what it takes to build a giant space gun? Same. So we went ahead and built one.
Go behind the scenes at Longshot’s Alameda facility for an inside look at the construction of our Mini-Gun test system. This build is a key step toward higher-frequency testing, faster iteration, and scalable ground-based launch technology. More to come.
Longshot is still awaiting NEPA approvals to begin work on a patch of land alongside the Tonapah regional airport near the town of Tonapah in Nye County, Nev., where it plans to build a much larger gun approaching a size that could get a payload into orbit.“The Nevada site is one-mile long, 100-ft wide, and would have a tube made of steel with a 3-ft interior diameter,” sys Grace. “It will stretch over half a kilometer, and would have multiple [gas injection] boosters along it.” Rather than rely on a single burst of energy to propel the payload, the Longshot method has smaller bursts of gas injected along the way. “So instead of one boom with all that temperature and pressure, we have pop, pop, pop all the way down. And the longer we can make it, the more gentle it can be.”Once approvals are secured, Grace says construction would involve a lot of the same materials and labor found in natural gas transmission. “Each injection [into the tube] is pressurized gas, so we’ll have a lot of nitrogen handling, hydrogen handling, big compressors. And in terms of material sourcing and flanging and welding, we expect it's the same kind of pipe welding you find in gas infrastructure.”Test firings so far have been into catch boxes and berms rather than going for launch distance, but the company is exploring obtaining permission to send a payload “to some altitude,” says Nathan Saichek, Longshot’s chief technology officer. The company has begun in-house designs for the Nevada facility, but Saichek says their aerospace expertise sometimes interferes with construction engineering tasks. “What we need is a civil engineer; aerospace engineers [like us] will over-engineer a concrete pad.”
Jan 14, 2026Longshot is rethinking access to space with wave-riding hypersonic vehicles that skip along the atmosphere like a stone on water. In this deep dive, the team explains how vehicle geometry, thermal protection, and advanced simulation tools come together to survive extreme heat, pressure, and forces on the path to Mach 25, and why this first-principles approach could change launch economics forever.
