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A Quest Across the Country: Launching a Minimum Diameter Rocket in California

 

Efficiency is one of the most unforgiving constraints in rocket design. Every gram matters, and every system must justify its existence. While LetSpace’s two-stage rocket Scorpion was awaiting its long-delayed launch, the team began work on a separate vehicle designed around this principle alone. The result was TDR-2, better known as Minmus: a minimum-diameter rocket built to produce maximum performance (if you’re a fan of Kerbal Space Program, you may understand the reference).

Minmus represents the most up-to-date rocket design launched by LetSpace. It features a significantly reduced airframe diameter, redesigned avionics, dual-deployment recovery, and live GPS tracking—similar to Scorpion, but condensed into roughly one-third of the original size. The goal was not simply to fly another rocket, but to demonstrate that the same systems integration could be delivered while reducing the weight. For high-altitude rocketry, this is critical.

What made the Minmus mission particularly ambitious was not just the rocket, but the launch site. The Friends of Amateur Rocketry (FAR) site in California is the only feasible location for a future space-shot launch, and reaching it from Texas presented a logistical challenge nearly as complex as the rocket itself. The mission objectives were therefore twofold: first, to successfully build and fly a minimum-diameter rocket, and second, to find a low-cost, repeatable method of transporting flight hardware across the country. Every decision was documented for use in future launches, including the eventual spaceshot.

The plan seemed straightforward. A five-person launch team would depart early Wednesday morning, arrive in California by Friday, launch on Saturday, and return immediately afterward. At 4:00 a.m. Wednesday morning, the team left LeTourneau and drove fourteen hours straight to New Mexico. Thursday allowed for a brief stop at the Grand Canyon (it was spring break, after all) before the plan rapidly began to unravel.

Within an hour of arrival, a blizzard rolled through northern Arizona (yes, you read that correctly), covering the ground and the roads in four inches of snow. The team was trapped, forced to camp there overnight where temperatures dropped to 14°F. By morning, the snow on the roads was cleared, but a ten-car pileup still blocked the highway to California. Waiting was not an option. If the team did not make it to California that night the mission would be cancelled.

Most teams would have turned around. LetSpace did not.

A single unmaintained service road offered a narrow bypass around the accident. After a slow hour of ruts, ice, blind corners, and improvised navigation, accompanied by some timely assistance from an Arizona truck driver, the team cleared the obstruction. They arrived in California roughly three hours behind schedule, tired, cold, but still on mission.

 

          

Above: Arizona after blizzard and California's Mojave Desert. Images taken 8 hours apart.

Despite the travel chaos, Minmus and all flight hardware arrived at FAR in perfect condition. The site itself is stark yet functional: a cluster of beige buildings, launch rails, and bunkers set deep in the Mojave Desert. Assembly proceeded smoothly, noticeably easier than Scorpion, a direct result of improved design. Minmus was placed on the rail and prepared for flight.

Just before final call, a FAR volunteer stopped the team.
“You’re forgetting something,” he said.
A pause. What?
“A picture!” He laughed and assembled the team for what he deemed the most important part of the launch: a commemorative photo.

Moments later, the team moved into the bunker. Telemetry was live. GPS was locked. Avionics were nominal. The countdown began.

“Three… two… one… launch.”

Minmus left the rail cleanly, which was an immediate relief after witnessing another rocket fold itself in half earlier that day. It accelerated smoothly, disappearing into the sky, reaching a maximum velocity of Mach 0.85 and an apogee of approximately 11,000 feet.

Above: A close-up of motor exhaust immediately after ignition

At apogee, however, an unexpected event occurred: the main parachute deployed early, likely due to over-pressurization of the recovery compartment. With no port drilled to equalize pressure with the thinning atmosphere, the main compartment had come open with the shock from the deployment of the drogue parachute. The flight was still a success, but Minmus was now drifting toward the foothills of the Sierra Nevadas.

Recovery required one final test. The team drove through the empty grid of California City (a planned master community that was never built) before hiking five miles off-trail into the mountains. Minmus was found resting intact in a small bush between two ridgelines, completely undamaged. The rocket was recovered, packed out, and carried home.

This mission delivered more than flight data. The logistics of cross-country transport, launch-site operations, weather contingencies, and recovery procedures were all recorded for future launches with larger vehicles. Minmus itself will be used again. It is slated to be repurposed as the second stage of LetSpace’s next two-stage rocket, launching in Spring 2026. Each mission builds on the last, and Minmus proved that smaller, smarter designs can still punch far above their weight.