MARCH 22ND 2026
F2LG entered development 4 months ago to increase the performance and reliability of the F2RE system for the start of crewed spaceflight to Droo and Luna.
Teams have made rapid progress rebuilding the system from scratch, including the vehicle, pad, and vizzy with an expected launch in under a month.
This update will provide some information on the status of F2LG and its readiness ahead of its debut flight, which is expected to carry the CSS-2 module into low Droo orbit.
CSS-2 interior teaser
GNC
Taking lessons learned from the frequent launches of F2RE, our teams realised that the GNC was not reliable enough or simple enough to support modifications for each individual mission.
This resulted in several errors and mission delays in 2025, which was deemed unacceptable, so the entire vizzy has been torn up and completely remade from scratch, halving its size and making modifications far easier to make.
These massive simplifications have created a flight computer that can be transferred over to other vehicles such as Gryphon, which is planned. In preparation for F2LG's debut flight, the teams completed well over 100 simulated flights over a 2-month period.
F2LG simulation testing
Second Stage
The second stage for F2LG has received numerous changes, including a simplified tank structure with more hardware being mounted externally, such as the transfer tubes and composite overwrapped pressure vessels (COPVs), reducing build time and complexity.
Teams decided to make a switch from a singular Aeolus 2 to dual Aeolus V1.7 engines to reduce operational costs, as Aeolus 2 was designed to be reused rather than expended.
Over the last month and a half, we completed our first second stage build and concluded structural qualifications testing at a safety margin of 150%. Engines have been installed ahead of stacking onto the first stage.
F2LG second stage at the hangar
First Stage
The first stage of F2LG hasn't had as many changes as the second stage. However, the tanks were simplified, and an engine bay cavity was eliminated to increase propellant capacity.
The landing legs were shortened back to their original length seen on Block 1 to lower their mass as landing accuracy is expected to increase, and the aerodynamic control surfaces were increased in strength after issues were found during multiple F2RE flights.
The propellant feed systems have also been redesigned to support quicker turnarounds to reduce the size of the fleet sitting in storage.
The first build has arrived at the hangar after completing structural qualification testing. Engine installation is underway for a fully integrated static fire test expected to take place within the next two weeks pending work completion.
F2LG first stage with engines
Pad 01B
Pad 01B is going under a full revamp based on lessons learned from F2RE missions, including a rebuild of the tank farm to support a 30-minute propellant loading target and increase fluid storage capacity.
This is the leading item in possible delays due to the complexity of the tank farm systems, but as of writing we are expecting work to be completed by the end of March.
The transporter erector has also been completely remade to support the new fluid systems and increase reliability of the hydraulic systems.
The new TE undergoes testing at Pad 01B
The dual-purpose tower at the pad has been demolished pending a full rebuild to support the new F2LG height and Nebulon crew capsule.
Additionally, a small village is under construction next to the pad to house Droods temporarily as they prepare for their missions to space.
Village construction work
Overall, work has progressed rapidly with minimal disruptions. F2LG is expected to be a massive improvement from its predecessors. You can observe the improved performance in this diagram below.
Performance diagram
After F2LG is operational, the next item on the list will be the first test flight of the Gryphon launch system from Base Alpha. This program has encountered major delays since beginning in 2024. We hope to make an update on its status soon.
Thank you for taking time to read this. We hope to see you for F2LG's first launch in April.