Blue Whale 1 is a two-stage orbital launch vehicle capable of placing a 150 kg payload into a 500 km Sun-Synchronous Orbit with the fully reusable first stage.

By using liquid oxygen and methane as propellants for both stages, BW1 emits far fewer carbon pollutants into the atmosphere. It also enables higher engine performance and better maintainability. For lightweight construction, Blue Whale is mainly constructed from high-strength carbon composites, improving payload mass fraction for such a small and lightweight launch vehicle.

The flight test program will begin in late 2024, followed by commercial flights in 2025. With a total launch price of less than $3M, it is the most affordable launch vehicle in the world.

Blue Whale 1 Specification

Since 2021, the Jeju Launch Center has been the home stadium for Perigee.
In May 2023, Perigee signed an agreement with the Jeju municipal government to build and operate Korea’s first commercial launch pad on its soil.

Jeju Island, located at the southernmost tip of South Korea, provides the widest range of launch azimuths in South Korea. This allows for a variety of missions to be carried out with inclination angles ranging from 97 degrees for sun-synchronous orbits to 60 degrees for mid-inclination missions.

In addition, it boasts excellent accessibility as it is directly connected to major cities in East Asia.

SPIDER1 sounding rocket is being launched in the Esrange Space Center (Image courtesy: SSC/Marcus Lindh)

BW1 is powered by nine "Blue 1S" main engines and a single "Skyblue" upper-stage engine. Developed and produced entirely in-house, Blue engines are designed to be the simplest engines possible for the given performance. The simple and straightforward design reduces total part counts, making them the most affordable yet most reliable engines of their kind.

Blue 1S is a 30 kN thrust, turbopump-fed engine. With a chamber pressure of 80 bar and a single shaft turbopump that runs at 50,000 rpm, the engine is the smallest and the lightest powerplant ever built for an orbital class booster. For high reliability at a low cost, the engine is designed in a way such that high-volume production and quality assurance can be done.

Skyblue is a low-thrust, pressure-fed engine designed for vacuum uses. The engine uses a spark ignition system capable of up to five restarts. A pressure-fed cycle was selected for the ultimate simplicity of the system. This, along with a single-element injector and an ablative chamber design, makes Skyblue the most affordable and reliable engine for in-space operations.

BW1 engine specification

Composite tank for BW1 upper stage being cryo-tested.

The avionics has the greatest impact on the actual operating cost and reliability of the launch vehicle. Distributed throughout the launcher, the avionics subsystem performs various functions throughout the mission and determines major phase changes. The key to good avionics design is striking an appropriate balance between system complexity and reliability, as well as performance, considering the mission.

Today, many launch vehicle companies purchase turn-key hardware for their avionics from various third-party suppliers. While this can reduce development time and cost, it can increase the system mass and degrades mission flexibility and reliability. Furthermore, the presence of unnecessary functionality and the operator’s lack of full understanding of the system can often lead to unexpected behaviors that cause a mission failure. At Perigee, most of the core components that go into the launch vehicle are designed and produced in-house. This includes engine controllers, flight controllers, power management boards, batteries, harnesses, cryogenic cameras for observing the inside of the tanks, capacitance sensors for determining propellant levels, and much more.

Maximum simplicity is another important design philosophy for Perigee avionics. In most cases, boards with different functions are often merged into a single PCB so that only a few types of microcontrollers oversee the entire mission. This enhances the level of integration between the launcher and the avionics subsystems and allows all the required functionality to be implemented within the simplest design possible.

The motto, "as simple as possible", also applies to the software design. To minimize all possible exceptions, every function is performed by a simple monolithic firmware that sequentially processes the defined modes. In addition, emergency loops at various levels exist to detect all known emergency cases from the previous test data and automatically judge and stop the flight preparation if necessary.

For a fault-tolerant design, an appropriate level of redundancy that does not increase the system’s complexity is applied to the BW1 avionics. Most flight critical parts feature redundant designs. In addition, rigorous environmental tests and in-flight verification has been made to identify and resolve possible failure modes, increasing the overall reliability even further.

Finally, to increase the consistency and reliability of the mission configuration file, HILT (Hardware-in-the-loop test) is performed before each flight with all the subsystems and sensors combined.