ISAR Aerospace: Pioneering European Access to Space

Introduction

ISAR Aerospace, a Munich-based German aerospace company founded in 2018, is at the forefront of Europe’s burgeoning private space industry. Named after the Isar River that flows through Munich, the company is dedicated to providing affordable, sustainable, and flexible access to space for small and medium-sized satellites. With a vertically integrated approach, significant funding, and a focus on innovative technology, ISAR Aerospace is poised to make history with the upcoming launch of its Spectrum rocket. As of March 17, 2025, the company is in the final stages of preparation for its maiden test flight, scheduled for no earlier than March 20, 2025. This article reviews ISAR Aerospace, its flagship product—the Spectrum rocket—and the details surrounding its highly anticipated first launch.

Company Overview

ISAR Aerospace was established in 2018 by founders Daniel Metzler (CEO), Markus Brandl, and Josef Fleischmann, emerging as a spin-off from the Technical University of Munich’s rocket technology initiative, WARR. The company’s mission is to lower the barriers to space access, making it cost-efficient and sustainable for satellite constellations and other payloads. Headquartered in Ottobrunn, near Munich, ISAR employs over 400 people from more than 50 nations, reflecting its diverse and international workforce.

The company has raised over €400 million in funding, making it one of the most well-capitalized launch startups in Europe. Key funding milestones include:

• Seed Round (2018): Initial angel investment from Bulent Altan (former SpaceX executive) and others.
• Series A (April 2020): $17 million led by Earlybird Venture Capital and Airbus Ventures.
• Series B (December 2020): $91 million led by Lakestar, with participation from HV Capital, Vsquared Ventures, and others.
• Series C (March 2023): $165 million from investors including 7-Industries Holding, Bayern Kapital, and Lombard Odier.
• Series C Extension (2024): An additional $70 million from the NATO Innovation Fund and others.

Additional grants, such as the €10 million European Innovation Council (EIC) Horizon Prize for “Low-Cost Space Launch” in January 2022, have bolstered ISAR’s financial position. This funding has enabled the company to pursue its ambitious goal of developing and launching the Spectrum rocket, a two-stage orbital launch vehicle designed to compete in the growing small satellite launch market.

ISAR Aerospace distinguishes itself through its vertical integration strategy, manufacturing approximately 80% of its rocket components in-house. This approach reduces dependency on external suppliers, cuts costs, and allows for greater control over technology development. The company leverages advanced manufacturing techniques, such as 3D printing for rocket engines and automated processes for carbon composite structures, to achieve high efficiency and scalability.

Products: The Spectrum Rocket

The cornerstone of ISAR Aerospace’s offerings is the Spectrum rocket, a two-stage, liquid-fueled launch vehicle designed specifically for small and medium satellites. Spectrum aims to provide a flexible, cost-effective solution for deploying payloads into low Earth orbit (LEO) and sun-synchronous orbit (SSO), targeting a price point of approximately €10,000 ($11,700) per kilogram.

Specifications

• Payload Capacity:
  • Up to 1,000 kg to low Earth orbit (LEO).
  • Up to 700 kg to sun-synchronous orbit (SSO).
• Stages: Two stages, both powered by ISAR’s in-house developed Aquila engines.
• Propellant: Liquid oxygen (LOX) and propane, chosen for their high energy density, non-toxic properties, and environmental friendliness.
• Height: Compact design, though exact dimensions are not publicly specified, optimized for efficiency and payload performance.
• Engines:
  • First Stage: Nine Aquila engines, providing the primary thrust for liftoff and ascent.
  • Second Stage: One Aquila engine, equipped with a multi-ignition system for precise orbital insertion, eliminating the need for an additional kick stage.
• Structure: Primary structure made from a single-part carbon composite, manufactured using automated processes for lightweight durability and scalability.
• Price Point: Targeted at €10 million per launch, making it competitive in the small launch vehicle market.

Technology Highlights

The Spectrum rocket incorporates cutting-edge technologies to maximize performance and reduce costs:

• Aquila Engines: Developed entirely in-house, these engines use a turbopump to deliver propellant at high pressure. The second-stage engine’s multi-ignition capability allows for multiple burns, enhancing flexibility for complex mission profiles. In 2023, ISAR conducted 124 hotfire tests of the Aquila engine at Esrange, Sweden, with one engine fired six times without refurbishment, exceeding performance expectations.
• Additive Manufacturing: Complex engine components are 3D-printed from high-performance metals, reducing part count and lead times while improving design flexibility.
• Carbon Composites: The rocket’s lightweight structure enhances payload capacity and is produced through automated manufacturing, ensuring consistency and scalability.
• Non-Toxic Propellants: The use of LOX and propane aligns with ISAR’s commitment to sustainability, offering high performance without the environmental drawbacks of traditional fuels.

Launch Configurations

Spectrum offers three mission profiles to accommodate diverse customer needs:

1. Dedicated Launch: Customers determine the orbit and launch time for a single payload.
2. Lead Launch: A primary customer sets the destination and timing, with additional payloads sharing the ride.
3. Rideshare: Routine missions to predetermined orbits, ideal for smaller satellites seeking cost-effective access.

This flexibility positions Spectrum as a versatile option for satellite operators, research institutions, and commercial entities.

Upcoming Launch: Spectrum’s Maiden Flight

As of March 17, 2025, ISAR Aerospace is on the cusp of a historic milestone: the first test flight of the Spectrum rocket. The launch is scheduled to occur no earlier than March 20, 2025, from the Andøya Spaceport in Norway, pending weather, safety, and range availability conditions.

Launch Site: Andøya Spaceport, Norway

ISAR Aerospace secured a 20-year exclusive lease for a launch pad at Andøya Spaceport in April 2021. Located in northern Norway, Andøya is ideal for reaching sun-synchronous and polar orbits, with inclinations between 87.4 and 108 degrees. The spaceport, which has a history of over 1,000 suborbital launches since the 1960s, is expanding to support orbital missions, with ISAR as a key partner. The Spectrum rocket is already on-site, having been transported there for final testing phases.

Preparations and Milestones

The road to this launch has been marked by several critical achievements:

• Engine Testing: ISAR conducted extensive testing of the Aquila engines at Esrange, Sweden, with a notable 30-second static fire test of the first stage completed on February 14, 2025, and subsequent tests of both stages by early March 2025. These tests confirmed the rocket’s readiness for flight.
• Static Fire Test (February 21, 2025): A full-up static fire of the Spectrum rocket validated the integration of its nine first-stage engines and single second-stage engine, clearing a major technical hurdle.
• Launch License: On March 17, 2025, the Norwegian Civil Aviation Authority granted ISAR approval for launch operations, with the final barrier being the issuance of the launch operator license, expected imminently.

Payload and Mission Profile

The inaugural flight will carry approximately 150 kg of payload, including seven small satellites from five European institutions (Germany, Norway, and Slovenia), selected through a competition run by the German Aerospace Center (DLR). This test flight aims to demonstrate Spectrum’s capability to deliver payloads to a polar orbit, a critical step in validating its design and performance.

Timeline and Delays

ISAR initially targeted a 2022 launch, but technical challenges and rigorous testing pushed the timeline to 2023, then 2024, and finally 2025. The delays reflect the company’s commitment to ensuring reliability, a priority underscored by CEO Daniel Metzler: “We designed, built, and tested everything ourselves to be fully independent.” The successful static fire test in February 2025 and the securing of regulatory approval signal that the launch is now imminent.

Future Launches

Following the maiden flight, ISAR plans a second test mission within six months, carrying 19 spacecraft from institutional and commercial customers across Austria, Bulgaria, Finland, Germany, Norway, and Spain. Commercial launches are already booked, including:

• D-Orbit (2025+): An Italian space logistics company’s ION space tug to SSO.
• Exotrail (2024-2029): Multiple launches for the French company’s spacedrop delivery service.
• Arctic Ocean Surveillance (by 2028): A collaboration with the Norwegian Space Agency to launch two satellites from Andøya.

ISAR aims to scale operations to 30-40 launches per year in the long term, leveraging additional launch facilities, such as the Guiana Space Centre in French Guiana, where it was selected by CNES in July 2022 to operate from the Kourou Diamant site.

Strategic Importance and Market Position

ISAR Aerospace operates in an emerging market for small satellite launches. Competitors include Germany’s Rocket Factory Augsburg (RFA) and HyImpulse Technologies, as well as international players like Rocket Lab and SpaceX. ISAR’s vertical integration, competitive pricing, and European focus give it a unique edge, particularly amid concerns over Europe’s reliance on foreign launch providers like SpaceX’s Falcon 9.

The company’s partnerships with Airbus Defence and Space, the German Aerospace Center (DLR), and others, along with political support from figures like Bavarian Prime Minister Markus Söder, underscore its role in enhancing European space sovereignty. Chief Commercial Officer Stella Guillen has emphasized, “There is no European sovereignty without sovereign and competitive access to space—from Europe.”

Summary

ISAR Aerospace stands at a pivotal moment as it prepares for the Spectrum rocket’s first test flight on March 20, 2025. With a robust design, innovative technology, and a clear vision for sustainable space access, the company is well-positioned to become a leader in the European NewSpace ecosystem. The success of this launch will not only validate years of development but also signal Europe’s growing capability to independently access space, paving the way for a new era of satellite deployment and scientific exploration. As ISAR Aerospace moves from “Isar to space,” the world watches closely to see how this German startup will shape the future of orbital transportation.