The Vega C rocket is scheduled to launch on April 29, 2025, at 11:15 CEST (06:15 Kourou time) from Europe’s Spaceport in French Guiana. This will be the fourth launch of the Vega C, an upgraded version of the Vega rocket, and it will carry the European Space Agency’s (ESA) Biomass satellite into a Sun-Synchronous Orbit at an altitude of approximately 666 kilometers. Spacecraft separation is expected to occur about 57 minutes after liftoff.

The Biomass Mission

The primary payload of this launch is the Biomass satellite, an Earth Explorer mission by ESA. This mission is dedicated to observing Earth’s forests to gain crucial insights into their state and how they are changing. Biomass aims to enhance our understanding of the role forests play in the Earth’s carbon cycle. Forests absorb a significant amount of carbon dioxide from the atmosphere annually, and deforestation and degradation, particularly in tropical regions, lead to the release of stored carbon back into the atmosphere. Quantifying the global carbon cycle is essential for understanding and addressing climate change.

Biomass carries the first P-band synthetic aperture radar (SAR) to observe Earth from space. The P-band wavelength, around 70 cm, allows the radar signal to penetrate through the forest canopy. This unique capability enables the satellite to collect information on the height and structure of different forest types and to measure the amount of carbon stored in the world’s forests and how it changes over time. The mission is expected to last at least five years, during which it will witness at least eight growth cycles of the world’s forests. The data collected will also provide insights into the rates of habitat loss and its impact on biodiversity within forest environments.

The Vega C Rocket

The Vega C (for Consolidated) is an enhanced version of the Vega rocket, designed for launching small to medium-sized satellites into various orbits. Developed by Avio, with ESA and the Italian Space Agency (ASI) as key partners, Vega C aims to provide increased performance and flexibility compared to its predecessor, without a significant increase in cost.

Key Features and Specifications:

• Height: Approximately 35 meters
• Mass at liftoff: Around 210 tonnes
• Stages: Four
  • First Stage (P120C): A solid rocket booster providing significant thrust at liftoff. Notably, this booster is common with the Ariane 6 launcher, creating synergies in production and cost efficiency. It has a height of 13.38 m, a diameter of 3.4 m, and uses HTPB/AP/Al as propellant, delivering a maximum thrust of 4323 kN with a burn time of 135.7 seconds.
  • Second Stage (Zefiro 40): Another solid rocket booster, replacing the Zefiro 23 used in the original Vega. It is larger and more powerful, with a height of 8.07 m and a diameter of 2.4 m, using the same propellant as the first stage and providing a maximum thrust of 1304 kN for 92.9 seconds.
  • Third Stage (Zefiro 9): A solid rocket motor, also used in the original Vega. It has a height of 4.12 m and a diameter of 1.9 m, utilizing HTPB/AP/Al propellant and generating a maximum thrust of 317 kN for 119.6 seconds.
  • Fourth Stage (AVUM+): A liquid-propellant upper stage with restart capability (up to five burns), allowing for precise orbital adjustments and the deployment of multiple payloads into different orbits. It has a height of 2.04 m and a diameter of 2.18 m, using UDMH/N2O4 as propellant and providing a maximum thrust of 2.42 kN with a burn time of up to 924.8 seconds.
• Payload Capacity:
  • Sun-Synchronous Orbit (SSO): Up to 2,300 kg (at 700 km altitude)
  • Low Earth Orbit (LEO): Up to 3,300 kg
  • Polar Orbit: Up to 2,500 kg
• Fairing: Enlarged compared to the original Vega, with a diameter of 3.3 meters and a height of over 9 meters, nearly doubling the payload volume.

Launch History:

The Vega C made its maiden flight on July 13, 2022, successfully delivering the LARES 2 satellite and several smaller payloads into orbit. However, its second launch on December 21, 2022, resulted in a failure of the Zefiro 40 second stage, leading to the loss of two Pléiades Neo Earth-imaging satellites. The rocket returned to successful flight on December 5, 2024, with the deployment of the Copernicus Sentinel-1C Earth observation satellite. The upcoming launch on April 29, 2025, will be its fourth mission.

Significance of the Launch

This launch is significant for several reasons:

• Return to Flight Confidence: Following the anomaly in its second flight, the successful launch in December 2024 was crucial for restoring confidence in the Vega C program. This mission aims to further solidify its reliability.
• Advancing Earth Science: The Biomass mission is expected to provide unprecedented data on the state of Earth’s forests, which is vital for understanding the global carbon cycle and the impacts of climate change.
• European Autonomous Access to Space: The Vega C is a key component of Europe’s independent access to space, complementing the Ariane series of launchers and providing a versatile option for a wide range of payloads and mission requirements.
• Technological Advancement: The Vega C incorporates several technological enhancements over its predecessor, including more powerful solid rocket motors and an improved upper stage, showcasing European expertise in space transportation.

The launch of the Vega C with the Biomass satellite on April 29, 2025, represents an important step for both the Vega C program and for Earth science. The data from Biomass will be invaluable for monitoring forests and understanding their critical role in the Earth’s climate system, while a successful launch will further validate the capabilities and reliability of the enhanced Vega C rocket.