Syracuse 4B & Heinrich Hertz

Launch Time
Wed Jul 05, 2023 22:00 UTC

Last flight of Ariane 5, after 117 flights. In 27 years of service, Ariane 5 has launched dozens of commercial payloads, as well as multiple major scientific missions (XMM Newton, Rosetta, Herschel, Planck, BepiColombo, JWST, and JUICE), and Europe's very first spacecraft, the ATV.

Flight VA261.


Ariane 5 ECA
Image Credit: Arianespace
Status: Retired
Price: $200.0 million
Liftoff Thrust: 15,120 kN
Payload to LEO: 21,000 kg
Payload to GTO: 10,500 kg
Stages: 2
Strap-ons: 2
Rocket Height: 53.0 m
Fairing Diameter: 5.4 m
Fairing Height: 17.0 m

Mission Details

Syracuse 4B

The Comsat-NG (Communication par satellite de nouvelle génération), then renamed Syracuse-4, contract signed in December 2015 covers the construction and launch of two military communications satellites for the French armed forces, to replace the Syracuse 3A and 3B satellites, launched in 2005 and 2006, respectively. These new satellites will enter into service in 2021 and will give France a higher-performance system featuring new services.

Offering a design life of 15 years, the two satellites will have identical X- and Ka-band payloads, built by Thales Alenia Space as the prime contractor. One will use the full electric Spacebus-Neo platform, while the other will be built on the full electric Eurostar-3000EOR platform. The Syracuse-4 satellites will feature unrivaled resistance to even the most extreme jamming methods, thanks to state-of-the-art equipment, including an active anti-jamming antenna and a digital onboard processor.

Payloads: 1
Total Mass: 3,572.0 kg
Geostationary Transfer Orbit

Heinrich Hertz

The German Heinrich Hertz or H2Sat aims to explore and test new communications technologies in space at a technical and scientific level in order to determine how broadband communications, for example, can result in high data rates for mobile final users.

The development is performed by OHB System on behalf of the space agency of the German Aerospace Center (DLR) using funding provided by the German Federal Ministry of Economics and Technology (BMWi) with the participation of the Federal Ministry of Defence (BMVg).

Mission objectives are:

* Scientific/technical verification of hardware and software and scientific experiments in the area of communications.
* Preparations/testing of pre-operational Satcom services for German (public-sector) users.

Payloads: 1
Total Mass: 3,408.0 kg
Geostationary Transfer Orbit


ELA-3, Guiana Space Centre, French Guiana, France



99th orbital launch attempt


296th mission
2nd mission of 2023
284th successful mission
2nd consecutive successful mission

Ariane 5

117th mission
2nd mission of 2023
112th successful mission
20th consecutive successful mission