| Model of a Sentinel-1 satellite (with radar antenna missing) | |
| Mission type | Earth observation |
|---|---|
| Operator | ESA |
| Website | Sentinel-1 (ESA) |
| Mission duration | Planned: 7 years [1] |
| Spacecraft properties | |
| Spacecraft type | Sentinel-1 |
| Bus | Prima [2] |
| Manufacturer | Thales Alenia Space Airbus Defence and Space [1] |
| Launch mass | 2,164 kg (4,771 lb) |
| Start of mission | |
| Launch date | 4 November 2025, 21:03 UTC |
| Rocket | Ariane 62 (VA265) [3] [4] |
| Launch site | Kourou ELA-4 [3] |
| Contractor | Arianespace |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Altitude | 693 km [5] |
Sentinel-1D is an upcoming European radar imaging satellite. It is the second of two additional satellites in the Sentinel-1 constellation, part of the European Union's Copernicus programme on Earth observation. The satellite is equipped with a C-SAR sensor, capable of providing high-resolution imagery regardless of weather conditions. [6] [7] [8] [9] Sentinel-1D will be launched on Ariane 6 in late 2025. [10] It is designed to substitute Sentinel-1A, which has been in orbit for 11 years at the time of Sentinel-1D's launch, long beyond its planned mission duration. Sentinel-1D will work in tandem with Sentinel-1C. [11]
Development contract was signed with Thales Alenia Space of Italy in December 2015. [12] In November 2022, the satellite's launch was scheduled for the second half of 2024. [13] In January 2025, ESA signed a contract with Arianespace to launch the satellite in the second half of 2025 on Ariane 6. [14]
In September 2025 the satellite was transported from the cleanroom in Cannes, France, via Turin, Italy to French Guiana by the Ukrainian Antonov Airlines. [15] [16] At the same time, control teams at ESOC in Darmstadt, Germany begun simulations of the Sentinel-1D's Launch and Early Orbit Phase (LEOP). This is the first time an ESOC-operated satellite is launching on Ariane 6. [17]
In early October 2025, the satellite has undergone functional tests at Guiana Space Centre and had its AIS antenna assemblies integrated. [18] The spacecraft Flight Readiness Review took place in mid-October, paving the way for fuelling. By 20 October, the spacecraft was fuelled and on 24 October, it has been encapsulated inside the Ariane 6 fairing. [19] [20]
The launch is planned for 4 November 2025 at 21:03 UTC with the first acquisition of signal from the satellite expected at 22:22 UTC. The ESA Web TV broadcast will begin at 20:15 UTC. [21] [11]