Pléiades Neo 5 & 6 | Vega-C

Featured image credit: ESA/CNES/Arianespace – Photo Optique Video du CSG – S. Martin

Lift Off Time/Launch Window (Subject to change)	December 21, 2022 01:47:00 UTC December 20, 2022 22:47:00 GFT
Mission Name	Pléiades Neo 5 & 6, Flight VV22
Launch Provider (What rocket company is launching it?)	Arianespace
Customer (Who’s paying for this?)	Airbus Defence and Space – Intelligence
Rocket	Vega C
Launch Location	ELV-1, Centre Spatial Guyanais, Kourou, French Guiana
Payload mass	1,940 kg (4,280 lb)
Where are the satellites going?	643 km (Pléiades 5) and 617 km (Pléiades 6) circular orbit at 97.89° inclination (altitude at initial separation 628 km)
Will they be attempting to recover the first stage?	No, this is not a capability of Vega
Where will the first stage land?	The booster will crash into the Atlantic Ocean
Will they be attempting to recover the fairings?	No, this is not a capability of Vega
Are these fairings new?	Yes
How’s the weather looking?	N/A
This will be the:	– 2nd flight of the Vega C rocket – 1st operational flight of the Vega C rocket – 22nd launch of a Vega rocket (any variant) – 47th launch from pad ELV-1 (formerly ELA-1) – 317th orbital launch from Centre Spatial Guyanais (any rocket) – 182nd orbital rocket launch attempt for 2022
Where to watch	Official Arianespace livestream

What Does All This Mean?

Arianespace is launching its small-lift rocket, Vega C, from its equatorial launch site in French Guiana. It is sending several satellites to a Sun-synchronous orbit (SSO). The main payload is a pair of Pléiades Neo satellites, Pléiades Neo 5 & 6. These are high resolution Earth observation satellites.

What Are Pléiades Neo 5 & 6?

Pléiades Neo 5 and 6 are the last batch in a series of next-generation imaging satellites that will generate very high resolution Earth observation imagery. Their predecessors, Pléiades-Neo 3 and 4, launched in April and August 2021 respectively.

Airbus Defence and Space has funded, owned, and operated the Pléiades-Neo program entirely on its own. The satellites have an imaging system that gives 30 cm resolution. This specific SSO orbit enables it to overfly a location twice every day.

Airbus describes the satellites as having defense applications, such as monitoring opposing forces’ positions. They also describe urban applications such as monitoring the effects of climate change or pollution, or to monitor emergency services response.

In addition, Airbus mentions the powerful use of the generated images to assist in map-making and map updating in up to 1:2000 scale.

Vega C Rocket

Arianespace considers Vega to be its small-lift rocket. Vega sits alongside its siblings, the heavy lift Ariane V and medium lift Soyuz. The rocket’s name comes from the brightest star in the constellation of Lyra. It consists of three solid motor stages with a liquid propellant upper stage on top, making four stages in total.

Built by the Italian aerospace company Avio, the rocket is 34.8 m (114 ft) tall overall, and has a diameter of 3.4 m (~11 ft) at its widest section. Its mass at time of launch is 210,000 kg (463,000 lbs). It can deploy a payload mass of 2,200 kg (4,850 lbs) to a polar orbit of 700 km altitude with 90° inclination.

Vega had one launch failure (VV15) in 2019 and another (VV17) in 2020. The anomaly on VV15 was found to most likely be due to a thermo-structural failure in the forward dome area of the Z23 motor. The failure on VV17 was confirmed in December 2020 to be due to incorrectly connected cables in the rocket’s AVUM upper stage.

Vega C (Consolidation) is an upgrade to the previous Vega rocket which has flown several times before. Vega C has more powerful solid rocket motors in the first and second stages. The first stage motor will also be also used as side boosters on Ariane 6. Vega C has a larger payload fairing, allowing twice the volume of previous Vega variants. Vega C’s inaugural flight, a test mission, took place on July 13, 2022. This flight is Vega C’s first operational flight.

Vega C First Stage – P120C

The first stage, known as P120C, is 11.7 m long, with a diameter of 3.4 m. Its total mass at time of launch is 154,600 kg (341,000 lb). It uses Hydroxyl-terminated polybutadiene (HTPB) for propellant. This is a substance that combines the fuel and the oxidizer together. The Polar Satellite Launch Vehicle (PSLV) rocket flown by the Indian Space Research Organisation (ISRO), and the M-5 rocket flown by the Japan Aerospace Exploration Agency (JAXA), also use HTPB.

When all its propellant has been consumed, the remaining dry mass is only 11,000 kg (24,000 lb).

The rocket motor burns for a duration of 132.8 seconds, and has a specific impulse (its efficiency) of 278.5 seconds. While burning, it generates an average thrust of 4,650 kN (1,050,000 lbf).

Vega Second Stage – Zefiro 40

The second stage, called Zefiro 23, has a length of 7.6 m, and a diameter of 2.3 m. Its total mass at time of launch is 39,200 kg (~86,400 lb).

The rocket motor burns for a duration of 93 seconds, and has a specific impulse of 293.5 seconds. While burning it delivers an average thrust of 1,304 kN.

When depleted of fuel, the left-over shell has a mass of 2,080 kg.

Vega Third Stage – Zefiro 9

The third stage, known as Zefiro 9, has a length of 3.9 m and a diameter of 1.9 m. Its total mass at time of launch is 11,406 kg (25,146 lb).

This stage’s motor burns for a duration of 117.1 seconds, with a specific impulse of 295.2 seconds. During its firing, it generates an average thrust of 314 kN.

After its burn, the remaining chassis and nozzle have a mass of 906 kg.

Vega Fourth Stage – AVUM+

The final stage of the Vega rocket, called AVUM+ (for Attitude & Vernier Upper Module), has a length of 1.7 m and a diameter of 1.5 m. This stage uses hypergolic propellants, specifically unsymmetrical di-methyl hyrdazine (UDMH) for fuel and nitrogen tetroxide (N2O4) as oxidizer.

The propellant mass on this stage is 740 kg. After burning, the remaining dry mass of the stage is 590 kg.

This stage’s engine burns for a duration of 940 seconds, with a specific impulse of 314.6 seconds. After this burn, it enters a coast phase for 37 minutes. Following the coast period, the engine will restart for a second burn. The second burn lasts for just over one minute.

After the second burn, the main payloads Pléiades Neo 5 & 6 will be deployed. This will mark the end of the VV22 mission, after about 55 minutes of flight time.