The European Space Agency (ESA) has recently announced several exciting initiatives that are worth paying attention to.

In the short term, it will continue strengthening its cooperation with NASA in the United States. This is understandable because the planned debut of the ESA’s new Ariane 6 rocket was postponed. Consequently, the ESA has been forced to rely on partner countries for space launches.

However, the ESA is determined to tackle this challenge — the space mission plans for 2024-2025 include room for a new version of the Ariane 6 rocket that will launch a variety of interesting experiments into orbit. Of particular interest will be a demonstration of Replicator, Europe’s demonstration of the possibilities of 3D printing in space.

Read on to learn about this and many other exciting plans the ESA has in store for the next year.

Anticipating Ariane 6’s Debut Launch

July 9 will finally see the long-awaited launch of the European heavy rocket, Ariane 6, which will restore the ESA’s ability to independently conduct space missions. Europe has lacked a launch vehicle capable of delivering a payload into orbit since the last Ariane 5 launched from the Kourou Cosmodrome in French Guiana on July 5, 2023. Now, it is finally getting its long-awaited replacement.

Ariane 6 will have two main types:

  1. Ariane 62 is a medium-class launch vehicle equipped with two side boosters. Ariane 62 will be able to deliver a payload weighing up to 4.5 tons to geostationary Earth orbit (GEO). With a starting mass of 540 tons, it will be powerful enough to carry several small satellites (mainly telecommunications) into space. This rocket is intended to be the primary workhorse for the commercial orders that the ESA hopes to receive from European and international space companies and start-ups. 
  2. Ariane 64, meanwhile, is a heavy launch vehicle equipped with four side boosters for launching large scientific and military satellites into orbit. This rocket will be able to place a payload of up to 11.5 tons into GEO. Its starting mass, fully fueled, will be 870 tons. 
Ariane 6 schema
Schematic representation of the device of two modifications of Ariane 6.
Credit: ESA

The upper stage of the Ariane 6 will be capable of performing multiple re-ignitions of its cryogenic liquid rocket engine, Vinci, allowing it to deploy several spacecraft into different orbital altitudes during a single launch. This capability is expected to reduce the cost of placing payloads into orbit, making the rocket more competitive compared to other launch vehicles in the orbital launch market.

After Ariane 6’s first launch, which is scheduled for July 9, 2024, the rocket’s primary developer, ArianeGroup, hopes to rapidly increase the volume of commercial customers over the next two years. The plan is to eventually launch 10 rockets per year. Currently, there are 30 Ariane 6 missions planned, which indicates a certain level of confidence in the European rocket. 

Over the next 10 years, Ariane 6 will become a core part of European Earth observation, geolocation, and navigation missions. The rocket will also play a prominent role in space security missions, which are becoming increasingly relevant in light of current geopolitical tensions on the Eurasian continent.

Replicator demo: 3D printing in space

The first Ariane 6 launch will not only be notable because it will be the rocket’s debut but also for its payload. Of particular interest will be the Replicator mission, which will demonstrate the possibilities of 3D printing technology in space. 

Replicator was developed by a Polish-German startup, Orbital Matter, which positions itself as the first “space construction company.” The demonstration version of the 3D printer was specially designed to function in microgravity and space vacuum conditions. 

replicator prototype by Orbital Matter
Demo version of Replicator by Orbital Matter.
Credit: ESA

 The concept of 3D printing in space is not new, with the first demonstration of such technology happening 10 years ago. In 2014, a metal 3D printer was installed on board the ISS, with which several mechanical parts were printed. At that time, however, printing took place within the space station, in conditions that replicated atmospheric conditions as closely as possible. Replicator, on the other hand, promises automatic 3D printing in the more unforgiving conditions of open space.

To make extravehicular 3D printing possible, Orbital Matter engineers had to rethink the entire approach to 3D printing. They designed the device in such a way that it does not emit heat into the environment during printing, a necessary condition for its correct operation in orbit, since convection cooling, which is possible in Earth’s atmosphere, is impossible in the vacuum of space. Heat loss in orbit can only occur by radiation, and it can take a substantial amount of time for even a small heated object to cool. By removing the factor of heat entirely from the 3D printing process, Replicator can print large modular objects in space, potentially including space telescopes, telecommunications satellites, orbital solar power plants, or even full-fledged space stations. 

Replicator will be installed aboard a miniature (10×10×30 cm) Orbital Matter CubeSat, which will separate from Ariane 6 at an altitude of 580 km. The technology demonstration was made possible with the support of ESA PUSH, a European initiative providing financial support to the most promising space startups in Europe. Last year, one of the winners of ESA PUSH 2023 was the Parisian startup RIDE!, which has offered Orbital Matter its launch brokerage services. RIDE! will also be responsible for deploying the CubeSat into orbit and managing its flight, in collaboration with ESA.

According to representatives of Orbital Matter, modular 3D printing and construction in orbit could prove to be 70% more efficient and cost-effective than terrestrial construction and launching pre-built structures into orbit. Orbital Matter has already successfully demonstrated the operation of Replicator in artificial vacuum conditions on Earth, so the upcoming launch of Ariane 6 is meant to confirm the feasibility of the technology, bringing humanity one step closer to future mega-constructions in orbit. 

ESA Probe-3: Orbital Solar Exploration Tandem

In September 2024, an ambitious European solar monitoring mission will also be launched, which will demonstrate high-precision satellite formation technology. According to the mission plans, two different spacecraft, the CSC (Coronagraph Spacecraft) and the OSC (Occulter Spacecraft) will be launched on a highly elliptical orbit with a perihelion (the point in an orbit closest to the Earth) of 600 km and an apogee (the most distant point of an orbit) of 60,560 km. An Indian launch vehicle, PSLV-XL C-62, will be used to launch the satellites in tandem. 

During their orbit, the satellites will maintain tight formation, flying only 144 meters apart, in essence forming a single “virtual” satellite without the need for additional adjustments to their orbital position from the flight control center on Earth. The precise distance of the satellites from each other is necessary for the implementation of Probe-3’s primary mission: the study of the solar corona. 

The distance was calculated so that the shadow cast by the disk of the OSC satellite, which will be constantly positioned closer to the Sun, always falls precisely on the CSC, leaving only a faint view of the solar corona in its field of view. This is where its ultraviolet radiation detectors will be aimed. Such a tandem setup will allow the CSC to conduct sensitive research on the solar corona without the risk of being blinded by the bright glare of the Sun’s photosphere.

ESA Probe-3 mission
3D rendering of the OCS/CSC satellite tandem, ESA Probe-3 mission.
Credit: ESA

Previously, the close tandem technique was demonstrated by the Swedish company Prisma, whose two satellites orbited at a distance of 10 meters from one another during short time intervals, with an error of only a few centimeters. Probe-3 will demonstrate the orbit of two satellites in tandem for 6 hours during one approach, with an acceptable margin of error of only millimeters, an order of magnitude higher than previous achievements. This flight time was deemed to be optimal from the point of view of fuel consumption since a tandem flight lasting more than 6 hours would lead to the rapid exhaustion of the OSC/CSC engines’ fuel reserves.

The Probe-3 mission is thus significant not only for what it will learn about the solar corona but, perhaps more importantly, because it will pave the way for the creation of even more elaborate “virtual” satellite structures involving larger numbers of spacecraft. Its automatic distance maintenance technology will also be useful during orbital docking maneuvers, which would no longer require a human operator.

The methods of remote navigation, rendezvous, and approach that will be used during the Probe-3 demonstration will be used in future space missions to return Martian soil samples to Earth, as well as during the operation of technologically complex satellite constellations requiring multiple satellites to work together as a single “virtual” cluster. 

ESA’s Hera will evaluate DART’s performance

September 26, 2022, saw the first successful demonstration of asteroid deflection technology when NASA’s DART spacecraft collided with the asteroid Dimorphos, deflecting its orbital path around its parent asteroid, 65803 Didymos. 

Dimorphos asteroid
Photo of Dimorphos, taken moments before the NASA DART impact.
Credit: NASA

Although DART’s front-facing cameras filmed the collision, and while subsequent observations did observe a shortening of Dimorphos’s orbital period around Didymos, scientists require further data to be able to fully analyze the effectiveness of DART’s kinetic impact. Therefore, even during the planning phase of the NASA DART mission, it was decided that an unmanned spacecraft would assess its effectiveness after two years. This spacecraft is Hera, for which ESA was responsible for construction and deployment.

The assessment of the consequences of the DART mission will be carried out by carefully measuring the size and morphology of the crater that was formed on Dimorphos after the collision. As it orbits the asteroids, Hera will also probe the debris cloud formed after the DART impact. 

Hera will also carry two small probes, Milani and Juventas, which will be released on approach to the Dimorphos. Milani will conduct a spectral analysis of the surface of the asteroids, as well as the composition of the cloud of dust and debris. Juventas will be aimed at studying Dimorphos’s subsurface structure and determining its gravity. It will also provide necessary data on the mechanical response during the attempted landing on Dimorphos. The X-Band Radio Science (X-DST) instrument will measure the gravity of the binary asteroid system by studying fluctuations in the radio wave range caused by the rotation of these celestial bodies.

The optical survey of the surface of the asteroid will be carried out using a pair of Asteroid Framing Cameras (AFC). Other optical images will be obtained using Small Monitoring Cameras (SMC). Meanwhile, the Thermal InfraRed Imager (TIRI) module will provide images in the infrared range, and the Planetary Altimeter (PALT) will guide the position of the probe in space with an accuracy of half a meter. Hera will also be equipped with a HyperScout-H hyperspectral camera, which will be able to make spectral images in the range from 665 to 975 nm and survey the surface of the asteroid in 25 spectral ranges. 

main components and modules installed of ESA Hera
A diagram showing the main components and modules installed on ESA Hera.
Source: The Planetary Science Journal

ESA’s Hera mission has two main headquarters. The first is the European Space Research and Technology Center (ESTEC) in Noordwijk, Netherlands, where design work and assembly of the 1,128-kilogram probe took place. The other facility, the European Space Operations Center (ESOC) in Darmstadt, Germany, will assume control of the mission after the launch of the spacecraft in October 2024 (exact date yet to be determined). 

The Hera mission will not be launched by Ariane 6 but by SpaceX’s Falcon 9. The new rocket, which is to be launched in July, will still be relatively untested, and thus will not be able to guarantee the necessary level of reliability required for complex scientific missions like Hera. So, as before, the choice was made in favor of SpaceX. 

The return of Vega-C

The July debut of Ariane 6 will not be the only long-awaited appearance of an ESA launch vehicle. The first flight of the updated mid-range Vega rocket, named Vega-C (Vega Consolidation), is also scheduled for this fall. The rocket made a successful debut in July 2022, which was followed by a failed launch in December of the same year. As a result, the ESA decided to take a two-year break to completely rethink the rocket. 

The new rocket is being developed by ArianeGroup jointly with the Italian Space Agency (ASI). The new version will receive a more powerful P120C booster (the same one that will lift Ariane 6). The second-stage Vega rocket, the Zefiro 23, was also replaced by the latest modification, the Zefiro 40. It was a malfunction within this propulsion system during the December 2022 launch that initially delayed the Vega-C. 

Zefiro 40 rocket engine
A Zefiro 40 rocket engine during a demonstration burn, March 8, 2018.
Credit: ESA

The third stage of the launch vehicle will be equipped with one Zefiro 9 rocket engine. The fourth and final module, the AVUM+, was also redesigned. The new rocket modification will eventually be equipped with a reusable Space Rider vehicle, which will allow the return of particularly sensitive payloads to Earth. The Space Rider, however, will not be installed during the upcoming launch of Vega-C, with its first demonstration not expected until July 2025. 

The new Vega-C will be able to deliver up to 2.3 tons 700 km into orbit, which is almost double what the original version of Vega was capable of. The rocket will also be able to put into orbit a combined payload, including large quantities of CubeSats weighing up to 1 kg, as well as larger mini-satellites weighing up to 400 kg. The payload configuration will vary from mission to mission, giving the new Vega-C a good level of scalability. 

The Vespa-C payload adapter will allow for the placement of two satellites weighing over 400 kg on the rocket, while the Vampire cargo compartment is the main adapter for large single payloads weighing up to several tons. The new Vega-C modification will also allow for the possibility of transferring payloads between orbits of different types. The Vega Electrical Nudge Upper Stage (VENUS) module will be responsible for this, allowing the deployment of satellite constellations for lunar missions or the maintenance of already operational satellites. 

Vega-C launch vehicle mission capabilities
Vega-C payload capabilities.
Credit: ESA

If the mission schedule remains unchanged, we could see Vega-C launch from ESA’s main spaceport in Kourou as early as fall 2024. Modification C, however, will not be the final development of the Vega launch vehicle: the first launch of the next modification, Vega-E (Vega Evolution), which will be equipped with a new M10 propulsion engine, running on a mixture of cryogenic liquid oxygen and methane, is already planned for 2027. The M10 engine is still under development but it is intended for installation on the third and fourth stages of the Vega rocket, significantly increasing its versatility.

Vega rockets comparison
Comparison of three different Vega rockets.
Credit: ESA

As you can see, the ESA has a lot of plans for 2024. The agency seems to be waking up from a long sleep caused by budget disputes and the constant postponement of its rocket launches and space missions. However, everything seems to indicate that this period of uncertainty is a thing of the past for Europe’s main space agency.