1999 – 2019 : 20 years of the ARA association activity

During these 20 years of existence, the ARA association adressed several fields related to atmospheric reentry :

  • Atmospheric reentry systems and programs : this was the core of the ARA Days international conference that took place 5 times between 2006 and 2015 in the beautiful Arcachon Bay area, west of the Bordeaux city and its world renowned vineyards.
  • Technology : the most prominent action in this field was the study on the experimental maneuvering reentry vehicle Pre-X instrumentation that the ARA association launched in 2004. This program was funded by CNES, the french space agency, and the Aquitaine Region Council.
  • Science et Education : several grants have been offered to help students attend scientific conferences. The ARA association also supported a number of PhDs. More recently (2015) the ARA association started its workshop series on reentry related topics.
  • Information and communication : this is a long-lasting action which aimed to promote the atmospheric reentry community, and highlight the association members skills and experience in that field. Workshop series and ARA Days have contributed to this action.

The present page of this website gives an overview of some remarkable accomplishments of this 20 years period.

For more information, contact us

In year 2020, acknowledging the worldwide deep transformations of the atmospheric reentry field that occured since its foundation, the ARA association renewed its statutes and changed his name for HyFAR-ARA (which stands for Hypersonic Flight and Atmospheric Reentry –Association pour la Rentrée Atmosphérique)


International conferences on the shore of Arcachon Bay

Flagship event of the association’s life, the ARA Days permitted to gather hundreds of scientists and engineers coming from dozens of countries on the shore of Arcachon Bay to share a common passion of atmospheric reentry.

Each of the 5 editions came with its share of remarkable communications. We want to highlight some key dates among these 5 editions :

  • 2006 : maiden edition
  • 2008 : 10 years of l’ARD
  • 2015  : the year of the IXV flight

The ARA Days series paused in 2015. The association is presently working to revive this tradition of international conferences in the Aquitaine Region

These conferences have been organized with the support of Avantage Aquitaine

Workshop series

Short meetings on highly specific topics

International conferences such as ARA Days allow to gather numerous scientists and engineers on a single place.

They are thus an extremely efficient way to share and relay their participants knowledge and competencies. The counterpart is their sometimes spanning over too much topics that prevents attendants to witness all interesting information presented. Plus they require preparation a long time before their occurrence and somewhat heavy logistics. Duration often up to 4 to 5  days may also cause a difficulty for some people to attend the conferences.

It thus appeared that workshops focused on very specific topics over shorter durations could be an interesting complement to large conferences.

The idea was the to offer the opportunity of deeper exchanges on their very specialties to scientists and engineers.

ARA thus decided to test this short workshop format in january 2015 on the subject of space debris. The outcome of two days of presentations and discussions was the identification of a certain number of  high priority issues to solve and the derivation of recommendations for their assessment. These were officially presented during the fifth ARA Days in May 2015 (see the presentation below).

The good feedback we received after this first experiment led us to schedule a second edition in 2017. Addressing issues interesting more precisely professionals from Aquitaine Region area, the objective was to perform an inventory of the industrial and research ecosystem of the Region in the field of atmospheric reentry and to foster collaborative projects.

Other workshops are planned, with the intention to increase the number of editions between two important events such as the ARA Days.

2015 : Space debris workshop

Abundant and out of control debris in earth orbits is an increasing concern for space business, and induce satellites operators to tackle the problem with great care. France thus enforced the so called “law on space operations” (in french LOS : Loi sur les Opérations Spatiales) in year 2008.

This law makes mandatory to operators to discard their satellites from useful earth orbits once they have reached their life end. They can comply with this regulation by transfering satellites to far away “parking  orbits”, or by destroying them through active transfer toward atmospheric reentry trajectories.

In that second case, operators must demonstrate that these reentries are safe for populations. This implies that the  assessment of satellites breakdown and debris reentry be computed with high reliability physical and numerical models.

ARA in collaboration with CEA, the french atomic energy commission (which was then, and still is, member of ARA together with Airbus DS, Herakles Safran, Bordeaux University and Aquitaine Region), organized a workshop on this topic on 20-21 January 2015. This workshop took place at the “Institut Laser et Plasma” (Plasma and Laser Institute) in Le Barp (France), a town in the Bordeaux area.

This event gatherd over 50 participants from french industry, university and public institutions : Airbus DS (Toulouse, Bordeaux, Les Mureaux), CEA (Bordeaux and Le Ripault facilities), CNES (Toulouse, Paris), CNRS (Toulouse, Orléans), Herakles/SAFRAN (Bordeaux), DGA (Rennes), Bordeaux University, INRIA (Bordeaux facility), ONERA (Toulouse), University of Pau, and small industry representatives.

The conclusions of this workshop mays be found in the presentation below.

2017 : wokshop “Challenges and perspectives of atmospheric reentry in New Aquitaine Region”

The objectives of this workshop were the following :

  • have major institutions and industry representatives present their vision of close term atmospheric reentry business and research evolution, and how they prepare for it
  • have local key actors of the domain present their know-how and expertise
  • cross both informations to get a picture of New Aquitaine activity and competencies in the field of atmospheric reentry, derive a common strategy, identify resaerch and development perspectives, outline potential programs and projects

2022 : ATD3 Workshop

The AeroThermoDynamics and Design for Demise (ATD3) Workshop managed by ESA and CNES took place in Bordeaux from 27 to 28 October 2022. HyFAR-ARA was locally in charge of the Workshop organisation.

The workshop gathered over 50 participants from more than 10 countries during the two days.


Since the launch of the first Sputnik in 1957, more than 6,000 rockets have put into orbit nearly 13 000 satellites, of which about 8000 are still present (active or inert).

A galore of debris adds up to these objects [1]: more than 600 destroyed satellites (explosions, collisions…), launcher stages and various debris (launcher elements, tools…). A total of approximately 36,000 objects larger than 10 cm, representing nearly 10,000 tons, are circulating today in Earth’s orbits.

The creation of satellite constellations worth thousands of objects (Starlink…) has made these numbers soar (see figure), with the risk of a rapid saturation of useful orbits as well as an increase in the risks of collisions and debris production.

The workshop in a nutshell

The workshop is organized  by the Working Group “ATD3” managed by ESA and CNES through the ESA Technology Directorate and the CNES Research and Technology Directorate.

The ATD3 working group is a regular forum  (normally every year) at European level to facilitate the discussions (at technical and scientific level), collect and disseminate information, propose new topics/activities and plan (roadmap definition and coordination).

The 2022 edition was the first in person workshop since the 2018 edition in Germany (2 videoconferences took place since then :  16 September 2020 and 2 December 2021, this last one registering over 150 participants)

The main objectives of the working group are:

  • Setting of a framework for verification, validation and comparison of numerical methods for space object reentry simulation tools.
  • Disseminating recent results within the ATD3 community. Members include academics ( in particular PhD students) and experts from industry
  • Coordinating and discussing future activities. The objective is to get expert opinion from the academic and industry sector regarding future activity in the domain of aerothermodynamics and design for demise.

The format is a sequential list of presentations of about 20 minutes each, with 5 minutes brief Q&A session per presentation


The ATD3 2022 home page on the HyFAR-ARA website

The ATD3 2022 home page on the ESA website


[1] , issue of 4 April 2022



Projects to foster research and innovation

Without projects to support scientific research and technological developments, both may stop short quickly.

Ambitious programs are a powerful stimulus for innovation, and contribute to federate the teams engaged in their realization.

According to that, and since its very first days in business, one of the driving policies of the association has been the promotion of flight experiments.

As a consequence of this commitment,  a research and technology program was initiarted in the frame of the Pre-X and EXPERT experimental flight vehicles.

Following HyFAR-ARA (then ADTMRA) association proposal, CNES (french space agency) and Aquitaine Region signed on October 22nd 2004 a protocol which allowed to fund studies on in flight diagnostics design for these two vehicles.

The objective of the Pre-X program was to design, develop and flight test a prototype of lifting body reentry vehicle.

EXPERT was a second experimental atmospheric reentry vehicle, more oriented towards scientific research.

The CNES-Aquitaine Region protocol engulfed part of Pre-X and EXPERT program tasks dedicated to the payloads design, more specificaly embarked instrumentation

Partners in the consortium created to complete the program :

  • EADS-ST (prime contractor) : catalycity experiment, radiometer, laminar/turbulent transition, instrumentation plan, system design, Pre-X mock-up.
  • CEA : catalycity experiment, radiometer, laminar/turbulent transition
  • SPS : flaps, generic shingle, instrumentation plan, system design
  • INRIA : radiometer, laminar/turbulent transition (thesis : “numerical schemes”)
  • ONERA : laminar/turbulent transition, instrumentation plan
  • Dassault : instrumentation plan, system design

This program, funded  by CNES and Aquitaine Region (3.7M€), ended in 2005. Pre-X was followed by the IXV reentry vehicle, an ESA managed project directly derived from Pre-X. IXV succesfully flew in year 2015