public static Astronaute chargerXml(XmlNode rootNode)
        {
            XmlNode nodeAstronaute = rootNode;

            string tmp_nom = nodeAstronaute.SelectSingleNode("nom").InnerText;

            Astronaute result = new Astronaute(tmp_nom);
            return result;
        }
 public void addParticipant(Astronaute astronaute)
 {
     participants.Add(astronaute);
 }