Space flights expose astronauts to medical risks, particularly respiratory risks, which are exacerbated in microgravity. Devices such as standard oxygen therapy and non-invasive ventilation (NIV) are used, but their performance in microgravity remains poorly studied. Parabolic flights allow these technologies to be evaluated in conditions similar to those encountered during space missions. In an initial study conducted in microgravity during a parabolic flight campaign, the T1 ventilator proved superior to the other devices tested on the test bench. However, its performance in healthy volunteers has not yet been evaluated. The central hypothesis of this exploratory study on healthy volunteers is that non-invasive ventilation, particularly with the CaStar UP helmet (Intersurgical), could offer superior performance to the standard oxygen mask in microgravity, thanks to better leak reduction (data from preclinical work on a test bench).

Inclusion Criteria:

• Healthy volunteers (male or female)
• Aged 18 to 65
• Affiliated with a Social Security scheme and, for non-French residents, holders of a European Health Insurance Card (EHIC) or a Global Health Insurance Card (GHIC)
• Agreeing to participate in the study
• Agreeing to participate in the study
• Having given their informed consent in writing
• Who have undergone a medical examination similar to a standard aeronautical medical examination for private pilot fitness

Exclusion Criteria:

• Individuals who have participated in a previous biomedical research protocol
• whose exclusion period has not ended.
• Individuals in a subordinate relationship with the principal investigator or scientific director.
• Pregnant or breastfeeding women (urine pregnancy test for women of childbearing age).
• Protected adults (under guardianship, curatorship, or judicial protection)
• Flu-like symptoms, digestive symptoms (nausea, vomiting), fever.
• Altered mental state (flight-related anxiety, phobic state).
• Failure to attend the Novespace safety briefing.