{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T10:36:10Z","timestamp":1777890970588,"version":"3.51.4"},"reference-count":60,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2021,10,20]],"date-time":"2021-10-20T00:00:00Z","timestamp":1634688000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UID\/EMS\/50022\/2020"],"award-info":[{"award-number":["UID\/EMS\/50022\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Energies"],"abstract":"<jats:p>The development of electric aircraft is becoming an important technology for achieving the goals set by the European Commission for the reduction of gases emissions by 2050 in the aeronautical transportation system. However, there is a technology gap between the current values of specific power in commercial electric machines and those required for aeronautical applications. Therefore, the search for alternative materials and non-conventional designs is mandatory. One emergent solution is using superconducting machines and systems to overcome the current limits of conventional electrical machines. This work reviews the new hybrid and all-electric aircraft tendencies, complementing it with recent research on the design and development of high specific power superconducting machines. This includes the main topologies for hybrid and all-electric aircraft, with an overview of the ongoing worldwide projects of these aircraft types, systematizing the main characteristics of their propulsion systems. It also includes the research on superconducting machines to achieve high specific power and consider the impact on the redesign of aircraft systems, the electrical, cooling, and fuel source systems.<\/jats:p>","DOI":"10.3390\/en14216861","type":"journal-article","created":{"date-parts":[[2021,10,20]],"date-time":"2021-10-20T07:05:57Z","timestamp":1634713557000},"page":"6861","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Barriers and Challenges Going from Conventional to Cryogenic Superconducting Propulsion for Hybrid and All-Electric Aircrafts"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5536-9038","authenticated-orcid":false,"given":"Francisco Ferreira","family":"da Silva","sequence":"first","affiliation":[{"name":"IDMEC, T\u00e9cnico Lisboa, University of Lisbon, 1049 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9674-5490","authenticated-orcid":false,"given":"Jo\u00e3o F. P.","family":"Fernandes","sequence":"additional","affiliation":[{"name":"IDMEC, T\u00e9cnico Lisboa, University of Lisbon, 1049 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7072-5184","authenticated-orcid":false,"given":"Paulo Jose","family":"da Costa Branco","sequence":"additional","affiliation":[{"name":"IDMEC, T\u00e9cnico Lisboa, University of Lisbon, 1049 Lisbon, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,20]]},"reference":[{"key":"ref_1","unstructured":"European Commission (2012). Flightpath 2050: Europe\u2019s Vision for Aviation\u2014Report of the High-Level Group on Aviation Research, EU Publications."},{"key":"ref_2","unstructured":"NASA Aeronautics (2019). NASA Aeronautics Strategic Implementation Plan: 2019 Update."},{"key":"ref_3","unstructured":"Advanced Research Projects Agency-Energy (ARPA-E) (2021, February 11). Aviation-Class Synergistically Cooled Electric-Motors with Integrated Drives (ASCEND) SBIR\/STTR. 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