April 8, 2026, 4:03 p.mApril 8, 2026, 4:03 p.m
According to former Swiss astronaut Claude Nicollier, the return of the manned lunar mission “Artemis 2” is considered the most critical phase of the flight. The re-entry of the Orion capsule into the Earth’s atmosphere in particular represents a major technical challenge.
The re-entry of the Orion capsule into the Earth’s atmosphere is the most critical phase.Image: keystone
Nicollier, who himself completed four return flights from space, referred to the significantly higher speed in an interview published on Wednesday with the French-speaking Swiss radio and television RTS.
While spacecraft return from low Earth orbit at around 28,000 kilometers per hour, a lunar mission returns almost 40,000 kilometers per hour, said the 81-year-old from Vaud.
This higher speed means a significant thermal load on the heat shield of the Orion capsule. Although the system was tested on the unmanned Artemis I mission, there are still concerns in this regard, said Nicollier.
The four-person crew of the Artemis II mission is on its way back to Earth after its moon flyby. According to the US space agency NASA, re-entry into the atmosphere and splashdown in the Pacific are scheduled for Friday evening (US local time). (hkl/sda)
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