Artemis II heat shield aced its blistering reentry, ghostly underwater photo reveals

Artemis II aced its trial-by-fire reentry, despite some concerns that the Orion spacecraft's heat shield would not hold up, a ghostly photo of the spacecraft's underside taken soon after splashdown reveals.

NASA's preliminary post-splashdown investigation indicates that Orion's heat shield suffered minimal char loss, its ceramic tiles were uncracked, and the reflective thermal tape was still present in numerous places — ensuring that the capsule’s four-person crew was safe during their fiery plunge through Earth’s atmosphere.

"Initial inspections of the system found it performed as expected, with no unusual conditions identified," NASA officials wrote in a statement released Monday (April 20). "Diver imagery of the spacecraft’s heat shield initially taken after splashdown and further inspections on the recovery ship found the char loss behavior observed on Artemis I was significantly reduced, both in terms of quantity and size."

The Artemis II heat shield, an ablative coating of silica fibers inside a polymer resin, was designed to protect the mission's crew from the 24,664 mph (39,693 km/h) reentry — a blistering speed that transformed the surrounding air into a plasma inferno half as hot as the sun's surface.

But the shield's doubtful suitability for this final leg of the journey left experts concerned. Notably, Charles Camarda, a former NASA astronaut and heat-shield research engineer who flew on the first space shuttle following the Columbia disaster, lambasted the decision as "playing Russian roulette" with the crew's lives.

That's because the Artemis II mission's heat shield was the same as the one used for Artemis I, and that shield cracked and charred upon reentry.

For the uncrewed Artemis I mission, NASA performed a "skip" reentry, in which Orion bounced off Earth's upper atmosphere, like a stone on a lake, before reentering. According to NASA, this maneuver would extend the range that Orion flew between reentering the atmosphere and splashing down in the Pacific Ocean, thereby improving landing accuracy and making the ride smoother for astronauts.

But a later inspection of the heat shield alarmed NASA engineers, revealing that the shield's Avcoat material had charred and cracked, and was missing several bolts. Ground testing at NASA's arc jet facility replicated the conditions of reentry, finding that the skip return had enabled pockets of gas to build up inside and fracture the shield.

This led NASA to opt for a lofted entry profile for Artemis II (the same type of reentry used in the Apollo missions), sacrificing accuracy and astronaut comfort to send the mission's "Integrity" spacecraft on a more direct path through the atmosphere. Now, an early analysis appears to show the agency's bet paid off.

Meanwhile, the mission's Space Launch System rocket, once notorious for its numerous leaks and launch scrubs, also performed well, according to NASA. The agency got its numbers right too, achieving a landing with pinpoint precision similar to those of the Apollo missions.

"Orion splashed down with precision, just 2.9 miles [4.7 kilometers] from the targeted landing site," NASA representatives wrote in the statement. "Initial assessments showed entry interface velocity was within one mile-per-hour [1.6 km/h] of predictions."

While NASA is using its initial assessments to herald future missions in the Artemis program as being "on track," doubts persist. Artemis III is slated to launch for an Earth-orbit docking test with its lunar lander module in 2027 before Artemis IV and V target successive moon landings in 2028. Whether those landers ‪—‬ alongside other mission-critical hardware, such as lunar spacesuits ‪—‬ arrive in time or delay the program further remains to be seen.

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