{"id":82836,"date":"2026-04-10T00:01:00","date_gmt":"2026-04-10T06:01:00","guid":{"rendered":"https:\/\/www.opinionpublica.tv\/portada\/?p=82836"},"modified":"2026-04-09T19:35:20","modified_gmt":"2026-04-10T01:35:20","slug":"coming-home-may-be-the-most-dangerous-part-of-artemis-ii","status":"publish","type":"post","link":"https:\/\/www.opinionpublica.tv\/portada\/coming-home-may-be-the-most-dangerous-part-of-artemis-ii\/","title":{"rendered":"Coming home may be the most dangerous part of Artemis II"},"content":{"rendered":"\n
\"Coming<\/figure>\n\n\n\n

The Artemis II heat shield, NASA agrees, is flawed.<\/p>\n\n\n\n

The heat shield is the critical layer at the bottom of a spacecraft that protects it \u2014 and the astronauts inside \u2014 from searing temperatures upon re-entering the Earth\u2019s atmosphere. If the shield fails, the underlying metallic structure could melt, rupture and disintegrate.<\/p>\n\n\n\n

And there is no backup, and no way for the astronauts to escape.<\/p>\n\n\n\n

NASA officials, however, are confident that despite the known shortcomings of the heat shield, the four Artemis II astronauts will remain alive and comfortable as they arrive at Earth on Friday evening at a speed of nearly 24,000 miles per hour, concluding a 10-day trip to the moon and back.<\/p>\n\n\n\n

Extensive analysis and testing of the heat shield material \u201cgot us comfortable that we can undertake this mission with lots of margin to spare,\u201d Jared Isaacman, the NASA administrator, said in an interview in January.<\/p>\n\n\n\n

However, Charlie Camarda, a former NASA astronaut and an expert on heat shields, says NASA should never have launched Artemis II. The agency does not understand well enough the chances that the heat shield might fail, he says, and the mission, a success so far, could end with the deaths of the astronauts.<\/p>\n\n\n\n

\u201cI\u2019m going to pray that nothing happens,\u201d he said during an interview a few days before the launch of Artemis II.<\/p>\n\n\n\n

His hunch is that there is a 95 percent chance that the astronauts will return safely. But that would mean a 1-in-20 odds of a disaster.<\/p>\n\n\n\n

Compare that with the roughly one-in-nine-million chance that the International Air Transport Association calculates for dying in a commercial airline accident.<\/p>\n\n\n\n

The crux of the disagreement lies in how much certainty is needed when a definitive, perfect answer is impossible.<\/p>\n\n\n\n

During Artemis I, a flight without astronauts that circled the moon in 2022, the capsule, known as Orion, survived re-entry. Had there been astronauts aboard, they would not have noticed anything amiss.<\/p>\n\n\n\n

But when the capsule was pulled out of the ocean, the heat shield \u2014 the same design as the one on the Artemis II spacecraft \u2014 was unexpectedly pockmarked, with sizable chunks missing.<\/p>\n\n\n\n

A couple of years of investigations followed. NASA officials said their analysis looked at what might happen under worst-case assumptions. Those findings, along with changes in the re-entry path for the astronauts\u2019 return to Earth during Artemis II, provide a significant safety margin, they have said.<\/p>\n\n\n\n

The Artemis II crew is aware of the flight\u2019s risks and how NASA has addressed them. \u201cWe have actually been there every single step of the way of the spacecraft being built,\u201d Reid Wiseman, the commander of Artemis II, said in September last year.<\/p>\n\n\n\n

Dr. Camarda counters that NASA still does not understand the basic physics of what happened during the Artemis I mission and thus cannot truly say what the worst-case scenario might be.<\/p>\n\n\n\n

NASA officials have downplayed concerns about the heat shield.<\/p>\n\n\n\n

During a news conference in January 2024, Amit Kshatriya, now the associate administrator of NASA, said the Artemis I heat shield had experienced \u201cunexpected phenomena that we need to make sure we understand perfectly.\u201d But, he said, it provided \u201cvery good performance from a thermal protection standpoint.\u201d<\/p>\n\n\n\n

Photographs of the Artemis I heat shield remained out of public view until they appeared in a report by the agency\u2019s inspector general, an independent watchdog, in May 2024.<\/p>\n\n\n\n

The heat shield is made of a material called Avcoat, similar to what was used during the Apollo program more than 50 years ago. By design, as it absorbs the heat of re-entry, it gradually chars and burns off, preventing the heat from reaching the rest of the capsule.<\/p>\n\n\n\n

In the investigation of the Artemis I heat shield, engineers concluded that inside some portions of the heat shield, gases built up, and the pressure created cracks, causing chunks of Avcoat to break off suddenly instead of burning slowly and steadily.<\/p>\n\n\n\n

For future missions, the Avcoat formula has been modified to make it more porous to allow gases trapped inside to escape.<\/p>\n\n\n\n

That left a conundrum of what to do with Artemis II.<\/p>\n\n\n\n

For this mission, the heat shield, using the original formula, was already finished and attached to the Orion capsule. Replacing the shield or the entire capsule would have pushed the launch farther into the future.<\/p>\n\n\n\n

Instead, NASA engineers concluded that a steeper, shorter re-entry trajectory would minimize the time during which the vehicle would experience high temperatures and help keep the astronauts safe.<\/p>\n\n\n\n

Dan Rasky, a heat shield engineer who retired from NASA in December, shares Dr. Camarda\u2019s objection to this decision.<\/p>\n\n\n\n

\u201cLet me just give you an analogy,\u201d he said. \u201cIf you\u2019re driving down the highway and if there\u2019s pieces of one of your tires that start coming off, do you just keep driving and just hope it\u2019s OK? Or do you pull over and change your tire because you\u2019re worried about a blowout?\u201d<\/p>\n\n\n\n

The decision to fly Artemis II as is without changing the heat shield was \u201cnot prudent,\u201d he said. \u201cIn fact, it\u2019s reckless.\u201d<\/p>\n\n\n\n

If the Artemis II heat shield performs as well as the one used on Artemis I, the astronauts will splash down in the Pacific with no problem.<\/p>\n\n\n\n

But the situation raises uncomfortable echoes of two of NASA\u2019s worst days: Jan. 28, 1986, when the space shuttle Challenger broke up 73 seconds after launch, and Feb. 1, 2003, when the Columbia shuttle disintegrated on its return from orbit.<\/p>\n\n\n\n

For both Challenger and Columbia, warning signs had occurred during earlier shuttle flights. But managers mistakenly drew comfort from the fact that the earlier missions had continued without issue, instead of acting with urgency to fix the problems that later led to the deaths of the Challenger and Columbia astronauts.<\/p>\n\n\n\n

Now, the key question for Artemis II and its flawed heat shield: Could cracks form and spread at a catastrophic rate?<\/p>\n\n\n\n

Calculating this possibility precisely is extraordinarily difficult.<\/p>\n\n\n\n

Simulating the hypersonic flow of air molecules around the bottom of a space capsule taxes the fastest of computers. For heat shields, other complex phenomena must be accounted for as well: the flow of heat created by the compression of air molecules and the difficult-to-predict process of how cracks form and propagate in Avcoat, sometimes suddenly.<\/p>\n\n\n\n

\u201cWhat I would do is I would take the time to stand down,\u201d Dr. Camarda said. \u201cI would put together a team to develop a real analysis capability,\u201d incorporating all of the underlying physics.<\/p>\n\n\n\n

That is not what NASA has done, said Danny Olivas, another former NASA astronaut and a scientist with expertise in the properties of materials.<\/p>\n\n\n\n

\u201cCharlie is 100 percent correct,\u201d Dr. Olivas said. \u201cWe don\u2019t have a physics-based model for this. It\u2019s an impracticality and almost an impossibility because of the way this material behaves.\u201d<\/p>\n\n\n\n

But Dr. Olivas, who said he had initially had doubts about launching Artemis II with a known flaw, was ultimately reassured by the analysis that NASA did perform.<\/p>\n\n\n\n

Unlike Dr. Camarda, Dr. Olivas was recruited by NASA to conduct an independent technical review of NASA\u2019s investigation, and he recommended the creation of a larger panel of outside experts, which the space agency did.<\/p>\n\n\n\n

Dr. Olivas said that NASA\u2019s simulations assumed that if the temperature rose to a certain level inside one of the Avcoat blocks, it would crack, and that if it did crack, a layer of Avcoat would pop off the entire block. That would create a cavity where heating would accelerate and another layer would pop off.<\/p>\n\n\n\n

Even with those assumptions, which Dr. Olivas described as \u201cconservative,\u201d repeated simulations examining a multitude of re-entry variations found that enough of the heat shield would survive, and so would the capsule.<\/p>\n\n\n\n

An additional analysis looked at what would happen if an entire block of Avcoat fell off. It concluded that a structure below the heat shield made of carbon fiber and titanium would keep the crew cabin intact through re-entry.<\/p>\n\n\n\n

He said NASA engineers were cooperative.<\/p>\n\n\n\n

\u201cWhat I will tell you is that every single time I talked to somebody, they had Columbia on the front of their mind,\u201d he said. \u201cThey were thankful that I pushed them. They were thankful that I doubted them. They were thankful that I forced them to basically prove it.\u201d<\/p>\n\n\n\n

He said that he had also tried to make himself available to any dissenters who might have felt cowed by NASA leadership from raising their concerns, and that he had not heard from any.<\/p>\n\n\n\n

That was very different from the culture he encountered in the aftermath of the loss of Columbia, Dr. Olivas said.<\/p>\n\n\n\n

In January, Mr. Isaacman invited Dr. Olivas and Dr. Camarda to a day of technical presentations where NASA engineers explained their rationale for using the flawed heat shield.<\/p>\n\n\n\n

Dr. Camarda was not convinced. \u201cNASA definitely does not have the data to show that it\u2019s safe,\u201d he said. \u201cI realized that they were using the same flawed thinking and crude analysis tools, similar to Columbia, similar to Challenger.\u201d<\/p>\n\n\n\n

For Dr. Olivas, however, that meeting closed a few remaining concerns, and he sent a text message to Mr. Wiseman, saying he was confident that NASA had done a good job of mitigating the risk for the Artemis II crew.<\/p>\n\n\n\n

\u201cI wouldn\u2019t have told them that, out of respect for them or the family, if I didn\u2019t feel that way,\u201d Dr. Olivas said. \u201cI would never have rubber-stamped it for NASA\u2019s sake.\u201d<\/p>\n\n\n\n