Orion’s heat shield can withstand heat of more than 2,700 degrees

Hearing flight is over. The astronauts’ capsule Orion will enter the Earth’s atmosphere on Saturday a little before three in the morning Finnish time.

The capsule has traveled more than 1.1 million kilometers in space. It still has to endure the last and rather violent part in the Earth’s atmosphere.

In the atmosphere, Orion encounters friction and condensing gases. Only after the heat, a series of brake umbrellas are released from Orion’s upper part, which slow Orion’s movement to less than 30 kilometers per hour.

Orion will dive into the Pacific Ocean on Saturday morning at around 3:07 a.m. Finnish time, if everything goes as planned.

Atmospheric in the upper layers, Orion’s speed is still around 39,000 kilometers per hour. Orion then flies at about 11 kilometers per second.

The condensing gases and the resulting friction raise the temperature outside the capsule to over 2,700 degrees Celsius. Nasan animated from landing you can see how the capsule appears to be on fire.

Orion is turned to meet the atmosphere in a position where the heat shield on its bottom receives atmospheric gases.

The heat shield becomes visible from the bottom of Orion only when the Orion service module that served the astronauts detaches from the habitation module just before the atmosphere.

Before the atmosphere, Orion corrected its orbit one more time. This is how the astronauts ensure that Orion arrives in the expected area in the Pacific Ocean.

Return The country has been secured many times.

Many experts considered the heat shield to be the weakest link in flight. The heat shield is made of a substance named avcoat.

The US space agency Nasa urged it already in the 1960s for the first hearings. Avcoat’s materials transfer the heat shield heat from the surface then.

Current fears are experiences Artemis I:n koelennolta in December 2022.

There were no astronauts on the flight, but Orion’s heat shield had to for the same test as now. Everything didn’t go quite as planned.

Big parts the heat shield broke. However, the temperature inside the capsule did not rise.

Nasa after the flight of Orion I thoroughly analyzed the risks himself and with external forces.

In wind tunnels and other tests, it was found that too many gases remained inside the heat shield.

The protection did not “breathe” enough. So Nasa fixed and updated the structure of avcoat in countless tests in 2023 and 2024.

Therefore, Nasa is now sure that the temperature inside Orion will not rise at all this time either. .

Orion does not plunge directly into the atmosphere like the capsules of the Apollo space flights more than 50 years ago.

Instead of a direct plunge, Orion briefly pops upwards, out of the atmosphere.

The ship moves for a while like a flat stone thrown into a pond, which pops up from the surface of the water.

With the help of popping, Orion balances the heat load. In addition, air traffic control can delimit the area of ​​the Pacific Ocean where Orion is to land.

Radio connection to air traffic control is interrupted during the return for approximately 3–6 minutes.

Radio communication is based on electromagnetic waves that travel in the atmosphere. Radio signals cannot pass through the plasma layer.

Near the earth and the sea, the radio connection to Orion is restored.

Soon Orion and its brake shadows will be visible in the sky. Seeing the capsule and its colorful brake umbrellas is always a place of joy for the recipients.

This joy was always palpable when the astronauts returned to Earth from the Apollo missions in 1968–1972.

US Navy ships are waiting for Orion less than a hundred kilometers off the coast of California, near San Diego.

of the United States naval vessel John P. Murtha first picks up astronauts on deck with helicopters. They first have to undergo a medical examination.

Soon, Orion, a capsule that has shriveled a little in the heat, will also be lifted onto the deck.

Despite the bumps of the rest of the way, the capsule will find a place of honor. It will be placed in one of the numerous aviation museums in the United States.