The Orion Heat Shield: How the Orion Space Shuttle gets there, and how to get back to the Moon in the next big test
The atmosphere on Earth will get hotter and more humid when Orion comes back, causing the pressure and temperature in the air to shoot around the vehicle. The air will get so hot that nitrogen and oxygen molecules in the atmosphere will break apart, causing a flow of ionization around Orion that will block communications for several minutes. Joe Bomba worked on developing the heat shield for the flight, and he said it was the most nerve-wracking part of the mission.
The capsule is not carrying astronauts. But one day, it’s supposed to. NASA needs to get Orion home safely to keep on track with its Artemis programme, which aims to eventually return humans to the Moon’s surface.
“The next big test is the heat shield,” Nelson had told CNN in a phone interview Thursday, referring to the barrier designed to protect the Orion capsule from the excruciating physics of reentering the Earth’s atmosphere.
There were some issues with the power flow between the two parts of the vehicle. But most of the journey has gone remarkably well.
Artemis Mission Objectives: Testing the Atmosphere of a Very Thin Ocean for the Return of the Orion Capsule
There is currently one mannequin and a floating snoozing doll staffing the interior of the space station. NASA is not testing any life-support systems on this flight, so temperatures in the crew cabin are a bit chilly, around 10–12 °C.
What is being tested are the effects of space radiation on simulated humans. The capsule contains a pair of fake human torsos, one wearing a vest that protects it against radiation and the other not, but a fake human torso. When Orion flies out of and back into Earth’s magnetic shield, there are detectors on the torsos that measure radiation dosage. The effects of radiation on organisms are being measured. None of this data can be studied until after splashdown.
On the scheduled return date, it is expected to return to Earth off of the coast of San Diego, California. Nujoud Fahoum Merancy, NASA’s chief of exploration mission planning, said during the agency broadcast on 5 December that they were aiming for a very thin slice of atmosphere.
The capsule will jettison part of its cover around 7 kilometres above Earth’s surface and then deploy 11 parachutes in rapid sequence, to slow the capsule for splashdown. The capsule will be pulled on board the well deck by recovery teams on the waiting ship.
“At present, we are on track to have a fully successful Mission with some bonus objectives that we’ve achieved along the way,” said Mike Sarafin, Artemis mission manager, in a press conference on Thursday. He went on to say the main objectives for the day of splashdown are to test Orion’s re-entry and to practice the retrieval of the spacecraft from the ocean.
It allows teams on the ground to better coordinate recovery efforts as a result of skip entry. NASA has a contract with Lockheed for the missions.
Orion will arrive back at our planet at a tremendous speed of 25,000 mph, and by moving through Earth’s atmosphere, it will slow to 325 mph. It will deploy its 11-parachute system beginning at an altitude of about 5 miles, which will slow it to less than 20 mph as it splashes down.
After traveling over three quarters of a millionmiles between the moon and Earth, the mission is near the inner layer of the planet’s atmosphere. It’s set to splash down at 12:40 p.m. ET Sunday in the Pacific Ocean off Mexico’s Baja California. NASA will be airing live coverage of the event on Sunday.
The Orion capsule had been slated to splash down near San Diego, but NASA officials said Thursday that rain, wind and large waves had moved into that area, and it no longer complied with the space agency’s weather criteria.
The mission to set the stage for Orion’s next trip to the Moon: An A-plus for the crew of NASA’s Space Mission
The spacecraft was traveling about 32 times the speed of sound (24,850 miles per hour or nearly 40,000 kilometers per hour) as it hit the air — so fast that compression waves caused the outside of the vehicle to heat to about 5,000 degrees Fahrenheit (2,760 degrees Celsius).
TheDisadvantages of g- Forces in space are mitigated by the fact that the heat and force of reentry is divided into two events.
While there are no astronauts on this test mission — just a few mannequins equipped to gather data and a Snoopy doll — Nelson, the NASA chief, has stressed the importance of demonstrating that the capsule can make a safe return.
It sets the stage for Orion’s next trip, which will be a loop around the Moon with astronauts on board. But that flight, Artemis II, won’t come before 2024 at the earliest.
Orion traveled roughly 1.3 million miles (2 million kilometers) during this mission on a path that swung out to a distant lunar orbit, carrying the capsule farther than any spacecraft designed to carry humans has ever traveled.
A secondary goal of this mission was for Orion’s service module, a cylindrical attachment at the bottom of the spacecraft, to deploy 10 small satellites. After being thrown into the air, four of the satellites failed, including a miniature lunar landers developed in Japan and one of NASA’s own satellites intended to explore interplanetary space.
Images of Earth, the lunar surface and a “Earth rise” were captured by the spaceship on its trip.
“Not an A-plus, simply because we expect things to go wrong. And the good news is that when they do go wrong, NASA knows how to fix them,” Nelson said. But “if I’m a schoolteacher, I would give it an A-plus.”
The Artemis Space Mission: Measuring the Optical Capacitor Temperature and Protecting the Interior of the Reactor Capsule
The capsule is currently floating in the Pacific Ocean, where it will remain for a day while NASA collects more data and conducts some tests. That process, much like the rest of the mission, aims to ensure the Orion spacecraft is ready to fly astronauts.
We are testing the heat that has come and been generated on the capsule. We want to make sure that we characterize how that’s going to affect the interior of the capsule,” NASA flight director Judd Frieling told reporters last week.
During Sunday’s descent, the three parachutes fully inflated, putting the brakes on the spacecraft to slow it from 25,000 miles per hour to just 20 as it hurtled through the atmosphere. The Artemis team is going to be analyzing the capsule’s metrics in detail. “First we’ll be looking at: Did the heat shield do its job in rejecting heat and taking care of the heat pulse such that the internal cabin pressure stays at a moderate mid-70 degrees for astronauts when they’re in there?” says Sarah D’Souza, the deputy systems manager at the NASA Ames Research Center who helped develop Orion’s thermal protection system.
The shield is made of thick blocks of Avcoat which burns off when it gets hotter than 5,000 degrees Fahrenheit, about half the temperature of the sun. She says that they want to be sure that the design will keep humans safe.
The return of Orion to the Moon for the next 50 years: Status of the next Orion mission and a new service module at the Kennedy Space Center
Nelson had a press conference during which he stressed safety and habitability. “This time we go back to the moon to learn to live, to work, to invent, to create, in order to go on out into the cosmos to further explore,” he said. “The plan is to get ready to go with humans to Mars in the late 2030s, and then even further beyond.”
Orion’s return to Earth came 50 years to the day after Eugene Cernan and Harrison Schmitt became the last humans to land on the Moon, on the Apollo 17 mission.
NASA engineers will now analyse data from sensors inside the capsule, as well as other information gathered during the flight and splashdown, to decide what needs tweaking before Artemis II. “This is going to tell us what we need to do, change or modify for the next mission,” says Shannon Walker, a NASA astronaut.
The Artemis II flight’s construction is well underway. The next European-built service module is already at the Kennedy Space Center in Florida and being assembled with the next Orion capsule.