Rocket Design: Some Things Never Change
Despite the passage of half a century, the core principles behind rocket design have remained largely unchanged. According to Adam Gilmour, CEO of Gilmour Space Technologies, the fundamental concepts of rockets haven’t evolved significantly over the last 70 years. “No one’s come up with a warp-drive or an anti-gravity drive or anything like that,” he explained.
The Saturn V rocket, one of NASA’s most iconic creations, was used for all Apollo missions and stood at an impressive 111 meters tall. It relied on a single large rocket for launch, but during the Space Shuttle era, NASA shifted to using three rocket engines. The Artemis missions are following a similar approach, with the Space Launch System (SLS) utilizing one main rocket along with two booster rockets on either side.
Interestingly, Artemis II is using components that have already been to space on previous shuttle missions, including casings on the booster rockets and repurposed space shuttle engines. The fuel used in these rockets also remains consistent with what was used in the Apollo era. “An extensive amount of R&D was done in the 50s, 60s, and 70s to look at any and every type of fuel you could possibly combine, to see which one worked the best,” Mr. Gilmour said. “The reality is the fuel that has the best performance is hydrogen and oxygen. They’re very simple products.”
Computing Power: From Apollo to Artemis
One of the most critical components of the original Apollo missions was the spacecraft’s digital computer and the hand-coded software that made the flights possible. The Apollo Guidance Computer was capable of handling many aspects of piloting, including guidance, navigation, and control. However, its capabilities were limited compared to modern devices. “They went all the way to the Moon and back with a computer that had a hundredth or a thousandth of the capability of your phone,” Mr. Gilmour said.
The Apollo Guidance Computer had only 74 kilobytes of memory and about 4Kb of RAM. Despite this, the astronauts found workarounds to complete their missions. During the Apollo 8 mission, astronaut Jim Lovell entered incorrect code into the guidance computer, requiring him to use an onboard sextant to determine the spacecraft’s location manually.
Today, the computing power available is vastly superior. The Command and Data Handling Console on the Orion spacecraft can process data 20,000 times faster than Apollo’s systems and has 128,000 times more memory. However, the real nerve center of the operation remains the same: the Christopher C. Kraft Jr. Mission Control Center, known as Houston, has been in the same building at the Johnson Space Center since 1965.
A Giant Leap for Toilets
The toilet situation during the Apollo era was far from ideal. Astronauts had to use urine collection bags, which required them to roll on a cuff. This method worked for male astronauts but was not suitable for female crew members. For feces, plastic bags were used, and there were even incidents like the one on Apollo 10, where a “turd” floated through the cabin.
The first space toilet was introduced on Russia’s Soyuz spacecraft in 1967, but it was uncomfortable and rarely used. Today, the Universal Waste Management System aboard the Orion spacecraft is much more advanced, resembling a high-tech camp toilet. It includes features for both male and female anatomy and uses suction to manage waste in zero gravity.
However, even the most advanced toilets can encounter issues. The Artemis II crew experienced a toilet problem after launch, but it has since been resolved. If the toilet fails, they may have to revert to the Apollo-era methods.
Getting Back to Earth
Returning to Earth is one of the most physically demanding parts of a space mission. The Orion spacecraft is equipped with a large heat shield made from Avcoat, a material used in the original Apollo missions. However, some experts believe the slight changes in the new version could cause serious issues during re-entry.
Apollo spacecraft re-entered Earth’s atmosphere at around 35,000 km/h—10 times faster than a bullet. The Artemis II mission will see the spacecraft return at an even higher speed, approximately 40,000 km/h, making it the fastest re-entry ever attempted with astronauts on board.
To avoid potential problems, the “skip-entry” maneuver used during Artemis I has been replaced with a more direct re-entry pathway. Once back on Earth, the Artemis II astronauts won’t need to undergo a 21-day quarantine due to fears of lunar pathogens. In 1969, the Apollo 11 astronauts were quarantined for a week in a converted Airstream caravan before being moved to a specialized facility. They found the conditions oppressive, with Michael Collins famously saying, “I want out.”
For more updates on the Artemis II mission, tune in to the podcast Science Friction: Artemis Explained from ABC Radio National.
