We're fortunate to live on Earth, a place with atmospheric protection, moderate temperatures, and what we consider a "relatively normal" level of gravity. Life might not be as comfortable elsewhere with different conditions.
Take space, for instance. There's virtually no gravity in space, causing human bones to weaken and even making it hard to tell if you're hungry because your body doesn't sense the usual cues without gravity. So, zero gravity isn't exactly human-friendly. However, it doesn't mean everything goes haywire in weightlessness. In fact, some things become even more powerful.
Protein crystals form under microgravity conditions in the Kibo module of the space station. Image source: Japan Aerospace Exploration Agency (JAXA)
Companies are racing to develop a unique space-derived glass fiber: ZBLAN. Image source: Official website of the US National Laboratory on the International Space Station
Less defective fiber materials
"Super pure fluoride" (ZBLAN) is a special fiber optic material mainly used in medical products, fiber lasers, and near-infrared fields, and has long been considered an outstanding product in the space manufacturing industry.
According to research by NASA, ZBLAN manufactured in microgravity environments is smoother and clearer than those manufactured under Earth's gravity, and may also prevent defects.
According to the latest news from Space News on February 23, the US Silicon Valley startup "Defect Photonics" produced over 5 kilometers of ZBLAN on the International Space Station (ISS) within two weeks. Their goal is to use ZBLAN to manufacture submarine cables. ZBLAN is much more transparent than silica (the fiber glass in underwater communication cables), and the increased transparency means less signal attenuation. In the future, the company plans to continue manufacturing more preforms in space using microgravity.
Stronger microgravity cement
Cement is the most basic material needed for building houses. According to a paper published in the "Journal of Astronomy" in 2019, astronauts aboard the ISS successfully mixed cement in a microgravity environment for the first time. The results were unexpected: the microstructure of the cement samples processed on the space station changed significantly compared to those processed on Earth.
Researchers sent the basic components of cement to the ISS, then mixed water and the main mineral component of cement, tricalcium silicate, in a bag, and let it harden for 42 days through hydration. The results showed that the cement mixed in microgravity did indeed cure like it does on Earth.
The cement on Earth has a layered structure due to gravity, while the ISS lacks gravity, so the density of the mixed cement is very uniform, which means space cement is stronger. At the same time, space cement has more voids, and the porosity significantly affects the performance of cement materials. This result marks an important step towards the goal of "building houses on the moon" for humanity.
"Regenerated" flatworms with stronger performance
The first batch of animals sent into space was not the stray dog named "Laika", but a group of fruit flies. On February 20, 1947, fruit flies rode a V-2 rocket into space, then returned and survived. Scientists sought to explore the effects of space radiation on organisms, so they chose fruit flies genetically similar to humans. Today, simple invertebrates are still sent into space aboard rockets just to see what happens.
According to the official website of the ISS US National Laboratory, on January 10, 2015, 15 flatworms were launched into space via the SpaceX-5 commercial resupply mission. These flatworms had their heads and tails cut off, placed in a tube half filled with air and half with water, and then spent 5 weeks on the ISS. Flatworms are animals with strong limb regeneration abilities. If you cut a flatworm in half at its waist, the severed parts can develop into two complete individuals. However, upon returning to Earth, they underwent a miraculous change and grew two heads directly from one trunk.
Frightened scientists cut off both heads of the flatworms, only to find that two heads grew back again. Space permanently changed these flatworms. Scientists hope to understand the effects of the space environment on the human body by studying the changes in flatworms before and after their journey into space.
Stronger "space proteins" with enhanced performance
When drugs are manufactured in space, their performance also becomes stronger.
Protein crystal growth experiments are important projects in space flight activities. On the ground, it is difficult to produce single, pure protein crystals due to gravity, while the unique microgravity environment in space allows proteins to stretch and bind more fully, filter out impurities better, and ultimately form nanoscale, high-purity, and highly uniform protein crystals.
NASA has been committed to protein crystal growth experiments on the ISS. As of 2021, pharmaceutical companies and academic researchers have conducted more than 500 protein crystal growth experiments on the ISS, making it the largest single category experiment conducted on the space station to date. They have modified protein crystals, facilitating the discovery of a new drug for treating tuberculosis and finding new mechanisms for delivering anticancer drugs.
The Japan Aerospace Exploration Agency (JAXA) is also one of the institutions active in microgravity protein crystal growth research. One study examined the crystal structure of a protein associated with Duchenne muscular dystrophy. Microgravity crystallization research has produced several promising compounds, including one molecule called TAS-205.
In addition, large pharmaceutical companies are increasingly recognizing the benefits of crystal growth in microgravity for drug development. For example, Merck's PD-1 drug originated from protein purification and crystallization experiments on the ISS. As early as 2019, Merck published a study reporting that protein crystallization under microgravity conditions enhanced the efficacy of its cancer drug Keytruda. According to the latest news in February this year, sales of the drug in 2023 exceeded Remicade, making it the newly crowned "drug king" globally.
