Crew-13 Lifts Off as Gut Bacteria Study Explains Why Astronauts Get Constipated

NASA astronauts Jessica Watkins and Luke Delaney, Canadian Space Agency astronaut Joshua Kutryk and Roscosmos cosmonaut Sergey Teteryatnikov lifted off aboard SpaceX's Crew Dragon at 11:10 a.m. local time from Cape Canaveral, Florida, according to Bloomberg. The capsule, named Grace, is on its second flight after the Axiom-4 mission, NASASpaceflight reported on 29 September. It was scheduled to dock at the ISS Harmony forward port at 8:00 p.m. EDT the same day.

The launch is routine. The science riding with the crew, and the science already coming back from orbit, are not.

On 28 September, ScienceDaily reported findings from the University of Copenhagen, conducted with NASA, that analysed blood samples from 52 astronauts who spent months aboard the space station. The researchers found signs that gut bacteria begin fermenting protein to a greater extent than usual within weeks of arrival. That shift persisted until the astronauts returned to Earth. Protein fermentation happens when intestinal bacteria run out of dietary fibre and turn to protein instead. It is not unique to spaceflight, but the timing and persistence in orbit are.

"The lack of gravity in space probably causes food to move more slowly through the intestine, and this fits with the fact that we are seeing signs of increased protein fermentation. This may also help explain constipation in astronauts," said Henrik Roager, an associate professor at the university's Department of Nutrition, Exercise and Sports and a co-author of the study.

The mechanism matters beyond discomfort. Lars Ove Dragsted, the study's senior author, warned that products of protein fermentation are often associated with negative health consequences. These include kidney damage, potential effects on mood and reduced ability to focus. As space agencies prepare for longer missions to the Moon and eventually Mars, those side effects stop being a minor operational annoyance and start being a mission risk.

What the crew is flying into

Crew-13 will join Expedition 75, which has already been busy. NASASpaceflight reported on 24 September that an EVA on 1 September, US EVA-99, lasted six hours and 49 minutes. During that spacewalk, astronauts installed a retroreflector on the Harmony module and swapped a high-definition camera on the station's truss. One crew member experienced shoulder mobility issues during the spacewalk when a joint heater harness caught in the joint. The suits are Shuttle-era, and the report notes that various issues have delayed station spacewalks and forced repairs.

Work aboard the station continues on other fronts, including preparations for iROSA solar array installation on two power channels. The mission is not just a crew rotation. It is a science platform with a maintenance backlog.

Ground-based research is pushing in the same direction. Microsoft Research published a blog on 30 September describing a machine learning pipeline that forecasts space weather risk across 66,935 substations in the continental United States. The system combines solar wind observations, forecasts of the Auroral Electrojet and Disturbance Storm Time indices, and local geology to produce location-specific risk estimates 30 to 60 minutes ahead of impact. It detected nearly 80 percent of major space-weather events during the evaluation period.

That kind of warning matters because extreme space weather can induce currents in transmission networks that damage equipment. The May 2024 geomagnetic storm degraded GPS accuracy and satellite operations, with knock-on effects for farming in North America and Europe. The pipeline is a research prototype, not an operational service. But it is an example of the same logic driving orbital science: use local data to make decisions faster.

Hardware and money follow

The commercial side of space science is moving too. Varda, a California startup, raised a $251 million Series D to advance pharmaceutical manufacturing in space, Endpoints News reported on 30 September. The company is one of a small group betting that microgravity can produce drug formulations that are difficult or impossible to make on Earth.

On 1 October, TechCrunch reported that Satlyt, founded by a former Google and SpaceX product manager, raised an $8 million seed round to run AI on satellites. The company is not building spacecraft. It is building software to let satellites share computing jobs, and it flew Google DeepMind's Gemma model on a Momentus spacecraft earlier this year. According to TechCrunch, that test cut the size of a transmission about onboard software errors by more than 60 percent. Satlyt's software is set to launch on a SpaceX rocket alongside the first prototype for Google's Project Suncatcher. CNBC reported on 1 October that the prototype is scheduled to fly on the Transporter-18 mission from Vandenberg.

The economics of that push remain unsettled. At the AI Infra Summit in Santa Clara in mid-September, Viasat chief data and AI officer Sumeet Singh said launch costs of $2,500 to $3,000 per kilogram would need to fall to roughly $200 to $500 per kilogram for orbital data centers to make financial sense, according to Data Center Knowledge. Cowboy Space Corp. COO Joe Yaffe said reliance on a single dominant launch provider has become a bottleneck in its own right. Deepak Sachdeva, CIO of the US Air Force, said the technology is not yet ready for operational adoption at scale. "From a consumer-to-consumer level, I think it's ready. But from an operational need, which is global in its nature, I think there is still some work to be done," he said.

Europe is trying to build its own position. At the Pretzl Connect 2026 press event, Kate Underhill, future space transportation propulsion architect at the European Space Agency, told EE Times that space systems typically operate at least 10 years behind consumer electronics and that component buying is constrained by minimum order quantities. She cited an ESA attempt to order 20 laser diodes from a German company that required a minimum of 10,000 units. Underhill also noted that any US component on a satellite triggers ITAR compliance, a persistent hurdle for European manufacturers trying to build ITAR-free spacecraft.

Lithuania's Blackswan Space closed a €2.5 million round led by Iron Wolf Capital, Tech.eu reported on 30 September, bringing total funding to €3.2 million. The company is taking its autonomous navigation payload into orbit in 2027 and aims to support Europe's first in-space refuelling mission a year later.

Back in low Earth orbit, Russia's next-generation crewed spacecraft remains a drawing-board project with a moving name. Ars Technica reported on 30 September that Roscosmos chief executive Dmitry Bakanov has dropped the "Eagle" name favoured by his predecessor. Parachute drop tests are due this autumn in the Far East, with emergency rescue mode tests later this year and maximum dynamic pressure tests in 2027. A debut crewed launch is currently stated as 2028 or 2029, likely on an Angara A5M rocket. Four years ago, President Vladimir Putin spoke confidently about the same spacecraft and the resumption of Russia's lunar programme. The date has moved since.

None of this changes the fact that the most concrete science result this week came from 52 blood samples and a question about constipation. It is a reminder that human spaceflight is still, in large part, a medical experiment with a launch window.