Hypatia astronauts suggest using menstrual blood as fertilizer for plants on Mars 

The all-female crew of the Hypatia II mission has concluded that menstrual blood could be a useful natural fertilizer for growing food in greenhouses on Mars. 

This is one of the key findings from a two-week simulated space mission in the Utah desert, which studied how Mars exploration would affect women's bodies.  

The 'astronauts' of Hypatia II are two aerospace engineers, two mathematicians, a geologist, a mechanical engineer, a telecommunications engineer, a nanotechnologist and a publicist, who conducted the research during the experiment.  

The team also found that using a menstrual cup is compatible with space missions and could even be an advantage. They also found that the participating women kept their body weight and strength, though their muscle mass decreased. 

The seven scientists lived for two weeks at the Mars Desert Research Station (MDRS) in Utah, USA. They faced physical challenges and had limited access to food and water, similar to what would happen on Mars. 

Engineer Helena Arias said their body measurements showed a loss in muscle mass after the mission. However, weight and strength stayed the same thanks to daily 30-minute workouts and proper nutrition. 

Besides survival and scientific tasks, the crew also studied gender bias in space exploration. One focus was on managing menstrual cycles. "Ours is the first crew of female astronauts to use a menstrual cup in a simulated mission," they said.  

Their goal was to highlight the natural female cycle and "reject the masculinized view of space exploration." They said menstruation and the use of menstrual cups are "compatible" with these types of missions and may "even add value." 

Using menstrual blood as fertilizer 

Geologist Marina Martínez explained that menstrual blood from two crew members was used as a natural fertilizer for plants as part of a project with Barcelona's Hospital Sant Pau. "Until now, no scientific study has really checked if menstrual blood is an effective natural fertilizer," said Martínez. 

Initial tests showed that mixing menstrual blood with water helped legume plants grow faster and develop more roots. Martínez, who managed the mission's greenhouse, said that in a mission where most food is dehydrated, fresh green shoots are "very valuable." 

Physically demanding work 

The Hypatia II mission included many extravehicular activities, with 22 trips outside the base (two per day, lasting three to four hours). Four of these were to install a special device called a trihedron outside the base, in collaboration with the European Space Agency (ESA). This device helps calibrate satellites that orbit Earth. 

The astronauts designed and built the trihedron, then fixed it to a concrete patch outside using a drill. The device will be used by future crews and research teams to improve satellite data for weather, ocean, and climate studies. This type of calibration helps confirm things like the sea level rising by five millimeters a year and Arctic ice shrinking by over 12% per decade. 

New research sreas 

The mission also included new research in geology. The team collected samples from 12 sites in Utah using an X-ray fluorescence gun, which helped them choose quality samples and understand the local geological history, which is similar to Mars. 

They found a mineral with 40% strontium, a sign of liquid water in dry environments like Utah. Although strontium hasn't yet been found on Mars, the crew said that if it ever is, it would confirm the presence of rivers in the past. Other water-related minerals, like gypsum and silica, have been found both on Mars and in Utah. 

The team also worked on sustainability. Communication officer Jennifer García Carrizo said they saved over 800 kilowatts of energy, enough to power a house for nearly three months. Each crew member used just 10.5 liters of water per day, much less than the 105 liters used by someone in Barcelona.  

In total, they saved over 10,500 liters of water, equal to more than 100 seven-minute showers. They also reduced carbon emissions by over 600 kilograms, equal to driving over 3,600 kilometers, and avoided producing almost 80 kilograms of waste, the weight of nearly 4,000 half-liter plastic bottles. 

One of the project's aims is to inspire young girls to pursue science. Team artist Anna Bach wrote and illustrated a children's book called "The Mars Explorers", about the group’s adventures in the Mars camp. 

New Mission in 2027 

The Hypatia Mares association announced a new mission in 2027, supported by the La Caixa Foundation. It will be led by aerospace engineer Estela Blay from the Institute of Space Studies of Catalonia (IEEC). Crew members will include Laura González and Lucía Matamoros, who were reserves for Hypatia II. 

The search for up to six new women began Monday on the Hypatia Mares website. "We’ll try to find different profiles to create a multidisciplinary and intergenerational crew of women who want to show that science is the future so new generations have role models," said Blay. 

Candidates can submit their research or outreach projects about space exploration until May 31. The location of the new mission hasn’t been decided yet, it could focus on Mars again or shift to the Moon. The new crew will be announced in fall 2025.