NASA and the China National Space Agency (CNSA) plan to send astronauts to Mars as early as the next decade. Naturally, this ambitious goal requires a great deal of planning, research, and the anticipation and preparation for all potential challenges in advance. Among them, astronaut health and safety are paramount. In addition to the hazards associated with the long transit times – radiation and the effects of long periods in microgravity – there’s the issue of Mars itself. Aside from exposure to elevated radiation levels, Martian gravity is about 38% of Earth’s.

This has the potential to lead to long-term health risks. An international team of researchers is currently studying how Martian gravity will affect a key aspect of human health: skeletal muscle. This muscle, which is the most abundant tissue in the human body (accounting for more than 40% of total body mass), is essential to movement and metabolic health. What’s more, this tissue is especially sensitive, and lower gravity could potentially result in the substantial loss of muscle strength, size, and performance. It is therefore important to determine how this muscle tissue will fare in the Martian environment.

The research team was composed of scientists from the Institute of Medicine at the University of Tsukuba, Tohoku Medical Megabank Organization, the Advanced Research Center for Innovations in Next-GEneration Medicine (INGEM), the Beth Israel Deaconess Medical Center, the Brigham and Women’s Hospital, the Japan Aerospace Exploration Agency’s (JAXA) Space Environment Utilization Center, and multiple universities. The results of their research appeared in the journal Science Advances

*Experiments aboard the International Space Station with mice showed that muscle atrophy can be mitigated and prevented in lower gravity. Credit: NASA/ESA–T. Pesquet*

For their experiment, the team studied how lower gravity affected skeletal muscle tissue in 24 mice sent to JAXA’s Kibo experimental module. These mice were then placed in a JAXA-developed centrifuge device called the Multiple Artificial-gravity Research System (MARS), where they were subjected to four different levels of gravity – microgravity, 0.33 g, 0.67 g, and 1 g – over a 28-day period. The mice were subjected to pre-flight testing before launch at NASA’s Kennedy Space Center, where they were returned for post-flight sampling.

These samples were then examined by scientists at the Metabolism and Muscle Biology Lab in the Department of Nutrition at the University of Rhode Island (URI). As Professor Marie Mortreux, who leads the MMBL, attested in a Rhoby Today news story:

While we can simulate spaceflight on Earth in humans, it’s extremely complicated and costly. We have centrifuges that can be used to temporarily expose humans to certain gravity levels, but it is not homogeneous nor constant. We used gravity levels that were equally separated, to have a better picture of the dose-response of each system to gravity. The test group that was exposed to 0.33g was extremely close to Martian gravity (0.38g). Our findings for that group can be translated into actions to enable Mars exploration.

Mortreux and her team analyzed the weight, strength, and movement of the mice once they were returned to NASA’s Kennedy Space Center. Their analysis showed that 0.33 g mitigated spaceflight-induced muscle atrophy, with full prevention at 0.67 g. They also measured the mice’s forelimb grip strength using Electrical impedance myography (EIM), which showed that 0.67 g was sufficient to maintain muscle performance.

*The research team at Kennedy Space Center confirming the protocol and timing prior to receiving animals for post-flight sampling. Credit: URI*

Their results collectively demonstrated that 0.67 g is a critical threshold for mitigating muscle atrophy caused by prolonged spaceflight. In addition, an analysis of the mice’s blood plasma identified 11 metabolites that showed gravity-dependent changes, suggesting they could serve as potential biomarkers to monitor physiological adaptations in astronauts. This work builds on previous research she performed with Professor Mary Bouxsein (a co-author on the study) at Harvard Medical School.

Whereas Dr. Bouxsein developed the ground-based mouse model of partial gravity in the early 2010s, Montreux developed the rat model of partial gravity at Harvard. As such, the two are well-acquainted with the impact that different gravity levels have on musculoskeletal tissues.

“Since this mission aimed to assess gravity as a continuum, we were perfectly positioned to see if our ground-based results had similar outcomes when reduced mechanical loading was applied in orbit,” said Montreux. “Working with an international team was challenging and exciting. I think my experience working in Italy, France, and the United States prepared me for those big-scale collaborations.”

One takeaway from this study is that future missions to Mars will need to be mindful of mitigating skeletal muscle loss during the long transit between Earth and Mars. For astronauts to maintain mobility, muscle strength, and carry out regular science operations. The same holds true for their physical health upon returning to Earth.

These findings suggest that rotating toruses would be a wise addition to any future spaceflight plans, a la NASA’s Non-Atmospheric Universal Transport Intended for Lengthy United States Exploration (NAUTILUS-X) and similar aspects.

Further Reading: Rhody Today, Science Advances

Riverside County Sheriff Chad Bianco, who is a leading Republican candidate for governor, has seized more than 650,000 ballots from last November’s election and is investigating whether they were fraudulently counted.

“This investigation is simple: Physically count the ballots and compare that result with the total votes recorded,” Bianco said at a news conference Friday.

The unusual probe drew a sharp rebuke from California Atty. Gen. Rob Bonta, who said in a statement Friday that it is “unprecedented in both scope and scale” and appears “not to be based on facts or evidence.”

“There is no indication, anywhere in the United States, of widespread voter fraud,” Bonta said. “Counts, recounts, hand counts, audits, and court cases all support this.”

According to Bonta’s office, Bianco’s department on Feb. 26 seized about 1,000 boxes of ballot materials in Riverside County related to the November election for Proposition 50, which temporarily redrew the state’s congressional districts to favor Democrats in response to partisan redistricting in Republican states, including Texas.

The sheriff said his investigators are looking into allegations by a local citizens group that “did their own audit” and found that the county’s tally was falsely inflated by more than 45,000 votes — a claim that local election officials have refuted.

President Trump, who remains fixated on his 2020 election loss, continues to amplify election conspiracy theories and has repeatedly called for the federal government to “nationalize” state-run elections to counter what he says is widespread fraud.

Bonta and California Secretary of State Shirley Weber, both Democrats, have vowed to fight federal interference that could affect voting in California, including efforts to seize election records, as the FBI recently did in Georgia.

Bianco is an outspoken Trump supporter who said in an endorsement video in 2024 that, after 30 years of putting criminals in jail, he figured it was “time to put a felon in the White House — Trump 2024, baby” — referencing Trump’s conviction by a New York jury for falsifying business records.

Bianco’s investigation, which includes all the ballots cast in Riverside County in November, raises questions about how he would handle the election denialism movement if elected governor.

A poll released last week by UC Berkeley’s Institute of Governmental Studies and co-sponsored by The Times showed Bianco and conservative commentator Steve Hilton leading the crowded field of gubernatorial candidates by slim margins, in a left-leaning state.

Last fall, Prop. 50 passed in Riverside County with 56% of the vote — a margin of more than 82,000 ballots.

A citizens group called the Riverside Election Integrity Team has said it performed an audit finding that 45,896 more ballots were counted than were cast.

In a lengthy February presentation to the Riverside County Board of Supervisors, Registrar of Voters Art Tinoco disputed that figure, saying it was based on a misunderstanding of raw data that had not been fully processed.

The actual discrepancy, Tinoco said, was 103 votes, a variance of 0.016% that was far below what he said was the state’s preferred 2% margin of error for certifying results.

Bianco on Friday said that there “is no acceptable error, small or large, in our elections.”

The sheriff did not name the Riverside Election Integrity Team, but his description of the allegations brought to him by “a group of citizen volunteers” matched theirs.

Bianco said the investigation was “not a recount” for the Prop. 50 contest and was “just as much to prove the election is accurate as it is to show otherwise — we will not know until the count is complete.”

Bonta said his office has “attempted to work cooperatively” with the Sheriff’s Department to understand the basis for the probe. The sheriff, Bonta said, “has delayed, stonewalled, and otherwise refused to work with us in good faith” and failed to provide most of the requested documents.

“We’re concerned that there is not sufficient justification for seizing every ballot that was cast in this very largely populated county,” an official in Bonta’s office said in an interview Friday night.

In a March 4 letter to Bianco, the attorney general cited Bianco’s plan to use sheriff’s department staffers, “who are not trained and have no experience,” to count the ballots.

“Let me be clear: this is unacceptable,” Bonta wrote. “Your decision to seize ballots and begin counting them based on vague, unsubstantiated allegations about irregularities in the November special election results sets a dangerous precedent and will only sow distrust in our elections. You are also flagrantly violating my directives.”

At his news conference Friday, Bianco fired back by calling Bonta “an embarrassment to law enforcement.”

A Riverside County Superior Court judge, Bianco said, has ordered the appointment of a special master to oversee the ballot count.

In a statement Friday, Secretary of State Weber said “the Sheriff’s assertion that his deputies know how to count is admirable. The fact remains that he and his deputies are not elections officials and they do not have expertise in election administration.”