Space travel has always tested the human body by the effects of the new conditions of altered gravity on biological systems. It has long been known that continuous exposure to microgravity conditions human physiology and causes effects that compromise muscular, sensory, endocrine and cardiovascular functions. But is it also risky to be exposed to altered gravity for short periods of time?

Now, a paper published in the journal Acta Astronautica examines the effects of microgravity generated by a parabolic flight on the human immune system. After a short exposure to altered gravity, there were no significant changes in the defensive capacity of blood cells in the volunteers who took part in the study.

NASA is on track to launch a crewed mission around the Moon in November of next year after a successful unmanned test flight, the US space agency said Tuesday.

NASA officials provided an update on the Artemis program, which aims to return humans to the Moon for the first time since the historic Apollo missions ended in 1972.

The first Artemis mission wrapped up in December with an uncrewed Orion capsule returning safely to Earth after a more than 25-day journey around the Moon.

Artemis 2, scheduled to take place in late November 2024, will take a four-person crew around the Moon but without landing on it.

"We're looking forward to that crew flying on Artemis 2," NASA associate administrator Jim Free told reporters. "Right now there's nothing holding us up based on what we learned on Artemis 1."

NASA is to reveal the members of the Artemis 2 crew later this year. All that is known so far is that one of them will be a Canadian.

The second astronaut from the United Arab Emirates is still adjusting to life off the planet, after rocketing to the International Space Station last week.

Johns Hopkins Medicine researchers are collaborating with NASA to send human heart "tissue-on-a-chip" specimens into space as early as March. The project is designed to monitor the tissue for changes in heart muscle cells' mitochondria (their power supply) and ability to contract in low-gravity conditions.

The tissue samples will be launched into space aboard SpaceX CRS-27, a resupply mission to the International Space Station, slated for liftoff no earlier than Tuesday, March 14, at NASA's Kennedy Space Center in Florida.

Astronauts on board during the mission will also introduce three FDA-approved medicines to the samples in efforts to prevent heart cell changes known or suspected to occur in those undertaking long-duration spaceflights.