Monday, November 29, 2021

Health risks of space tourism: Is it responsible to send humans to Mars?




Sat, November 27, 2021

About 60 years ago, humans acquired the technological ability to travel to space. By now, science fiction franchises like "Star Trek" inspired entrepreneurs such as Jeff Bezos to translate their wealth into enterprises of space tourism. Bezos recently expressed the desire to send 1 trillion humans into space in the distant future, because Earth will not be able to accommodate all of them. Unfortunately, humans were not selected by Darwinian evolution to survive for long periods of time in space.

The hazards from energetic particles have been known since the early days of space exploration. On Earth, humans are protected from these charged particles, which originate from the Sun and our Milky Way galaxy. Earth is shielded by its magnetic field and atmosphere. Mars has no magnetic field or atmosphere to shield humans from the damage caused by cosmic radiation.


Human astronauts outside the Earth's magnetic "womb" get zapped by solar energetic particles, mostly during sporadic solar flares that last from minutes to hours. Such flares are prominent when the sun is "active", namely during solar maxima in its 11-year cycle of surface activity. The most energetic solar particles can be deadly. Humans have a better chance of survival on Mars when the Sun is least active, namely during solar minima.

But even if humans avoid the radiation from the Sun, there is an additional risk from Galactic cosmic rays. During a space journey that lasts more than three years, these Galactic particles would be life-threatening as well. The potential cumulative effects from space radiation must be studied thoroughly before sending humans for missions that last more than a few years. Protection could potentially be offered in deep caves under the Lunar or Martian surface.

Our solar system receives only a fraction of the Galactic cosmic rays, thanks to magnetic shielding by the so-called heliosphere, located at a hundred times the Earth-Sun separation, where the Solar wind meets the interstellar medium. The heliosphere was traversed by NASA's Voyager 1 space craft in 2012 and by Voyager 2 in 2018. The instruments onboard these missions revealed that the heliosphere blocks about three-fourths of the galactic cosmic rays.

As of now, scientists are unable to forecast reliably the levels of Galactic cosmic radiation throughout the solar system. The very region that shields the galactic radiation is the one that is least understood.

Space missions, such as Voyager, New Horizons, Interstellar Boundary Explorer and Cassini-Huygens, revealed the frontal extent of the heliosphere and the incoming stream of hydrogen atoms from the galaxy, but the fundamental features of the heliosphere remain unknown. In particular, the global shape and distribution of cosmic radiation are uncertain.

Before sending humans to long space journeys, more resources should be allocated to studying the radiation filtered by the heliosphere. Better understanding of our own environment will also help us forecast whether life exists on Earth-like planets around other stars.

Some habitable planets are protected from energetic particles by their atmosphere and magnetic field, as well as by the analog of our heliosphere, labeled "astrosphere" for other stars. We currently know very little about astrospheres in general. Studies of the heliosphere would help us understand the critical mechanisms that controls the properties and shielding of energetic particles that pose a threat to extraterrestrial life.

The human body is fragile. Humans cannot safely venture to long journeys beyond our immediate vicinity near Earth. Before sending human-astronauts to long expeditions we must ensure that we are not sending them to their death. Ahead of dreaming about a large human population on Mars, as advocated by Elon Musk, we must understand the radiation environment throughout the solar system.

A safe bet, for the time being, is to send our technological kids, in the form of robots like the Perseverance rover or futuristic AI-astronauts. Artificially-made hardware is manufactured to be far more resilient to damage by energetic particles than the human body. And we should be proud of launching our technological products to space as we are of sending our biological kids to explore the world.

Merav Opher is a professor in the Astronomy Department at Boston University. She is currently the William Bentinck-Smith fellow at the Harvard Radcliffe Institute. She is the leading SHIELD, a NASA DRIVE Science as principal investigator. SHIELD is a multi-institutional effort with more than 45 leading scientists across a dozen institutions. She was the chair-elect of the APS Topical Group in Plasma Astrophysics; member of the Decadal Survey in Space Physics of Solar and Heliospheric Panel and the last three NASA Heliophysics Mission Senior Review Panels.

Avi Loeb is a professor of science at Harvard University, head of the Galileo Project, founding director of Harvard University's - Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University from 2011-2020. He chairs the advisory board for the Breakthrough Starshot project and is a former member of the President's Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of "Extraterrestrial: The First Sign of Intelligent Life Beyond Earth" and a co-author of the textbook "Life in the Cosmos."




Why farts in space are dangerous: For a man, it’s a minor odor, but for mankind, it’s a massive smell.

BY ALANIS HAYAL ON NOVEMBER 27, 2021


NASA astronauts have shown that something that most of us do without thinking at least a dozen times a day could endanger astronauts in orbit.

Every day, the average person farts up to 15 times.

It’s not a major concern if you work outside, but it’s more difficult if you work in an office or shop, and it may be fatal if you’re an astronaut.

It is, to begin with, rather antisocial.

Mike Massimino was a member of the Columbia crew in 2002 on a mission to repair the Hubble Space Telescope, and he returned to space in 2009 aboard Columbia’s sister ship Atlantis.

Unpleasant bodily scents do not disappear in the same manner they do on Earth, he noted.

Mike explained to Gizmodo, “Farts have a tendency to linger.””

The airflow isn’t as as strong as it is on Earth.

You need to add airflow to get rid of pollutants and carbon dioxide.”

He argues that astronauts’ digestive systems don’t perform as effectively in zero gravity and that they become “a little choked up.”

When an astronaut smells a fart coming on, they normally want to get to the lavatory, where there is at least a little more ventilation to help break up the stench.

“It’s probably comparable to how it works on Earth,” he continued, “either you do it in private or you make people upset at you.”

Mike cautions that simply having a good time on the International Space Station could lead to “crew conflict.”

“If you fart, the gas stays right there,” says Derrick Pitts of The Franklin Institute in Philadelphia, a space expert.

It doesn’t appear to be getting any better.

“If you fart in zero G, you have a serious problem,” he adds.

Clayton C Anderson, a NASA astronaut who spent 152 days onboard the International Space Station in 2007, acknowledged to receiving complaints about the scents he left laying around the station.

“Just ask a couple members of my staff! So much so that one of my spacewalking (EVA) teammates – who shall remain nameless – would frequently give me unambiguous verbal indicators that my gas was fragrant in a bad sense “On Quora, he admitted it.

Farts in space, on the other hand, imperil more than just a spacecraft full of disgruntled people.

Many of the gases produced naturally by our digestive systems are combustible, therefore a spacecraft fire is extremely deadly.

Five planned space stations for tourists and astronauts

Human population in space could rise in future, as private companies and space agencies look to set up more space stations

In October, Jeff Bezos’ Blue Origin announced plans to build a private space station in Earth orbit, called Orbital Reef. Photo: Blue Origin

There has been a continuous presence of humans in space since 2000, when the International Space Station became operational.

Now, as the floating laboratory gets closer to its inevitable retirement, there are questions around what would replace it.

Private companies are looking to commercialise low Earth orbit, with space stations that would welcome tourists, researchers and astronauts.

Meanwhile, government space agencies have increased their focus on the Moon, with Nasa, China and Russia looking to build a lunar base.

The National highlights some of the space stations that were announced by private companies and governments.

Orbital Reef

In October, Jeff Bezos’ Blue Origin announced plans to build a private space station in Earth orbit, called Orbital Reef.

The space tourism company hopes to build a “mixed-use business park” and is promising access to media, tourists, astronauts and researchers.

It is going to be a commercially developed, owned and operated low-Earth orbit station, built in partnership with Boeing, Redwire Space, Sierra Space, Genesis Engineering Solutions and Arizona State University.

“For over sixty years, Nasa and other space agencies have developed orbital space flight and space habitation, setting us up for commercial business to take off in this decade,” Brent Sherwood from Blue Origin said at the time of the announcement.

“We will expand access, lower the cost, and provide all the services and amenities needed to normalise space flight. A vibrant business ecosystem will grow in low Earth orbit, generating new discoveries, new products, new entertainments, and global awareness.”

The plan is to begin operations within this decade, after launching a power system, core module, life habitat and a science module. This would enable the station to host up to 10 people, initially.

Genesis Engineering Solution, an aerospace and technology provider, would supply single-person spacecraft on the station, allowing those on board to go on spacewalks.

Starlab

Less than a week before the Orbital Reef announcement, Nanoracks had unveiled plans of a commercial space station that would aid efforts in scientific research and tourism.

Founded in 2009, Nanoracks is a commercial space company that has sent more than 1,300 research payloads and small satellites to the ISS.

It would include a large inflatable habitat, designed and built by Lockheed Martin, a metallic docking node, a power and propulsion element, a robotic arm for servicing cargo and payloads, a laboratory to host research, science and manufacturing capabilities.Now, it has gone into partnership with Voyager Space, a company into space exploration, and aerospace firm Lockheed Martin to build its first free-flying space station, called Starlab.

Up to four astronauts would be able to occupy the station. The company hopes to begin operations by 2027.

Axiom Station

Space infrastructure company Axiom is planning to launch a commercial module to the ISS that would become its own independent station once the ISS retires.

The station will offer access to researchers, astronauts and tourists. By 2028, the Axiom modules would be ready to detach from the ISS, allowing microgravity research, manufacturing and life support testing.

The first two modules that will be launched would each have four crew quarters.

Axiom also plans to launch the first paying crew to the ISS next year.

Lunar Gateway

Nasa has ambitious plans to build a station in the Moon’s orbit.

Called the Lunar Gateway, the station would host astronauts before they land on the lunar surface, using a human landing system.

It is part of the space agency’s deep space exploration plans, which includes building a sustainable human presence on the Moon under the Artemis programme, and sending astronauts to Mars from there in future.

Plans for the Gateway includes a Habitation and Logistic Outpost, an initial crew cabin that would offer astronauts basic life support and space to prepare for their trip to the lunar surface.

Nasa chose SpaceX to deliver cargo and other supplies to the station.

China-Russia lunar station

Earlier this year, China and Russia unveiled plans to build the International Lunar Research Station.

The proposal involves sending several Chinese and Russian missions to the Moon over a 15-year period.

Rendering of International Lunar Research Station.

Five facilities and nine modules are planned for the station, intended to support long and short missions to the Moon's surface and orbit.

The plan includes a facility that would support round-trip transfer between Earth and the Moon, lunar orbiting, soft landing, take-off on lunar surface and re-entry to Earth.

A long-term support facility on the surface will include a command centre, energy and supply modules, and thermal management.

Designs also include a “hopping robot” and smart mini-rovers that would move around the surface of the Moon.

The plan is to launch six missions by 2025 during phase one of the station’s construction.

It was reported that China is also working on a lander for human Moon missions.

China has astronauts in low Earth orbit who live on Tianhe, the core cabin module of its Tiangong space station.

Updated: November 26th 2021, 9:00 PM













No comments: