Fwd: Manned mission to Mars an unlikely proposition

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From: "Gary Johnson" <gjohnson144@comcast.net>
Date: September 22, 2013 9:41:31 AM GMT-06:00
To: "Gary Johnson" <gjohnson144@comcast.net>
Subject: FW: Manned mission to Mars an unlikely proposition

 

 

      Sep. 22, 2013 7:54 AM   |  

Manned mission to Mars an unlikely proposition

Current limits on exposure to radiation make chances of flight in near future pretty slim

Why can't we go to Mars?: NASA and Congress keeps saying the ultimate goal is a human mission to Mars, the Red Planet is beckoning. But the reality is: the U.S. can't send humans to Mars. Why? FLORIDA TODAY's Todd Havlorson reports. By Caroline Perez. Posted Sept. 22, 2013.

Written by
Todd Halvorson
FLORIDA TODAY

Zoom

Mars / NASA

Days in space

A look at a list of explorers with the most time in space indicates that space radiation exposure limits on Russian cosmonauts are less restrictive than those imposed on American astronauts. 

World Ranking

Sergei Krikalev (1)	803 days	6 flights
Alexander Kaleri (2)	769 days	5 flights
Sergei Andeyev (3)	749 days	3 flights
Gennady Padalka (4)	710 days	4 flights
Valery Polyakov (5)	679 days	2 flights
Anatoly Solovyev (6)	651 days	5 flights
Yuri Malenchenko (7)	641 days	5 flights
Viktor Afanasyev (8)	556 days	4 flights
Yury Usachev (9)	553 days	4 flights
Musa Manarov (10)	541 days	2 flights

 

Top U.S. astronauts

Michael Fincke (20)	382 days	3 flights
Peggy Whitson (22)	376 days	2 flights
Michael Foale (24)	374 days	6 flights
Jeffrey Williams (29)	363 days	3 flights

Looking for The Best

Wanted: A U.S. astronaut to make a historic flight to Mars. Must tolerate confined spaces, isolation and a hazardous work environment for up to 30 months. The payoff: an historic legacy.

Most people can't measure up.

Through extensive psychological testing, researchers have found that people who are highly goal-oriented have an elevated need for achievement and can maintain good interpersonal relationships are better suited for the rigors of isolation and confinement.

So those are the kinds of people NASA looks for.
But the risk of developing behavioral problems or psychological conditions increases, the longer the mission.

U.S. astronauts who travel to the International Space Station usually stay for up to six months. But a round-trip mission to Mars will take future space travelers an estimated 2½years.

Studies have shown that crew members on long-term space flight simulations suffer from hypokinesis, an increase in sedentary activity during waking hours, and frequent sleep disturbances, which suggests a disruption of the sleep-wake cycle.

However, the psychological effects of long-term space travel aren't all bad. U.S. astronaut and Navy Cmdr. Chris Cassidy told Florida Tech students in a space-to-ground interview arranged by FLORIDA TODAY, he's having the time of his life on his mission stay.

"The best thing is not the fun things you do, but the people you experience them with," he said. "The times that we had will be memories in our lives forever."

By Jennifer Nessmith, for FLORIDA TODAY

About the Project

From a virtual visit to the International Space Station via uplink from Kennedy Space Center to an onsite tour of the European Space Research and Technology Centre in Noordwijk, Netherlands, Florida Tech communication students got out of the classroom and into the field to learn about the health effects of space travel and write about it for FLORIDA TODAY.

The collaborative effort teamed FLORIDA TODAY staff with Florida Tech associate professor Heidi Hatfield Edwards' students with the focus on science reporting. The students gained experience writing stories, recording and editing audio and video, and using social media professionally.

The situation is prompting a wholesale reconsideration of how much space radiation astronauts can be exposed to and whether those limits should be eased to enable deep-space exploration. .

The prospect raises scores of thorny questions, including these:

• Should astronauts be allowed to volunteer for a flight when NASA knows space radiation exposure limits almost surely will be exceeded?

• Should a true understanding of the risk, and informed consent, be enough for someone to volunteer for a Mars mission?

• Should the NASA Chief Astronaut, or NASA Chief Medical Officer, be given authority to grant individual waivers to the limits?

• Should NASA, Congress or the White House have the authority to knowingly approve a waiver, or going even further, a one-way mission to the red planet — one that includes no plans for a return to Earth?

The jury is still out. The National Academy's Institute of Medicine took up the issue this year and is deliberating. A report is due in April 2014.

NASA's Astronaut Office already weighed in.

"The Astronaut Office actively supports readdressing the policies for crew health standards for exploration missions … primarily because NASA will likely exceed the current medical standards to effectively pursue exploration" beyond low Earth orbit, Behnken said.

 

Here's the situation:

On a 500-day round trip to Mars, astronauts would fly outside the Earth's magnetic field, which largely protects International Space Station crews and the planet from deadly forms of space radiation. Those flying beyond Earth orbit would face consequential radiation risks, including exposure to:

• Solar energetic particles generated by solar flares or coronal mass ejections from the sun.

• Galactic cosmic rays from exploding stars, quasars and gamma ray bursts outside our solar system.

Shielding and sheltering measures can protect crews from solar energetic particles, but new breakthroughs in lightweight materials are needed to make deep-space missions possible.

Galactic cosmic rays, however, are penetrating and can cause acute radiation sickness. Exposure also can cause circulatory and neurological diseases, and can result in latent cancer effects — astronauts could get cancer and die earlier than they otherwise would. 

NASA follows standards established by the National Council of Radiation Protection and Measurement. Models based partly on data collected in the aftermath of the 1945 Hiroshima atomic bombing were used to set those standards.

Astronauts are not allowed to accumulate a career radiation dose that would exceed a 3 percent increase in lifetime risk of developing a fatal cancer.

In considering an easing of the limit, the Astronaut Office says other issues also should be addressed. NASA analyses show current limits also would:

• Ostensibly discriminate against women.

• Reduce the pool of astronauts who qualify for mission assignments.

Male and female astronauts face the same level of risk — the 3 percent increase in what NASA calls "Risk of Exposure-Induced Death" for fatal cancer.

But women have a lower threshold for space radiation exposure than men, largely because the increased risk from breast, ovarian and uterine cancers.

Consequently, the exposure limit for women is set 20 percent lower than the comparable limit for men. That effectively means women qualify for as few as 50 percent of potential mission assignments when compared to men, former NASA Chief Astronaut Peggy Whitson said.

"So in particular, in my case, if I had a Y chromosome, I would be qualified. But because I have two Xs, I'm not," she said. 

Also a problem: The number of astronauts qualified for particular mission assignments.

Case in point: the selection of Scott Kelly to fly a yearlong ISS mission with Russian cosmonaut Mikhail Kornienko beginning in the spring of 2015.

Many factors were considered in the selection process. Among them: Command experience, Russian language proficiency and expertise in spacewalking and robotic arm operations.

But the pool dried up when space radiation exposure limits also were considered.

"We were effectively limited to three candidates for two positions (prime and back-up)," Behnken said.

In this case, Kelly was a standout candidate anyway. But in the future, the best pick for a particular mission — say, a Mars expedition — could be sidelined by space radiation exposure limits, Whitson said.

As far as a one-way trip to Mars? 

"I think across the board the one-way mission needs to have a very high reward aspect to it — the national objective sort of award," Behnken said. "There are many things we do in wartime situations — that we ask people to step up and accomplish for us. We need that level of reasoning from the Astronaut Office perspective."

That said, Behnken added this: "The one-way mission to Mars is not one I would see the Astronaut Office having a line of people signing up for."

 

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