Boeing to Launch CST-100 Starliner to ISS on Dec 20, 2019

NASA gave its approval Dec. 12 to proceed with the launch later this month of Boeing’s CST-100 Starliner commercial crew spacecraft on an uncrewed test flight to the International Space Station.

At the end of a Flight Readiness Review at the Kennedy Space Center, NASA officials approved plans to launch the Starliner on its Orbital Flight Test (OFT) mission on a United Launch Alliance Atlas 5 at 6:36 a.m. Eastern Dec. 20. A launch on that day would result in the spacecraft docking with the ISS a little more than a day later, remaining there for nearly a week before landing at White Sands Missile Range in New Mexico in the predawn hours of Dec. 28.

“I’m happy to announce we’re go for launch,” NASA Deputy Administrator Jim Morhard said in a media teleconference shortly after the review concluded.

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Bad for Astronauts: Extended Exposure to Cosmic Rays may Cause Dementia

What happens to an astronaut's brain during a mission to Mars? Nothing good. It's besieged by destructive particles that can forever impair cognition, according to a UC Irvine radiation oncology study appearing in the May 1 edition of Science Advances.

Charles Limoli and colleagues found that exposure to highly energetic charged particles - much like those found in the galactic cosmic rays that bombard astronauts during extended spaceflights - cause significant damage to the central nervous system, resulting in cognitive impairments.

"This is not positive news for astronauts deployed on a two- to three-year round trip to Mars," said Limoli, a professor of radiation oncology in UCI's School of Medicine. "Performance decrements, memory deficits, and loss of awareness and focus during spaceflight may affect mission-critical activities, and exposure to these particles may have long-term adverse consequences to cognition throughout life."

For the study, rodents were subjected to charged particle irradiation (fully ionized oxygen and titanium) at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory before being sent back to Limoli's Irvine lab.

The researchers found that exposure to these particles resulted in brain inflammation, which disrupted the transmission of signals among neurons. Imaging revealed how the brain's communication network was impaired through reductions in the structure of nerve cells called dendrites and spines. Additional synaptic alterations in combination with the structural changes interfered with the capability of nerve cells to efficiently transmit electrochemical signals. Furthermore, these differences were parallel to decreased performance on behavioral tasks designed to test learning and memory.

Similar types of more severe cognitive dysfunction are common in brain cancer patients who have received various photon-based radiation treatments at much higher doses. In other research, Limoli studies the impact of chemotherapy and cranial irradiation on cognition.

While cognitive deficits in astronauts would take months to manifest, Limoli said, the time required for a mission to Mars is sufficient for such deficits to develop. People working for extended periods on the International Space Station do not face the same level of bombardment with galactic cosmic rays, as they are still within the protective magnetosphere of the Earth.

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Now there is a nice natural control study: examine communities at high altitude.  Is 'cognitive impairment' at old age more prevalent than those who have lived their lives at sea level? Make sure you eliminate those who fly frequently from either study.  We know high altitude communities have a higher rate of brain cancer.  How about dementia and whatnot?  If not, perhaps this ought to be reconsidered.

Lunar Gravity Insufficient for Human Orientation?

Keeping upright in a low-gravity environment is not easy, and NASA documents abound with examples of astronauts falling on the lunar surface. Now, a new study by an international team of researchers led by York University professors Laurence Harris and Michael Jenkin, published today in PLOS ONE, suggests that the reason for all these moon mishaps might be because its gravity isn't sufficient to provide astronauts with unambiguous information on which way is "up".

"The perception of the relative orientation of oneself and the world is important not only to balance, but also for many other aspects of perception including recognizing faces and objects and predicting how objects are going to behave when dropped or thrown," says Harris. "Misinterpreting which way is up can lead to perceptual errors and threaten balance if a person uses an incorrect reference point to stabilize themselves."

Using a short-arm centrifuge provided by the European Space Agency, the international team simulated gravitational fields of different strengths, and used a York-invented perceptual test to measure the effectiveness of gravity in determining the perception of up. The team found that the threshold level of gravity needed to just influence a person's orientation judgment was about 15 per cent of the level found on Earth – very close to that on the moon.

The team also found that Martian gravity, at 38 per cent of that on Earth, should be sufficient for astronauts to orient themselves and maintain balance on any future manned missions to Mars.

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