Heart becomes more spherical when exposed to long periods of microgravity in space, a change that could lead to cardiac problems, a new research has found.
The findings from a study of 12 astronauts represent an important step toward understanding how a spaceflight of 18 months or more could affect astronauts' heart health, researchers said.
"The heart doesn't work as hard in space, which can cause a loss of muscle mass," said James Thomas, Moore Chair o f Cardiovascular Imaging an d Lead Scientist for Ultrasound at NASA, and senior author of the study.
"That can have serious consequences after the return to Earth, so we're looking into whether there are measures that can be taken to prevent or counteract that loss," Thomas said. The researchers said that knowing the amount and type of exercise astronauts need to perform to keep the heart healthy is going to be very important to guarantee their safety on a long flight like a mission to Mars.
Thomas added that exercise regimens developed for astronauts could also be used to help maintain heart health in people on Earth who have severe physical limitations, such as people on extended bed rest or those with heart failure. The research team trained astronauts to take images of
their hearts using ultrasound machines installed on the International Space Station. Twelve astronauts participated, providing data on heart shape before, during and after spaceflight.
The results show the heart in space becomes more spherical by a factor of 9.4 per cent, a transformation similar to what scientists had predicted with sophisticated
mathematical models developed for the project. By validating those models, the study could also lead to a better understanding of common cardiovascular conditions in
patients on Earth.
"The models predicted the changes we observed in the astronauts almost exactly. It gives us confidence that we can move ahead and start using these models for more clinically
important applications on Earth, such as to predict what happens to the heart under different stresses," Thomas said.
The team is now working to generalise the models to analyse such conditions as ischemic heart disease, hypertrophic cardiomyopathy and valvular heart disease.

China has restored communications with its space program’s troubled “Jade Rabbit” moon rover, but engineers are still working to fix its mechanical problems, state media said Thursday.

The official Xinhua News Agency cited Pei Zhaoyu, the lunar probe program’s spokesman, as saying the rover had survived the frigid cold of the lunar night that started Jan. 25.The “Jade Rabbit” rover was designed to roam the lunar surface for three months while surveying for natural resources and sending back data. But it ran into problems as it was shutting down in preparation for the lunar night, which lasts two weeks.

The problems were a rare setback for China’s burgeoning space program, which in recent years has conducted space walks and placed a space station in orbit.

Pei said the rover had “come back to life” despite space experts’ earlier concerns that it might not survive the extremely low temperatures of the lunar night, when the temperature drops to minus 180 degrees Celsius (minus 292 Fahrenheit).

“The rover stands a chance of being saved now that it is still alive,” Pei was quoted as saying. He said it was still unclear what caused the problem.

The mission has been a popular success for China’s military-backed space program. Updates on the moon rover’s progress have been posted on an unofficial Chinese microblog account written with the Jade Rabbit’s voice, attracting tens of thousands of comments by Chinese Internet users.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

A Soyuz capsule carrying three astronauts successfully docked with the International Space Station early Thursday, bringing the size of the crew at the orbiting outpost to six. The new crew's six-month mission will include a spacewalk with the Olympic torch.

American Michael Hopkins and Russians Oleg Kotov and Sergei Ryazansky traveled six hours in the capsule from the Russian-leased launch pad in Kazakhstan before linking up with the space station's Russian Poisk research module at 6.45 a.m. Moscow time (0245GMT).

Kotov is the most experienced member of the crew with two previous six-month missions in space under his belt, while Hopkins and Ryazansky are both on their first missions.

The incoming crew entered the station nearly two hours after the docking, where they were welcomed by Russia's Fyodor Yurchikhin, NASA's Karen Nyberg and Italy's Luca Parmitano, who have been on the orbiting lab since May and will be returning to Earth in November.

Kotov and Ryazansky will have the honor of taking the Olympic torch into open space in November as part of the relay of the Olympic flame ahead of the Winter Games being held in Russia's Sochi in February. The torch will not be lit however, because of safety concerns. It will only arrive at the station in November with the next mission.

Shortly after entering the station, Hopkins, Kotov and Ryazansky had a chat via a video-link with their families back at the Baikonur launch pad where they had seen them off more than eight hours before.

Radiant but visibly tired, the astronauts were yawning as they were talking to their families. They had been up for about 20 hours.

Hopkins' mother described the launch as a "heart-stopping experience."

"It was a pretty good ride, mom. It was a lot of fun," Hopkins replied in the live broadcast on NASA TV.

An experiment to measure the earth's circumference, claimed to have been conceived 2,300 years ago, was carried out by more than hundred school students here today by using Qutub Minar's shadow. 

For the first time Qutub Minar was used as a towering gnomon- an object that by the position or length of its shadow serves as an indicator to measure the earth's circumference. 

Known as 'Eratosthenes' experiment, it saw the students also measuring the shadow of sun using gnomon sticks. 

The students also measured the shortest shadow at local noon on autumnal equinox which falls on September 23 every year. 

The event was organised by Science Popularization Association of Communicators and Educators (SPACE). 

"Despite issues like protruding balconies from the Minar and the shadow falling on different structures, most students achieved above ninety-five per cent accuracy in measuring the earth's circumference," said SPACE president C.B. Devgun. 

"Gnomons of all sizes and shapes have been used previously. For instance, huge objects such as samrat and ram yantra at Jantar Mantar and sundial at Barapullah have been used for experimentation ," he added.