London, Oct 24 : Scientists are developing an optical distress beacon for astronauts working outside their spacecraft, which would enable their screams for help to be heard in space in case of an emergency.

According to a report in New Scientist, the device could provide an alert if an astronaut is unable to speak or radio links fail.

The distress beacon will be attached to sensors monitoring heartbeat or breathing, and will have LEDs visible up to 800 meters away.

“The astronaut might even flash them to send messages in Morse code,” said Sarah Harris of Harvey Mudd College in Claremont, California, who is developing the device with staff at the Aerospace Corporation in El Segundo, California.

Extra-vehicular activities are becoming more common.

In 2007, there were 23 EVAs involving International Space Station crew members, for example, more than double the figure for 2005. (ANI)