Wednesday October 17, 2018
Home Science & Technology NASA engineer...

NASA engineers build Stopwatch to measure accurately Fraction of a billionth of Second

The timer is to be used for the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) scheduled for launch in 2018

0
//
58
NASA Headquarter in USA, VOA
Republish
Reprint

Washington, March 28, 2017: NASA engineers have built a stopwatch that can measure accurately fraction of a billionth of a second.

The timer is to be used for the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) scheduled for launch in 2018, NASA said.

ICESat-2 will use six green laser beams to measure height. With its incredibly precise time measurements, scientists can calculate the distance between the satellite and the Earth below, and from there record precise height measurements of sea ice, glaciers, ice sheets, forests and the rest of the planet’s surfaces.

NewsGram brings to you current foreign news from all over the world.

“Light moves really, really fast, and if you’re going to use it to measure something to a couple of centimetres, you’d better have a really, really good clock,” said Tom Neumann, ICESat-2’s Deputy Project Scientist.

If its stopwatch kept time even to a highly accurate millionth of a second, ICESat-2 could only measure elevation to within about 500 feet.

Scientists would not be able to tell the top of a five-storey building from the bottom. That does not cut it when the goal is to record even subtle changes as ice sheets melt or sea ice thins.

NewsGram brings to you top news around the world today.

To reach the needed precision of a fraction of a billionth of a second, engineers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, had to develop and build their own series of clocks on the satellite’s instrument — the Advanced Topographic Laser Altimeter System, or ATLAS.

This timing accuracy will allow researchers to measure heights to within about two inches, NASA said in a statement on Monday.

ATLAS pulses beams of laser light to the ground and then records how long it takes each photon to return.

This time, when combined with the speed of light, tells researchers how far the laser light travelled.

This flight distance, combined with the knowledge of exactly where the satellite is in space, tells researchers the height of the Earth’s surface below.

The stopwatch that measures flight time starts with each pulse of ATLAS’s laser. As billions of photons stream down to Earth, a few are directed to a start pulse detector that triggers the timer, said Phil Luers, Deputy Instrument System Engineer with the ATLAS instrument. (IANS)

Click here for reuse options!
Copyright 2017 NewsGram

Next Story

Chandra Observatory By NASA Back in Action

Scientists are currently performing analyses and tests to determine what options were available to recover the gyro to operational performance

0
NASA, space
NASA's Chandra Observatory back in action. Pixabay

NASA Chandra X-Ray Observatory, observing the universe in high-energy light since 1999, is back in action after suffering a glitch due to the failure of the gyroscope and going into safe mode last week.

The cause of Chandra’s safe mode on October 10 has now been understood and the Operations team has successfully returned the spacecraft to its normal pointing mode, according to the US space agency.

“The safe mode was caused by a glitch in one of Chandra’s gyroscopes resulting in a 3-second period of bad data that, in turn, led the on-board computer to calculate an incorrect value for the spacecraft momentum. The erroneous momentum indication then triggered the safe mode,” NASA said in a statement late on Monday.

The team has completed plans to switch gyroscopes and place the gyroscope that experienced the glitch in reserve.

Once configured with a series of pre-tested flight software patches, the team will return Chandra to science operations which are expected to commence by the end of this week, NASA said.

On October 10, Chandra X-ray Observatory entered safe mode, in which the observatory is put into a safe configuration, critical hardware is swapped to back-up units, the spacecraft points so that the solar panels get maximum sunlight, and the mirrors point away from the Sun.

Chandra is 19 years old, which is well beyond the original design lifetime of five years. In 2001, NASA extended its lifetime to 10 years.

NASA
NASA’s Dawn spacecraft, which has been orbiting the dwarf planet Ceres since March 2015, is also nearly out of fuel and might run out as early as October. Flickr

The US space agency said that it was also continuing to work towards resuming science operations of the Hubble Space Telescope that on October 5, entered safe mode after one of the three gyroscopes (gyros) being used to point and steady the telescope failed.

Gyroscopes help spacecraft maintain proper orientation.

Scientists are currently performing analyses and tests to determine what options were available to recover the gyro to operational performance.

Till that time, science operations with Hubble have been suspended.

You May Also Like to Read About- Invasive Species May Not Be All Bad: Scientists

Besides Chandra and Hubble, NASA’s planet-hunting Kepler space telescope is also almost out of fuel. Kepler has found about 70 per cent of all known alien worlds to date.

NASA’s Dawn spacecraft, which has been orbiting the dwarf planet Ceres since March 2015, is also nearly out of fuel and might run out as early as October.

The space agency’s Mars rovers Opportunity and Curiosity too have faced issues of late. (IANS)