NASA’s DSCOVR Probe Resurrected to Monitor Space Weather

I was thoroughly amused when I first read about a satellite launch that was postponed for incredible 14 years in the US due to frivolous political reasons. Here is the story of the DSCOVR probe brain child of former US Vice-president Al Gore. He hypothesised about a probe in space capable of streaming live images of illuminated side of the Earth that could be available online. He believed that such advanced images would be a great learning opportunity and would inspire enthusiastic youngsters. But the idea was scorned by Republicans who ridiculed it as “multi-million dollar screen saver”. NASA meanwhile formulated a complementary mission by soliciting expert recommendations. Accordingly, it designed a mission which besides acting as educational tool could carry bunch of sophisticated instruments which can measure the radiations reflected by the Earth back into space.

Initial proposal was to include two earth science instruments: EPIC and NISTAR. EPIC is the Earth Polychromatic Imaging Camera for capture the images of the sun-lit side of the earth. The images will allow the determination of physical quantities like ozone, aerosols, dust, volcanic ash, cloud height and vegetation cover. NISTAR (National Institute of Standards and Technology Advanced Radiometer) will audit the atmospheric pollution by measuring the amount of the radiations emitted and retained by the Earth. Emitted radiations lower the temperature while retaining more emissions would make Earth warm.

Thus, NASA constructed the satellite (also called as Triana) by 2000 and was readied for launch. During the Presidential elections in 2001, George W Bush defeated Al Gore as a result the project shelved in NASA’s rooster. While politics has been one of the reasons for halting this project, NASA head argued that space shuttle’s crowded launch calendar as the major stumbling block. In November 2001, the satellite was sent to storage at Goddard Space Flight Centre. It would have remained indefinitely lost if not for the interest of the space-weather forecasters of NOAA (National Oceanic Atmospheric Administration) and USAF (United States Air Force). In 2008 Congress approved the revival of the satellite and then further tests were carried out to refurbish it. During its resurrection, scientists identified a serious anomaly in the functioning of the EPIC instrument. Most of them were glad that the satellite wasn’t flown into space as it would have revealed the defect which would be more embarrassing.

After 14 years of prolonged delay, Earth Monitoring Satellite DSCOVR (Deep Space Climate Observatory) of NASA scheduled for launch on January 29^th was deferred to February 18^th. The project is a joint collaboration between the NASA, NOAA and USAF. The satellite will be put in the L1 (Lagrange Point 1), the neutral gravity point between Earth and Sun, approximately 1 million miles from Earth by the launch vehicle Space X Falcon V 1.1. Satellite will weigh 570 kg at the time of launch and has mission life of 5 years. L1 is a good point to monitor the Sun because constant stream of particles or the solar storms reached L1 about an hour before reaching Earth. DSCOVR can thus send warning signals to Earth 15 to 60 minutes ahead of surge of particles and magnetic field termed as Coronal Mass Ejection (CME) associated with geomagnetic storm of Sun. These solar storms have severely impact on the public transport system by disabling the power grids, telecommunications, GPS-positioning systems etc. The collateral damages in event of a severe solar storm might run into $2 trillion and its full recovery can take 4 to 10 years. Moreover bursts of ionised particles and radiations pose severe threat to astronauts and other orbiting satellites in the space. This aspect has been the special interest for the USAF which is funding its launch.

The satellite has five instruments on board. Besides NISTAR and EPIC, it has Electron Spectrometer, Pulse Height Analyser (PHA) and Solar Wind Plasma Sensor (Faraday Cup) and Magnetometer (MAG) to measure solar wind velocity, its magnitude and direction of solar wind magnetic field and sends the warning signal.

Till now estimates about the Earth’s radiations were arrived at by stitching up the data obtained by various satellites orbiting it. DSCOVR will observe the entire sunlit side of Earth and hence the estimates would be more accurate. It will thus help in making climate simulations. It is expected to succeed NASA’s ACE (Advanced Composition Explorer) satellite launched in 1997 which has worked well beyond its expected life period. At present ACE is the only satellite providing real time information about solar radiations and winds from the L1 orbit. To sum up, DSCOVR will measure magnetic field intensity, direction and distribution of incoming ions and electrons in the solar wind plasma according to their energies which enables scientists to determine solar wind plasma velocity, density and temperatures.

No country is immune to the cascading effects of politics- be it a developed country like India or the most powerful nation of the World, the US.

 

 

 

@ Copyrights reserved.