NASA’s engineers have started testing the concept for a new propulsion system that could reduce the time it takes for spacecraft to enter the interstellar space. This proposed propulsion (also called ‘Proton Power System’ would interact with particles discharged by the sun, repelling protons to generate thrust and accomplish extraordinary speeds. Scientists say this could carry spacecraft to the heliopause in only 10 years – a feat that took the Voyager almost 35 years. The suggested model is called the Heliopause Electrostatic Rapid Transit System (Herts) E-Sail, and it requires no built-in propellant to work.
As an alternative to built-in propellant, the E-Sail would be pushed by solar wind to touch the heliopause – the edge of our solar system. A gently rotating spacecraft would set up 10 to 20 electrically charged aluminium wires to make a massive 'E-Sail.' Each wire would be just one millimetre thick but range almost 12 and a half miles in length, almost the equal of 219 football fields.
The E-Sail would repel the protons flowing through the solar wind, generating the thrust. Bruce Wiegmann, an engineer in Marshall's Advanced Concepts Office and the chief researcher for the HERTS E-Sail, said:
“The sun releases protons and electrons into the solar wind at very high speeds – 400 to 750 kilometers per second. The E-Sail would use these protons to propel the spacecraft”
Engineers at the Marshall Space Flight Center in Huntsville, Alabama have initiated the tests which will last for over two years.
These tests will conclude the amount of protons bounced by the wires and the amount of electrons attracted to them.
The researchers will also conduct plasma testing, and expand models of the data for further development of the E-Sail.
This concept builds off a creation of Dr Pekka Janhunen of the Finnish Meteorological Institute, but scientists say there is still much to be tested, and it will possibly take at least 10 years before it can be put to practical use.
While the test will be carried out, during that time the effective area of the E-Sail would grow; at 1AU its operative area would be approximately 232 square miles, but at 5 AU this would shield more than 463 miles.
Normally, the energy of solar photons disperses when a solar sail craft touches the asteroid belt at 5 AU, the scientists explain, resulting the acceleration to stop.
But, it's believed that the E-Sail would carry on to accelerate far beyond this point. Wiegmann said:
“The same concerns don't apply to the protons in the solar wind. With the continuous flow of protons, and the increased area, the E-Sail will continue to accelerate to 16-20 AU – at least three times farther than the solar sail. This will create much higher speeds.”
NASA's Voyager 1 crossed the heliopause and went into the interstellar space in 2012, it took almost 35 years into its journey, and according to current calculation this radical 'proton power' system would take only 10.