The $10 billion James Webb Space Telescope successfully launched its thruster today and placed it at a destination that is expected to explore the mysteries of the universe in the coming years.
PT launched for nearly five minutes at 11 a.m. and put JWST into its specified orbit around the equilibrium point L2 1 million miles away from the earth. At this point, the gravity of the sun and the earth will remain in a relatively stable position, thus minimizing the need for course correction.
Today’s exercise took place 30 days after the launch of the telescope at the European Arianespace consortium’s spaceport in French Guiana on Christmas day. NASA, in cooperation with the European Space Agency and the Canadian Space Agency, played a leading role in the project.
“Welcome home, Webb!” NASA Director Bill Nelson said in a statement. “Congratulations to the team for their hard work to ensure Webb’s safe arrival at L2 today. We are one step closer to unveiling the mystery of the universe. I can’t wait to see Webb’s first new view of the universe this summer!”
Over the next few months, JWST will continue to cool its scientific instruments to a temperature range of 50 Kelvin (minus 370 degrees Fahrenheit). It will also fine tune mirror alignment and instrument settings to prepare for the first scientific observation in five months.
To align the 18 hexagonal segments of the 21 foot wide telescope, JWST will focus on a bright star called HD 84406 in the constellation Ursa Major and compare the images to guide the adjustment of each segment.
“You can’t see it clearly with the naked eye, but I heard you can see it with binoculars,” said Lee Feinberg, component manager of the optical telescope at NASA’s Goddard Space Flight Center.
JWST’s detector is designed for observation at infrared wavelength, which requires ultra-low temperature treatment of the instrument. To ensure that the sun’s rays do not heat up the instrument, the spacecraft is equipped with a five layer sunshade and will always be back to the sun.
“It can never look back at the sun, so it can only see part of the sky at the same time,” said amber Straughn, associate scientist of the project. The orientation of JWST also means that it can never look back at the earth or moon, or mercury or Venus.
But in a year’s time, the telescope will be able to study objects outside Earth’s orbit in unprecedented detail. Its sensitivity is 100 times that of the 32 year old Hubble Space Telescope. Its infrared focusing is very suitable for studying planets outside the solar system, distant galaxies and observing the boundary of the polar redshift in the universe.
In a conference call, Jane Rigby, an operations project scientist, said that the spatial area around L2 was saddle shaped, like Pringles potato chips. JWST is programmed to track the six-month orbit around cosmic potato chips, while L2 itself tracks the one-year orbit around the sun.
JWST is not the only telescope that uses L2 as a vantage point: NASA’s Wilkinson Microwave Anisotropy detector and ESA’s Planck and Herschel telescopes have been used on L2 in the past. At present, two telescopes share L2 area with Webb: ESA Gaia Observatory and Russia Germany specter RG detector.