James Webb Telescope Facts Including Cost, Orbit As Launch Date Set

The James Webb Telescope (JWST), which will enable humans to look further back in time than ever before, will be launched in December according to the space agencies behind the project.

NASA, the European Space Agency (ESA), and French company Arianespace have jointly agreed on December 18 as the launch date for the Ariane 5 flight VA256, which will carry the JWST to its vantage point in space.

The JWST is completed, and at the end of September the telescope will be shipped to the launch site at Europe's Spaceport in French Guiana. The Spaceport was also the launch site of ESA's CHEOPS mission in 2019. CHEOPS has been selecting so-called "Golden Target" planets outside the solar system, exoplanets, for follow-up investigation by the JWST.

The JWST will be positioned in orbit around Earth at an area called the Lagrange point two (L2), located about 93,000 miles (1.5 million kilometers) above the surface of Earth. Lagrange points around Earth, such as L2, make a great point to place satellites because the gravitational forces between our planet and the Sun are balanced here, meaning a satellite can be placed in a desired orbit without needing too many adjustments.

The total mass of the space telescope is around 6,200 kilograms (13,668 pounds), which includes the observatory, materials that will be consumed during its five to 10-year mission, and an adaptor that enables its launch from the Ariane 5 rocket.

JWST will improve on observations made by the Hubble Space Telescope thanks to its greater electromagnetic wavelength coverage and improved sensitivity. This means that the telescope will be able to observe the Universe in wider wavelengths of light and at lower frequencies than Hubble.

This is something that will be of particular benefit to planetary scientists examining the atmospheres of exoplanets and for cosmologists observing objects far too distant for Hubble to spot. Its observational power will be so great that it will be able to see objects so distant that they existed at the time of the formation of the first galaxies.

Because viewing objects at cosmic distances is akin to staring back in time, the JWST could even allow cosmologists to observe conditions in the Universe moments after the Big Bang.

The boost in observational power of the JWST is thanks to its gold-plated beryllium primary mirror, which is made up of 18 separate hexagonal segments. These connect to form a reflective surface that is 21 feet (6.5 meters) in diameter.

To protect it from the intense heat of the Sun and maintain its optimal operating temperature, JWST is equipped with a heat shield about the size of a tennis court, 70 feet by 47 feet.

Such an incredible piece of space tech takes a long time to develop and doesn't come cheap.

The JWST has been in development since 1996 with an initial budget of $500 million U.S and launch set for 2007. The project experienced several delays, including a redesign in 2005. Testing of the telescope's primary mirror was delayed in March this year as a result of the COVID pandemic.

With those delays have come significant increases in cost, with the development of the JWST now estimated to have cost $10 billion.

Günther Hasinger, ESA director of science, said in a press release on Wednesday: "We now know the day that thousands of people have been working towards for many years and that millions around the world are looking forward to.

"Webb and its Ariane 5 launch vehicle are ready, thanks to the excellent work across all mission partners. We are looking forward to seeing the final preparations for launch at Europe's Spaceport."

The James Webb Space Telescope Launches
An artist's impression of the James Webb Space Telescope unfolding from the Ariane 5 rocket that will carry it to space. The rocket has been confirmed for launch from Europe's Spaceport in French Guiana on December 18. ESA / D. Ducros/ESA