Vibration tests of NASA’s James Webb Space Telescope (JWST) resulted in “anomalous readings” according to NASA. The $8 billion telescope is undergoing a series of tests in preparation for its 2018 launch.

JWST is often described as the successor to the Hubble Space Telescope although it will study the universe in a different part of the electromagnetic spectrum (infrared) and will not be serviced by space shuttle astronauts. The space shuttle servicing missions brought a lot of attention to Hubble and enabled the telescope and its instruments to be repaired and upgraded five times over its 26 year (so far) lifetime.

The space shuttle program was terminated in 2011 and, in any case, JWST will not be in Earth orbit. Instead it will be located 1.5 million kilometers away at the Sun-Earth L-2 Lagrange point. It has a 5-year design lifetime, although many expect it will operate for at least twice that long. Scientifically, JWST will take the next step beyond Hubble to

study objects even deeper into the universe. The light from such

objects is “redshifted” into the infrared band, whereas Hubble’s

instruments observe primarily in the ultraviolet and visible

wavelengths.

The JWST program experienced considerable cost overruns and schedule delays, but since a program management revamping in 2011, has been holding to its revised cost and schedule estimates. Congress capped the development cost at $8 billion, with another $700 million for operations.The European Space Agency (ESA) is providing the October 2018 launch on an Ariane rocket at no cost to NASA as a partner in the program.

The revised schedule includes several months of margin in case unexpected problems, such as this one, are encountered.

NASA states that during a December 3 vibration test, “accelerometers attached to the telescope detected anomalous readings during a particular test. Further tests to identify the source of the anomaly are underway.” No damage to the telescope has been found so far.

More details will be provided when they are available.