Servicing Mission 2
(SM2)

Hubble’s second servicing mission greatly improved the telescope’s productivity, with the installation of new instruments that extended Hubble's wavelength range into the near infrared for imaging and spectroscopy, allowing us to probe the most distant reaches of the universe. The replacement of failed or degraded spacecraft components increased efficiency and performance.

Three categories of elements made up the mission payload:

Quick Facts

The Space Telescope Imaging Spectrograph’s (STIS) main function is spectroscopy - the separation of light into its component colors (or wavelengths) - so that astronomers can analyze the composition, temperature, motion, and other chemical and physical properties of the object the telescope is looking at.

STIS is an imaging spectrograph. It can produce the spectrum of large objects, like galaxies, covering many points across the image simultaneously. The instrument is sensitive to a wide range of wavelengths of light, spanning from ultraviolet through optical to near-infrared light.

STIS's two-dimensional detectors gather 30-times-more spectral data and 500-times-more spatial data than Hubble’s previous spectrographs, which were capable of only looking at one place at a time. The instrument can also act like a coronograph, by blocking the light from bright objects so that it can investigate fainter objects. Using STIS like a coronograph helps astronomers detect the signs of exoplanets orbiting extrasolar stars.

STIS stopped functioning in August 2004 due to a power supply failure. Servicing Mission 4 astronauts repaired it in 2009.

STIS Facts

The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) can study the dusty centers of galaxies and the formation of stars and planets. NICMOS consists of three cameras, which offer both infrared imaging and spectroscopic observations of astronomical targets.

NICMOS gave astronomers their first clear view of the universe at near-infrared wavelengths between 0.8 and 2.5 micrometers (800 to 2500 nanometres) - longer wavelengths than the human eye can see. Its near infrared detectors also perform more efficiently than previous infrared detectors, providing us with views of objects too distant for research by previous Hubble optical and ultraviolet instruments. The expansion of the universe shifts the light from very distant objects toward longer red and infrared wavelengths. NICMOS’s ability to detect these longer, red wavelengths allows us to see older, more distant objects.

Longer, infrared light also penetrates dust clouds more than visible light does, allowing us to see inside the gas clouds, called nebulae, where stars form.

NICMOS was operational from 1997 to 1999, when its cooling supply ran out. In March 2002, Servicing Mission 3B astronauts revived NICMOS by installing an electric cooler. In 2009, Servicing Mission 4 astronauts installed Hubble’s Wide Field Camera 3 (WFC3), which superseded the infrared capabilities of NICMOS.

NICMOS is currently not in operation.

NICMOS Facts

The crew took more than 150 other crew aids and tools on this mission. They range from a simple bag for carrying some of the smaller tools to sophisticated, battery-operated power tools.

A seven-member crew took part in this mission. Four astronauts conducted the planned spacewalks: Mark Lee, Gregory Harbaugh, Steven Smith and Joseph Tanner were part of the extravehicular activity crew. Kenneth Bowersox was the commander, Scott Horowitz was the pilot, and Steven Hawley was the Remote Manipulator System Operator.