Having been launched into low Earth orbit in 1990, the Hubble Space Telescope has continued to operate successfully over the years. Although not the first space telescope, Hubble is currently the most powerful and versatile space telescope, and one of the most important research instruments ever launched into space. Not only is it a critical research tool, but the Hubble’s success has also provided an enormous boost in the field of astronomy’s public relations.
Hubble’s Primary Mirror
The Hubble Space Telescope was launched into low Earth orbit in 1990 and is still in operation today. While not the first space telescope, the Hubble is one of the biggest and most versatile. It is an essential research tool and a public relations boon for astronomy. It was first used to study comets and other space objects, but it is now widely used for studying astronomical objects of a much smaller size.
The Hubble Space Telescope’s primary mirror has a diameter of 2.4 meters (7.8 feet) and a total collecting area of about 4.5 square meters. The mirror’s size affects the amount of light it can collect, and a bigger mirror means astronomers can detect fainter objects more easily. A bigger mirror also results in clearer images with higher resolution.
Hubble’s Scientific Instruments
Hubble’s scientific instruments provide astronomers with high-quality images of a wide variety of celestial objects. One of these instruments is the Fine Guidance Sensor, which provides pointing information for the telescope. Another instrument is the Space Telescope Imaging Spectrometer, which is used to obtain images of celestial objects at near-infrared wavelengths.
Hubble’s scientific instruments have changed a lot since its launch in 1993, due to advances in technology. The instruments now use charge-coupled devices (CCDs), which are solid-state silicon detectors. These are the same detectors that you see in video and digital still cameras. HST CCDs have high performance, fine spatial resolution, and wide dynamic range.
Hubble’s pointing accuracy and stability are achieved by an intricate onboard system. While Hubble does not have a propulsion system, its four flywheels are powered by motors. These wheels rotate up to 3000 rpm. The three gyroscopes in Hubble’s instrument suite measure the orientation of the spacecraft.
Hubble’s fine Guidance Sensors
The Fine Guidance Sensors (FGS) of the Hubble Space Telescope are sensitive instruments that help the telescope lock on to its target star. The FGSs also help scientists measure the positions and motions of stars. The sensors weigh nearly four hundred pounds (two hundred and nineteen kilograms).
These sensors were developed by the Perkin-Elmer Corporation, a company based in Danbury, Connecticut, and are a key component of the Hubble Space Telescope (HST). They serve as the astronomical telescope’s absolute pointing reference, allowing its Pointing Control System to maintain pointing stability. These sensors had to meet the stringent requirements of the HST, including high dynamic range and a wide field of view.
Hubble’s Imaging Spectrograph
Hubble’s imaging spectrograph is a powerful spectroscopic instrument that provides the spectra of celestial objects in ultraviolet light. It enables scientists to learn about objects and their past evolution. The STIS instrument has high spatial and temporal resolution and a high sensitivity to a range of light wavelengths. The STIS can analyze a wide range of objects including monster stars, black holes, and the intergalactic medium. It is also used to study the atmospheres of other stars.
The Hubble Imaging Spectrograph instrument enabled scientists to study the spectra of light from extrasolar planets. The instrument measured the color of light from planets before, during, and after they passed behind stars. The Hubble’s observations confirmed that the planets have blue light that scatters away from the star. But unlike Earth, the planets’ color is not comparable to ours.
Hubble’s near Infrared Camera
NICMOS, or the Near Infrared Camera and Multi-Object Spectrometer, is an instrument on the Hubble Space Telescope that detects light that has wavelengths between 0.8 and 2.5 micrometers. It is a sensitive instrument, but the detectors must be kept at extremely cold temperatures to be effective. For this reason, the detectors are kept in a cryogenic dewar, which contains frozen nitrogen ice. This system keeps them cold for years at a time.
Near Infrared observations can be used to discover details about nebulae, planets, and stellar formation that are not visible to human eyes. The Near Infrared Camera and Multi-Object Spectrometer is equipped with three cameras that have varying fields of view. Since the instrument was put on board the Hubble Space Telescope in 1997, three versions of the Wide Field camera have been installed.