5 Interesting Facts About Hubble Space Telescope

Mayukh Bari14 July 2020 12:05PM IST
3 min read205

Launched in April 24, 1990 Hubble Space Telescope (HST) is on a mission to discover new planets, stars and galaxys of this gigantic Universe. HST is the first space telescope ever built. The telescope is named after American astronomer Edwin P. Hubble (1889 - 1953).

In 1923, Hermann Oberth - considered a father of modern rocketry, along with Robert H. Goddard and Konstantin Tsiolkovsky - published Die Rakete zu den Planetenräumen ("The Rocket into Planetary Space"), which mentioned how a telescope could be propelled into Earth orbit by a rocket. Hubble was funded in the 1970s with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the 1986 Challenger disaster.

Marshall Space Flight Center (MSFC) was given responsibility for the design, development, and construction of this astronomical marvel. MSFC commissioned the optics company Perkin-Elmer to design and build the Optical Telescope Assembly (OTA) and Fine Guidance Sensors for the space telescope. Lockheed was commissioned to construct and integrate the spacecraft in which the telescope would be housed. Since its commission Goddard Space Flight Center is in control of this fine instrument.

Power Usage

On average, Hubble uses 2,100 watts of power, But availability is kept at around 2,800 watts all the time. Because the amount of power needed by the spacecraft varies from orbit to orbit. Hubble's six batteries are each constructed of 22 nickel-hydrogen (NiH2) cells.

Optical Precision

The primary mirror is 7.8 feet (2.4 meters) in diameter, while the secondary mirror is only 12 inches (30.5 centimetres) wide. The primary mirror of Hubble is so smooth that if the mirror were expanded to the diameter of Earth, the largest bump on the surface would only be six inches (15 cm) tall.

Data Transmission

It can collect an average of 18 GB of data each week. Therefore, the single-access antennas on Data Relay Satellites (TDRS), which have a higher data rate, are used to relay the large volumes of observational data from Hubble back to Earth.


Anyone can apply for time on the telescope. There are no restrictions on nationality or academic affiliation, but funding for analysis is available only to U.S. institutions. Competition for time on the telescope is intense, only 20% of the requests get approved for each cycle.


The telescope is in a low-Earth orbit and will decay in the mid-2030s without further boosts, ending the telescope's mission regardless of funding. The James Webb Space Telescope (JWST) is currently scheduled to launch March 30, 2021, and the same will take the place of the HST.

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