ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

The Hubble Space Telescope: Astronomers Eye in the Sky

Updated on January 24, 2010
Courtesy of NASA  8th Anniversary Image
Courtesy of NASA 8th Anniversary Image

Hubble: Astronomers’ Greatest Achievement

Astronomers dreamed of a telescope in space or an eye in the sky for many decades. The Hubble Space Telescope was the result of those dreams.

Courtesy of NASA/   1990 ready to go into space.
Courtesy of NASA/ 1990 ready to go into space.

The Design and Construction of the Hubble Space Telescope (HST)

In 1973 NASA selected a team to design the telescope and its instruments. The specs originally called for a 118” mirror but funding problems cut that down to 94.5”. Funding issues also made it necessary to establish a collaboration with European Space Agency (ESA) in 1975. ESA supplied some of the instruments and the solar panels to power the spacecraft. NASA guaranteed them 15% of the telescope’s observing time. Marshall Space Flight Center in Huntsville, Alabama was responsible for the design, development and construction. Goddard Space Flight Center in Greenbelt, Maryland developed the instruments and became the ground-control center.

It took almost a decade to construct and assemble. The precision ground mirror was finished in 1981 and the optical assembly in 1983. The entire spacecraft was finished in 1985. NASA originally scheduled the launch for 1986 but delayed it after the tragic Challenger incident. It was finally carried into space by the space shuttle Discovery on April 24, 1990.

 

Edwin Hubble   Public Domain Image
Edwin Hubble Public Domain Image

The Hubble Name

The telescope was named after the American astronomer Edwin Powell Hubble (1889-1953). He was responsible for expanding the universe beyond the Milky Way and the Hubble Space Telescope would end up taking fantastic images and expanding it even more.

 

Hubble Facts

Anyone can apply for time on the telescope. There are no restrictions on nationality or academic affiliations. But competition is very intense and less than 20% of the applications are approved.

Astronomers awarded 13 amateur astronomers time on Hubble between 1990 and 1997, but budget cuts stopped any further approvals.

Scheduling for time is not simple. Because of its low Earth orbit required to allow the space shuttle to reach it for servicing, most targets are hidden by Earth for about half of each orbit.

The original cost estimate was $400 million. The actual cost was more than $2 billion.

Size:

Length – 43.5’ (13.2 m)
Weight – 24,500 lbs (11,110 kg)
Maximum diameter – 14’ (4.2 m)
The only restriction on its size was it had to fit inside the space shuttle’s cargo bay.

Spaceflight:

Orbital altitude – 353 mi (569 km)
Orbital period – 97 minutes
Orbital speed – 17,500 mph (28,000 km/h)

Hubble has orbited billions of miles around the Earth, more than enough for a round trip to Saturn.

Hubble optics can observe everything but the Sun and Mercury. The sunlight would damage its sensitive detectors.

 

Credit: NASA,ESA and STScl
Credit: NASA,ESA and STScl

Hubble's First Image:

By avoiding the Earth's atmosphere, the HST gives sharper images and better resolution. The first image taken with the HST was intended to assist in focusing the telescope. This image is in open cluster NGC 3532, in the southern constellation Carina.

Credit: NASA - in true color.
Credit: NASA - in true color.

Hubble’s most imaged object: Earth – it has to image Earth to calibrate its imaging equipment and to make sure the cameras are still working.

 

Power Source: energy from the sun. It has two 24.6’ solar panels. The telescope on average uses 2800 watts.

Hubble can lock into a target without deviating more than 7/1,000of an arc second or about the width of a human hair seen at a distance of 1 mile (1.6 km).

The primary mirror has a diameter of 94.5” (2.4 m) and weighs 1.825 lbs (828 kg).
The secondary mirror has a diameter of 12” (.3 m) and weighs 27.4 lbs (12.3 kg).

For power storage Hubble has 6 nickel-hydrogen batteries with a storage capacity of approximately 20 car batteries.

Hubble transmits 120 GB of data per week. The data and pictures are stored on magneto-optical disks.

More than 4,000 astronomers around the world have used Hubble to observe the universe.

Hubble has provided data for over 6,300 research papers.

 

How Hubble Takes Pictures

The colored pictures are a combination of black & white exposures to which color has been added during the processing. It is equal parts art and science. The colors in the images are not always what we would see if we could see it in person. Color is used as a tool to depict how the object might look if your eyes were as powerful as Hubble’s, to see features invisible to the human eye or to bring out subtle details.

Astronomical objects come in wide range of colors. Hubble sees all the visible wavelengths of light and many more invisible to humans such as ultraviolet and infrared light.

Many full-color images are combinations of only three images; red, green and blue. That is how TV’s, computer monitors and video cameras recreate color.

 

Hubble’s Problems and Service Missions

 

Courtesy of NASA/   1993 docked with Endeavor.
Courtesy of NASA/ 1993 docked with Endeavor.

SM1 (Service Mission 1) in 1993

A little more than a month after launching, astronomers discovered a flaw in Hubble’s primary mirror. It was discovered the mirror had been ground to the wrong shape. This mission improved Hubble’s vision problems by installing an optical fix and a new camera.

Courtesy of NASA/   1997 Hubble against Earth's horizon.
Courtesy of NASA/ 1997 Hubble against Earth's horizon.

SM2 in 1997

Discovery astronauts improved Hubble’s ability to see further into the universe by installing cameras that could observe infrared light.

 

Courtesy of NASA/    1999 docked with Discovery
Courtesy of NASA/ 1999 docked with Discovery

SM3A in December of 1999

Hubble’s gyroscopes began to fail so this mission installed new gyroscopes. They also replaced sensing units and installed a new computer.

 

Courtesy of NASA/   2002 restored by Columbia astronauts.
Courtesy of NASA/ 2002 restored by Columbia astronauts.

SM3B in March of 2002

This mission installed a new camera bringing Hubble into the 21st century. They also replaced the solar panels with more efficient ones and new steering equipment.

 

Courtesy of NASA/ Atlantis bids Hubble a last farewell.
Courtesy of NASA/ Atlantis bids Hubble a last farewell.

SM4 in 2009

This was the last planned service mission for Hubble. They accomplished a never envisioned task. They repaired two instruments on-site that had stopped working. And since this was the last mission they did a major overhaul to renovate Hubble’s spaceflight systems. They also replaced any damaged protective blankets and installed a Soft Capture Mechanism which will allow a robotic spacecraft to attach itself to Hubble and guide its descent back to Earth when the time comes to retire the telescope.

 

Some of Hubble’s Discoveries

Hubble was instrumental in discovering dark matter, a mysterious substance that seems to cause the expansion of the universe to accelerate. It imaged a comet collision, tracked planetary storms, charted the outer solar system, showed us all the stages of evolution of a galaxy, and so much more. Hubble has given us our deepest look into space and our longest look back in time.
Hubble is still sending back images and data but no one knows for how much longer it will continue to operate.

 

September 2009 artist conception of JWST. Credit: NASA
September 2009 artist conception of JWST. Credit: NASA

Beyond Hubble

The next telescope to be launched is scheduled for 2014. The James Webb Space Telescope, named after a former NASA administrator, will be an infrared telescope with some visible light capabilities residing in an orbit about 1 million miles (1.5 million km) from the Earth. It will have a large mirror 21.3 feet (6.5 meters) in diameter and a sunshield the size of a tennis court. Both the mirror and sunshade will not fit onto the rocket fully open, so both will fold up and open once JWST is in outer space. It will have 10X the light gathering power of Hubble! JWST will peer deeper into the universe than ever before. Amazing discoveries are in our future!

 

Sources:

Astronomy Magazine Collector’s Edition – Hubble’s Greatest Pictures

www.hubblesite.org – the official website of the Hubble Space Telescope

www.jwst.nasa.gov – the official website of the James Webb Space Telescope

 

 

Comments

    0 of 8192 characters used
    Post Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)