Advanced Technology Large-Aperture Space Telescope

The Advanced Technology Large-Aperture Space (ATLAS) Telescope ["What Will Astronomy Be Like in 35 Years? "Astronomy" magazine, August, 2008] is a proposed 8 to 16-meter (320 to 640-inch) optical space telescope that if approved, built, and launched, would be a true replacement and successor for the Hubble Space Telescope (HST); with the ability to observe and photograph astronomical objects in the optical, ultraviolet, and Infrared wavelengths, but with substantially better resolution than the Hubble. Like the planned James Webb Space Telescope (JWST), the ATLAS Telescope will be launched to the Sun-Earth L₂ Lagrange Point, but instead of using the European Space Agency's Ariane 5 rocket, the ATLAS Telescope would be launched by the proposed Ares V cargo launch vehicle to be used for Project Constellation, which is due to come online in 2020.

Design

Two different designs have been floated by NASA engineers for the basic design and layout of the ATLAS Telescope. The 8-meter version, which was proposed in early 2008, would be an enlarged version of the current Hubble Space Telescope (HST), with a traditional "solid" 8-meter primary mirror, and a secondary mirror bouncing light images to various instruments located in the rear of the optical tube assembly.

The 16-meter version, on the other hand, would employ a folding segmented mirror similar to that proposed for the JWST. Because of the size of the payload fairing on the Ares V cargo launch vehicle, NASA engineers will be required to fold the mirror in such a way that it can be deployed without the assistance of astronauts, as the Space Shuttle, which launched the HST in 1990, will be long-retired by the time the ATLAS Telescope could be launched.

In both designs, the ATLAS Telescope will be able to be serviced on a regular basis, much like the HST has been. Using either a robotic ferry (the currently proposed method), or an astronaut crew flying in an Orion spacecraft (which will allow NASA to gain experience for future manned Solar System missions), instruments such as cameras would be replaced and returned to Earth for analysis and future upgrades. Like the HST and proposed JWST, the ATLAS Telescope would be powered by solar panels.

Mission

For either design, the ATLAS Telescope will be launched from the Kennedy Space Center's Launch Pad 39A atop of the Ares V rocket. Much like the proposed Orion/Altair flights to the Moon, the Ares V will place the ATLAS Telescope and the Earth Departure Stage (EDS) into a "parking" orbit, while engineers check out the systems of both the EDS and the ATLAS Telescope. Once cleared, the EDS will fire again and the ATLAS Telescope will then begin a three-month journey to the Sun-Earth L₂ Point, entering a so-called "halo orbit" around the point once it is reached.

While the 8-meter version could immediately get to work once it reaches halo orbit, the 16-meter version will be required to unfold its segmented primary mirror, something not yet tested with the JWST. Once successfully deployed and its instruments tested and calibrated, the ATLAS Telescope will then go to work, being able to see further than the 2.4-meter "eye" of the HST. Servicing missions, launched every 5 to 7 years, will allow astronomers to upgrade the ATLAS Telescope with new instruments and technologies that will come online down the road, and like the HST, the ATLAS Telescope should have a 15 to 20-year lifespan.

ee Also

*James Webb Space Telescope
*Orbiting Astronomical Observatory
*International Ultraviolet Explorer
*Astron-1
*FUSE
*GALEX
*Swift Gamma-Ray Burst Mission
*Extreme ultraviolet Imaging Telescope

References

External links

* [http://www.nasa.gov/mission_pages/constellation/ares/aresV.html NASA Ares V Cargo Launch Vehicle page]
* [http://www.tallgeorge.com/projectconstellation.php A Visual History of Project Constellation]