Science SXSW

The James Webb Space Telescope: The Most Advanced Space Telescope to-Date

One of the most interesting things that we were able to see at the SXSW Trade Show was the “Experience NASA” exhibit. At the exhibit, The National Aeronautics and Space Administration (NASA) had many of their current and upcoming missions on display. From the Mars Rovers, to the new Orion Spacecraft, to the NASA Centennial Challenges, to the ongoing Cassini–Huygens mission.1 However, my personal favorite booth was, easily, the James Webb Space Telescope.

James-Webb-Space-Telescope-1 The James Webb Space Telescope: The Most Advanced Space Telescope to-Date

A Scale model of the James Webb Space Telescope

If you are not familiar, the James Webb Space Telescope is the successor to the Hubble telescope. The telescope, when launched in 2018, will be the largest and most advanced telescope ever put into space:

The Webb Telescope is the successor to the iconic Hubble, and will be 100x more powerful. With mirrors taller than a four-story building and a giant tennis court-sized sunshield, Webb will be launched one million miles from Earth in 2018. It will reveal the Universe’s first stars and galaxies, will uncover newborn Solar Systems in nearby stellar nurseries, and will even be sensitive enough to examine the detailed makeup of the atmospheres of other rocky worlds.2

Webb-v-Hubble-1024x372 The James Webb Space Telescope: The Most Advanced Space Telescope to-Date

Size comparison between the Hubble Telescope and the James Webb Telescope. Images Via Goddard Resources and Hubble Site

During the SXSW Trade Show, I had a chance to speak with Jon Arenberg, the Chief Engineer for Northrop Grumman’s James Webb Space Program – NASA’s main contractor for the telescope. A couple of points that Jon brought up really drove home the immensity of the project.

First and foremost, the Webb Telescope will orbit the sun – that’s right, not the earth – at the L2 Lagrange point, around 1.5 million kilometers from earth – or around 4x further from the Earth than the Moon. In this orbit, the Earth itself will shield the Webb Telescope from the Sun. This is incredibly important, as the telescope will capture data and images in the infrared end of the light spectrum, which is primarily heat. Thus, the Webb Telescope must remain incredibly cold for its instruments to work effectively.

The James Webb Space Telescope will observe primarily the infrared light from faint and very distant objects. But all objects, including telescopes, also emit infrared light. To avoid swamping the very faint astronomical signals with radiation from the telescope, the telescope and its instruments must be very cold. Therefore, Webb has a large shield that blocks the light from the Sun, Earth, and Moon, which otherwise would heat up the telescope, and interfere with the observations. To have this work, Webb must be in an orbit where all three of these objects are in about the same direction. The answer is to put Webb in an orbit around the L2 point.3

The sheer distances involved also raises another important point about the telescope. Once the James Webb Space Telescope is at the L2 point, there will be no chance for the routine service/maintenance missions that the Hubble has enjoyed. Essentially, once it’s out there, it’s out there. Therefore, the engineering team is meticulously planning and carrying out the development of the telescope, particularly the mirrors. Dan Falk of Cosmos just wrote an incredible piece detailing the Webb Telescope and the engineering process. Falk detailed the meticulous nature of developing the mirrors:

The fine-polishing of the mirrors has to be carried out in stages: at [NASA’s] Goddard [Space Flight Center], engineers will work on the mirror surfaces until a precision of 100 nanometres is reached – that’s about one-thousandth of the thickness of a human hair. Then the mirrors will be sent to the Marshall Space Flight Centre in Alabama, where they’ll be cooled in a cryogenic chamber that mimics the conditions the telescope will experience in space – with engineers noting exactly how the mirror’s shape changes as the temperature drops. Then the mirrors return to Goddard for a final tweak.4

Once the Webb Telescope is in orbit and operating, its observations will be guided by four main overarching missions. The James Webb Telescope will:

  1. Search for light from the first stars and galaxies that formed after the Big Bang.5
  2. Study the formation and evolution of galaxies.6
  3. Study the formation of stars and planetary systems.7
  4. Study planetary systems and look for the origins of life.8
Webb-Telescope-Scale-Model The James Webb Space Telescope: The Most Advanced Space Telescope to-Date

A full-scale model of the James Webb Space Telescope, via WikiMedia

There are still considerable hurdles that NASA and Northrop Grumman must cross between now and the tentative launch date of October 2018. That said, if any organization can do it, it is NASA. After speaking with Jon Arenberg and other NASA officials at SXSW, it is quite clear that the program is in good hands. If you can’t wait until 2018, there are a whole host of ongoing missions and mission events this year.

Once the Webb telescope launches in 2018, it will take around 30 days to fully deploy. Here is an excellent video showing the deployment process and all of its complexities:

  1. Cassini is one of the most fascinating missions that NASA has undertaken. It has been one of, if not the most successful missions for the agency, in terms of data gathering and scientific discoveries. The unmanned Saturn orbiter discovered massive ice geysers erupting from the moon Enceladus which led to the discovery of a sub-surface ocean; it has studied the moon Titan in-depth, revealing a dynamic Earth-like landscape with rain, rivers, lakes and seas of liquid methane and ethane; it successfully landed a probe on Titan, the first landing ever on an object in the outer solar system, and returned valuable data and this image; and it has revealed Saturn’s rings to be incredibly active and dynamic. Cassini’s mission will continue until sometime in 2017, and will conduct countless more flybys and data-gathering objectives in the meantime.  
  2. Northrop Grumman, Media Resources, “James Webb Space Telescope at South by Southwest (SXSW)”  
  3. NASA, Explore James Webb Space Telescope, “About Webb’s Orbit”  
  4. Dan Falk, Cosmos,Pulling back the curtain on the Universe,” 23 March 2015  
  5. NASA, Explore James Webb Space Telescope, “The End of the Dark Ages: First Light and Reionization”  
  6. NASA, Explore James Webb Space Telescope, “The Assembly of Galaxies”  
  7. The Webb Telescope’s infrared lenses will allow astronomers to look through the massive clouds of dust that typically surround young stars. This will provide an unprecedented look at star-birth. NASA, Explore James Webb Space Telescope, “The Birth of Stars and Protoplanetary Systems”  
  8. NASA, Explore James Webb Space Telescope, “Planetary Systems and the Origins of Life”