The James Webb Space Telescope – Background and Status (and a bit of opinion):
AdminCadet: The first graphic above is artwork provided by NASA on the James Webb Space Telescope (JWST) as it would appear in orbit. [www.nasa.gov}. The second image is a photo taken during preparation for cryogenic testing of the primary mirror segment of the NASA James Webb Space Telescope (JWST). [Image Credit: NASA/MSFC/David Higginbotham/April 15, 2011]. The third image is a photo of a full-sized test unit of the Webb Telescope’s sunshield – it was stacked and unfurled for the first time in July 2014 in a clean room at the Northrop Grumman facility, California. [Photo Credit: NASA/Chris Gunn]. The final image is a graphic illustrating roughly where the James Webb Telescope will be placed in orbit when it is launched in 2018. [Art provided by jwst.nasa.gov].
The following background information was taken from the NASA James Webb Space Telescope website, jwst.nasa.gov:
About the Webb – “The James Webb Space Telescope (sometimes called JWST) will be a large infrared telescope with a 6.5-meter primary mirror. The project is working to a 2018 launch date. The Webb will… study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System… Webb is an international collaboration between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch… There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRSpec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor / Near InfraRed Imager and Slitles Spectrogaph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range… Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.” [Information provided by jwst.nasa.gov]
About Webb’s Orbit: “The James Webb Space Telescope will observe primarily the infrared light from faint and very distant objects… 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” Earth-Sun “L2 point. The L2 orbit is an elliptical orbit about the semi-stable second Lagrange point. It is one of the five solutions by the mathematician Joseph-Louis Lagrange in the 18th century to the three-body problem. Lagrange was searching for a stable configuration in which three bodies could orbit each other yet stay in the same position relative to each other. He found five such solutions, and they are called the five Lagrange points in honor of their discoverer.” [Information provided by jwst.nasa.gov]
[Reference the fourth image above to see the locations of the five Earth-Sun Lagrange points.]
AdminCadet – A bit of discussion and opinion:
As exciting as this program is, the cost of the JWST has increased substantially as the project has progressed. The Webb will cost approx $8.8 billion from development, launch, and five years of operations and science – several billion higher than originally projected. The money for this over-run is being approved by Congress on a year by year basis, mostly taken out of the NASA overall budget. [Personal note: I can remember a few years ago, when the Webb overruns were first made evident, that we were told all programs at NASA, including human space flight, will absorb this overrun – there will be no increase in NASA’s budget due to this issue.] As stated by space.com: “Before JWST entered development, around the turn of the century, program officials projected it would cost $1 billion to $3.5 billion and launch between 2007 to 2011, according to a Government Accountability Office report released Jan. 8, 2014.” [space.com – Dan Leone, Space News – Feb 5, 2014].
Many in NASA will breath a sigh of relief when the Webb is launched, since its high ticket price and overruns have been impacting several NASA programs including the human space exploration program. However, there are some who are concerned about the complex operations needed to autonomously deploy the Webb. The following video (see link below) was produced by Northrop Grumman and shows the over 30 day deployment sequences and operations that will be required to fully position and activate the James Webb. Since the telescope is so far away (on the far side of the moon’s orbit) there are no vehicles to reach it if anything goes wrong (unlike how the Shuttle was able to repair Webb’s predecessor, the Hubble telescope, and service it several times). And, as many know, and as Murphy can attest, complexity provides a host of opportunities for mechanical and electrical systems to go wrong.
The following NASA graphics illustrate how far away James Webb will be from the Earth – note the Hubble’s orbit shown in the second image [Graphic provided by jwst.nasa.gov]:
Here’s hoping this beautiful telescope is completed on its current schedule and launched and deployed with no issues. Success of this program will be a magnificent milestone in better understanding the universe we live in.
Credit for information and images are annotated above. For more information, visit http://www.jwst.nasa.gov