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The Next Generation Space Telescope

Rachel Lampman

Rachel Lampman

My name is Rachel Lampman.  I have lived in Idaho all my life and I attend school in Mountain Home.  In the fall I will attend Boise State University as an honors student.  I don’t know what I will major in, but I will continue learning Spanish in college, and I plan to explore a variety of majors in my first two years at BSU.  I have always been interested in science and math, so I will be sure to take a number of classes in these fields.  One of my goals is to study abroad for at least a semester in college.  I would love to travel to Argentina, Spain, or Chile so that I could be fully immersed in the Spanish language and thus become fluent.  When I’m not studying, a rare occurrence, I enjoy reading, spending time with my friends, cooking, running, and dancing.

The Next Generation Space Telescope

In August of 1990, the Hubble Space Telescope launched into orbit around Earth.  In the following years, it provided astronomers with breathtaking images of the cosmos that changed the way we thought about the universe.  But they weren’t satisfied with this telescope.  Not five years after Hubble was launched, serious plans were made for The Next Generations Space Telescope, later called the James Webb Space Telescope.  This telescope was designed to capture infrared light instead of visible light, like Hubble.  After many heart-wrenching delays due to funding, engineering difficulties, and most recently the Coronavirus pandemic, the James Webb Space Telescope will launch on October 31, 2021.  History is about to be made!

The James Webb Space Telescope, sometimes called JWST or simply Webb, is made up of three primary components.  First is the spacecraft bus which faces the sun and the earth.  The spacecraft bus houses the communications, power and cooling (Jordan).  The second component is the sun shield, which is kite-shaped and consists of five layers of a material called Kapton (Jordan).  Each layer is coated in aluminum, and the two layers closest to the sun are coated in silicon, all to reflect the heat of the sun and earth.  The final piece is the telescope itself.  This is comprised of the Optical Telescope Element (OTE) and the Integrated Science Instrument Module, which together are referred to as OTIS.

The James Webb Space Telescope was named after former NASA administrator from 1961-1968 James Edwin Webb.  This telescope features the largest mirror of any other space telescope and is optimized for the infrared end of the light spectrum (“Planets…”).  The way the telescope will settle into place is revolutionary as well.  It’s sunshield and even its primary mirror will fold up in the launch vehicle and deploy once it has reached its home away from home at the second Lagrange point (“Orbit”).  A telescope of this caliber does come at a significant cost, but there has been and will be sizable payouts.  The James Webb Space Telescope is worth investing in because of the ties it forges between NASA and other space agencies, the innovations in engineering that have occurred during its construction and the scientific discoveries it will make.

In October, Webb will launch from Arianespace’s ELA-3 launch complex at the European Spaceport located near French Guiana.  Webb truly is an international team effort.  The European Space Agency is providing the launch vehicle for Webb, the Ariane 5 rocket (“The Launch”).  This rocket happens to be one of the world’s most reliable launch vehicles, the Toyota of launch vehicles if you will.  It has a record of 80 successful launches in a row.  Besides the rocket and the associated launch services, the European Space Agency is providing two instruments for Webb, the Near-Infrared Spectrograph and the Mid-Infrared Instrument.  The Canadian Space Agency has also played an important role in the development of JWST.  They have provided the Fine Guidance Sensor (FGS), which will enable Webb to determine its position, locate its celestial targets, track moving targets and remain locked, with high precision, on a specific target (“Canada’s Role in Webb”).  In addition to the FGS, the Canadian Space Agency will provide the Near-Infrared Imager and Slitless Spectrograph, which will help scientists study exoplanets.  Outside of the three main space agencies involved in the Webb telescope, NASA, ESA, and CSA, “Thousands of scientists, engineers, and technicians from 14 countries, 29 U.S. states, and Washington D.C. contributed to build, test, and integrate Webb,” stated Lynn Jenner.  The JWST will be a general-purpose observatory, meaning that its observing plans will be determined from competitively selected proposals presented by scientists from around the world (Jenner).  International involvement in projects like the James Webb Space Telescope helps to build the relationship between the various countries.  It creates a common goal to work towards and fosters communication and understanding between the individuals involved that represent their home country.  In the end, international collaboration on the James Webb Space Telescope will result in a more united Earth.

After its launch in late October, JWST will travel to the second Lagrange point about 1 million miles away from Earth.  Lagrange points are the places where the gravitational forces acting on an object are balanced, in other words, three objects can orbit each other while maintaining their relative positions to one another (“Orbit”).  Orbiting at the second Lagrange point allows Webb’s sun shield to protect the mirrors from the light and heat of the sun and earth, and it allows Webb to stay in line with Earth as it orbits the sun.  Once the telescope has reached its orbit point, it will spend the next few months setting up.  Its first task will be to deploy the solar panels to power rocket thrusts that maintain its orbit.  In the first week the massive sunshield will fan out and within the first fortnight the primary mirror will unfold its side panels (“Orbit”).  It will take up to six months until Webb will be able to perform scientific operations.

One of the things that sets the James Webb Space Telescope apart from previous space telescopes is its complex and revolutionary engineering.  The most striking engineering advancement is Webb’s primary mirror.  It is nearly three times as large as Hubble’s mirror at 6.5 meters in diameter .  This will give Webb about 6.25 times the collecting area that Hubble had and a greater field of view and better spatial resolution than the Spitzer Space Telescope had available (“Comparison: Webb vs Hubble”).  Beryllium, a light yet strong metal used in everything from springs to jets, composes the primary mirror.  Beryllium can hold its shape across a wide range of temperatures, it’s not magnetic, and it effectively conducts heat and electricity (“Mirrors”).  Due to the great size of Webb’s mirror, it had to be able to fold to fit in the rocket, therefore the engineers made the mirror out of hexagonal segments.  Hexagons are the best choice because they don’t leave gaps in the mirror (circular segments would), and they create a roughly circular shape.  A circular mirrors is vital because it focuses the light to the center where the detectors are (“Mirrors”).  An oval mirror would result in images elongated in one direction and a square mirror would send most of the light away from the central area of the mirror (“Mirrors”).  In order for Webb to reach a perfect focus, tiny mechanical motors called actuators were attached to the back of the primary and secondary mirrors.  “Aligning the primary mirror segments as though they are a single large mirror means each mirror is aligned to 1/10,000th the thickness of a human hair” (qtd. in Mirror).  The design and development of Webb’s mirror has led to breakthroughs in engineering that will help with future telescopes and satellites.

Despite the huge importance of advancements in engineering and strengthened  international ties, the most valuable thing the James Webb Space Telescope will provide us is knowledge about our universe.  Over the years Hubble has been able to provide us with a slew of information, but because the space shuttle is no longer around to service it, Hubble will break down sometime in the next decade.  The Hubble Space Telescope and the James Webb Space Telescope are fundamentally different.  “JWST isn’t a direct successor to Hubble: Whereas Hubble is sensitive to visible wavelengths plus small bands of ultraviolet and near-infrared, JWST ranges from orange and red visible light to mid-infrared” (Clery 389).  Webb’s sensitivity to infrared light will allow us to observe the first stars and galaxies in the universe.  The oldest stars and galaxies are the farthest away from us because of the expansion of the universe (Reichhardt 141).  However, we won’t observe these objects in their current state, but rather as they were 13.6 billion years ago when they formed (“First Light”).  The speed of light is incomprehensibly fast, but it is still not infinite.  This means that light from distant objects takes time to reach us. Therefore, the light that reaches us from distant stars and galaxies is 13.6 billion years old.  We can’t see the “up-to-date” light because it is just beginning its long journey.  Because the universe is expanding and thus space is expanding, the light traveling through that space stretches to longer wavelengths (“First Light & Reionization”).  Longer wavelengths correspond to infrared light, whereas shorter wavelengths correspond to visible and ultraviolet.  With the James Webb Space Telescope, we will be able to capture the light that the expansion of the universe has shifted to the red and infrared end of the spectrum.  This will allow us to look at the oldest stars and galaxies in our universe, something we have never done before.

Have you ever wondered how galaxies were formed, how the chemical elements are distributed through the galaxies, or what happens when small and large galaxies collide? (“Assembly of Galaxies”).  These are all questions that the Webb telescope will be able to help us answer.

By studying some of the earliest galaxies and comparing them to today’s galaxies we may be able to understand their growth and evolution. Webb will also allow scientists to gather data on the types of stars that existed in these very early galaxies. Follow-up observations using spectroscopy of hundreds or thousands of galaxies will help researchers understand how elements heavier than hydrogen were formed and built up as galaxy formation proceeded through the ages. (“Assembly of Galaxies”)

Comparison is one of the most effective ways to learn more about a subject.  The JWST will allow us to compare old galaxies to new in order to learn about the process of their formation.

Another aspect of astronomy that Webb will help us to understand is the birth of stars and protoplanetary systems.  Huge clouds of gas and dust called nebulae form stars and early planetary systems.  Because it’s so gassy and dusty, we are unable to see the objects inside nebulae at visible wavelengths.  However, since infrared light, also known as infrared radiation, is essentially heat (at least we feel it as heat), it can be detected through the gas and dust of nebulae (“Birth of Stars”).  Imagine that I put my hand in a garbage bag, then took a picture using a regular camera.  In the picture, I would see only the garbage bag, not my hand.  Yet, if I took a picture with an infrared camera, I would see my hand, because the infrared radiation given off by my hand can be detected through the bag.  With its ability to see through the gas and dust of nebulae, Webb will help scientists to answer many questions about the birth of stars and protoplanetary systems, such as how clouds of gas and dust collapse form stars, why a majority of stars form in groups, and precisely how planetary systems form (“Birth of Stars”).

Arguably, one of the most exciting areas of research in astronomy is the study of exoplanets. “When JWST was conceived, studying the atmospheres of exoplanets was not on the minds of its developers.  Then in 2005, photons from the atmospheres of an exoplanet were detected for the first time using the Spitzer Space Telescope” wrote Kevin Heng, professor of astronomy and planetary science at the University of Bern.  This development, known as Spectroscopy, has allowed scientists to detect the various elements and molecules that make up the atmospheres of exoplanets, and prompted changes to the design of the JWST in order to prepare it for studying exoplanets.  Spectroscopy is essentially the study of matter via light.  When a planet transits a star, the light passes through the planet’s atmosphere.  The wavelengths of light that are absorbed in the planet’s atmosphere reflect the elements and molecules present in the atmosphere (“How Webb will Study Atmospheres”). Webb surpasses the abilities of Hubble and Spitzer to study exoplanets in two ways: First, its large mirror lets in more light which allows it to study fainter targets.  Second, the instruments on Webb support a greater range of frequencies and are more sensitive than any previous telescope (Heng 86).  Unfortunately, Webb does not have unlimited time, so scientists will have to carefully choose which planets they study.  The easiest planets to study are gas and ice giants.  The reason for this is the dip in light that happens when they transit their stars is easier to detect because of their large sizes (Heng 86).  According to Heng, the JWST will be able to study “a couple hundred” ice and gas giants.  This is extremely exciting because such a large sample will allow scientists to see statistical trends in their composition and properties.  Gas and ice giants have what are called primary atmospheres, whereas smaller rocky planets like Earth, Mars and Venus have secondary atmospheres.

Primary atmospheres are composed of the remnant gas of the protostellar nebula used to construct the star and its orbiting exoplanets and are predominantly made of hydrogen. … Secondary atmospheres originate from the geology (or biology) of an exoplanet. … Generally, we expect secondary atmospheres to be made up of heavier elements; if so, they would be more compact and thus more difficult to detect. (Heng 87)

Webb will only be able to study about 12 small, Earth-like, exoplanets.  The reason for this is that small exoplanets require more telescope time, they are more difficult to detect in the first place, and the makeup of their atmospheres is harder to determine.  Regardless of this limit, Webb will give us fantastic insight into all kinds of exoplanets and aid us in our quest to find life outside of Earth.

However, the James Webb Space Telescope is often criticized for its high cost and numerous delays.  The original cost estimate of the telescope was $500 million dollars in 1996, and it was expected to launch in 2011 (Clery 389).  Since then the launch date has been postponed several times and the cost has far exceeded the original estimate. In 2001, a report from the National Research Council priced Webb at $1 billion dollars (Cowen).  Two years later the budget more than doubled to $2.2 billion.  Another two years after that in 2005, staff at NASA reported that the JWST would cost $3.8 billion.  Later in 2010, an independent panel predicted the final cost of Webb to be $6.5 billion dollars (Cowen).  Today, the cost is capped at $8.8 billion.  Daniel Clery, a science correspondent from the U.K., writes “In 2011, when NASA reported to Congress that the launch would likely slip to 2018 and the cost total more than $8 billion, the House of Representatives appropriations committee responsible for science voted to cancel the program” (Clery 389).  Because of the efforts of astronomers, the JWST was not canceled.  However a cap was placed on the cost of the telescope and its expenses were closely monitored from that point onward.

It is important to note that deception is common when it comes to estimating the cost of NASA projects so the committees will approve as many projects as possible.  Because of this practice, the cost overruns of the James Webb Telescope are partly due to an initial underestimate of its cost. “It’s a game of lie and I’ll swear to it.  The whole community talks itself into unrealistic cost estimates… Everyone knows it’s wrong.  Every engineer knows it utterly without foundation, but engineers aren’t making decisions” (qtd. in Cowen) says NASA administrator Mike Griffin.  Beyond the issue of an underestimated price, the Webb telescope is a highly complex tool.  With its deployable sunshield and huge segmented mirror, engineers are having to do things no engineer has ever done before (Reichhardt 142).  Blazing the trail doesn’t come cheap or without its difficulties. Webb has exceeded its cost estimates, but they weren’t accurate estimates in the first place, and it is a highly complex piece of technology which requires time and money to build.

Despite its high cost to NASA, the Webb telescope has led to breakthroughs in engineering, international partnerships, and will, once it launches, teach us more about the universe than any other telescope before it.  With its revolutionary mirror and on-board instruments, Webb will look back in time at the oldest stars and galaxies, peer into nebulae to reveal how stars and planets form, and examine hundreds of exoplanets taking us one step closer to finding alien life.  According to Heidi B. Hammel, 1/30 of NASA’s budget is allocated to the Webb Telescope and NASA’s budget itself is only about 0.5% of the federal budget (Hammel 86).  While 8.8 billion dollars may seem like a lot of money, in the grand scheme of things it is a small price to pay for insight into the workings of our universe.



Works Cited

“Canada’s Role in Webb.” Canadian Space Agency,, 17 Feb. 2020,

“Assembly of Galaxies – Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

“Birth of Stars and Protoplanetary Systems – Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

Clery, Daniel. “After Hubble: The Webb Telescope’s Troubled History Poses Challenges for Other Contenders to Replace the World’s Most Popular Space Telescope.” Science, vol. 348, no. 6233, 2015, pp. 386–391. JSTOR, Accessed 19 Feb. 2021.

“Comparison: Webb vs Hubble Telescope – Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

Cowen, Ron. “Star Cents.” Science News, vol. 179, no. 8, Apr. 2011, pp. 22–26. EBSCOhost, doi:10.1002/scin.5591790824.

“First Light & Reionization – Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

Hammel, Heidi B. “Why We Should Build Webb.” Sky & Telescope, vol. 122, no. 6, Dec. 2011, p. 86. EBSCOhost,

Heng, Kevin. “A New Window on Alien Atmospheres.” American Scientist, vol. 105, no. 2, Mar. 2017, pp. 86–89. EBSCOhost, doi:10.1511/2017.125.86.

“How Webb Will Study Atmospheres of Exoplanets”, NASA Film, 5 Feb. 2020,

Jenner, Lynn. “NASA’s Webb Telescope Is an International Endeavor.” NASA, 1 June 2020,

Jordan, Gary. “Ep 31: The James Webb Space Telescope.” NASA, 8 Feb. 2018,

“The Launch – Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

“Mirrors Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

“Planets and Origins of Life – Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

“Orbit – Webb/NASA.” James Webb Space Telescope: Goddard Space Flight Center, NASA,

Reichhardt, Tony. “US Astronomy: Is the next Big Thing Too Big?” Nature, vol. 440, no. 7081, Mar. 2006, pp. 140–143. EBSCOhost, doi:10.1038/440140a.