• Who was James Webb? 
  • James E. Webb (1906-1992) ran the National Aeronautics and Space Administration (NASA) from 1961 to 1968, during the Presidencies of John F. Kennedy and Lyndon B. Johnson
  • Webb is considered to have done more than any other government official at the time to support both manned and unmanned space science
  • By the time James Webb retired in 1969, NASA had launched more than 75 space science missions, and landed the first human on the Moon, beginning along legacy of space exploration that continues today 
  • Why was the James Webb Space Telescope built? 
  • The James Webb Space Telescope (also known as JWST, or Webb) is by no means the first space-based astronomical observatory, but it is unique in terms of its powerful capabilities
  • Background: NASA’s Great Observatories Program launched four large space telescopes between 1990 and 2003:
    • Hubble Space Telescope (HST): Launched 1990 and designed to observe visible light and near-ultraviolet light.  It remains in operation.
    • Compton Gamma Ray Observatory (GRO): Launched 1991.  It was de-orbited in 2000 after a failed gyroscope.
    • Chandra X-ray Astronomical Facility (CXO): It was initially named the Advanced X-ray Astronomical Facility (AXAF) and was launched in 1999.  It remains in operation.
    • Spitzer Space Telescope (SST): Launched in 2003 and intended to observe in the infrared spectrum.  After it experienced a liquid helium depletion, it was removed from service in 2020.
  • Back to JWST: In 1989, the Space Telescope Science Institute and NASA held a Next Generation Space Telescope Workshop with 130 astronomers and engineers.  The group proposed that NASA investigate the feasibility of a 10 meter, passively cooled near-infrared telescope in a high-Earth orbit, or a 16 meter telescope based on the Moon.  In 1996, an 18-member committee formally recommend that NASA develop a space telescope that would search deep space in infrared light, extending our vision into deep space and back in time.  NASA agreed in 1997 and by 2002, teams were selected to build the instruments and get the James Webb Space Telescope program underway.
  • JWST, launched in 2021, now operates simultaneously with Hubble. While Hubble observes in the visible and near-ultraviolet spectrum, JWST observes in the infrared, and with significantly greater clarity, thanks to a much larger mirror, and significantly greater range possible in the infrared spectrum. 
  • Who designed, built, launched and operates the James Webb Space Telescope? 
  • NASA is the lead agency with overall responsibility for the JWST mission, in coordination with the European Space Agency (ESA) and the Canadian Space Agency (CSA). NASA’s Jet Propulsion Laboratory (JPL) was responsible for the Mid-Infrared Instrument including cryocooler and detector, NASA’s Marshall Space Flight Center developed the mirror technology and NASA’s Ames Research Center developed detector technology.
  • Northrop Grumman was NASA’s JWST prime contractor and industry team lead, and also designed and built the deployable sunshield, provided the spacecraft bus, and integrated the total system at Northrop Grumman’s Space Park facility in Redondo Beach, CA
  • Ball Aerospace built the advanced optical system, including the lightweight 25 square meter beryllium mirror system, and cryogenic actuators for each mirror segment that positioned the mirror segments within one ten-thousandth of the width of a human hair
  • L3’s Tinsley Laboratories ground and polished the mirrors, and L3 Harris integrated the components that make up the telescope’s optical system, including mirrors, combined and tested the four astronomical cameras, and rigorously tested these critical systems.
  • The European Space Agency (ESA), was responsible for the Near Infrared Spectrograph, Mid-Infrared Instrument Optics Assembly, Ariane Launch Vehicle and launch services, and the Canadian Space Administration (CSA) was responsible for the Fine Guidance Sensor/Near Infrared Imager and slitless spectrograph
  • In addition, thousands of skilled scientists, engineers and technicians from over 300 companies, universities and laboratories from 14 countries (and from 29 U.S. states and Washington D.C.) contributed to the design, assembly, test, integration, launch and commissioning of JWST
  • NASA and the JWST industry team led by Northrop Grumman, including industry partners Ball Aerospace, L3Harris, NeXolve and Raytheon, received the National Aeronautical Association’s prestigious 2022 Robert J. Collier Award for the James Webb Space Telescope
  • What scientific instruments does JWST have? 
  • Near Infrared Camera (NIRCam), which is an imager sensitive to light in the near infrared (with wavelengths just beyond those of visible light)
  • Near Infrared Spectrograph (NIRSpec), which also operates in the near infrared, with wavelengths just beyond the near infrared, but decomposes the light into its spectrum
  • Mid-Infrared Instrument (MIRI), which is JWST’s imager and spectrometer that is sensitive to light in the middle of the infrared range
  • Fine Guidance Sensor/Near Infrared Imager and Slitless Spectrograph (FGS/NIRSS), which is the guidance system used to align the telescope, and is also capable of capturing near-infrared and spectra
  • Once raw light data is captured by JWST’s sensors, it is digitized and encoded and then transmitted to Earth via a high frequency transmitter
  • On Earth, the Deep Space Network of large radio antennas receives the signals and forwards them to the Space Telescope Science Institute (STScI) in Baltimore, Maryland, where the data is translated into images for scientific study and public access. STScI also operates JWST.
  • Where in space is JWST located? 
  • Webb is located approximately 1 million miles (1.5 million kilometers) from Earth in a halo orbit around a position called the second Lagrange point (L2). This position allows JWST to remain in Earth’s shadow from the Sun, which, along with Webb’s sunshield, provides a cold and stable location required for its scientific infrared instruments to operate.
  • Why does JWST need a sunshield?
  • Webb’s sensitive telescope and instruments need to be continuously isolated from all sources of heat from the Sun, Earth, Moon, and the spacecraft itself, in order to perform its scientific mission. All of Webb’s components must be extremely cold in order to detect and observe very faint infrared images from deep space. 
  • What are JWST’s mission goals? 
  • Peer back 13.5 billion years to see the first stars and galaxies forming out of the darkness of the early universe
  • Gather observational and scientific data to understand how galaxies form and change over time
  • Gather data to understand how stars and planets are formed
  • Gather data from other planetary systems including looking for the building blocks of life
  • Gather data from objects in our own solar system
  • Key JWST facts 
  • 1996: NASA approved to develop new space telescope to view the universe in infrared light
  • 2002: NASA selects teams to build the new space telescope. TRW selected as prime (TRW later acquired by Northrop Grumman).
  • 2004: construction begins
  • 2019: final assembly and testing concludes
  • Launched: December 25, 2021
  • Launch site: Arianespace’s Guiana Space Center near Kourou, French Guiana
  • Launch vehicle: Ariane 5 ECA
  • Mission design life is 10 years but current estimates range between 10-20 years
  • Total payload mass: 6200 kg (13,670 pounds)
  • Diameter of Primary Mirror: 5 m (21.3 ft)
  • Size of Sun Shield: 197 m x 14.162 m (69.5 ft x 46.5 ft)
  • Orbit: 5 million km from Earth orbiting the L2 Point
  • Operating Temperature: under 50K (-370 F)
  • Single points of failure: Prior to Webb’s launch, there were 344 possible single points of failure in the system, meaning that if any one went wrong, the mission could be jeopardized.  Nothing did.
  • JWST cost at time of launch: $10B 
  • Webb’s major innovations 
  • Extremely precise, folding 21-foot diameter segmented primary mirror (18 segments)
  • Lightweight optics (beryllium mirrors)
  • Cryogenic actuators and mirror control
  • Wavefront sensing, to sense and control any errors in telescope’s optics
  • 5-layer sunshield design: Able to reduce temperatures from 185F (85C) on one side to -388F (-233C) on the other side
  • Sunshield coatings: Tennis court sized sunshield made of five thin layers of Kapton E with aluminum & doped-silicon coating
  • Improved infrared detectors with innovative arrays: lower noise, larger format, longer lasting
  • Micro-shutters: 100 x200micron shutters that can select many objects for simultaneous viewing
  • Cryocooler dedicated to cooling MIRI’s detectors
  • Graphite-epoxy composite backplane that had to carry 2 ½ tons of hardware and remain motionless so mirrors can see into deep space
  • Cryogenic data acquisition application-specific integrated circuit that can operate in super-cold temperatures
  • Some of Webb’s key discoveries 
  • Detected the most distant known galaxy (JADES-GS-z14-0). The Universe is 13.8 billion years old. The image Webb received from this galaxy was from when it was only 290 million years old.
  • Observed the most distant active super-massive black hole ever detected. TON 618 has a mass 66 billion times the Sun’s mass.
  • Detected the most distant and oldest black hole merger of two galaxies to date. The ZS7 system observed was 740 million years old.
  • Studied the atmospheres of several exoplanets and have detected potential bio-signatures, like dimethyl sulfide, in their atmospheres. One planet, K2-18b is a rocky world in its star’s habitable zone.
  • Detected complex organic molecules, including amino acids in some protoplanetary disks, providing evidence that the building blocks of life exist elsewhere in the universe
  • Observed the formation of numerous planets and found a new class of protoplanetary disks with ice-coated solids drifting from the outer region of the disk into the rocky-planet zone.
  • Observed massive “Red Monster” galaxies that are reddish in color due to high dust content, and that form stars at twice the usual rate for galaxies from the same era
  • Discovered Jupiter-mass binary objects (JuMBOs) within the Orion Nebula, which are planetary-mass objects (not stars) but may have a previously unknown formation mechanism at work
  • Discovered what appears to have been a Jupiter-size planet being absorbed into a star (ZTF SLRN-2020). Observations suggest the planet plunged into the star, rather than the star expanding and engulfing it.
  • Observed in great detail an unusual two-ring planetary nebula (NGS 1514) as its central slowly dying star ejects clumps of dust into space

An extensive catalog of JWST’s deep space images and pictures of the JWST spacecraft during assembly, integration, test and launch, plus articles on many of JWST’s discoveries can be found at: 

science.nasa.gov/mission/webb

The JWST scale model and display were made possible by a generous gift from Sue and Allan Frew