astronomy

Launch and commissioning of the James Webb Space Telescope

Launch and commissioning of the James Webb Space Telescope is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Launch and commissioning of the James Webb Space Telescope rather than just read about it. In short: The James Webb Space Telescope (JWST) is a space telescope designed primarily to conduct infrared astronomy. Its complex launch and commissioning process lasted from late 2021 until mid-2022.

Key takeaways

Launch and commissioning of the James Webb Space Telescope belongs to astronomy; place it in that map before memorising details.
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Reproduce the core statement of Launch and commissioning of the James Webb Space Telescope from memory before moving on to harder problems.

Reference excerpt

The James Webb Space Telescope (JWST) is a space telescope designed primarily to conduct infrared astronomy. Its complex launch and commissioning process lasted from late 2021 until mid-2022. The U.S. National Aeronautics and Space Administration (NASA) led JWST's development in collaboration with the European Space Agency (ESA) and the Canadian Space Agency (CSA), beginning in the late 1990s. The NASA Goddard Space Flight Center (GSFC) in Maryland managed telescope development, the Space Telescope Science Institute in Baltimore on the Homewood Campus of Johns Hopkins University operates JWST, and the prime contractor was Northrop Grumman. The telescope is named after James E. Webb, who was the administrator of NASA from 1961 to 1968 during the Mercury, Gemini, and Apollo programs. The launch (designated Ariane flight VA256) took place as scheduled at 12:20 UTC on 25 December 2021 on an Ariane 5 rocket that lifted off from the Guiana Space Centre in French Guiana. Upon successful launch, NASA administrator Bill Nelson called it "a great day for planet Earth". The telescope was confirmed to be receiving power, starting a two-week deployment phase of its parts and traveling to its target destination. A six-month commissioning phase followed of testing and calibrating scientific instruments, culminating in the first scientific results being publicly shared in July 2022. The telescope's nominal mission time is five years, with a goal of ten years. An L2 orbit is unstable, so JWST needs to use propellant to maintain its halo orbit around L2 (known as station-keeping) to prevent the telescope from drifting away from its orbital position. It was designed to carry enough propellant for 10 years, but the precision of the Ariane 5 launch and the first midcourse correction were credited with saving enough onboard fuel that JWST may be able to maintain its orbit for around 20 years instead. Space.com called the launch "flawless".

Launch

Rocket preparation Ariane 5 is a heavy lift two-stage rocket with two solid fuel boosters. It was used in its ECA variant, which offers the highest payload mass capacity. The total launch mass of the vehicle is of the order of 770,000 kg (1,700,000 lb). Spacecraft fuelling operations began on 25 November 2021, the fuelling system was disconnected on 3 December 2021, and verifications were concluded on 5 December 2021. The telescope's fuel system was filled with approximately 168 kg (370 lb) of hydrazine and 133 kg (293 lb) of dinitrogen tetroxide, needed to reach and maintain its orbit after separation from the launch vehicle. Following the rocket, which had already arrived on 29 November 2021, the telescope was moved to the final assembly building (Bâtiment d’Assemblage Final or BAF) on 7 December 2021. The payload was encapsulated inside the fairing on top of the rocket on 21 December 2021. Scientists and engineers who worked on the project described their feelings of anticipation and anxiety about the launch of the exhaustively tested nearly $10 billion instrument, commenting that it would be "an exciting moment" and they would feel "terrified the entire time".

Liftoff The launch (designated Ariane flight VA256) took place as scheduled at 12:20 UTC on 25 December 2021 on an Ariane 5 rocket that lifted off from the Guiana Space Centre in French Guiana. Upon successful launch, NASA administrator Bill Nelson called it "a great day for planet Earth". The telescope was confirmed to be receiving power, starting a two-week deployment phase of its parts and traveling to its target destination. The observatory was attached to the Ariane 5 via a launch vehicle adapter ring which could be used by a future spacecraft to grapple the observatory to attempt to fix gross deployment problems. However, the telescope itself is not serviceable, and astronauts would not be able to perform tasks such as swapping instruments, as with the Hubble Telescope. The telescope was released from the upper stage 27 minutes 7 seconds after launch, beginning a 30-day adjustment to place the telescope in a Lissajous orbit around the L2 Lagrange point. The telescope was launched with slightly less speed than needed to reach its final orbit, and slowed down as it travelled away from Earth, in order to reach L2 with only the velocity needed to enter its orbit there. The telescope reached L2 on 24 January 2022. The flight included three planned course corrections to adjust its speed and direction. This is because the observatory could recover from underthrust (going too slowly), but could not recover from overthrust (going too fast) – to protect highly temperature-sensitive instruments, the sunshield must remain between telescope and Sun, so the spacecraft could not turn around or use its thrusters to slow down.

Transit and structural deployment

The James Webb Space Telescope was released from the rocket upper stage 27 minutes after a flawless launch. Starting 31 minutes after launch, and continuing for about 13 days, JWST began the process of deploying its solar array, antenna, sunshield, and mirrors. Nearly all deployment actions are commanded by the Space Telescope Science Institute in Baltimore, except for two early automatic steps, solar panel unfolding and communication antenna deployment. The mission was designed to give ground controllers flexibility to change or modify the deployment sequence in case of problems.

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Illustrations

Worked examples

Example 1 — a first encounter with Launch and commissioning of the James Webb Space Telescope

Start with the simplest possible case. Write down what Launch and commissioning of the James Webb Space Telescope claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Launch and commissioning of the James Webb Space Telescope before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Launch and commissioning of the James Webb Space Telescope ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Launch and commissioning of the James Webb Space Telescope

In research: Launch and commissioning of the James Webb Space Telescope appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Launch and commissioning of the James Webb Space Telescope in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Launch and commissioning of the James Webb Space Telescope is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2021 in French Guiana, 2021 in science, Goddard Space Flight Center, so understanding it makes those chapters shorter.
In everyday life: Look for Launch and commissioning of the James Webb Space Telescope outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Launch and commissioning of the James Webb Space Telescope in 20 minutes

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Frequently asked questions

What is Launch and commissioning of the James Webb Space Telescope in simple terms?

The James Webb Space Telescope (JWST) is a space telescope designed primarily to conduct infrared astronomy. Its complex launch and commissioning process lasted from late 2021 until mid-2022.

Why does Launch and commissioning of the James Webb Space Telescope matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Launch and commissioning of the James Webb Space Telescope?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Launch and commissioning of the James Webb Space Telescope.