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10 Ways the Webb Telescope ‘Trains’ for Space

The James Webb Space Telescope will peer at the first stars and galaxies as a cosmic time machine, look beyond to distant worlds, and unlock the mysteries of the universe. But before it can do any of those things, it needs to “train” for traveling to its destination — 1 million miles away from Earth!

So how does Webb get ready for space while it’s still on the ground? Practice makes perfect. Different components of the telescope were first tested on their own, but now a fully-assembled Webb is putting all of its training together. Here are 10 types of tests that Webb went through to prepare for its epic journey:

1. Sounding Off

A rocket launch is 100 times more intense and four times louder than a rock concert! (That’s according to Paul Geithner, Webb’s deputy project manager – technical.) To simulate that level of extreme noise, Webb’s full structure was blasted with powerful sound waves during its observatory-level acoustic testing in August.

2. Shaking It Up

Webb will also have to withstand a super-bumpy ride as it launches — like a plane takeoff, but with a lot more shaking! The observatory was carefully folded into its launch position, placed onto a shaker table, and vibrated from 5 to 100 times per second to match the speeds of Webb’s launch vehicle, an Ariane 5 rocket.

3. All Systems Go

In July, Webb performed a rigorous test of its software and electrical systems as a fully connected telescope. Each line of code for Webb was tested and then retested as different lines were combined into Webb’s larger software components. To complete this test, Webb team members were staffed 24 hours a day for 15 consecutive days!

4. Hanging Out

After launch, Webb is designed to unfold (like origami in reverse) from its folded launch position into its operational form. Without recharging, the telescope’s onboard battery would only last a few hours, so it will be up to Webb’s 20-foot solar array to harness the Sun’s energy for all of the telescope’s electrical needs. To mimic the zero-gravity conditions of space, Webb technicians tested the solar array by hanging it sideways.

5. Time to Stretch

The tower connects the upper and lower halves of Webb. Once Webb is in space, the tower will extend 48 inches (1.2 meters) upward to create a gap between the two halves of the telescope. Then all five layers of Webb’s sunshield will slowly unfurl and stretch out, forming what will look like a giant kite in space. Both the tower and sunshield will help different sections of Webb maintain their ideal temperatures.

For these steps, engineers designed an ingenious system of cables, pulleys and weights to counter the effects of Earth’s gravity. 6. Dance of the Mirrors

Unfolding Webb’s mirrors will involve some dance-like choreography. First, a support structure will gracefully unfold to place the circular secondary mirror out in front of the primary mirror. Although small, the secondary mirror will play a big role: focusing light from the primary mirror to send to Webb’s scientific instruments.

Next, Webb’s iconic primary mirror will fully extend so that all 18 hexagonal segments are in view. At 6.5 meters (21 feet 4-inches) across, the mirror’s massive size is key for seeing in sharp detail. Like in tower and sunshield testing, the Webb team offloaded the weight of both mirrors with cables, pulleys and weights so that they unfolded as if weightless in space.

7. Do Not Disturb

Before a plane takeoff, it’s important for us to turn off our cell phones to make sure that their electromagnetic waves won’t interfere with navigation signals. Similarly, Webb had to test that its scientific instruments wouldn’t disrupt the electromagnetic environment of the spacecraft. This way, when we get images back from Webb, we’ll know that we’re seeing actual objects in space instead of possible blips caused by electromagnetic interference. These tests took place in the Electromagnetic Interference (EMI) Lab, which looks like a futuristic sound booth! Instead of absorbing sound, however, the walls of this chamber help keep electromagnetic waves from bouncing around.

8. Phoning Earth

How will Webb know where to go and what to look at? Thanks to Webb’s Ground Segment Tests, we know that we’ll be able to “talk” to Webb after liftoff. In the first six hours after launch, the telescope needs to seamlessly switch between different communication networks and stations located around the world. Flight controllers ran through these complex procedures in fall 2018 to help ensure that launch will be a smooth success.

After Webb reaches its destination, operators will use the Deep Space Network, an international array of giant radio antennas, to relay commands that tell Webb where to look. To test this process when Webb isn’t in space yet, the team used special equipment to imitate the real radio link that will exist between the observatory and the network.

9. Hot and Cold

Between 2017 and 2019, Webb engineers separately tested the two halves of the telescope in different thermal vacuum chambers, which are huge, climate-controlled rooms drained of air to match the vacuum of space. In testing, the spacecraft bus and sunshield half were exposed to both boiling hot and freezing cold temperatures, like the conditions that they’ll encounter during Webb’s journey.

But Webb’s mirrors and instruments will need to be colder than cold to operate! This other half of Webb was tested in the historic Chamber A, which was used to test Apollo Moon mission hardware and specifically upgraded to fit Webb. Over about 100 days, Chamber A was gradually cooled down, held at cryogenic temperatures (about minus 387 F, or minus 232.8 C), and then warmed back up to room temperature.

10. Cosmic Vision

When the Hubble Space Telescope was first sent into space, its images were blurry due to a flaw with its mirror. This error taught us about the importance of comprehensively checking Webb’s “eyes” before the telescope gets out of reach.

Besides training for space survival, Webb also spent time in Chamber A undergoing mirror alignment and optical testing. The team used a piece of test hardware that acted as a source of artificial starlight to verify that light would travel correctly through Webb’s optical system.

Whew! That’s a lot of testing under Webb’s belt! Webb is set to launch in October 2021 from Kourou, French Guiana. But until then, it’s still got plenty of training left, including a final round of deployment tests before being shipped to its launch location.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Webb 101: 10 Facts about the James Webb Space Telescope

Did you know…?

1. Our upcoming James Webb Space Telescope will act like a powerful time machine – because it will capture light that’s been traveling across space for as long as 13.5 billion years, when the first stars and galaxies were formed out of the darkness of the early universe.

2. Webb will be able to see infrared light. This is light that is just outside the visible spectrum, and just outside of what we can see with our human eyes.

3. Webb’s unprecedented sensitivity to infrared light will help astronomers to compare the faintest, earliest galaxies to today's grand spirals and ellipticals, helping us to understand how galaxies assemble over billions of years.

Hubble’s infrared look at the Horsehead Nebula. Credit: NASA/ESA/Hubble Heritage Team

4. Webb will be able to see right through and into massive clouds of dust that are opaque to visible-light observatories like the Hubble Space Telescope. Inside those clouds are where stars and planetary systems are born.

5. In addition to seeing things inside our own solar system, Webb will tell us more about the atmospheres of planets orbiting other stars, and perhaps even find the building blocks of life elsewhere in the universe.

Credit: Northrop Grumman

6. Webb will orbit the Sun a million miles away from Earth, at the place called the second Lagrange point. (L2 is four times further away than the moon!)

7. To preserve Webb’s heat sensitive vision, it has a ‘sunshield’ that’s the size of a tennis court; it gives the telescope the equivalent of SPF protection of 1 million! The sunshield also reduces the temperature between the hot and cold side of the spacecraft by almost 600 degrees Fahrenheit.

8.  Webb’s 18-segment primary mirror is over 6 times bigger in area than Hubble's and will be ~100x more powerful. (How big is it? 6.5 meters in diameter.)

9.  Webb’s 18 primary mirror segments can each be individually adjusted to work as one massive mirror. They’re covered with a golf ball's worth of gold, which optimizes them for reflecting infrared light (the coating is so thin that a human hair is 1,000 times thicker!).

10. Webb will be so sensitive, it could detect the heat signature of a bumblebee at the distance of the moon, and can see details the size of a US penny at the distance of about 40 km.

BONUS!  Over 1,200 scientists, engineers and technicians from 14 countries (and more than 27 U.S. states) have taken part in designing and building Webb. The entire project is a joint mission between NASA and the European and Canadian Space Agencies. The telescope part of the observatory was assembled in the world’s largest cleanroom at our Goddard Space Flight Center in Maryland.

Webb is currently at Northrop Grumman where the telescope will be mated with the spacecraft and undergo final testing. Once complete, Webb will be packed up and be transported via boat to its launch site in French Guiana, where a European Space Agency Ariane 5 rocket will take it into space.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.