About this page
WhereIsWebb tracks Webb’s flight to L2 in the weeks immediately after launch, its cooling to operating temperature, the major phases of the deployment/commissioning schedule, its current deployment/commissioning status, and the status of this state, as well as providing users with a 3D model of where Webb is located in a 3D solar system.
After launch and until Webb reaches its station in orbit around L2, WhereIsWebb tracks Webb’s journey to L2 by tracking its speed and distance from Earth to L2. Part of its journey to L2 WhereIsWebb will begin to follow Webb’s cooling to operating temperatures and dramatic temperature contrasts from its hot side to its cold side. It will continue to monitor temperatures until commissioning. WhereIsWebb also tracks the current deployment/go-live state of Webb and the status of that state with updates as well as the overall timeline and sequence of major deployment and go-live phases. One can also explore Webb’s location in 3D in a 3D solar system (and compare it to Hubble and other 3D spacecraft). The page is constantly updated as Webb moves, deploys, cools to operating temperature, and moves through its commissioning phases ultimately leading to the release of its first images.
WhereIsWebb works in concert with the “Deployment Explorer” page where you can explore the entire Webb deployment and provisioning sequence. Webb is the largest telescope ever launched into space. In order to integrate into the ESA Ariane 5 launcher, Webb was designed to fold up and then unfold (deploy) in flight towards L2. Within 2 weeks of launch, Webb goes from its compact launch configuration to its operational configuration that is almost the size of a tennis court. From this point on, Webb goes through its commissioning phases leading to the release of its first images. Explore the whole process interactively and explore status updates, videos, blogs and more at every step.
If you have any issues with the page, hold down the CTRL or CMD key and press the F5 key which will reload the page and should resolve all issues. (cntl/cmd shift R also works).
While Webb is in flight to L2, his trip is digitally tracked at the top of the page showing his progress in time, distance, speed, percentage of complete trip to L2. Below these numbers is a switchable timeline of DAYS/DISTANCE since launch, a thumbnail of Webb’s MOST RECENTLY COMPLETED deployment stage marking his place in TIME or DISTANCE on his 30-day journey to L2, followed by current deployment stage details displayed with larger image, info and links.
Once Webb reaches L2, this page will move on to tracking Webb’s commissioning steps, including the vital process of cooling to operating temperatures and aligning the mirrors, followed by commissioning the instrument . At this point, the top of the page will display a set of current fair weather daily temperature observations, followed by plots of those temperatures.
Deployment phases and stages
The most recently completed deployment/provisioning stage (unless marked as “Status: In Progress”) for Webb is displayed along a time/distance line that also indicates major deployment/ commissioning. A phase can consist of several steps. Note that the timing, duration and/or order of these phases and steps may change. This page displays the default/nominal timing and order. Phases mark the beginning and end of major groups of deployment stages. The most recent deployment/provisioning stage is indicated by an icon on the time/distance line and is detailed below with a larger image and links. Deployment/go-live phases and stages are displayed on line in a light blue overlay on screens large enough to display this information, otherwise hidden.
Explore ALL deployment stages
You can EXPLORE past and upcoming deployments on the way to L2 and when going live. The Deployment Explorer opens to the most recently completed Deployment/Provisioning step (unless it’s listed as “Status: In Progress”), all steps to the “left” (at the top of the tile navigation) are DONE, all steps to the “right” (on the thumbnail navigation bar at the top) are FUTURE.
Time vs. Distance View
The graduated horizontal line follows Webb’s progress on its journey to L2 orbit. It can be displayed in time view or as a percentage of the total distance traveled to reach the L2 orbit. The default display is a TIME line. Units are days. We refer to deployment events in terms of launch + elapsed time, so this view is useful for tracking deployments and time progression. Webb enters its L2 orbit at about 29.5 days on the timeline. In “distance” view, it shows the percentage of the total distance to Webb entering its L2 orbit. Note on smaller screens, labels are progressively simplified and/or removed.
Speed and distance
The speed and distance numbers displayed track the distance Webb traveled from Earth as it entered its L2 orbit. The numbers are derived from pre-calculated flight dynamics data that models Webb’s flight until it entered L2 orbit. The distance numbers displayed are approximate distance traveled as opposed to elevation. All speed and distance data is relative to an Earth-centered coordinate system.
With much higher speeds at the start of the trip, Webb covers a large percentage of the distance to L2 orbit at the start of its trip. This can be seen by switching the “time” vs “distance %” views on the “progress line”. Webb’s speed is at its peak when connected to pitcher thrust. It begins to slow rapidly after separation as it climbs the hill climbing the Earth’s gravity ridge to its orbit around L2. Note on the TIME view that Webb reaches the moon’s altitude in ~2.5 days (which is ~8% of the total travel time but ~25% of his travel distance). See the sections below on distance to L2 and arrival at L2 for more information on distance traveled to L2.
pass the moon
As noted above, this page displays Webb’s “distance traveled” as opposed to his altitude above Earth. Webb was launched from the sun-facing side of Earth and travels in a slightly curved path, so Webb’s “distance traveled” is greater than his altitude. Webb passing the Moon’s altitude is a good example of the difference, when Webb reached the Moon’s altitude (a) at launch time +~2.5 days, Webb had already traveled a distance (d) higher than the altitude of the Moon.
This page displays 2 “warm side” and 2 “cold side” temperatures on each side of the sunshade to illustrate the incredible engineering and effectiveness of the sunshade. A set of temperature observations from bellwether instruments are included which give a good indication of the temperature trends that govern commissioning activities.
Temperatures are updated once a day while Webb cools down, then once a week until the end of commissioning once they are at operational levels (see blog post: Final Temperature?). In general, temperatures change slowly, so this frequency is enough to give an overview of general trends. Temperatures are rounded to the nearest whole number and displayed in the user’s choice of Farenheit or Celsius with Kelvin in parentheses.
Distance to L2
L2 is about 1 million miles from Earth (932,056 miles/1.5 million km to be exact). But Webb never makes it to L2, he travels to get into a orbit around L2. Webb’s L2 orbit is very large and it enters its orbit before reaching the linear distance between Earth and L2. Webb’s orbit around L2 is known as the halo orbit which, rather than a single path, is an orbit that varies periodically through a series of paths around L2.
Arrival at L2 orbit
By design, Webb’s launch vehicle and trajectory puts Webb on course for an L2 orbit with only small inputs needed to fine-tune it. As he separates from the upper stage of the launch vehicle, Webb scales the gravity ridge from Earth into a halo orbit around L2. Once Webb is in his halo orbit, he will move up and down and over and along the shallow contour of the saddle at L2. Learn more about L2 in this blog entry.
To achieve the exact orbit needed, Webb’s trajectory is refined by a number of “burns” along the way. You can learn more about these Mid Course Correction (MCC) burns on the Deployment Explorer page. The final burn, MCC2, inserts Webb into the desired L2 halo orbit. The MCC2 burn is now scheduled for L+30 days. At the end of this engraving, we can say that Webb is “in L2 orbit” and therefore has “arrived at L2”.
Therefore this page, for calculation purposes, uses a distance to L2 orbit entry number (and timing) which is a sufficient distance and time after MCC2 burning to say “Webb is in L2 orbit “. Once in L2 orbit, this page will no longer track distance, but will track temperatures. The spacecraft will continue to cool to operating temperatures and numerous tests and calibrations will take place to prepare it for operations and its first images over the coming months.
Page Display Units
By default, the page loads and displays distances in miles, temperatures in Fahrenheit, i.e. English units (also known as Imperial System Units or USCS). If you would like the page to load and display in kilometers and the temperatures in degrees Celsius, i.e. metric system units, use the URLs below to select your preferred units. We do not use persistent cookies; so these URLs “store” your unit preferences. Once chosen, mark the URLs with your preferred units and use them instead of the default website link. NOTE: The EnglishMetric Page Units toggle button now reloads the page with these URLs.
KILOMETERS/metric units | MILES/English units