As it readies for science observations, the James Webb Space Telescope is in the final phase. The team said today that they are about two hundred activities away from being fully operational. The 200 are part of the final phase.

The home stretch is the 17 scientific modes we need to bring online in the next two months.

The team said they are looking into the details of the science instruments to complete the project. They will be measuring the performance of the science instruments in the next couple of months.

The first official images from the Space Telescope Science Institute are expected to be made public in July, according to Klaus Pontoppidan, the project scientist.

Parts of JWST. Credit: NASA

The early release observations will be a package of spectacular color images and spectrum to demonstrate that the telescope is fully operational.

The ERO images will be color images and will be able to be seen by humans.

The observatory is close to its final temperatures. The four science instruments that have been powered on are the Near-Infrared Camera, Near-Infrared Spectrometer, Near-Infrared Imager and Slitless Spectrometer, as well as the Fine Guidance.

Scott Friedman wrote in a post that the last set of activities included items for each instrument and mechanisms for the whole observatory.

The mechanisms and detectors of the instruments have been operated. We have more work to do before we are ready for the science observations that will reveal the secrets of the universe.

This includes an extensive set of calibrations and characterizations of the instruments using a wide variety of astronomical source to test out each instrument's capabilities and strengths.

The amount of light that enters the telescope will be measured. We will measure this throughput by observing standard stars whose light emission is known from data obtained with other observatories combined with theoretical calculations.

A portion of the Large Magellanic Cloud as seen by Spitzer and now JWST. Credit: NASA/JPL-Caltech (left), NASA/ESA/CSA/STScI (right)

They will calibrate each instrument by observing a small patch of sky in a nearby galaxy, the Large Magellanic Cloud, and comparing the images to previous observations by other observatories, including the Hubble Space Telescope. There are more comparisons of the first views of the instruments here.

The team will test out the ability of Webb to do time series observations, where one takes a long series of exposures to track what is happening during a transit. This is where an exoplanet passes in front of its host star, and JWST can measure the dimming of the star's light when planet goes in front.

They need to test moving target tracking. Since the objects are always moving, we have to adjust the pointing of the JWST to keep the object centered in the field. We are learning how to take data and do a lot of other things. We are finding out what the telescope can do.

The telescope is exceeding even the most optimistic predictions of what it will be able to see. The scientists said the sharper views they are seeing hint at even more possibilities for the types of science the new observatory will be able to perform.