On Jan. 30th, 2020, NASA’s Spitzer Space Telescope was retired after sixteen years of faithful service. As one of the four NASA Great Observatories – alongside Hubble, Chandra, and Compton space telescopes – Spitzer was dedicated to studying the Universe in infrared light. In so doing, it provided new insights into our Universe and enabled the study of objects and phenomena that would otherwise be impossible.
For instance, Spitzer was the first telescope to see light from an exoplanet and made important discoveries about comets, stars, and distant galaxies. It is therefore fitting that mission scientists decided to spend the last five days before the telescope was to be decommissioned capturing breathtaking images of the California Nebula, which were stitched into a mosaic and recently released to the public.
NASA’s Spitzer Space Telescope has reached the end of its life. Its mission was to study objects in the infrared, and it excelled at that since it was launched in 2003. But every mission has an end, and on January 30th 2020, Spitzer shut down.
The Omega Nebula (Messier 17), also known as the Swan Nebula because of its distinct appearance, is one of the most well-known nebulas in our galaxy. Located about 5,500 light-years from Earth in the constellation Sagittarius, this nebula is also one of the brightest and most massive star-forming regions in the Milky Way. Unfortunately, nebulas are very difficult to study because of the way their clouds of dust and gas obscure their interiors.
For this reason, astronomers are forced to examine nebulas in the non-visible wavelength to get a better idea of their makeup. Using the Stratospheric Observatory for Infrared Astronomy (SOFIA), a team of NASA scientists recently observed the Swan Nebula in the infrared wavelength. What they found has revealed a great deal about how this nebula and stellar nursery evolved over time.
Astronomers estimate that in about four billion years, our Sun will exit the main sequence phase of its existence and become a red giant. This will consist of the Sun running out of hydrogen and expanding to several times its current size. This will cause Earth to become uninhabitable since this Red Giant Sun will either blow away Earth’s atmosphere (rendering the surface uninhabitable) or expand to consume Earth entirely.
In a lot of ways, Earth is getting off easy with these predicted scenarios. Other planets, such as WASP-12b, don’t have the luxury of waiting billions of years for their star to reach the end of its lifespan before eating them up. According to a recent study by a team of Princeton-led astrophysicists, this extrasolar planet is spiraling in towards its star and will be consumed in a fiery death just 3 million years from now.
NASA’s TESS (Transiting Exoplanet Survey Satellite) has found its first Earth-sized planet located in the habitable zone of its host star. The find was confirmed with the Spitzer Space Telescope. This planet is one of only a few Earth-sized worlds ever found in a habitable zone.
The world’s largest airborne telescope, SOFIA, has peered into the core of the Milky Way and captured a crisp image of the region. With its ability to see in the infrared, SOFIA (Stratospheric Observatory For Infrared Astronomy) is able to observe the center of the Milky Way, a region dominated by dense clouds of gas and dust that block visible light. Those dense clouds are the stuff that stars are born from, and this latest image is part of the effort to understand how massive stars form.
The field of exoplanet research continues to grow by leaps and bounds. Thanks to missions like the Kepler Space Telescope, over four-thousand planets have been discovered beyond our Solar System, with more being confirmed all the time. Thanks to these discoveries and all that we’ve learned from them, the focus has begun to transition from the process of discovery to characterization.
For instance, a group of astronomers was able to image the surface of a planet orbiting a red dwarf star for the first time. Using data from the NASA Spitzer Space Telescope, the team was able to provide a rare glimpse at the conditions on the planet’s surface. And while those conditions were rather inhospitable – akin to something like Hades, but with less air to breathe – this represents a major breakthrough in the study of exoplanets.
Once it is deployed to space, the James Webb Space Telescope (JWST) will be the most sophisticated and advanced space telescope in operation. Carrying on in the tradition ofHubble, Kepler, and Spitzer, the JWST will use its advanced suite of infrared imaging capabilities to study distant exoplanets, learn more about the Solar System, and study the earliest galaxies in the Universe.
After numerous delays, NASA announced last summer that the much-anticipated JWST would be ready to launch by 2021. And in what is admittedly a very nice change of pace, NASA recently indicated that this is still a go! According to their latest update, the JWST has just completed its final vacuum test and is on track for launch in March of 2021.
When it is deployed to space, the James Webb Space Telescope (JWST) will be the most powerful and advanced telescope ever deployed. As the spiritual and scientific successor to the Hubble, Spitzer, and Kepler Space Telescopes, this space observatory will use its advanced suite of infrared instruments to look back at the early Universe, study the Solar System, and help characterize extra-solar planets.
Unfortunately, after many delays, there’s some good news and bad news about this mission. The good news is that recently, the Independent Review Board (IRB) established by NASA to assess the progress on the JWST unanimously decided that work on the space telescope should continue. The bad news is that NASA has decided to push the launch date back again – this time to March 30th, 2021.
As part of their assessment, the IRB was established in April of 2018 to address a range of factors influencing Webb’s schedule and performance. These included the technical challenges and tasks that need to be tackled by its primary contractor (Northrop Grumman) before the mission can launch. A summary of the report’s recommendations, and NASA’s response, can be read here.
In the report, the IRB identified technical issues, which including human errors, that they claim have greatly impacted the development schedule. As they stated in their Overview:
“The observation that there are no small JWST integration and test problems was not initially recognized by the Webb IRB, and this also may be true of others involved with JWST. It is a most important observation that will be apparent in subsequent Findings and Recommendations. It is caused by the complexity and highly integrated nature of the observatory. Specifically, it implies, as an example, that a very small human error or test anomaly can impact the schedule by months and the cost by tens of millions of dollars.”
The anomaly mentioned in the report refers to the “anomalous readings” that were detected from the telescope during vibration testing back in December 2016. NASA responded to this by giving the project up to 4 months of schedule reserve by extending the launch window. However, in 2017, NASA delayed the launch window again by 5 months, from October 2018 to a between March and June 2019.
This delay was requested by the project team, who indicated that they needed to address lessons learned from the initial folding and deployment of the observatory’s sun shield. In February of 2018, the Government Accountability Office (GAO) issued a report that expressed concerns over further delays and cost overruns. Shortly thereafter, the JWST’s Standing Review Board (SRB) made an independent assessment of the remaining tasks.
In May of 2018, NASA issued a statement indicating that they now estimated that the launch window would be some time in May 2020. However, they chose to await the findings of the IRB and consider the data from the JWST’s Standing Review Board before making the final determination. The new launch date was set to accommodate environmental testing and work performances challenges on the sunshield and propulsion system.
According to the IRB report, this latest delay will also result in a budget overrun. “As a result of the delay, Webb’s total lifecycle cost to support the March 2021 launch date is estimated at $9.66 billion,” they concluded. “The development cost estimate to support the new launch date is $8.8B (up from the $8B development cost estimate established in 2011).”
As Jim Bridenstine, the NASA Administrator, indicated in a message to the NASA workforce on Wednesday about the report:
“Webb is vital to the next generation of research beyond NASA’s Hubble Space Telescope. It’s going to do amazing things – things we’ve never been able to do before – as we peer into other galaxies and see light from the very dawn of time. Despite major challenges, the board and NASA unanimously agree that Webb will achieve mission success with the implementation of the board’s recommendations, many of which already are underway.”
In the end, the IRB, SRB and NASA are all in total agreement that the James Webb Space Telescope is a crucial mission that must be seen through. In addition to shedding light on a number of mysteries of the Universe – ranging from the earliest stars and galaxies in the Universe to exoplanet habitability – the JWST will also complement and enhance the discoveries made by other missions.
“The more we learn more about our universe, the more we realize that Webb is critical to answering questions we didn’t even know how to ask when the spacecraft was first designed. Webb is poised to answer those questions, and is worth the wait. The valuable recommendations of the IRB support our efforts towards mission success; we expect spectacular scientific advances from NASA’s highest science priority.”
The JWST will also be the first telescope of its kind, being larger and more complex than any previous space telescope – so challenges were anticipated from its very inception. In addition, the final phase consists of some of the most challenging work, where the 6.5-meter telescope and science payload element are being joined with the spacecraft element to complete the observatory.
The science team also needs to ensure that the observatory can be folded up to fit inside the Ariane 5 rocket that will launch it into space. They also need to ensure that it will unfold again once it reaches space, deploy its sunshield, mirrors and primary mirror. Beyond that, there are also the technical challenges of building a complex observatory that was created here on Earth, but designed to operate in space.
As a collaborative project between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA), the JWST is also representative of the new era of international cooperation. As such, no one wishes to see the mission abandoned so close to completion. In the meantime, any delays that allow for extra testing will only ensure success in the long run.
Good luck JWST, we look forward to hearing about your first discoveries!