NASA’s iconic airplane-borne SOFIA telescope has finally been rested

The entire world is familiar with NASA’s two iconic telescopes: James Webb Space Telescope and the Hubble Telescope that have given the American space agency an edge over others in the global space race. However, not many know about its flying observatory, an airplane-borne telescope called SOFIA or Stratospheric Observatory for Infrared Astronomy.  

SOFIA telescope has been in action for the past eight years (since 2014) being flown on unique space missions on a custom-made Boeing 747 SP jetliner that has made hundreds of flights so far. But now, unfortunately, its historic journey comes to an end, as the 2.7-metres-long telescope with a diameter of 2.5 metres and a capacity to carry up to 19 tonnes has finally retired after its final flight. Its speciality? To be able to fly 38000 to 45000 feet, that is above 99 percent of Earth’s infrared-blocking atmosphere, enabling astronomers to study the universe’s regions, that are otherwise not accessible with ground-based telescopes.  

Now many know, but the SOFIA telescope was a joint project by NASA and the German Space Agency (DLR) even though it was part of milestone NASA missions. Are you wondering what we are wondering? Why has this one-of-a-kind telescope put to rest? Turns out, it’s because flying a telescope on a jumbo-sized jet is too expensive (costs USD 85 million per year) to keep maintaining for years (yes, even for NASA!). As a result, NASA after a serious consultation with the German Space Agency has finally grounded SOFIA at its Armstrong Flight Research Centre, located off the desert region of Los Angeles. In fact, one can say, lately, SOFIA’s operating cost has been much higher than its scientific output, ultimately leading to its demise. Interestingly, this wasn’t the first time SOFIA’s funding and significance has come into question, it has been under the scanner since its first flight in 2014.  

Okay, so what made SOFIA last this long? Well, that has to be its innovative technique to study the infrared universe. As some of you might know, several celestial objects emit energy at infrared wavelengths and are otherwise invisible when viewed with visible light. As a result, only a super powerful infrared technology can observe these objects, exactly what SOFIA was designed to do. In fact, its infrared light was effective in tracing cosmic objects such as dust-shrouded stars and galaxies, without water vapour present in the Earth’s atmosphere absorbing that light. How? Well, contrary to other telescopes that sit on mountain tops and gazes at the sky, SOFIA could fly high above the water vapour (through the stratosphere at a height of 40000 feet or above) and capture a much better view.  

Thus, you can imagine that SOFIA’s legacy will live on forever; courtesy its contributions in the discovery of water molecules in the Clavius Crater, one of the largest lunar craters (located on the Moon’s southern hemisphere and visible from the Earth). This was an important finding as it helped scientists confirm that water was distributed across the entire lunar surface, and not just limited to cold, shadowed regions. Apart from this, SOFIA also helped to deduce the exact amounts of atomic oxygen present in our planet’s upper atmosphere in 2021. The other astronomical discoveries credited to the SOFIA telescope are: measuring cosmic magnetic fields permeating nearby galaxies, charting the growth of massive stars and observing Pluto’s faint shadow while it passed near a distant star. In addition, it also helped track eclipses of Saturn’s moon Titan and that of Kuiper Belt Object MU69. What’s interesting here is that, even if SOFIA will no longer carry out with its missions, the data from its last flight will help scientists to map stellar nebulas and help study magnetic fields of the Sculptor starburst galaxy.  

In fact, some of world’s distinguished astronomers are saddened at the thought of SOFIA’s farewell, as they believe the telescope was at its peak of scientific productivity, especially with respect to magnetic field and black hole research. However, majority of the scientist community agree that SOFIA has served to its optimum capacity and can no longer compete with the likes of Hubble Telescope, that has seven times the productivity as compared to SOFIA. But if you really think about it, there’s a legit reason why that’s normal. While Hubble telescope can view the universe from a single point, SOFIA can’t possibly fly nonstop. So, it’s fair to say, the comparison is unfair. Wouldn’t you agree?  

Bonus fact: SOFIA telescope will end up in an American space museum.