The Earth's atmosphere often muffles views from ground-based telescopes when observing space. Now, a research collaboration between NASA, the Canadian Space Agency, and various universities has built a new kind of telescope called Superpressure Balloon-borne Imaging telescope (SuperBIT).
SuperBIT has a mirror of 0.5 meters in diameter and is built to orbit 40 kilometers above the Earth’s surface. It is set afloat by a football stadium-sized helium balloon with a volume of 532,000 cubic meters. Both its construction and operation cost around $5 million, or 1000 times less than similar satellites.
In its final test flight in 2019, researchers found that it has excellent pointing stability, with a variation of less than one thirty-six thousandth of a degree for over an hour. This means it could take images similar in quality to those by the Hubble Space Telescope (HST), 547 kilometers (340 miles) above Earth.
Building balloon-based telescopes was not possible in the past as balloons stay adrift for just a few days. For SuperBIT however, NASA developed ‘superpressure’ balloons that can contain helium for months. This is enough time to orbit the Earth several times.
SuperBIT can also return its payload to Earth, meaning its design can be tweaked and improved over time and needn’t undergo expensive space-bourne repairs, like the HST. This is additionally useful as digital cameras upgrade every year, meaning that the telescope could be equipped with new cutting-edge cameras upon each descent, thus improving the quality of space photography faster than at present.
HST will not be repaired again after it inevitably falls. After this, the European Space Agency (ESA) and NASA will only capture images at infrared wavelengths via telescopes such as the James Webb Space Telescope or a single optical band, like the Euclid observatory. This would make SuperBIT the only way to capture high-resolution multicolor optical and ultraviolet observations.
SuperBIT is scheduled for deployment in April 2022. Its first mission will be to observe clusters of galaxies in search of dark matter.