How a balloon-borne experiment can do the job of the Hubble space telescope

Editors’ notes

An astronomical telescope designed to enhance the aging Hubble Space Telescope lifted off from New Zealand’s south island on April 16 2023. Nonetheless as a sphere the size of a football stadium rose silently and slowly over the Tauhinukorokio mountains, calls started coming in from residents.

Local police and radio stations, on the other hand, had been briefed by Nasa that the giant helium balloon would grab the two-ton SuperBIT telescope to 40km above sea stage, over the next three hours. The mission, whereby we were alive to, was to check whether a balloon-borne telescope may capture deep space images with excessive adequate determination to glance the unknown substance, dubbed dark matter, that is 85% of all material in the universe.

The observations and subsequent data analysis have proved that balloon-borne experiments can be fair as beneficial as those launched by rockets, nonetheless are well-known cheaper. It is miles now as a lot as scientists, govt agencies and private companies to make the most of them.

For the next month, polar stratospheric winds carried SuperBIT around the world every eight days, mainly over the Antarctic ocean nonetheless clipping the tip of South America. It went the place the wind carried it, nonetheless may discover about in any route.

Each day, solar panels recharged its batteries. At night, it photographed the sky, together with the Tarantula nebula, a gentle offer 160,000 gentle years away, and clusters of galaxies 20,000 instances farther.

Without a tripod, SuperBIT frail gyroscopes to stabilize any swinging (we stumbled on that the stratosphere is remarkably calm … aside from in turbulence above the Andes, the place SuperBIT once dropped 1,000 toes). It was the first balloon-borne telescope to achieve Hubble-admire performance for the short wavelengths of gentle that are visible to a human impress.

The balloon and the telescope persevered to work perfectly, nonetheless satellite communication hyperlinks gradually failed. We mediate radiation damaged SuperBIT’s antennae. We may gathered download data by shedding hard drives, attached to the telescope, to the ground. Nonetheless ultimately, Nasa wanted their balloon back, so we introduced the telescope down by parachute to Argentina.

This was SuperBIT’s fifth flight, constructing on ten years of graft.

Balloon advantages

Now not like orbital missions, if balloon payloads don’t work first time, they can be fastened and relaunched. This fosters uncomplicated, creative acquire. Formula now proven to work in space consist of hair gel (to sustain things), chicken roasting bags (to maintain them warm), and parts of bows frail by Olympic archers (to let them gallop).

Failure and success are both alternatives to learn. After each flight, we make-do-and-mend, or toughen the skills. For example, since cameras have rapidly purchased greater and cheaper, we have fitted SuperBIT with a original sensor each year. All this reduces costs.

Most of the stamp of traditional spaceflight is to mitigate the danger of failure. Compromises are always wanted between safety, protecting costly equipment and getting data.

If a balloon mission goes harmful, it usually matters less, because we glean the equipment back. SuperBIT was built mainly by Canadian Ph.D. students, who have already spun-out a original tech company.

Possibility management is varied for balloons, and Nasa doesn’t always glean the balance factual. Waiting for “supreme” weather and the perfectly designed balloon grounded all launches from Texas in 2017. Physically no longer attainable calculations of danger, such as a balloon bursting three instances, nearly tanked the 2023 program.

A balloon can only burst once. Nonetheless France’s and Canada’s space agencies, the US National Center for Atmospheric Research and the UK Science Research Council have all proved that a balloon can be relaunched every few days. Possibility assessment can be extra realistic. Balloon teams can continually test, play around with and toughen the course of. For rocket launches, there is one chance only.

Rising international hobby

Geography is important in growing a successful national balloon program. Nations with expansive landmass can carry out short flights within their like airspace, such as Canada and the US. Northern European international locations can exhaust stable and reliable summer time winds to lengthen flights across the Atlantic ocean, for example from Scotland to Canada.

Nations can also launch from the territory of partner nations around the world, such as the UK launching from Australia.

Geopolitics also influences the alternative of flight path: a lesson correctly learned from the rogue Chinese balloon that flew over the US in 2023 and was ultimately shot down. Crossing any nation’s airspace requires permission, and we avoid war zones or areas of struggle the place the balloon may be mistaken for a antagonistic target. That is one reason we launched from New Zealand.

Government hobby in national balloon programs is increasing, as original material science and manufacturing ways have created balloons that retain helium, lengthening flights from days to months. The US reaffirmed their hobby in a 2023 govt paper and Canada, France and Sweden have long-established balloon programs.

The UK ran a world-leading balloon program till the 1990s. Abandoning it misplaced an opportunity to train scientists and engineers into leadership roles. British teams are gathered often invited to affix French or US satellite missions, nonetheless we no longer lead or resolve what gets built. We foresee few technical, geographic or political barriers to the UK restarting a balloon program in parallel to its nascent rocket launches.

Balloons are excessive adequate

Officially, space begins 100km above sea stage. Nonetheless there is no magic line, and valuable diminutive atmosphere above 40km. There, stars stop twinkling and the sky is black. Long exposure astronomical photographs become pin sharp and reveal faint, distant objects that are blurred to astronomers on the ground.

Balloon cameras or spectrographs can also discover about down, and are excessive adequate to capture Earth observations fair admire those from satellites. They can also take atmospheric measurements around them, together with of the ozone layer in the stratosphere.

Balloons may well no longer replace all rockets, as they can’t travel greater than 40km. And although helium is a finite resource, balloons are extra “environmentally-friendly”. They require no rocket fuels at some stage in launch, don’t add to increasing space particles in orbit—and at the stop of their working lifestyles, they aren’t burnt up in the atmosphere. What’s no longer to admire?

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