Ambitious new space missions owe thanks to balloons
Two new NASA space missions will probe mysteries that have long stumped astrophysicists and the rest of us: How did the universe begin? What gives cosmic rays such incredible energy?
Both endeavors are rooted in NASA’s balloon science program, which for 30 years has dispatched sensitive instruments skyward tethered to enormous gas-filled balloons to troll Earth’s atmosphere.
The PIPER balloon mission (Primordial Inflation Polarization Explorer) will soar 20 miles over the earth in several flights in the next few years. The balloon-borne observatory will probe the first moments of the universe’s existence, searching for evidence to confirm that our nascent universe expanded by a trillion-trillion times almost instantly after the Big Bang.
And in August, the Cosmic Ray Energetics and Mass Instrument (CREAM), which originated as a balloon mission, was carried aboard the Space X Dragon spacecraft to its new home on the International Space Station, where it was installed and dubbed ISS-CREAM.
Now from its perch about 250 miles above the Earth, the refrigerator-sized device will provide an unprecedented look at the deluge of particles from deep space that constantly shower earth. ISS-Cream will directly sample cosmic rays unimpeded by earth’s atmosphere, measuring the high-energy particles for longer periods and at higher speeds. Scientists estimate it will gather ten times more data than it did before.
ISS-CREAM began its cosmic ray investigation in a far less rarified setting, during seven long-duration balloon flights circling the South Pole from around 120,000 feet.
The evolution of the CREAM project demonstrates the use of balloons as a test bed for space instrumentation.
“A balloon mission can go from an idea in a scientist’s head to a flying payload in about five years,” said Jason Link, a University of Maryland, Baltimore County research scientist at NASA’s Goddard Space Flight Center, where CREAM was designed and built. “In fact, many scientists who design experiments for space missions get their start in ballooning. It’s a powerful training ground for researchers and engineers.”
The scientific balloons are made of a lightweight polyethylene film, similar to sandwich wrap. The most commonly used balloons can inflate to 40 million cubic feet, big enough to fit a football stadium. Inflated with helium gas, they float at altitudes around 120,000 feet, more than twice as high as commercial airplanes. The balloons carry payloads weighing up to 8,000 pounds, about the weight of three small cars.
NASA’s Balloon Program and private industry continue to investigate the potential future use of balloons to explore other planets and space bodies. NASA has focused on Mars, Venus and Titan for possible use of scientific balloons to gather data where platforms such as satellites and rovers will not work.
Balloons aren’t foolproof. BETTII, a complex balloon mission intended to investigate cold objects emitting light in the far-infrared region of the electromagnetic spectrum, was launched on June 8, 2017. The next day as the flight was nearing its end the costly payload detached from the parachute and fell 130,000 feet in 12 minutes.
“BETTII is one of the more complex balloon experiments ever flown,” said Stephen Rinehart, principal investigator at Goddard. “As a research community, we understand that this risk is necessary for the scientific and technical progress we make with balloons.”
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