Author: Jeremy Eggers

NASA’s next super pressure balloon (SPB) mission out of Wanaka, New Zealand, is enabling a pioneering method for studying high-energy cosmic rays from space using a detector looking down on the Earth’s atmosphere.

The Extreme Universe Space Observatory on a Super Pressure Balloon (EUSO-SPB) is a mission of opportunity flying on the 2017 SPB test flight with the goal of detecting high-energy cosmic rays from the farthest reaches of space as they penetrate the Earth’s atmosphere.

As these high-energy particles enter the atmosphere, they interact with nitrogen molecules in the air and create a UV fluorescence light. EUSO will be flying at some 110,000 feet (33.5 km) looking down on a broad swathe of the Earth’s atmosphere to detect the UV fluorescence from these deep space cosmic rays coming in from above.

Angela Olinto, professor at the University of Chicago and EUSO-SPB principal investigator, discusses the mission, science, and team behind it all in this video.

The acting U.S. Ambassador to New Zealand, Chargé d’Affaires Candy Green, paid a visit to Wanaka Airport, New Zealand, March 23 to see first-hand NASA’s super pressure balloon operations, the science it supports, and the combined U.S.-Kiwi team behind it all.

While on site, Green observed the final flight readiness test of the University of Chicago’s Extreme Universe Space Observatory-Super Pressure Balloon (EUSO-SPB) payload, received updates on this year’s campaign and toured NASA’s new balloon launch pad.

In addition, Green presided over an impromptu NASA Honor Awards ceremony recognizing the contributions of a number of Kiwi officials crucial to establishing Wanaka as NASA’s mid-latitude, long-duration balloon facility.

Open House Event

During the visit, NASA, the Wanaka Airport, and the Queenstown Airport Corporation played host to a “Locals Day” Open House event, with nearly 250 members of the local community attending to learn more about the super pressure balloon technology and the science it supports.

“It was phenomenal to see such an incredible turnout from the community,” said Debbie Fairbrother, NASA’s Balloon Program chief. “We really appreciate all the support we’ve received here, the interest in our balloon program, and our partnership with the airport team. It’s just like family.”

Launch Window Opens

The launch window for opened Saturday, March 25 (NZ time), however, the opening day did not present a launch opportunity due to forecast weather.

Forecast winds are variable at times and otherwise not aligned in a direction that will support a launch opportunity. Winds need to be light and flowing in a reliably easterly direction to support a launch attempt.

“Given all the variables we work with, the least of all being Mother Nature, seeing favorable launch conditions on the first day of a campaign’s launch window is uncommon for our operations,” said Gabe Garde, NASA mission manager for this year’s flight campaign. “As with previous campaigns, our team will assess weather daily to determine if the conditions are right to support a launch attempt.”

NASA’s Scientific Balloon Team kicked off a day-long hang test of the Extreme Universe Space Observatory-Super Pressure Balloon (EUSO-SPB) payload March 23, a key step to certifying the flight readiness of this year’s super pressure balloon mission lifting off from Wanaka, New Zealand.

The hang test is a complete test of all primary balloon systems—tracking, telemetry, communications, and flight termination systems—as well as all redundant systems to ensure the flight readiness of the balloon and payload.

“All our test and integration work is running along smoothly,” said Gabe Garde, NASA mission manager for the super pressure balloon launch. “Today’s test is the culmination of more than a year of preparation work all leading up to the team declaring the balloon and payload as flight ready for the mission. After today, much will be in the hands of Mother Nature as well as in receiving overflight clearance permissions from a handful of countries.”

Earlier in the day March 23, NASA leadership at headquarters and NASA’s Wallops Flight Facility, home to NASA’s Balloon Program, granted “Approval to Proceed” or ATP for this year’s mission.

The launch window for the 2017 New Zealand super pressure balloon mission opens March 25. NASA will assess weather conditions day-to-day beginning Friday, March 24, to determine if conditions favor a next-day launch attempt. Current weather forecasts don’t appear favorable for a Saturday launch due to precipitation and winds; however, a final assessment won’t be made until March 24.

Later today, March 23, the Wanaka Airport and the NASA and Science teams on-site will host a Locals Day Open House event from 4 to 6 p.m. at the Wanaka Airport main hangar. Visitors will have the opportunity to learn more about the super pressure balloon technology, the EUSO-SPB science instrument flying on this year’s mission, and to meet and talk with the engineers and scientists who make it all happen.

For more information on the EUSO-SPB mission, see: http://astroserve.mines.edu/euso_spb/2017-spb.html.

For more information on NASA’s Scientific Balloon program, see: www.nasa.gov/scientificballoons.

While the launch window for NASA’s next Super Pressure Balloon launch from Wanaka, New Zealand, opens March 25, there are a number of factors that need to align prior to making an actual launch attempt.

Operationally, all the balloon systems—power, communications, telemetry, etc.—need to be checked out and tested. Today, as seen in the accompanying video, the team completed a test integrating the balloon to the recovery parachute. Later this week, the team will conduct a hang test of the integrated payload/gondola—literally suspending the payload from the launch vehicle—to ensure system compatibility prior to operations.

Administratively, NASA is working closely with the U.S. Department of State to secure overflight clearances from countries in the southern hemisphere that could potentially be in the balloon’s flight path. In addition, the team will have an “approval to proceed” meeting with senior managers later this week to ensure the flight readiness of the balloon.

Finally, there’s Mother Nature, who has an ever-present seat at the table when it comes to deciding when to attempt a launch. Managers assess weather conditions 13 hours before the beginning of initial launch preparations to determine whether or not conditions are conducive for launch. Winds need to be light and flowing in a reliable direction both at the surface and at 300 meters (1,000 feet). Since the balloon flight train is nearly 300 meters long, an inconsistent wind pattern could cause a shearing effect once the balloon is launched. Also, winds in the stratosphere at a pressure altitude of 7 millibars (about 110,000 feet or 33.5 km) are key to watch as that is where the balloon will fly once launched.

So, while NASA’s Balloon Team can confidently say the launch window will open March 25, the alignment of all these conditions (with Mother Nature issuing a final go for launch) may not occur at the beginning of the window. NASA will assess launch conditions daily and issue updates on whether or not a launch attempt is scheduled.

And, so begins an incredible exercise of patience and flexibility that is the hallmark of any NASA balloon launch campaign.

Aviators, skydivers and other altitude-seeking enthusiasts flying out of Wanaka Airport, New Zealand, are double taking at a new topographical feature reminiscent of an alien crop circle.

Rest assured, the nearly 2,000-foot (600-meter) diameter circle with a pie-shaped wedge on one side and spokes on the other is no extraterrestrial footprint and it’s definitely no hoax. It’s NASA’s newest launch pad for launching the agency’s most advanced high-altitude, heavy-lift scientific balloon: the super pressure balloon.

Construction on the project began in earnest Feb. 28 to meet a balloon launch date that could be as early as March 25. By the time the project is complete, nearly 2,000 loads of gravel will be trucked in and compacted to form the pad.

The four spokes emanating from the center and toward the west, each nearly 1,000 feet (300 meters) long, align with magnetic compass directions at 240, 260, 290 and 320 degrees. On launch day, balloon flight experts from NASA’s Columbia Scientific Balloon Facility will assess meteorological data and determine if the conditions are suitable to support a launch opportunity. If so, the wind direction—reliably toward the east at the Wanaka Airport during the fall—will determine which spoke the team will use to layout the nearly 800-foot-long flight train, which consists of the balloon film (493 feet long/150 meters) and recovery parachute with cable ladder (279 feet long/80 meters).

The balloon launch vehicle, a specially outfitted heavy-duty crane, will stage near the center of the circle with the balloon gondola suspended by the crane. After the balloon is inflated and released, the pie-shaped area allows the crane operator room to maneuver and make last second tweaks to ensure the balloon flight train is nearly perpendicular to the ground prior to release/launch.

The new pad is the first major project in developing a long-term super pressure balloon launch site in Wanaka. Earlier in 2017, NASA signed a 10-year lease with the Queenstown Airport Corporation to conduct balloon operations from a newly acquired piece of land adjacent to the Wanaka Airport.

In preparation for NASA’s next Super Pressure Balloon flight from Wanaka, New Zealand, NASA’s balloon team unpacked the top and bottom fittings of the balloon March 17 to perform test and integration work prior to launch.

The 18.8-million-cubic-foot (532,000-cubic-meter) balloon is enormous – about the size of a football stadium – when fully inflated. The balloon’s inflated shape is an oblate spheroid, or less technically, it’s the shape of a pumpkin. The fittings are essentially the north and south poles of the spheroid. The top fitting has valves where inflation tubes are connected to the balloon. The bottom fitting connects to a parachute, and then the parachute connects to the balloon gondola, which houses the payload and supporting instruments.

Given that the balloon is made of 22 acres (8.9 hectares) of polyethylene film and weighs 5,240 pounds (2,377 kilograms), unpacking the balloon is not a trivial activity. Nearly a dozen technicians working different functions carefully opened up the steel-plate-lined shipping box containing the balloon. From there, an overhead crane was used to lift the fittings out while the team worked along either side of the balloon to keep the film safe during the overall operation.

NASA is currently targeting no earlier than March 25 for launch. The 2017 mission is a continuation of efforts to test and validate the SPB technology, a technology that could significantly expand flight opportunities for missions requiring long duration flights with day/night exposure in a flight regime that closely mimics space. In addition, the balloon team will fly a fluorescence detector and supporting technologies for the University of Chicago’s Extreme Universe Space Observatory, a high-energy cosmic ray particle astrophysics payload. This suborbital flight is a precursor for a mission being planned to launch the EUSO telescope to and install it on the International Space Station (ISS).

Read more about the EUSO-SPB team and their mission at their blog site here: http://astroserve.mines.edu/euso_spb/Blog.html

NASA’s Balloon Program Office successfully completed the second test flight of its Super Pressure Balloon (SPB) at 3:54 p.m. EDT, Saturday, July 2, setting a new flight duration record for a mid-latitude flight of a large scientific research balloon.

The mission, which began at 7:35 p.m. EDT, May 16 (11:35 a.m., May 17, in New Zealand time), launched from Wanaka, New Zealand, and ran a total of 46 days, 20 hours, and 19 minutes.

“We’re extremely pleased with the flight time we achieved with this mission, far and away the longest mid-latitude flight of a NASA heavy-lift balloon to date,” said Debbie Fairbrother, NASA’s Balloon Program Office chief. “We’ll continue to strive for even longer duration flight, 100 days or more, and what we learn from this year’s mission will help take us there.”

Having identified a safe landing area over the southern tip of Peru, balloon operators from NASA’s Columbia Scientific Balloon Facility in Palestine, Texas, sent flight termination commands at 3:14 p.m. EDT, July 2. The 18.8-million-cubic-foot (532,000-cubic-meter) balloon then separated from the payload rapidly deflating, and the payload floated safely to the ground touching down in a mountainous area about 20 miles north of Camana, Peru. NASA coordinated with officials in Peru prior to ending the balloon mission; recovery of the payload and balloon is in progress.

The decision to conclude the mission came after NASA’s balloon operators noted altitude variations during the last few weeks of the flight over the Pacific Ocean. The variance occurred at night and especially when flying over cold storms, with temperatures dropping as low as negative 80 degrees Celsius.

“Balloons are thermal vehicles, and some altitude variance isn’t uncommon during periods of extreme cooling and heating,” said Fairbrother. “Given the occasional periods of altitude variation we noted, and at times the magnitude we observed, we’re eager to retrieve the balloon and payload so we can analyze the flight data and balloon.”

Engineered to fly at 110,000 feet through the day/night cycle, at times the balloon dropped as low as 80,000 feet with the lowest drop nearing 70,000 feet when flying over a severe cold storm. However, at sunrise, the balloon always ascended back to 110,000 feet and repressurized.

One possible explanation for the greater degree of variance seen in this year’s flight, according to program officials, is that the balloon may have bled off some helium during one of the initial, harsher cold storms and then resealed itself. More data is needed, however, to determine the cause of the variance, underscoring the importance of recovering the balloon and payload for analysis.

“At its core, this was always a test flight,” said Fairbrother. “We’re looking forward to the this next phase of analysis. We’ll apply any lessons learned to future missions as we continue to eye our 100-day duration goal.”

A number of “firsts” were marked by this year’s SPB flight. It was the first time SPB carried a science payload, the Compton Spectrometer and Imager (COSI), during a mid-latitude flight. The science team from the University of California, Berkeley, detected their first gamma ray burst May 30. Gamma ray bursts are comprised of the most energetic form of light and can last anywhere from milliseconds to several minutes. The phenomenon is associated with many types of deep space astrophysical sources, such as supernovas and the formation of black holes. The COSI gamma ray telescope observed the burst for nearly 10 seconds.

Also, the balloon is the first to complete a mid-latitude circumnavigation, doing so in just 14 days, 13 hours, and 42 minutes. In addition, for NASA’s Balloon Program overall, it was the first time in nearly 25 years the team operated balloons in the northern and southern hemispheres concurrently, with SPB flying in the southern hemisphere and then with balloon flight operations in Palestine, Texas. The Texas flight, known as the Balloon-borne Imaging Telescope (SuperBIT), launched June 30 and ran for just over 10 hours.

“This mission marked the most rigorous test yet of a super pressure balloon and brings the NASA and the Orbital ATK Columbia Scientific Balloon Facility (CSBF) team even closer to setting a longer flight duration record in the future,” said John Pullen, vice president and general manager, Technical Services Division of Orbital ATK’s Space Systems Group. “Our Orbital ATK CSBF team is proud to have reestablished the CSBF facility as a launch site by successfully conducting the second mission on June 30 that contained the Balloon-borne Imaging Telescope. All of these accomplishments point to future growth for NASA’s scientific balloon program, which continues to offer reliable and affordable options for exploring the universe.”

This was NASA’s second mid-latitude super pressure balloon flight in the southern hemisphere. The first, in 2015, flew for 32 days. The overall flight duration record for an SPB is 54 days of flight, set in 2009 with a 7-million-cubic-foot SPB. The overall flight duration record of any NASA heavy-lift scientific balloon is 55 days, set by the Super-TIGER flight over Antarctica in 2013.

NASA’s Wallops Flight Facility in Virginia manages the agency’s scientific balloon flight program with 10 to 15 flights each year from launch sites worldwide. Orbital ATK, which operates NASA’s Columbia Scientific Balloon Facility in Palestine, Texas, provides mission planning, engineering services and field operations for NASA’s scientific balloon program. The CSBF team has launched more than 1,700 scientific balloons in the over 35 years of operation.

For more information on NASA’s Balloon Program, visit: www.nasa.gov/scientificballoons.

Forty days at float as of Saturday, June 25, and NASA’s super pressure balloon (SPB) is presently flying above the south Pacific as it continues on its long-duration technology test and science flight.

For the past two weeks, the balloon has etched out a whimsical groundtrack over the Pacific, slipping out of the more southerly stratospheric cyclone pattern and then floating nearly to the equator before turning west, south, and now east toward South America.

“The balloon has flown longer than its predecessor, flying through the rigors of the heating and cooling experienced in the day/night cycle,” said Debbie Fairbrother, NASA’s Balloon Program Office chief. “We continue to monitor the balloon, conducting daily analyses of the balloon’s health and trajectory.”

The balloon is designed to float at a constant pressure altitude of 7 millibars. However, the actual altitude at float is also dependent on the environmental conditions where colder weather below could lead to lower float altitudes. To date, the balloon has flown over a number of cold storms, which has resulted in the balloon losing its differential pressure and experiencing some altitude variance at night.

“The heating and cooling cycle puts a lot of stress on the balloon, but it was engineered to withstand the extra wear,” said Fairbrother. The previous record flying through the day/night cycle was 32 days, 5 hours, set in 2015 with an SPB flight that launched from Wanaka, New Zealand. The overall record for any SPB flight is 54 days, set by a 7-million-cubic-foot SPB flight over Antarctica in 2009.

Aside from the technology test of the balloon itself, the SPB is carrying the Compton Spectrometer and Imager (COSI) gamma ray telescope. The COSI team reports that the science instrument continues to collect good data.

Balloon flight operators at NASA’s Columbia Scientific Balloon Facility in Palestine, Texas, are monitoring the mission around-the-clock. Anyone can track the progress of the flight from this website: http://www.csbf.nasa.gov/newzealand/wanaka.htm 

While the Compton Spectrometer and Imager (COSI) gazes into space, another experiment is listening for whispers from the Earth itself. Housed in two humble white boxes tucked behind COSI’s solar panel, a triad of microphones are recording infrasound – sound too deep for humans to hear. Infrasound sources include volcanoes, earthquakes, ocean waves, the aurora, explosions, rocket launches…and many more.

The power of infrasound lies in its ability to travel vast distances. Higher frequency sounds dissipate rapidly: this is why bass notes carry much further than treble notes, and why thunder from a nearby lightning strike is a sharp crack, as opposed to the muffled boom of a faraway storm. The exceptionally deep sounds in the infrasound range can travel around the world multiple times.

Networks of ground-based infrasound detectors are located around the world. The sensitivity of these microphones can be their own worst enemy, however. The slightest gust of wind can overwhelm faint acoustic waves from the other side of the planet. Also, the temperature structure of the troposphere (the lowest layer of the atmosphere) tends to channel sound waves away from the Earth’s surface.

Infrasound sensors on balloons may offer significant advantages. Since they move at the same speed as the wind, they never feel its effects. Modeling suggests they can record sounds at much greater distances compared to those on the ground, and perhaps detect signals that never reach the surface at all. Despite this, no infrasound microphones have been deployed above 8 kilometers from the early 1960s to 2014, a gap of over half a century. Thus, the true diversity of atmospheric sounds remains unknown.

The infrasound payload on board the super pressure balloon was developed by the University of North Carolina at Chapel Hill. The exceptionally light (<3 kg) instrument package has three primary objectives: 1) characterize the sound field of the stratosphere 2) record an “event” (earthquake, bolide, etc) and 3) quantify the impact of local acoustic or electromagnetic noise from COSI and the balloon itself.

If successful, this experiment will collect the most infrasound data ever recorded during a single flight; indeed it will increase the time coverage of available acoustic data in the stratosphere by an order of magnitude. The detection range and sensitivity of free flying acoustic stations will be well characterized, and the magnitude of humanity’s contribution to the global infrasound wave field will be quantified.

Unlike COSI, however, the data are not telemetered. The recorder must be recovered, or the microphones will take their secrets to the bottom of the sea. Thus, the UNC team watches nervously as the superpressure balloon drifts across the open ocean, and crosses their fingers that nothing goes wrong.

Listen to previous infrasound recordings here: https://soundcloud.com/nasa/sets/high-altitude-student-platform 

Danny Bowman, University of North Carolina at Chapel Hill