Session K4: Cosmic Ray Science Interest Group II

Evolution of NASA Scientific Ballooning and Particle Astrophysics Research

Particle astrophysics research has a history in ballooning that spans over 100 years, ever since Victor Hess discovered cosmic rays on a manned balloon in 1912. The NASA Particle Astrophysics Program currently covers the origin, acceleration and transport of Galactic cosmic rays, plus the Nature of Dark Matter and Ultrahigh Energy Neutrinos. Progress in each of these topics has come from sophisticated instrumentation flown on Long Duration Balloon (LDB) flights around Antarctica for more than two decades. Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging opportunities that promise major steps forward for these and other objectives. NASA has continued development and qualification flights leading to SPB flights capable of supporting 1000 kg science instruments to 33 km for upwards of hundred day missions, with plans for increasing the altitude to 38 km. This goal is even more important now, in view of the Astro2010 Decadal Study recommendation that NASA should support Ultra-Long Duration Balloon (ULDB) flight development for studies of particle astrophysics, cosmology and indirect detection of dark matter. The mid-latitude test flight of an 18.8 MCF SPB launched from Wanaka, NZ in 2015 achieved 32 days of nearly constant altitude exposure, and an identical SPB launched from Wanaka in 2016 with a science payload flew for 46 days. Scientific ballooning as a vital infrastructure component for cosmic ray and general astrophysics investigations, including training for young scientists, graduate and undergraduate students, leading up to the 2020 Decadal Study and beyond, will be presented and discussed.   

The Cosmic Ray Energetics And Mass Project

The balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment was flown for \textasciitilde 161 days in six flights over Antarctica, the longest known exposure for a single balloon project. Elemental spectra were measured for Z $=$ 1- 26 nuclei over a wide energy range from \textasciitilde 10$^{10}$ to \textgreater 10$^{14}$ eV. Building on the success of those balloon flights, one of the two balloon payloads was transformed for exposure on the International Space Station (ISS) Japanese Experiment Module Exposed Facility (JEM-EF). This ISS-CREAM instrument is configured with redundant and complementary particle detectors. The four layers of its finely segmented Silicon Charge Detector provide precise charge measurements, and its ionization calorimeter provides energy measurements. In addition, scintillator-based Top and Bottom Counting Detectors and the Boronated Scintillator Detector distinguish electrons from nuclei. An order of magnitude increase in data collecting power is expected to reach the highest energies practical with direct measurements. Following completion of its qualification tests at NASA Goddard Space Flight Center, the ISS-CREAM payload was delivered to NASA Kennedy Space Center in August 2015 to await its launch to the ISS. While waiting for ISS-CREAM to launch, the other balloon payload including a Transition Radiation Detector, which is too large for the JEM-EF envelope, has been prepared for another Antarctic balloon flight in 2016. This so-called Boron And Carbon Cosmic rays in the Upper Stratosphere (BACCUS) payload will investigate cosmic ray propagation history. The overall project status and future plans will be presented.   

EUSO-SPB and the future of Space observations of UHECRs

Space Missions will be key in the future of studies of ultra-high energy cosmic rays (UHECRs), particles that reach $10^{20}$ eV. We will discuss the progress by an international collaboration, named JEM-EUSO for Extreme Universe Space Observatory (EUSO) at the Japanese Experiment Module of the International Space Station (ISS). The collaboration built a 1 meter refractor to be flown on a NASA super pressure balloon (SPB), named EUSO-SPB. EUSO-SPB is scheduled to fly in the Spring of 2017 in the NASA SPB campaign out of Wanaka, New Zealand. It will detect for the first time fluorescence from above the UHECR showers. A smaller payload named mini-EUSO is being built for deployment to the ISS in the Fall 2017. Mini-EUSO will study the UV backgrounds relevant for UHECR observations from the ISS altitude. Plans for exploring direct Cherenkov from ultra-high energy neutrinos are also being pursued by the collaboration including the Cherenkov from Astrophysical Neutrinos Telescope (CHANT) project.   

Measuring the Cosmic Particle Radiation from electrons to actinides - HNX/TIGERISS

The Heavy Nuclei eXplorer (HNX) mission will measure the abundances of nuclei from Carbon (Z$=$6) to Curium (Z$=$96) in the cosmic radiation with the resolution to identify the atomic number of each detected nucleus. HNX will measure a significant number of actinides. HNX utilizes two high-precision instruments, the Extremely-heavy Cosmic-ray Composition Observer (ECCO) and the Cosmic-Ray Trans-Iron Galactic Element Recorder (CosmicTIGER), located in a SpaceX DragonLab capsule orbiting the Earth. This talk will discuss the motivating science, the HNX mission, the design and performance of the HNX instruments, and another new instrument, TIGERISS (Trans-Iron Galactic Element Recorder on the ISS), that will be proposed as an intermediate between SuperTIGER and HNX.