NASA has published a shortlist of six missions its considering for launch from the year 2022.
All are part of the space agency's “Explorers Program”, which aims to do heliophysics and astrophysics on modest budgets. The program runs “Medium-Class” missions with a budget cap of US$250m and “Missions of Opportunity” that get just $70m to play with. Over 90 Explorer missions have run since the first in 1958.
The Medium-Class missions NASA's decided to fling some exploratory cash at are:
- Arcus – an effort to explore “the formation and evolution of stars, galaxies and clusters of galaxies using high-resolution X-ray spectroscopy to characterize the interactions between these objects and the diffuse million-degrees gas that surrounds and permeates them”;
- Fast INfrared Exoplanet Spectroscopy Survey Explorer (FINESSE) – an effort to “investigate the processes that govern planet formation and global climate, and probe the mechanisms that establish atmospheric chemical composition and shape atmospheric evolution. It would perform transit spectroscopy of at least 500 exoplanet atmospheres in the visible and near infrared range for planets
- SPHEREx – AKA the 'Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer' This mission would “perform an all-sky near-infrared spectral survey to probe the origin of the universe, explore the origin and evolution of galaxies, and explore whether planets around other stars could harbor life.”
The Missions of Opportunity bidding for a green light are:
- COSI-X – The Compton Spectrometer and Imager Explorer would launch a “small complete superpressure balloon” with “wide-field-of-view telescope designed to survey the gamma-ray sky at 0.2-5 MeV, performing high-resolution spectroscopy, wide-field imaging, and polarization measurements.” The mission would “map gamma-rays from antimatter around the Milky Way's center, as well as from newly-formed radioactive elements in the debris of stellar explosions.”
- ISS-TAO – As the first acronym implies, the Transient Astrophysics Observer on the International Space Station would put a wide-field X-Ray on the ISS to “observe numerous events per year of X-ray transients related to compact objects. The mission’s primary goal is the detection of X-ray counterparts to gravitational waves produced by neutron stars merging with black holes and other neutron stars. Other targets would be supernova shocks, neutron star bursts, and high redshift gamma-ray bursts.”
NASA's already conditionally-selected a mission called “CASE”, or Contribution to ARIEL Spectroscopy of Exoplanets. CASE would provide “packaged detectors” to the ESA's planned Atmospheric Remote-sensing Exoplanet Large-survey (ARIEL). Doing so would help that effort's attempts “to understand the early stages of planetary and atmospheric formation during the nebular phase and the following few millions of years.”
Making this shortlist means the projects mentioned above have scored funding for a nine-month implementation concept study. More reviews await each project after that document is completed and assessed, but NASA is hopeful it will launch one of the missions above by the year 2022. ®