NASA is planning to maximize the scientific potential of the maiden launch of its next generation launch vehicle, the Space Launch System (SLS), by selecting 11 tiny satellites to ride shotgun. The little probes, known as CubeSats, will be transported in the SLS's upper stage adaptor, presenting a cost-effective delivery option for experiments designed to function beyond low-Earth orbit.
The first unmanned flight of the SLS – designated Exploration Mission-1 (EM-1) – will primarily be tasked with analyzing the heavy lift capabilities of the launch vehicle itself, as well as the performance of NASA's next-generation Orion spacecraft, as it is inserted into a retrograde orbit stretching around the Moon.
The satellites are set to begin deploying roughly 10 minutes after separation from the upper stage of the launch vehicle, using a spring-based system to safely detach. The deployment of the various mini-satellites will be will be ordered and timed on the basis of their mission goals.
Each of the CubeSats will be no bigger than a large shoebox (10 x 10 x 11 cm / 3.9 x 3.9 x 4.3 in), and weigh no more than 1.3 kg (3 lb). Currently only three of the 11 minisatellite designs have been selected for further development, with further petitions still under consideration by the agency.
The three named satellites being developed to fly aboard the SLS are the BioSentinel, Near Earth Asteroid (NEA) Scout and the Lunar Flashlight. BioSentinel will be tasked to carry a payload of yeast into interplanetary space, in an attempt to better understand the detrimental effects of deep-space radiation on living organisms. The mission will last for 18 months, and could be instrumental in the development of medical treatments aimed at keeping astronauts safe over the course of a prolonged mission to another planet.
The NEA Scout mission will attempt to rendezvous with a small asteroid. Once deployed, the minisatellite will use a solar sail for propulsion. Upon arrival it will make observations on some of the asteroid's key characteristics, such as size, rotation and shape, as well as characterizing any debris fields present around the asteroid. Such scrutiny will be instrumental in informing any future manned mission to such a celestial body.
Finally, the Lunar Flashlight CubeSat will be observing Earth's own Moon, making passes over craters ordinarily shrouded in perpetual darkness. Like the NEA Scout mission, Lunar Flashlight will feature a solar sail, which it will utilize not only for propulsion, but also to reflect light into the dark craters.
This light will reflect off icy deposits in the bottom of the craters and back to the satellite, where it will be analyzed by an on-board spectrometer. Such missions are vital for pinpointing locations ripe for in-situ resource harvesting, which could in turn pave the way for a potential permanent lunar base.
With the capacity to carry 11 such missions, the 2018 launch of the SLS will transport a significant scientific payload as it puts the uncrewed Orion spacecraft through its paces.
The following video courtesy of NASA outlines the launch and deployment of the minisatellites.