NASA Developing Larger SLS Cubesat Payload Adapter; Consider A2 & A3 Payloads

NASA is looking to bolster its capabilities for deploying cubesats on the upcoming iteration of the Space Launch System (SLS); however uncertainty remains about whether secondary payloads will find their way onto the upcoming Artemis 2 and 3 launches.

Artemis 1 lwas the maiden launch of the SLS carring the uncrewed Orion spacecraft on its uncrewed mission to the Moon and back. Artemis 1 was also set to carry 13 cubesats but only 10 cubesats ready in time for integration into the payload adapted, in the fall of 2021.

Credit: NASA

NASA selected 13 cubesats, each measuring 6U in size (roughly 10 by 20 by 30 centimeters), several years ahead of the launch of Artemis 1. Since that selection, cubesat technology has progressed significantly, with the satellites growing in size to accommodate supplementary capabilities like propulsion or to house more advanced payloads. elevate our capabilities" in this domain.

"A 6U cubesat was huge back in those days" and we need to "elevate our capabilities"" - David Hitt of Jacobs Space Exploration Group 

To meet these evolving demands, NASA has unveiled a new payload adapter dubbed "Nest," specifically designed for the Block 1B version of the SLS featuring the more potent Exploration Upper Stage. The Nest adapter boasts an impressive 15 payload mounting locations, tailored to accommodate dispensers suitable for cubesats of varying sizes, including 6U, 12U, and even 27U.

The earliest application of the new Nest adapter is expected during the Artemis 5 launch – the second flight of the Block 1B version of the SLS, which is currently slated for no earlier than 2029. Currently there is no current obligation to launch cubesats on the inaugural Block 1B launch, Artemis 4, scheduled for 2028.

As for the remaining two Block 1 SLS missions, Artemis 2 and 3, their cubesat inclusion remains uncertain. NASA is continuing internal deliberations concerning near-term opportunities, indicating that final determinations are in the works. Both Artemis 2 and Artemis 3 could potentially accommodate cubesats. However, a peculiar challenge emerges for Artemis 2.

Artemis 2 CubeSat Deployment Challenge

Both the upper stage and any secondary payloads liberated from it would follow a "high ballistic trajectory," poised for an Earth reentry within hours. Meaning any cubesats launched on Artemis 2 would have an approximate eight-hour window to alter their trajectories, or they will follow the SLS upper stage on a high-altitude return trajectory.

Artemis 3 CubeSat Bus Stops

Artemis 3 is anticipated to feature multiple "bus stops" for deploying secondary payloads, akin to the approach adopted during Artemis 1. The specifics of this deployment will be solidified once the flight path is finalized.

Cubesats could potentially be selected for Artemis 3's launch, no earlier than the conclusion of 2025, contingent upon considerations such as payload mass allocation, suitability for the flight path, and alignment with NASA's scientific, technological, and exploratory objectives.

Artemis 1 CubeSats Plagued By Failure

The cubesats that journeyed aboard Artemis 1 yielded a varied set of outcomes. Some reported partial or complete success, while several experienced operational hitches. Among the 10 cubesats on Artemis 1, eight successfully established communication post-deployment, and five at least partially attained their mission objectives.

One notable success story is BioSentinel, heralded as the pioneer cubesat to conduct biological research in deep space. The spacecraft transmitted radiation environment data for nine months after its launch, at a distance of 21 million kilometers from Earth. However, cell growth did not occur onboard, likely attributed to expiration during the protracted pre-launch period.

LunaH-Map, was a cubesat intended to orbit the moon and search for water ice at its poles. Regrettably, a malfunctioning valve in the propulsion system hindered its capacity to execute the necessary maneuvers to achieve the intended orbit. NASA disclosed on August 3 that efforts to rectify the faulty valve had been discontinued, rendering the spacecraft non-operational.

Despite this setback, LunaH-Map successfully demonstrated the proficiency of its primary instrument, a neutron spectrometer, by collecting data during a flyby of the moon shortly after its November launch. 

As NASA looks towards returning humanity to the Moon, this time to stay; they will continue to look for new or improved ways to add capabilties to launch cubesats along the way.