OCT. 3, 2021–With the Artemis I launch campaign accelerating, four of the planned 14 CubeSats have missed their ride to the Moon. The four nanosatellites—Lunar Flashlight, CU-E3, and the twin Cislunar Explorers—missed their integration window after difficulties meeting the Artemis I launch schedule.
The satellites had previously missed their first integration window, but due to delays in Artemis I testing, were given a second chance and were scheduled to arrive at KSC’s Multi-Payload Processing Facility on September 26, 2021, with integration into the Orion Stage Adapter originally scheduled for the 28th alongside the BioSentinel satellite. However, according to insider sources, the four satellites were removed from the integration schedule while BioSentinel, the only other CubeSat remaining to be integrated, was successfully installed into the Orion Stage Adapter on schedule.
With the Orion Stage Adapter now scheduled to arrive at the Vehicle Assembly Building on Monday, October 4, ahead of integration on Thursday in preparation for Orion stacking, the four CubeSats must now find an alternative ride to the Moon.
Lunar Flashlight, the most high-profile of the four satellites, is a 6U CubeSat designed and operated by NASA’s Jet Propulsion Laboratory in conjunction with Marshall Space Flight Center, Georgia Tech, and UCLA. Its mission is to enter lunar orbit in order to uncover water ice deposits using an infrared spectrometer.
Selected by NASA’s Advanced Exploration Systems in early 2015 to fly on Artemis I, Flashlight endured months of trouble attempting to make its deadline due to its new propulsion system. The Lunar Flashlight Propulsion System, a first-of-its-kind system using a new “green” fuel pioneered by the Air Force Research Laboratory, has to be handed off to Marshall for fueling before its launch, adding an extra stop to the satellite’s journey from JPL to KSC.
The second CubeSat, the Earth Escape Explorer (CU-E3), is another 6U CubeSat developed by University of Colorado Boulder as part of the NASA CubeQuest challenge. CU-E3’s mission as an Artemis I secondary payload was to utilize a gravity assist around the Moon in order to enter a heliocentric orbit, slowly distancing from Earth, in order to test long-distance CubeSat communications technology. By the end of its one-year mission, the satellite is supposed to reach over six million miles from Earth.
The last mission to miss its launch is Cislunar Explorers, a pair of 3U CubeSats developed by Cornell University that had already been officially removed from the Artemis I manifest but had been offered a second chance due to the SLS stacking delays. The satellite pair’s mission is to test a new propulsion system based on water electrolysis, generating hydrogen and oxygen as needed to propel the spacecraft. The two satellites were to use their thrusters in order to enter lunar orbit, using commercial, hobbyist-grade cameras and sensors in order to navigate.
How these satellites will reach the Moon after missing Artemis I is uncertain. Lunar Flashlight will likely be the first to secure a new ride, due to its nature as a government-built, high-profile mission. The fate of CU-E3 and Cislunar Explorers is still unknown. However, there are still options.
For example, Spaceflight, Inc. recently unveiled their Sherpa-ES cislunar transfer vehicle, set to launch in late 2022 alongside Intuitive Machines’ Nova-C uncrewed lunar lander on a Falcon 9. Sherpa-ES is an excellent match for any of the three CubeSat missions, with the transfer vehicle offering last-mile trajectory optimization that SLS would not be able to deliver. The satellites could also fly captive on ULA’s Vulcan during lunar missions onboard Centaur V’s aft bulkhead carrier, or secure a dedicated mission on a vehicle like Rocket Lab’s Electron, like the CAPSTONE mission.
While unfortunate for the CubeSat teams, the missed integration window and Biosentinel’s final integration is a sign that Artemis I is rapidly approaching launch. With the integrated modal test now complete, the early 2022 launch date for Artemis I is closer than ever.
This article was updated on October 3, 5:40 p.m. PT, in order to reflect the Orion Stage Adapter’s integration date slipping from Tuesday, Oct. 5, to Thursday, Oct. 7. The OSA is still scheduled to move into the VAB tomorrow, Oct. 4.