|Mission type||Technology demonstration|
|Operator||University of Colorado Boulder|
|Mission duration||1 year (planned)|
|Spacecraft||Earth Escape Explorer|
|Spacecraft type||6U CubeSat|
|Bus||XB1 (Blue Canyon Technologies - BCT)|
|Manufacturer||University of Colorado Boulder|
|Launch mass||14 kg (31 lb)|
|Dimensions||10 cm × 20 cm × 30 cm|
|Start of mission|
|Launch date||November 2021 (planned) |
|Rocket||SLS Block 1|
|Launch site||KSC, LC-39B|
|Reference system||Heliocentric orbit|
|Flyby of Moon|
|Frequency||C-band: 5182 MHz|
X-band: 8447.6 MHz 
|Capacity||13 bit/s (at 27 million km) |
|EIRP||108 dBm |
The Earth Escape Explorer spacecraft is a student-driven effort at University of Colorado Boulder to design and build the spacecraft as part of the NASA CubeQuest Challenge. It will be one of thirteen CubeSats to be carried with the Artemis 1 mission into a heliocentric orbit in cislunar space on the maiden flight of the Space Launch System (SLS) and the Orion spacecraft, scheduled to launch in 2021.
Once deployed in the vicinity of the Moon, CU-E3 will use a lunar gravity assist to propel itself into heliocentric orbit, trailing the Earth and slowly distancing itself over time. By the end of its one-year mission, CU-E3 is planned to be as far as 27 million kilometers from Earth. The spacecraft will use a commercial 6U CubeSat satellite body (bus) called XB1 of Blue Canyon Technologies (BCT), measuring about 10 cm × 20 cm × 30 cm. The mass is about 14 kg (31 lb). Electric power will be provided by solar panels and stored in rechargeable lithium batteries.
The mission is focused upon advancing deep space CubeSat communication techniques using an innovative reflective array antenna, an X-band transmitter for downlink and a C-band transmitter for uplink. The antenna array is "planar", meaning all of the elements are in one plane, yet provide a large aperture for beam steering and make possible high data rates. ATLAS Ground Networks will be the ground station for their uplink and downlink communications. Their telecomm package is called High-Rate CubeSat Communication System (HRCCS).