OrCa2 Spacecraft

12U CubeSat with reflective panels covering much of the exterior, but also including a full suite of active electronics.

OrCa2 inherited many of the same key design features of OrCa1, e.g., it is a 12U CubeSat with reflective panels covering much of the exterior, but also introduces a number of key enhancements, such as the inclusion of a full suite of active electronics.

The Georgia Institute of Technology (Georgia Tech), in collaboration with the Georgia Tech Research Institute (GTRI), has developed the Orbital Calibration 2b (OrCa2b) mission to improve space domain awareness. OrCa2b’s external panels have precise and well-characterized reflective properties that will permit various calibration activities from ground-based optical sensors, with the goal of improving the tracking and detection of resident space objects (RSOs).

OrCa2b is a 12U CubeSat designed, fabricated, assembled, and tested almost entirely in-house using GT/GTRI facilities. It will be regularly observed using Georgia Tech’s Space Object Research Telescope (GT-SORT), with additional tracking support from the International Laser Ranging Service (ILRS). A number of experiments can be conducted with these measurements, such as pose estimation, validation of RSO trajectory propagations with complementary ground-based laser ranging data, multi-spectral analysis, low-light detection algorithms, and validation of atmospheric scattering models.

Its core mission objectives are still focused on the improvement of space domain awareness through the development of improved tracking capabilities and numerical modeling. 

The OrCa2’s primary mission objectives are:

1. Provide a well-characterized orbiting target for ground-based optical measurement calibration.
2. Gather on-orbit optical measurements for assessment of space-based, or hybrid (ground and space-based), tracking methodologies.
3. Gain flight heritage on various experimental sensor and small-satellite technologies

After deployment on orbit, the spacecraft will detumble and settle into a nominal Suntracking orientation. The current insertion orbit for OrCa2 is a “dawn-dusk” sunsynchronous orbit (SSO), that will allow the panel with the solar cells mounted on it to continually point at the sun for uninterrupted power generation. Originally, OrCa2 was slated to deploy into a Geosynchronous Transfer Orbit (GTO), so a 1 cm thick shielding box was developed to provide the non-radiation-hardened electronics some protection against the high radiation levels in that orbit. When the orbit was changed to be an SSO, the structure was not modified, as the electronics compartment provides a convenient method for integration. 

The OrCa2 structure follows a 12U CubeSat standard, and closely follows the earlier design of OrCa1. It is designed to fit within a Rocket Lab/Planetary Systems Corporation Canisterized Satellite Dispenser (CSD).

The reflective panels are a high-density polyethylene material manufactured by Labsphere† that have exacting spectral properties and near-ideal Lambertian reflectance (99% diffusion).

A primary electrical power system (EPS) with a 100 Whr battery pack, a Gomspace p31 power distribution board, and an on-board computing (OBC) system driven by a BeagleBone Black running a KubOS operating system. Attitude control is managed through three aircoil magnetometers and a single CubeSpace CubeWheel reaction wheel. Attitude knowledge will be determined from a SolarMEMs fine sun sensor, a 3-axis magnetometer, and an EPSON G370 inertial measurement unit (IMU). Sub-arcsecond attitude knowledge will also be possible through post-processing of the images taken from the imager. Positioning data will be provided through an on-board L1 GPS receiver.

OrCa2 will have two communications systems. The first is an Eyestar S4 system developed by NearSpace Launch, Inc. This system utilizes the Iridium satellite network to transmit and receive low-rate data packets. This provides nearly continuous communication coverage, and will serve to transmit housekeeping and positioning information throughout the mission lifetime. The Eyestar system is not intended for high-volume data transfers, so a separate S-band communication system will be included to downlink data from the imagers and other large data sets, e.g., raw GPS data, raw IQ data, IMU time series data, etc. Bulk housekeeping downloads and software updates will also be managed through the S-band system.

The primary payloads for OrCa2 include the imager and the reflective panels. The imager is a commercially available Hi-Q camera, originally developed for the Raspberry Pi community. This is a 12 megapixel, visiblespectrum detector, that will be paired with a space-rated Schneider Citrine lens that has heritage on prior CubeSat missions

Several other secondary payloads will also be flown on OrCa2 as a series of technology demonstrations. This includes an open-source, open-hardware software defined radio (SDR), a custom EPS system, a thermal infrared (TIR) detector, and a radiation sensor. The hope is to gain flight heritage and to raise the technology readiness level (TRL) on these components, with an eye towards flying them on future CubeSat missions. 

The OrCa2 mission was supported in part from Georgia Tech Research Institute (GTRI) Independent Research And Development (IRAD) funds, the Aerospace Corporation, and the Georgia Tech School of Aerospace Engineering. Computational results were supported in part through research cyberinfrastructure resources and services provided by the Partnership for an Advanced Computing Environment (PACE) at the Georgia Institute of Technology, Atlanta, Georgia, USA. Launch and integration services for OrCa2 are being provided by Parsons Corporation, and the U.S. Space Force’s Mission Manifest Office.

• SUN SENSOR - Solar MEMS NanoSSOC-D60
• EPS - GomSpace NanoPower P31u
• OBSW - Kubos
• RWS - CubeSpace CubeWheel
• TRANSCEIVER - NearSpace Launch EyeStar-S4

• IMU - EPSON G370