TECHNOLOGY AREA(S): Battlespace, Sensors, Space Platforms

ACQUISITION PROGRAM: Navy Ionospheric Model for Operations RTP (FNC), Air Ocean Tactical Applications POR

OBJECTIVE: Demonstrate a daytime F-region (thermospheric) wind sensor compatible with the resources available on a 6U (nominally <12kg, 10 cm x 20 cm x 30 cm) CubeSat.

DESCRIPTION: State-of-the-art sensor techniques to measure daytime thermospheric winds are either space-based in-situ or space-based remote-sensing techniques. The in-situ sensors are typically able to measure cross-track and/or along-track winds at the location of the satellite. Remote sensing instruments typically provide altitude profiles of neutral wind speed and direction, but no wind measurements that can be used operationally have yet been performed from a very small platform, such as a 6U CubeSat or smaller.

Any approach offered shall, at a minimum, enable the measurement of thermospheric wind speed, in one horizontal direction, with an accuracy and precision of at least 20m/s, and an along-track resolution of 500km or better from a 6U CubeSat platform. Preferred is a capability that will be able to cover the altitude region between 200km and 300km, either using a remote-sensing technique or an in-situ technique combined with non-spherical orbits. Candidate techniques include, but are not limited to, retarding potential analyzers, Fabry-Perot spectrometers, stepped Michelson interferometers, or Doppler asymmetric spatial heterodyne interferometers.

The altitude region is chosen, in part, to provide consistency with nighttime ground-based wind measurements utilizing the oxygen red line. Optimally, the approach would provide wind altitude profile data with vertical resolution of 25km or better. Low-cost approaches using commercial off-the-shelf (COTS) components or other high technical readiness level (TRL) components are encouraged, but not required.

This effort is focused on the sensor component, rather than a technical solution for capabilities typically provided by the spacecraft, such as commanding, downlink, on-board data storage, attitude determination, and control, power generation and storage, etc.

PHASE I: Define and develop a concept to perform the wind measurement from a 6U CubeSat platform (or smaller) considering the currently achievable resources available on such a platform, such as payload volume, power, and attitude control [Refs 2, 4]. Platform resources vary by vendor and are steadily increasing. They are available for review in the literature (see references for two examples) or directly from CubeSat vendors. The concept shall be compliant with at least one set of resources specified for a 6U CubeSat by a commercial CubeSat vendor [Refs 2, 4]. The concept description shall include a high-level design and corresponding performance modeling results based on solar minimum conditions and a local time coverage of at least six hours after sunset. All assumptions made for the performance modeling shall be clearly stated. No redundancy requirement is leveraged on the payload. For offers including in-situ sensors expected to be on platforms with low perigee orbits, details on the vertical and horizontal coverage and estimated orbit lifetimes shall be provided. Develop a Phase II plan.

PHASE II: Produce a laboratory prototype sensor based on the Phase I work. The prototype shall demonstrate the form and function of the critical sensor elements as accurately as possible. The prototype shall be capable of validating key sensor performance parameters; laboratory validations shall be conducted and documented by the awardee using the prototype hardware.

PHASE III DUAL USE APPLICATIONS: Finalize space flight sensor preliminary design for submission to Government (military and/or civilian) stake holders for consideration within future space flight opportunities to provide the data needed for next-generation whole atmosphere operational models. Federal stakeholders include PEO Space Systems (Navy), Space and Missile Command (Air Force), the Naval and Air Force Research Laboratories, the Navy and Air Force Operational Prediction Centers, NASA, and the NOAA Space Weather Prediction Center. Commercial potential exists with satellite development and operations companies.

REFERENCES:

1. Earle, G.D. et al. �A new satellite-borne neutral wind instrument for thermospheric diagnostics.� Review of Scientific Instruments 78, 114501, 2007. doi: 10.1063/1.2813343.

2. MAI-6000 6U CubeSat Bus, Adcole Maryland Aerospace, https://www.adcolemai.com/6u-cubesat-mai-6000

3. Nicholas, A.C. et al.� �WINCS on-orbit performance results.� Proc. SPIE 9604, Solar Physics and Space Weather Instrumentation VI, 960404 (21 September 2015), doi: 10.1117/12.2188403

4. Payload Specification for 3U, 6U, 12U and 27U, 2002367 Rev D, Planetary Systems Corp., Silver Spring, MD, August 2016, http://www.planetarysystemscorp.com/web/wp-content/uploads/2017/10/2002367E-Payload-Spec-for-3U-6U-12U-27U.pdf

5. Shepherd, G.G. et al.� �The Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite: A 20 Year Perspective.� Reviews of Geophysics, 50, RG2007, 2012. doi: 10.1029/2012RG000390

6. Englert C.R. et al. �Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration.� Reviews of Space Science, 212, 553-584, 2017. doi 10.1007/s11214-017-0358-4.

KEYWORDS: Space Weather; Thermospheric Wind; CubeSat Sensor; Upper Atmosphere; Remote Sensing; In-situ Sensing; Sensor Miniaturization