# RMCSat: An F10.7 Solar Flux Index CubeSat Mission
## 1 Introduction
The problem of under-sampling has been identified by the current observation program and a mitigation strategy of multiple ground-based stations in different longitudes has been suggested [1]. The investment required to implement this strategy could be substantial; however, if a strong correlation between 2800 MHz and another solar density flux frequency, 2695 MHz, can be established, the existing monitoring system of the latter frequency could be leveraged, with observations scaled to provide improved temporal coverage and thus more accurate F10.7 solar flux approximations. The United States Radio Solar Telescope Network (RSTN) is a distributed network of ground-based radio telescopes dedicated to measuring solar flux densities across a range of microwave frequencies from 245 to 15,400 MHz, including 2695 MHz. Four stations constitute the network, located in Massachusetts, Hawaii, Southern Italy, and Western Australia. Meaningful comparisons between RSTN and DRAO measurements are not currently possible, due to differing in  
Figure 1: Absorption windows for wavelengths within the Earth’s atmosphere. While the 10.7 cm radiation falls within a window of atmospheric transparency for transmission, the atmosphere is opaque to EUV wavelengths (10 to 120 nm) due to neutral particle absorption. The transmission of wavelengths more than 10 m is increasingly affected by charged particles in the ionosphere, with the minimum frequency of penetration governed by the local total electron content (TEC). Adapted from [9]. strument calibration standards and operational regimes between the two programs [15; 16]. As such, 2695 MHz data are currently unable to be scaled and directly substituted for F10.7 index applications. This paper introduces the mission concept and design of a space-based solution that would increase the geographical and temporal coverage of F10.7 measurements and provide redundancy to the existing solar monitoring system. A CubeSat platform is proposed by the Royal Military College of Canada (RMC) for extra-terrestrial solar flux observations of 2800 MHz and 2695 MHz frequencies. Satellite observations of 2800 MHz will increase the number and temporal coverage of daily F10.7 measurements available. The inclusion of solar flux emission observations at 2695 MHz into the mission of RMCSat allows for accurate comparisons between 2800 MHz and 2695 MHz without calibration issues, as the same instrument is collecting both frequencies at the same time. This will enable the accurate determination of the relationship between 2695 MHz and 2800 MHz flux values, act as an independent calibration source for RSTN terrestrial measurements during overlapping operations windows, and facilitate the use of RSTN flux values to critically supplement the existing F10.7 observation dataset. RMCSat is a technology demonstrator intended to validate the measurement of F10.7 from space that will allow the use of existing RSTN stations as new nodes in a continuous-observation global ground network. The use of satellite technology for this endeavor is a cost-effective approach compared to a worldwide network of perfectly calibrated solar observation stations. RMCSat is the first CubeSat mission undertaken by RMC and provides the additional benefit of being a training environment for personnel in space mission analysis and design, satellite assembly, integration and testing, and satellite operations. An overview of the RMCSat mission is presented here, describing the physics of F10.7 solar radio flux in Section 2, and the mission objective, the performance requirements, and the baseline mission concepts in Section 3. The 3U CubeSat satellite architecture is then outlined in Section 4 along with system budgets. A discussion of the future design considerations in Section 5 precedes the conclusion of the paper.