# Aerospace
## 11 Conclusions  
Small, low-cost satellites have the potential to perform targeted high-value science investigations, both as secondary payloads on traditional large planetary missions and individually using dedicated low-cost small launch vehicles. One of the major technical hurdles for interplanetary small satellites is that on arrival, they require large \(\Delta V\), several km/s particularly, to enter low-circular orbits. The study presented a detailed mission analysis for an ADEPT drag modulation concept to insert a single small satellite into a low-circular orbit around Mars and Venus as a secondary payload on a larger orbiter mission. Compared to the 1770 and 3130 m/s \(\Delta V\) required for propulsive orbit insertion into a 200 \(\times\) 2000 km orbit at Mars and Venus, aerocapture enables small satellites to perform orbit insertion with less than 35 m/s of propulsive \(\Delta V\). Additional propulsive burns may be required to correct apoapsis errors, which will require propellant and reduce mission life, but can be minimized using more advanced guidance schemes that provide better apoapsis targeting than the simple guidance scheme used in the study. The study then showed how drag-modulation aerocapture, when combined with very small B-plane targeting maneuvers, allows the delivery of multiple small satellites to various inclination orbits from a single host spacecraft or a dedicated cruise stage to form a constellation. Preliminary cost estimates indicate that by reducing the required orbit insertion \(\Delta V\) to under 50 m/s, aerocapture can potentially reduce the total mission cost of a 25 kg small satellite going to a low-circular Mars orbit from over USD 100 million to USD 20 million, nearly a factor of five. The substantial reduction in required propulsive \(\Delta V\) to enter low-circular orbit and the potential reduction in mission cost offered by aerocapture compared to propulsive insertion will enable a new paradigm of small satellite constellation concepts at Mars and Venus.  
Conceptualization, A.P.G.; Methodology, A.P.G., J.M.L. and S.J.S.; Software, A.P.G.; Writing--original draft, A.P.G.; Writing--review & editing, J.M.L. and S.J.S.; Visualization, A.P.G. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The results in this study can be reproduced using Jupyter Notebooks available at [[https://amat.readthedocs.io/en/master/mdpi-aerospace.html#adept-smallsat-aerocapture](https://amat.readthedocs.io/en/master/mdpi-aerospace.html#adept-smallsat-aerocapture)]([https://amat.readthedocs.io/en/master/mdpi-aerospace.html#adept-smallsat-aerocapture](https://amat.readthedocs.io/en/master/mdpi-aerospace.html#adept-smallsat-aerocapture)) (accessed on 7 March 2023). An archived PDF version of the Jupyter Notebooks is available at [[https://doi.org/10.13140/RG.2.2.29043.81441](https://doi.org/10.13140/RG.2.2.29043.81441)]([https://doi.org/10.13140/RG.2.2.29043.81441](https://doi.org/10.13140/RG.2.2.29043.81441)) (accessed on 7 March 2023). The study results were made with [[https://github.com/athulpg007/AMAT/tree/v2.2.22](https://github.com/athulpg007/AMAT/tree/v2.2.22)]([https://github.com/athulpg007/AMAT/tree/v2.2.22](https://github.com/athulpg007/AMAT/tree/v2.2.22)) (accessed on 7 March 2023). A copy of the AMAT v2.2.22 source code is available at the Zenodo archive [[https://doi.org/10.5281/zenodo.7542714](https://doi.org/10.5281/zenodo.7542714)]([https://doi.org/10.5281/zenodo.7542714](https://doi.org/10.5281/zenodo.7542714)) (accessed on 7 March 2023).  
The authors declare no conflict of interest.