# Metal Additive Manufacturing for Satellites and Rockets
## 3 Microsatellites  
Microsatellites have emerged during the last few years since they are relatively inexpensive and can be used for a broad range of applications [32; 33]. There have been diverse attempts to use 3D printing techniques for different parts of microsatellites, using polymers, metals, and hybrid materials, which were previously reviewed by our group [34], so that here only a brief overview of the most recent reports is given.  
[PERSON] et al. reported on a water resisitojet thruster system called \"Aquarius\" for the EQUULEUS CubeSat, which is planned to explore the Earth-Moon Lagrange point, whose vaporization chamber is prepared from the aluminum alloy AlSi\({}_{10}\)Mg and in which the cavity and flow paths are produced by additive manufacturing by a not-nearer defined  
Figure 3: Schematics of two directed energy deposition (DED) systems: (**A**) DED system using laser with powder feedstock; (**B**) DED system using electron beam and wire feedstock. Reprinted from [21], with permission from Elsevier.  
technique [35]. The same material was used for selective laser melting of a whole CubeSat structure to improve the accessibility to internal components by using a modular backplane system [36].  
[PERSON] et al. prepared a thermal management system for high power CubeSats to reach effective heat dissipation and used additive manufacturing by ultrasonic welding combined with CNC subtractive manufacturing for the preparation of the whole system, consisting of a rollout deployable radiator, a phase change material based thermal accumulator, and structurally integrated heat pipes [37].  
In his dissertation thesis, working on a CubeSat power management subsystem for the ALSat#1 mission, [PERSON] reports that one of the partners of the consortium uses metal additive manufacturing for the structural design of the satellite, without more specific information about the exact technique [38]. A CubeSat structure was also reported to be manufactured using selective laser sintering [39].  
An antenna for low-Earth orbit microsatellites, produced by electron beam melting, was reported by [PERSON] et al. [40]. Similarly, metasurface antennas especially for CubeSats and SmallSats were built by metal additive manufacturing combined with CNC milling [41]. Larger structures, such as a solar panel, were prepared by SLM, allowing for printing a double-layer aluminum structure with I-shaped beams (Figure 4), which was found to show significantly increased shielding, improved mechanical properties, and reduced mass, as compared to a conventional aluminum honeycomb panel [42].  
Generally, diverse parts of microsatellites have been prepared by metal additive manufacturing, interestingly not only in the laboratory, but also by companies such as Rocket Lab, SpaceX, or Blue Origin [43; 44; 45]. For the future, even printing directly in space was announced [46], indicating that this area of additive manufacturing for microsatellites has already reached a certain process maturity.  
While not much progress has been reported throughout the last year regarding metal additive manufacturing of microsatellites, many studies investigated the use of metal additive manufacturing for different parts of rockets, spaceships, etc. which will be discussed in the next sections.