# Internet of Spacecraft for Multi-Planetary Defense and Prosperity
## 5 Multi-Planetary Detection, Communications, and Defense: Live Long and Prosper
### Evolving the Networks of Survey Stations
Since the space increases over the growth of orbits, deploying more survey stations/spacecraft for planets of interest using this method will cover more space and further minimize the failure detection and warning. It is noteworthy that Figure 17 is just such an exemplary case of many; Mercury, Uranus, and Neptune are not shown for simplicity. All survey stations and spacecraft are inter-connected and can collaborate on a series of survey tasks to realize a better overall performance gain. On each Lagrange point, there may be more than one survey station/spacecraftneeded to fulfill the specific requirement. Eventually, a very large sphere of at least more than 30 AU in the radius can be covered under the SCADN so that many more space objects that previously could not be located/tracked by humans could be fully available in the database. Moreover, these survey stations/spacecraft could serve for other space exploration and scientific experiment tasks, thanks to their unique celestial coordinates. 4. All survey stations and spacecraft are expected to communicate and connect with each other using multiple state-of-the-art communications and networking technologies. Some of the unprecedented challenges for wireless communications are the very long distances over which the wireless signals need to travel and the solar flares that can seriously interrupt the radio communication. In addition, the meteorological  
Figure 17: An exemplary illustration of survey stations and spacecraft deployed under the SCADN framework; in particular, the survey stations/spacecraft are deployed at Lagrange points of the solar planets (dimensions of orbits, planets and spacecraft are not scaled). conditions on Earth and other celestial bodies can lead to degradation in wireless communications. Although the low data rate communication over very long distances in deep space is proven to be working well (such as Voyager 1 and 2 that are currently around 155.6 AU and 129.9 AU from the Sun), a high data rate can still be challenging even today. Another challenge is the significant latency. With 1 AU distance meaning 499 s for light to travel in free space, the distance between Saturn's L\({}_{3,\,\text{S-S}}\) and Saturn itself is 19 AU or 9481 s (around 158 min) for light to fly. The communication latency between Neptune and its L\({}_{3,\,\text{S-N}}\) is around 500 min. Moreover, the latency between Earth and Lagrange points of different planets varies over time. 5. Considering the challenges of wireless communications over extremely long propagation, particularly the very large latency, using Earth as the only routing point to store, exchange, and process data and telemetry commands from survey stations/spacecraft may lead to a very long latency and low efficiency. There are several potential solutions to this dilemma. For example, it would be beneficial to enable artificial intelligence (AI) and edge computing on the survey stations/spacecraft so that they could process the image and data extracted from space and determine if any detection falls into interest or any further resource (other survey stations/spacecraft and computing power) is needed to assist in the task. Moreover, any communication interruption due to interference could be mitigated when using some of the available survey stations/spacecraft as relays. Eventually, such an AI and edge computing assisted, cell-free architect can improve the overall system efficiency of wireless communications in deep space and identify the objects of interest. 6. Such a multi-task capable SCADN framework can facilitate more interesting space exploration missions and astronomical research. For example, the survey stations within the framework can be used to search for and observe exoplanets and black holes. The spacecraft/spacacships can even be dispatched to investigate any space object of interest in their vicinity so that some mysterious or strange objects (e.g., 'Oumuamua) and their origins could be better understood.