a markedly lower-cost structure. In 2018, the Starship system was redesigned to use stainless steel instead of carbon fiber construction, to improve performance while drastically decreasing cost. Private passenger Yusaku Maezawa has contracted to fly around the Moon in a Starship vehicle in 2023. The company's long-term vision is the development of technology and resources suitable for human colonization of Mars. SpaceX started manufacturing the first prototypes of Starship in 2019 at the company's facility in Boca Chica, Texas, later renamed Starbase. It is developing Starship using iterative design principles, aiming to build and test several prototypes at a fast pace. The first successful suborbital flight and landing of a full Starship prototype was achieved in May 2021. Starlink Starlink is an internet satellite constellation under development by SpaceX that consists of thousands of cross-linked communications satellites in ~550 km orbits. Owned and operated by SpaceX, its goal is to address the significant unmet demand worldwide for low-cost broadband capabilities. Development began in 2015, and initial prototype test-flight satellites were launched on the SpaceX Paz satellite mission in 2017. In May 2019, SpaceX launched the first batch of 60 satellites aboard a Falcon 9. Initial test operation of the constellation began in late 2020 and first orders were taken in early 2021. Customers were told to expect internet service speeds of 50 Mbps to 150 Mbps and latency from 20 ms to 40 ms. In December 2022, Starlink reached over 1 million subscribers worldwide. The planned large number of Starlink satellites has been criticized by astronomers due to concerns over light pollution, with the brightness of Starlink satellites in both optical and radio wavelengths interfering with scientific observations. In response, SpaceX has implemented several upgrades to Starlink satellites aimed at reducing their brightness. The large number of satellites employed by Starlink also creates long-term dangers of space debris collisions. However, the satellites are equipped with krypton-fueled Hall thrusters which allow them to de-orbit at the end of their life. They are also designed to autonomously avoid collisions based on uplinked tracking data. In December 2022, SpaceX announced Starshield, a program to incorporate military or government entity payloads on board a Starlink-derived satellite bus. The Space Development Agency is a key customer procuring satellites for a space-based missile defense system. Other projects In June 2015, SpaceX announced that they would sponsor a Hyperloop competition, and would build a long subscale test