1.3 Why? (Applications)

“The stars are calling and we must go” ~ Michael Watkins

Space takes a lot of money and a lot of effort so the reasons for going to space must be compelling. Let’s get the intangible yet compelling justifications out of the way first. The notion of space instills a sense of pride and curiosity at every scale of our society, as an individual level, a country, and a world. We have been looking at the heavens since the beginning of time and have wondered what’s out there. We want to be the best as individuals and as societies, building upon the progress of our predecessors while standing out from them [Griffin]. Some of the urge to explore space is to scratch these emotional itches and inspire the next generation. Regardless, there exist plenty of reasons to justify spending a quarter of a penny of every US Congressional budget dollar on space exploration [Hawking].

_{“Why we should go to space” by Stephen Hawking. Video courtesy of NASA.}

Humanity’s justifications for space exploration are rooted in self-interest and in curiosity. If there’s one basic instinct that persists throughout all life, it is survival. Humans will become extinct at some point in the future, but by becoming a spacefaring civilization, we can prolong the inevitable. By staying on Earth, we are guaranteed extinction upon the Earth’s expiration date. Still, even before leaving Earth, humans must worry about the possibility of near-Earth objects (NEOs) that enter our atmosphere and cause a premature mass extinction, like the Cretaceous–Paleogene extinction event. By progressing space technology, we can deflect or redirect NEOs; NASA has a planetary defense coordination office dedicated to this topic! The final big-picture anthropocentric justification is the scarcity of resources on Earth that may be augmented by space resources [Wertheimer]. Asteroid mining is speculated to bring in trillions of dollars by bringing in achondrites (precious metals), which are rich in platinum group metals (ruthenium, rhodium, palladium, osmium, iridium, and platinum) used in high-performance electronics [Glester]. Other space resources include water and solar power.

Our curiosity leads us to use space as a medium to demonstrate the technology and advance science otherwise unachievable on Earth. Technological advancements may also be mixed with self-serving goals, such as satellite communications, direct broadcast, navigation, and surveillance [SMAD]. Some technologies take the advantage of the gravity-free environment, such as space manufacturing and hyper-efficient propulsion. Science data from satellites help us monitor the weather or combat climate change. Earth-observing satellites must orbit in space to sweep over large expanses of Earth’s surface and atmosphere (remote sensing) or collect in-situ measurements of atmospheric gases. A partial list of space system classifications includes communication, positioning and navigation, weather, remote sensing, and launch [Weigel]. Astronomy, astrobiology, and planetary science are predominantly sciences for the sake of knowledge. As we mature into a spacefaring civilization, these sciences will become more pragmatic.

Astronomical questions are addressed with space-based telescopes and observatories, which avoid atmospheric aberrations to achieve the clearest view of planets, stars, and galaxies. Clarity begets hypersensitive measurements that can detect exoplanets. Earth’s atmosphere absorbs much infrared and ultraviolet light so we must send telescopes into space to specifically observe these wavelengths. Some observatories are placed farther than just low-Earth orbit to escape the atmosphere; the James Webb Space Telescope will orbit the sun, a million miles away from Earth at the second Lagrange point to use the Earth as a sun shield [NASA].

Planetary science missions strive to better understand the history of our solar system and the distribution of life within it [NASA]. These missions have visited every planet and a variety of small bodies in our Solar System. The morphology these spacecraft have taken includes orbiters, probes, and rovers, with considerable efforts dedicated to Mars and future efforts dedicated to returning to the Moon. “NASA’s robotic explorers gather data to help scientists understand how the planets formed, what triggered different evolutionary paths among planets, what processes have occurred and are active, and how Earth among the planets became habitable. In searching for evidence of life beyond Earth, scientists use these data to map zones of habitability, study the chemistry of unfamiliar worlds, and unveil the processes that lead to conditions necessary for life. With this knowledge, NASA is enabling safe and effective human missions to destinations beyond low Earth orbit” [NASA].