Why should we care about space science? - with Anu Ojha

The speaker begins by expressing gratitude for being invited to speak and sets the stage for a discussion on the importance and relevance of space exploration. Despite the many challenges faced on Earth, space is prioritized due to its inspirational nature. The speaker aims to provide insight into why space exploration is crucial and plans to cover the lecture in about an hour, leaving time for questions. The speaker's roles with the United Kingdom Space Agency and other institutions are mentioned, clarifying that any opinions expressed are personal. The proximity of space, defined as 100 kilometers above Earth, is highlighted, emphasizing the difficulty of overcoming Earth's gravity for space travel. The breathtaking views from the International Space Station and the scientific and engineering challenges of space exploration are also discussed.

The speaker transitions to a live demonstration of rocket propulsion, explaining the fundamental chemistry behind rocket technology. The demonstration involves a 'whoosh bottle' using ethanol as fuel and oxygen from the air as an oxidizer. The process of vaporizing ethanol in a large drinks container simulates a rocket motor, illustrating how exothermic chemical reactions propel rockets. The speaker discusses the history of rocketry, the differences between solid and liquid fuel rockets, and the challenges of cooling fuels like kerosene and liquid hydrogen for efficient rocket propulsion. The demonstration concludes with a visual effect of a small-scale rocket combustion, emphasizing the principles of thrust and momentum change.

The speaker delves into the field of astronomy, showcasing the impact of the James Webb Space Telescope launched on Christmas Day 2021. This telescope, located 1.4 million kilometers from Earth, has already begun to transform our understanding of the universe. Images from the telescope reveal the birth and death of stars, the existence of thousands of galaxies in a small patch of sky, and the potential for more stars in the universe than grains of sand on Earth's beaches. The speaker emphasizes the importance of space-based astronomy in expanding our knowledge of the cosmos.

The focus shifts to lunar exploration, starting with the Apollo program and its geopolitical drivers during the Cold War. The speaker discusses the significance of the Moon in the night sky and uses visual aids to demonstrate the actual scale of the Earth-Moon system. The Moon's distance is shown to be much greater than commonly depicted, highlighting the vastness of space. The speaker also touches on the Apollo missions, emphasizing their achievements and the scientific value of lunar exploration. The discussion includes the long-term impact of human presence on the Moon, such as the preservation of footprints and tire tracks for millions of years.

The speaker discusses the challenges and triumphs of human space flight, starting with the economic and geopolitical reasons behind the shift from the Apollo program to the development of the space shuttle. The space shuttle was designed to reduce the cost of accessing space by being partially reusable. The speaker also highlights the Soviet Union's achievements in building space stations, leading to the collaboration on the International Space Station (ISS). The ISS is described as a continuous human presence in space, hosting scientific experiments and serving as a platform for international cooperation. The speaker also mentions the United Kingdom's involvement in human space flight, including the first British astronaut, Dr. Helen Sharman, and Tim Peake's mission.

The speaker demonstrates the necessity of pressure suits in space using a kettle of hot water and a syringe to illustrate how pressure affects the boiling point of water. The demonstration shows that lowering the pressure above a liquid reduces its boiling point, which is crucial for understanding the human body's response to low atmospheric pressure in space. The speaker explains that while human tissue is elastic and will not explode, exposure to low pressure can be deadly, leading to rapid unconsciousness and severe physiological effects. The historical significance of pressure suits is highlighted through the tragic loss of the Soyuz 11 crew, emphasizing the importance of wearing pressure suits during launch and landing.

The speaker shifts focus to robotic exploration, highlighting the advancements in technology that have allowed spacecraft like NASA's Juno to capture detailed images of Jupiter and its moons. The discussion covers the transformative impact of robotic missions on our understanding of the solar system, including the discovery of volcanic activity on Io and potential signs of life on Enceladus. The speaker emphasizes the importance of these missions in expanding our knowledge beyond what is possible with human exploration alone.

The speaker discusses the various applications of satellites, particularly in monitoring Earth's environmental and atmospheric conditions. Weather satellites are highlighted for their role in saving lives through hurricane forecasting. The speaker also demonstrates the use of thermal infrared technology to visualize temperature differences, explaining how this technology is used in space-based instruments to monitor ocean currents and atmospheric pollutants. The importance of satellite data in understanding climate change and environmental issues is emphasized, showcasing the value of Earth observation satellites in providing real-time, high-resolution data.

The speaker concludes by emphasizing the integral role of space in our daily lives, highlighting the economic, technological, and societal benefits of space exploration. Telecommunication satellites, navigation systems like GPS, and Earth observation satellites are all critical to modern society. The speaker notes that the space sector generates significant revenue and supports a large workforce, making it a key component of the global economy. The speaker also reflects on the unique perspective space provides on Earth, reinforcing the idea that space is not just a national but a societal infrastructure.

The speaker outlines the future of space exploration, highlighting both the challenges and opportunities that lie ahead. The development of high-performance computing, AI, and machine learning are set to revolutionize the way we process and utilize data from space. The speaker also discusses the potential of mega constellations like Starlink to provide global internet connectivity, emphasizing the importance of access to data for future prosperity. However, the speaker warns of the risks of orbital collisions and the need for responsible management of space debris. The rapid advancements in space technology by various countries, including China, India, and the United Arab Emirates, are also noted, showcasing the increasingly competitive and international nature of space exploration.

The speaker focuses on Mars, detailing its geological features and the scientific interest in its past and potential for life. Mars is described as having an atmosphere similar to Earth's but with conditions that would make liquid water boil and freeze simultaneously. The speaker discusses the evidence of ancient river systems and sedimentary rocks, suggesting a warmer, wetter past for Mars. The loss of Mars' magnetic field and its implications for atmospheric stripping are also covered. The speaker shares samples of Martian meteorites and the ongoing mission of the Perseverance rover and Ingenuity helicopter, highlighting the scientific efforts to understand Mars and search for signs of life.

The speaker argues for the continued importance of human space exploration, despite advancements in robotic technology. The Apollo 17 mission is highlighted as an example of human achievement in space, contrasting the capabilities of human astronauts with those of robotic systems. The speaker emphasizes the need for a synergy between robotic and human exploration in future space missions. The Artemis program and the plans for a lunar orbital space station called the Gateway are discussed, showcasing the international and inclusive nature of current space exploration efforts. The speaker concludes by reflecting on the unique perspective space provides on Earth, reinforcing the idea that space exploration is essential for understanding and safeguarding our home planet.

The speaker concludes the lecture by acknowledging the extended duration and expressing hope that the content was engaging and thought-provoking. An invitation for questions from the audience is extended, providing an opportunity for further discussion and clarification on the topics covered.