satellites

Isaac Arthur explores space-based solar power, in which satellites beam energy down via microwaves to rectennas on Earth. He discusses feasibility, profitability and its role in spurring space colonization.

The Thought Emporium shows how to receive clear images directly from GOES-15, 16 and 17 and Himawari 8 geostationary weather satellites with software-defined radio. It covers the extra effort needed to receive GOES data.

Branch Education explains how Starlink works, from the ground dish and satellites to phased-array beam steering and data routing. Animations cover how a beam stays connected to a satellite moving at 27,000 km/h.

A 105-minute technical deep dive from Noise In Space evaluating whether Starlink satellites could work as synthetic aperture radar. It covers SAR signal-to-noise, amplifiers, antennas, duplexing, phased array beamforming and simulations of V2 Mini and V3 satellites.

Kurzgesagt explains how accumulating space junk could trigger a collision cascade (Kessler syndrome) that makes launches too dangerous and traps humanity on Earth.

Scott Manley covers how GPS works and how civilian accuracy went from a planned 100 meters to about one meter. He explains the technology and the removal of restrictions that made this possible.

A 43-minute skeptical critique arguing that Starlink fails to live up to its promises, covering satellite lifespan, costs, bandwidth and viability. The creator later added an update about FCC grant requirements.

EEVblog's Dave Jones critiques Reflect Orbital's plan to sell sunlight to solar farms after dark using orbital mirrors. He walks through the numbers to show the idea does not work out.

An animated Gabbard diagram of objects in low Earth orbit from 1959 to 2021, showing altitude over time. It highlights major debris-generating events and how low-altitude debris decays out of orbit.

Mark Handley of UCL explains, with simulation visualizations, how early Starlink satellites without inter-satellite links could still give low-latency wide-area communication by hopping via ground relays. He shows it can beat fibre on many long paths.

Trevor Paglen's 30C3 talk on photographing and documenting the secret state, including CIA flights, spy satellites and military sites, to reveal the geography of covert programs.

Robert Wills of TNMoC explains the Apollo Guidance Computer hardware and software, then walks through the Apollo 11 landing procedure step by step, including the 1202 alarms.

Explains the proposed NASA JPL plan to use the Sun as a gravitational lens, sending solar sail craft to its focal region to image an exoplanet's surface. It covers the distances involved, how imaging with the Sun would work and the mission design.

Michael Steil and Christian Hessmann's 34C3 talk explaining the Apollo Guidance Computer end to end: hardware design, operating system, and mission software.

SpaceX's livestream of the Falcon Heavy test flight, including the launch, side booster landings and Tesla Roadster payload. It was the first launch of the most powerful operational rocket at the time.

Destin Sandlin of Smarter Every Day gives a talk to an aerospace audience, comparing how Apollo was engineered and managed with NASA's Artemis program. He raises concerns about unresolved details, the number of launches and in-orbit fuel transfer needed to reach the Moon, and the loss of institutional knowledge.

Tim Dodd of Everyday Astronaut tours SpaceX's Starbase with Elon Musk as guide. They cover the high bay, grid fins, Raptor V2, the HLS lander and stage separation, and Musk explains his engineering management process.

Carl Sagan's narration of the Pale Blue Dot passage, reflecting on the Voyager photograph of Earth as a tiny speck in space. It is a short meditation on humanity's smallness and shared home.

The first episode of CuriousMarc's series restoring a real Apollo Guidance Computer, led by AGC expert Mike Stewart. They set up a makeshift lab in a Houston hotel room to open up a rare machine owned by a private collector.

A short clip of Dr. Robert Zubrin, author of The Case for Mars, answering why humanity should go to Mars. He argues that societies grow by challenging themselves and that exploration inspires young people.

PBS Space Time explains the proposal to use the Sun's gravity as a giant lens, sending a train of small light-sail spacecraft to the focal point roughly 550 AU out. It covers how such a telescope could image exoplanets in surprising detail and the engineering challenges involved.

Everyday Astronaut's Tim Dodd runs an hour-long, data-driven analysis of what rockets actually emit and how that compares with airliners and other industries. It breaks down exhaust by propellant type, per-passenger and total emissions, and ways launches could be cleaner.

Isaac Arthur explains the orbital ring, a megastructure launch-assist system that could move bulk cargo cheaply to orbit and beyond. He compares it with space elevators and discusses power transmission.

Cody's Lab builds a 200-billionth-scale model to show how far away the nearest stars are, using parallax and light speed. A short astronomy explainer on interstellar distances.

Destin Sandlin tours United Launch Alliance's rocket factory with CEO Tory Bruno, showing friction stir welding, structural rocket skins and large milled parts.

SpaceX engineers present at NVIDIA's GPU Technology Conference on a multi-physics code that simulates the full-scale Raptor methane engine. It covers GPU-based turbulent combustion modeling with adaptive grids and wavelet compression.

David Kipping presents his proposed Terrascope, a telescope that uses Earth's atmosphere as a lens to achieve enormous magnification. He covers the history of telescopes and his path to the idea, plus Sol-scope and Jupiter-scope variants.

NASA JPL engineers explain the final minutes of the Curiosity rover's entry, descent and landing on Mars, which combined aerobraking, a parachute and a skycrane. It lays out the tight sequence of events that all had to work automatically.

Everyday Astronaut explains the basic physics of rocket engines, the main engine cycles and fuel types, then compares SpaceX's methane-fueled full-flow staged combustion Raptor to other engines. It runs nearly 50 minutes with chapter markers.

Kurzgesagt explains stellar engines such as the Shkadov thruster and Caplan thruster, which could move the Sun and solar system across the galaxy over millions of years to avoid hazards and reach new regions.

Veritasium's Derek Muller visits NASA JPL to see the Mars helicopter Ingenuity before it was mounted on the rover. He explains how it can fly in Mars's thin atmosphere with large, fast-spinning contra-rotating rotors and low mass, and covers power and cold.

Astronaut Mike Mullane explains normalisation of deviance, where teams gradually come to accept violations of their own safety standards. He uses the Challenger shuttle disaster as the main case, drawing on NASA's ignored warnings before the launch. It is the first part of a talk given to a fire-fighters' association.

Isaac Arthur's in-depth look at what it would take to settle and eventually terraform Mars. He covers the challenges and the scale of the work needed to make it a home for humanity.

Kurzgesagt lays out a speculative plan to terraform Venus, covering its hostile atmosphere and how it might be made Earth-like, with a sources page linked.

A minutephysics explainer showing that the Moon's path around the Sun is not a spiral but closer to a 12-sided polygon with curved corners. It argues the Moon arguably orbits the Sun rather than the Earth.

A PBS Space Time episode asking whether Venus would be a better colonization target than Mars. It covers Venus's habitable altitudes, floating balloon habitats, and the term surfacism.

Real Engineering explains why SpaceX is building Starlink, including the economics of satellite internet. It covers the latency advantage of light in vacuum over fiber for long-distance links.

A Kurzgesagt animation walking through how a Mars base could be built and why it would be punishing, covering radiation, temperature extremes, toxic dust and the need for shielding.

Commander Chris Hadfield performs a revised version of David Bowie's Space Oddity, recorded aboard the International Space Station. It was released as a music video in 2013.

NASA's animated explanation of the Curiosity rover's Mars landing, which relied on a complex automated sequence taking about seven minutes. It features NASA engineers discussing the risks before the 2012 landing.