Nuclear Power in Space, Planetary Defense Insights, and an Aurora Alert for Northern Skies

Astronomy Daily — S05E135 — Wednesday, July 8, 2026 1. World's First Commercial Nuclear-Powered Satellite Reaches Orbit SpaceX's Transporter-17 rideshare mission carried City Labs' BOHR CubeSat to orbit on July 7, the first commercially built satellite to fly a nuclear-powered payload — a tritium betavoltaic cell that generates electricity continuously, day or night, regardless of sunlight. Key points • Launched July 7, 2026 at 3:12am EDT from Vandenberg Space Force Base aboard a Falcon 9, part of the 81-payload Transporter-17 rideshare mission. • BOHR (Betavoltaic Orbital High-Reliability) CubeSat built by City Labs, a Miami/Florida-based company. • Uses a 'NanoTritium' betavoltaic device — converts beta particles from the radioactive decay of tritium directly into electricity via a semiconductor. • Power output is tiny (micro-to-milliwatt range) but continuous — unaffected by eclipse periods or solar panel orientation. • Tritium's 12.3-year half-life means the power source stays effective for two decades before decaying to harmless helium-3. • FAA authorised the launch after finding public radiation exposure would stay below one millirem under conservative assumptions. 2. New Zealand's Fuel-Free Thruster Passes First Orbital Test Auckland-based Zenno Astronautics has successfully tested its 'Supertorquer' — an attitude-control thruster that uses superconducting magnets to push against Earth's own magnetic field, generating thrust with no propellant at all. Key points • Zenno Astronautics is a spin-off from the University of Auckland, New Zealand. • The system, called 'Supertorquer', completed its first in-orbit test in early July 2026. • Superconducting magnets, powered by solar panels, interact with Earth's magnetic field to generate torque and maintain a satellite's orientation — no propellant is consumed. • Until recently this kind of superconducting hardware was too large and complex to fit aboard a small satellite; miniaturisation has now made it practical. • Because it needs no fuel, the technology could in principle keep a satellite maneuvering indefinitely, as long as it has sunlight for power. • Zenno co-founder/company messaging: 'We are essentially looking to remove all reliance on Earth's resources so that we can build a sustainable industry in space.' 3. Tianwen-2 Arrives at Quasi-Moon Kamo'oalewa — And Upends the 'Piece of the Moon' Theory China's Tianwen-2 sample-return spacecraft has arrived at near-Earth asteroid Kamo'oalewa after a 400-day, 1-billion-kilometre journey, beaming back the first close-up image — just as new JWST data throws serious doubt on the leading theory of where this strange little world came from. Key points • Tianwen-2 launched May 29, 2025, and reached Kamo'oalewa on July 6, 2026, arriving at a station-keeping distance of about 20 km. • China National Space Administration (CNSA) publicly announced the arrival July 6, releasing the first close-up image via Xinhua. • Kamo'oalewa (asteroid 2016 HO3) is one of only seven known 'quasi-satellites' of Earth — it orbits the Sun but stays in a stable dance alongside our planet, and has done so for roughly 100 years, with about 300 more to go. • The image reveals a small, asymmetrical rock roughly 20-30 metres across. • Long-standing hypothesis (since 2021): Kamo'oalewa is a fragment blasted off the Moon's far side by the impact that created the Giordano Bruno crater, 1-10 million years ago — based on its reflectance spectrum resembling space-weathered lunar soil. • New twist: a July 1 JWST preprint (Sharkey et al.) models Kamo'oalewa's albedo (reflectivity) at around 0.59 — far higher than the Moon's ~0.12 — which is incompatible with a lunar origin and points instead toward a rare E-type silicate asteroid. 4. Jeremy Hansen Steps Back From Active Astronaut Duty Jeremy Hansen, the Canadian Space Agency astronaut who became the first Canadian to fly around the Moon aboard Artemis II in April, announced July 6 that he's stepping back from full-time astronaut service this September. Key points • Hansen flew as mission specialist on Artemis II in April 2026, alongside NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch — the first crewed lunar mission in over 50 years. • He becomes the first Canadian to travel beyond low Earth orbit / around the Moon. • Announced via social media and a Canadian Space Agency statement on July 6, 2026. • Transition takes effect this September, after 32 years of military service and 17 years as a CSA astronaut. • He will continue serving as a reservist with the Royal Canadian Air Force and says he remains committed to Canada's space program in a new capacity. • Joined CSA in the 2009 astronaut recruitment campaign after a career as a Royal Canadian Air Force fighter pilot. 5. Aurora Alert: G1 Geomagnetic Storm Possible July 9 Space weather forecasters are watching a combination of a fast coronal mass ejection and an Earth-facing coronal hole that could combine to produce a minor...