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March 21 in Universe History: Space Missions, Satellites and Exploration

March 21, 2026
March 21 has produced notable milestones in space exploration, planetary science, orbital operations, launch systems, and deep-space engineering. Below is a curated chronological selection of universe-related events connected to this date.
1963 On 21 March 1963, transmitters aboard the Soviet Mars 1 probe fell silent. The final radio contact occurred when the craft was about 106 million km from Earth, ending communications during cruise and leaving it to proceed toward its planned Mars flyby without further telemetry, after earlier relays had returned measurements of interplanetary conditions between Earth and Mars.
1965 On 21 March 1965, Ranger 9 launched from Cape Canaveral on an Atlas-Agena vehicle, targeting a lunar impact at Alphonsus. During descent it transmitted live TV images broadcast to the public, closing the Ranger program with high-resolution photography and providing geological context for lunar landing analysis and mission planning by later explorers while validating guidance and imaging systems.
1999 On 21 March 1999, an International Launch Services Proton rocket lifted off from Baikonur and carried the AsiaSat 3S commercial communications satellite into geosynchronous transfer orbit, demonstrating late-1990s heavy-lift commercial launch operations and enabling additional regional telecom capacity after on-orbit raising, testing, and handover to the satellite operator.
2000 On 21 March 2000, during vibration testing at JPL, the High Energy Solar Spectroscopic Imager spacecraft was substantially damaged after a test device delivered about 20 g, far above intended levels, cracking two solar arrays and harming the structure. The mishap prompted an independent failure review and delayed the solar-flare physics mission’s launch.
2001 On 21 March 2001, Space Shuttle Discovery landed at Kennedy after STS-102, completing the first Expedition crew rotation for the International Space Station and returning Expedition 1 to Earth. The mission also delivered and later returned the Leonardo multipurpose logistics module with supplies and racks, advancing early station assembly, joint operations, and orbital logistics procedures.
2012 On 21 March 2012, Cassini’s Imaging Science Subsystem spent about 12 hours searching for possible small satellites near the stability region 60 degrees ahead of Titan in its orbit around Saturn, at the L4 Lagrange point. The campaign aimed to detect new moons or refine faint-object orbits, improving hazard assessment and observation planning during continuing mission operations at Saturn.
2017 On 21 March 2017, the NASA Planetary Data System issued the PDS4 Standards Reference v1.8.0, defining label structures, data types, and conformance rules used to archive and distribute planetary science products. Tied to PDS4 Build 7b, it provided a stable specification for mission teams, reviewers, and software tools that ingest, validate, and serve NASA planetary datasets.
2017 On 21 March 2017, the MESSENGER MDIS CDR/RDR Software Interface Specification was updated, defining products, labels, indices, and SPICE geometry for distribution via the Planetary Data System. The document specified file organization and access rules so tools and researchers could ingest and analyze Mercury imaging data consistently across archives.
2018 On 21 March 2018, Soyuz MS-08 lifted off from Baikonur carrying Oleg Artemyev and NASA astronauts Drew Feustel and Ricky Arnold on a two-day flight to the International Space Station, sustaining uninterrupted human orbital residency. The launch began their Expedition 55/56 increment and set up docking and hatch operations planned for March 23.
2019 On 21 March 2019 local time in French Guiana, Arianespace launched Vega from Europe’s Spaceport, delivering ASI’s PRISMA satellite to a sun-synchronous orbit. The AVUM stage performed two burns for injection and then executed a disposal burn for reentry, enabling hyperspectral imaging for environmental monitoring, agriculture, and pollution tracking.
2020 On 21 March 2020, Arianespace and Starsem successfully delivered 34 OneWeb satellites to low Earth orbit on Soyuz Flight ST28, advancing deployment of the broadband constellation. The launch increased the number of spacecraft available for global connectivity services and continued the program’s early launch cadence.
All names in this article
Alphonsus Arianespace ASI AsiaSat 3S Atlas-Agena AVUM Baikonur BOLT-2 BurstCube Cape Canaveral Cassini CRS-30 Dragon Drew Feustel Europe’s Spaceport Expedition 1 Expedition 55 Expedition 56 Falcon 9 French Guiana High Energy Solar Spectroscopic Imager Imaging Science Subsystem Ingenuity International Launch Services JPL Kennedy L4 Lagrange point Leonardo Marina Vasilevskaya Mars 1 MDIS Mercury MESSENGER Mid-Atlantic Regional Spaceport NASA Planetary Data System National Reconnaissance Office NROL-123 Oleg Artemyev Oleg Novitskiy OneWeb PDS4 Standards Reference Perseverance PRISMA Proton Ranger 9 Ricky Arnold Rocket Lab Electron Saturn Soyuz Flight ST28 Soyuz MS-08 SpaceX SPICE Starsem Terrier-Improved Malemute Titan Tracy Dyson Vega Wallops Wallops Island Asia Europe Russia Air Force Research Laboratory Earth Mars Moon Sun International Space Station Space Shuttle Discovery STS-102

March 20 in Universe History: Space Missions, Astronomy and Exploration

March 20, 2026
March 20 has produced notable milestones in space exploration, astronomy, launch operations, communications infrastructure, and deep-space engineering. Below is a curated chronological selection of universe-related events connected to this date.
1916 On March 20, 1916, Albert Einstein submitted his review Die Grundlage der allgemeinen Relativitätstheorie to Annalen der Physik; later printed that year, it consolidated general relativity’s field-equation framework and became a cornerstone for modern gravitational physics and astronomy, supporting predictions such as light deflection, perihelion precession, and gravitational waves.
1964 On March 20, 1964, the convention establishing the European Space Research Organisation (ESRO) entered into force, creating a joint European framework to pool resources for space science. ESRO’s programs, tracking and data facilities, and cooperative governance later fed into the 1975 merger that formed the European Space Agency for broader civil-space activities.
1982 On March 20, 1982, astronauts Jack R. Lousma and C. Gordon Fullerton arrived at NASA’s Kennedy Space Center to prepare for STS-3 through mission reviews and Shuttle Training Aircraft landings. Their arrival came mid-countdown and set up a March 22 launch of Columbia, enabling continued thermal characterization and early Remote Manipulator System operations in flight.
1996 On March 20, 1996, the first launch attempt for Space Shuttle Atlantis mission STS-76 was scrubbed before cryogenic tanking began because of high-wind concerns at Kennedy Space Center. Managers then recycled the countdown and launched successfully on March 22, enabling the third Shuttle–Mir docking and transfer of astronaut Shannon Lucid for a long-duration stay aboard Mir.
2000 On March 20, 2000, the Dumsat payload flew on a Soyuz mission from Baikonur Cosmodrome as part of early operational use of the Fregat upper stage, an engineering step toward more flexible multi-burn injection profiles. The flight helped validate Fregat’s restartable capabilities.
2000 On March 20, 2000, International Gemini Observatory announced that an 8.1-meter primary mirror had arrived safely at the Gemini South site on Cerro Pachón after a long transport. The mirror’s arrival marked a major step toward first light later in 2000, as the telescope approached operations with advanced optical and infrared imaging capabilities.
2004 On March 20, 2004, Boeing reported that a Delta II rocket lifted off from Cape Canaveral Air Force Station’s SLC-17B and successfully deployed GPS IIR-11 to transfer orbit after a 68-minute flight, marking the 50th satellite launched for the U.S. Air Force Global Positioning System.
2010 On March 20, 2010, International Launch Services scheduled a Proton-M/Breeze-M mission with the EchoStar XIV communications satellite from Baikonur, documenting a commercial launch campaign and the operational cadence of multi-burn upper-stage profiles for geostationary delivery.
2024 On March 20, 2024, China launched the Queqiao-2 relay satellite on a Long March-8 rocket from the Wenchang Space Launch Site to provide Earth–Moon communications services, a key step for near-term far-side sample-return operations and longer-term south polar exploration in the Chinese lunar program.
2025 On March 20, 2025, the Voyager 1 team watched the probe execute stored commands that revived long-idled backup attitude-control thrusters and confirmed success when heater temperatures rose within about 20 minutes. The maneuver preserved pointing capability and reduced risk ahead of a planned communications pause.
2026 On March 20, 2026, NASA’s Artemis II Space Launch System rocket and Orion spacecraft arrived at Launch Pad 39B at Kennedy Space Center after crawler-transporter rollout from the Vehicle Assembly Building, positioning the first crewed Artemis stack for pad-level checkouts, systems verification, and launch-readiness work for a four-astronaut lunar flyby.

March 20 in Technology History: Standards, Patents and Breakthroughs

March 20, 2026
March 20 has produced notable milestones in patents, networking, software standards, web platform development, aerospace engineering, industrial standardization, and modern computing. Below is a curated chronological selection of technology-related events connected to this date.
1883 On 20 March, the Paris Convention for the Protection of Industrial Property was signed, creating a foundational international framework for patents, trademarks, and industrial designs and establishing principles such as national treatment and priority rights for applicants.
1883 On 20 March, Jan Ernst Matzeliger received US Patent 274,207 for a lasting-machine concept that mechanized a key shoemaking step, enabling faster, more consistent shoe production and helping industrialize footwear manufacturing in the late 19th century.
1883 On 20 March, Thomas Edison’s US Patent 274,290 for a system of electrical distribution was granted, reflecting early architectures for delivering electric power to many loads and contributing to the technical and commercial evolution of centralized electric lighting networks.
1883 On 20 March, an Edison patent document for an incandescing electric lamp, US Patent 274,294, was issued, capturing period engineering choices around lamp construction in the early incandescent era and providing primary technical text and drawings via the patent PDF.
1969 On 20 March, a pre-countdown test for Mariner G revealed problems affecting the spacecraft’s central computer sequencer and an infrared radiometer, triggering troubleshooting and ultimately a launch postponement and showing how end-to-end systems testing gates interplanetary missions.
1970 On 20 March, RFC 37, Network Meeting Epilogue, etc., was published, recording early ARPANET design discussions, including process communication concepts that helped shape later socket-style abstractions and the culture of open technical memos in Internet engineering.
1970 On 20 March, RFC 38, Comments on Network Protocol from NWG/RFC #36, circulated, providing contemporaneous critique and clarification of proposed host-to-host protocol ideas in the formative ARPANET period and exemplifying rapid iterative review in early networking research and development.
2006 On 20 March, ISO announced a new website section aimed at helping small and medium-sized enterprises implement ISO 9001 and ISO 14001 management system standards, reflecting a strategy to lower adoption barriers.
2009 On 20 March, ISO publicized a new CD collection containing ISO and IEC standards and guides for testing laboratories and inspection bodies, packaging conformity-assessment documentation into a single product.
2012 On 20 March, W3C published the CSS Speech Module as a Candidate Recommendation, specifying aural CSS properties to control text-to-speech presentation and audio cues and marking a standards-track milestone toward interoperable speech media support across user agents.
2014 On 20 March, W3C advanced CSS Shapes Module Level 1 to Candidate Recommendation, defining shape-based float areas that affect text wrapping and pushing the web platform toward richer layout geometry beyond rectangular boxes.
All names in this article
Accelerometer Ambient Light Sensor Bitstring Status List v1.0 Controlled Identifiers v1.0 COSE CSS Lists and Counters Module Level 3 CSS Namespaces Module Level 3 CSS Shapes Module Level 1 CSS Speech Module CSS Writing Modes Level 3 Data Integrity ECDSA Cryptosuites v1.0 Data Integrity EdDSA Cryptosuites v1.0 Generic Sensor API Gyroscope Input Events Level 2 ISO 14001 ISO 22095-2 ISO 22095-3 ISO 45001 ISO 9001 ISO/TR 8344 Jan Ernst Matzeliger JOSE Magnetometer Manifest for Web Application Mariner G Microsoft Orientation Sensor Payment Method Identifiers RFC 37 RFC 38 RFC 486 Surface Duo 2 Surface Headphones Thomas Edison Verifiable Credential Data Integrity 1.0 Verifiable Credentials Data Model v2.0 W3C WAI-ARIA 1.0 User Agent Implementation Guide Windows 10 Windows Server 2016 Paris Rome CSS Lists CSS Namespaces CSS Shapes CSS Speech CSS Writing Voyager 1