You asked about Aviation and Space
146 people built something like it. 0 are gone.
That is 0% of the ones whose fate we could settle, against 23% across the whole register.
| Launched | What it was | Today |
|---|---|---|
| 2016-01-01 | Building humanity’s multiplanetary future. · relativityspace.com | still up |
| 2016-01-01 | YCAstranis Advanced satellites for high orbits. · astranis.com | still up |
| 2021-01-01 | Seamless mobility to, through, and from space. It starts with 100%… · stokespace.com | still up |
| 2016-01-01 | YCBoom Economically and environmentally sustainable supersonic travel · boomsupersonic.com | still up |
| 2022-01-01 | First electric business aircraft designed for hydrogen propulsion · beyond-aero.com | still up |
| 2017-06-01 | YCPyka Autonomous electric airplanes · flypyka.com | still up |
| 2021-01-01 | The lightest electric aircraft motors in the world. · h3x.tech | still up |
| 2021-01-01 | YCAlbedo Full-stack VLEO satellite missions · albedo.com | still up |
| 2024-01-01 | Supersonics for the new Jet Age · astromecha.co | still up |
| 2019-01-01 | Heart makes electric airplanes with an all-electric range of 250 miles · heartaerospace.com | still up |
| 2022-01-01 | Bluetooth to Space · hubble.com | still up |
| 2021-01-01 | YCREGENT All-electric seagliders for fast, affordable regional transportation · regentcraft.com | still up |
| 2022-06-01 | We're building satellites to create a real-time 3D map of the world. · arraylabs.io | still up |
| 2021-06-01 | Turning space into a transportation layer for Earth · inversionspace.com | still up |
| 2022-01-01 | YCWyvern High-res hyperspectral pictures of Earth from space · wyvern.space | still up |
| 2021-06-01 | Moving Things Around in Space, Imaging Space Objects When We're Not · turionspace.com | still up |
| 2019-06-01 | Last-mile delivery for satellites. · epic-aerospace.com | still up |
| 2024-06-01 | Data centers in space · starcloud.com | still up |
| 2020-01-01 | YCFarcast We build advanced satcom user terminals · farcast.com | still up |
| 2025-01-01 | Reusable Satellites · reditus.space | still up |
| 2021-06-01 | Vertical takeoff and landing aircraft for major airlines · odysaviation.com | still up |
| 2021-01-01 | We make satellites to image everywhere on Earth, every 15 minutes · albaorbital.com | still up |
| 2025-01-01 | High Thrust Space Vehicles for Satellite Defense · orbitalops.tech | still up |
| 2022-06-01 | Airplanes anyone can fly · airhartaero.com | still up |
| 2019-01-01 | Flying motorcycles · jetpackaviation.com | still up |
| 2021-06-01 | Orbital logistics: Unleashing space industry, from Earth to asteroids · transastra.com | still up |
| 2025-09-01 | The Modular Interceptor Platform · wardstone.us | still up |
| 2026-01-01 | Space solar arrays that grow to the size of a football field in orbit · beyondreachlabs.com | still up |
| 2024-01-01 | Agent-Driven Engineering · navier.ai | still up |
| 2024-09-01 | YCApolink 24/7 satellite connectivity in low Earth orbit · apolink.space | still up |
| 2023-01-01 | YCRadical Building persistent, high-performance infrastructure in the sky · radicalaero.com | still up |
| 2017-06-01 | Tesseract builds better thrusters for modern satellites · tesseract.space | still up |
| 2024-01-01 | YCBasalt Constellations as a Service · basalt.space | still up |
| 2024-01-01 | YCElodin Unified flight software and hardware for the mission of tomorrow · elodin.systems | still up |
| 2025-01-01 | Building lunar landers · instinct-space.com | still up |
| 2022-06-01 | YCVelontra Hypersonic space plane that can take-off from any location and weather · velontra.com | still up |
| 2026-01-01 | Moon Hotel -> The Intergalactic Construction Company of Earth · gru.space | still up |
| 2022-06-01 | We make the world's most efficient aircraft · seaflight.tech | still up |
| 2023-01-01 | Emission free hydrogen electric aircraft · stralis.aero | still up |
| 2017-01-01 | Boeing for electric planes · weflywright.com | still up |
| 2021-06-01 | We visually monitor space objects for governments and defense · heo-robotics.com | still up |
| 2026-09-01 | AI spacecraft operators that lives onboard the vehicle · orcaaerospace.com | still up |
| 2026-01-01 | Foundation models for 24/7 Earth Observation · axionorbital.space | still up |
| 2026-06-01 | We make silicon on the Moon, to power everything in space. · ethos-space.com | still up |
| 2024-09-01 | AI that gets aircraft flying faster · tryforerunner.com | still up |
| 2021-01-01 | The highest-accuracy global weather data from low-cost flat satellites · careweather.com | still up |
| 2025-01-01 | AI for air traffic control · enhancedradar.com | still up |
| 2024-06-01 | Building low-cost cruise missiles · aresindustries.com | still up |
| 2026-01-01 | Robotics for Space R&D · generalastro.com | still up |
| 2016-06-01 | Prime Lightworks Inc. manufactures electric propulsion systems for… · primelightworks.com | still up |
| 2023-06-01 | Building and Protecting an Exciting Future · singularityus.com | still up |
| 2024-09-01 | YCConsus The fastest and cheapest way to use AI with ITAR or CUI data. · consus.io | still up |
| 2026-06-01 | YCExosat Building a neutral, sovereign alternative to Starlink · exosat.com | still up |
| 2026-06-01 | YCSkymerse Autopilot for Flight Operations · skymerse.com | still up |
| 2024-06-01 | In-Space Refueling · spaceium.com | still up |
| 2022-12-20 | obsidian.md | still up |
| 2022-07-06 | outverse.com | still up |
| 2024-01-01 | YCLegora The AI workspace for lawyers · legora.com | still up |
| 2023-08-19 | carloslagoa.com | still up |
| 2022-07-26 | dock.us | still up |
How this compares
Y Combinator reports its own outcomes, including acquisitions. The other two are judged by asking the domain, so they are not measured the same way and are never averaged together.
The register re-probes every domain it holds. Some that answered last month stop answering. We send that list — what went quiet, and what it was — once a month. Nothing else.
How this was made. Show HN entries are every post from 2021 to 2023 with at least five points that linked to its own domain; code hosts and free hosting are excluded, because a repository outlives the effort behind it. Product Hunt entries needed 100 votes — a far higher bar, so they are the promoted top slice rather than a like-for-like sample. Both are judged by asking the domain whether it still answers: gone means it no longer resolves, refuses the connection, serves a parking page, or says plainly that it shut down. An HTTP error is not counted as gone — a server answering 404 is one somebody still pays for, and an audit of 25 gone-calls found two such sites alive with only a moved homepage. Y Combinator entries use the status YC publishes itself, which is why only those can say acquired. Squatted domains — a lapsed name now serving somebody else's site — are not detected, so these figures run slightly low.