You asked about Aviation and Space
18 people built something like it. 1 is gone.
That is 6% of the ones whose fate we could settle, against 23% across the whole register.
| Launched | What it was | Today |
|---|---|---|
| 2021-01-01 | Seamless mobility to, through, and from space. It starts with 100%… · stokespace.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 |
| 2021-01-01 | YCREGENT All-electric seagliders for fast, affordable regional transportation · regentcraft.com | still up |
| 2021-06-01 | Turning space into a transportation layer for Earth · inversionspace.com | still up |
| 2021-06-01 | Moving Things Around in Space, Imaging Space Objects When We're Not · turionspace.com | 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 |
| 2021-06-01 | Orbital logistics: Unleashing space industry, from Earth to asteroids · transastra.com | still up |
| 2021-06-01 | We visually monitor space objects for governments and defense · heo-robotics.com | still up |
| 2021-01-01 | The highest-accuracy global weather data from low-cost flat satellites · careweather.com | still up |
| 2021-06-01 | YCStownest Flexible On-Demand Storage Space for Household, SMEs & Travellers. · stownest.com | still up |
| 2021-06-01 | YCDeskimo Workspaces on demand, paid by the minute. · deskimo.com | still up |
| 2021-06-01 | YCEpsilon3 AI-Powered ERP, MES, and Test Software for Complex Operations · epsilon3.io | still up |
| 2021-06-01 | AI-Driven Tech & Space Optimization to Scale Restaurants · onestopkitchen.com | gone |
| 2021-06-01 | Near Space Flying Machines · kalamlabs.in | still up |
| 2021-06-01 | YCCabal Private workspace for founders, investors, and advisors to collaborate · getcabal.com | still up |
| 2021-01-01 | YCRoutine AI-native all-in-one workspace for startups · routine.co | still up |
How this compares
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.