FAQ
What does Loft do?
It imports an OpenRocket .ork design and simulates the flight in your browser — apogee, velocity, Mach, stability, and recovery — and compares against the numbers OpenRocket stored in the file. No accounts, no ads, no tracking.
Is my design uploaded anywhere?
No. Parsing, the motor database, and the whole simulation run on your device. Nothing about your design leaves the browser. The one optional network call is the “re-fly for today's weather” feature, which sends only a launch-site latitude/longitude to Open-Meteo — never your design.
Can I trust it for a waiver or a cert flight?
Treat every figure as an estimate to verify independently, not as authority. Loft shows the numbers and their assumptions; it never issues a go/no-go. The motor's printed data and your RSO are authoritative. See the limitations log.
Why doesn't my apogee match OpenRocket exactly?
Mostly the drag model. Loft's subsonic drag buildup is simpler than OpenRocket's, so it usually predicts a slightly higher apogee. Fast (transonic) flights differ more and are flagged as extrapolated. The Validation page shows the comparison on your own file; Methods explains the model.
Which motors and file formats are supported?
Current OpenRocket .ork files (and gzip-wrapped or raw OpenRocket XML). A .orkreferences a motor without embedding its thrust curve, so Loft resolves it against a bundled set of real ThrustCurve.org curves. If your motor isn't in the set, Loft tells you rather than guessing. RockSim .rkt and RocketPy import are planned, not in yet.
Does it work offline?
Yes — once loaded, install it or just revisit and it runs with no connection: the app, the motor database, and the simulation are all client-side. Only the live-weather re-run needs a signal.
What about RocketPy?
Planned. Loft's simulation core is deliberately format-agnostic — importers are thin adapters into one internal model — so a RocketPy importer is future work that plugs into the same engine, not a rewrite.
It couldn't read my file, or a part was skipped.
Loft degrades gracefully: unknown components are skipped with a note rather than failing the whole import. If something's wrong or missing, please open an issue with the file — it's the fastest way to get the parser improved.
Is it really free / open source?
Yes. MIT-licensed, part of Fusion Space. Fork it, deploy your own, no attribution required. The point of the open repo is that the math is inspectable.