Plan and timeline
This page is an estimate, not a promise. It says how likely each of hpr-sim’s goals is to work out, how much work each still needs, and when each release could be ready. It was made on October 6, 2026, from the roadmap and the project’s pace up to that day. It goes out of date as work ships or the roadmap changes, so read its dates as a forecast from that day.
How far to trust it.
- What kind of figure: an estimate, from a count of the work left and the pace so far.
- Based on: the first 20 days of the project (September 17 to October 6, 2026), in which 169 changes that each finish a milestone increment were merged (of 222 merged in all), about 8.5 a day. The open-ended milestones in that time took 3 to 6 times the increments first planned for them. The same history sets the pace, so it is not an independent check.
- What to rely on instead: the roadmap for what comes next and in what order; a published release for what is done.
In short
The dates are when each release’s code could be ready. A release is out once Neer, the project’s owner, publishes it.
- Release 0.1, the simulator: code ready around October 9, 2026; by October 11 if the work grows.
- Release 0.2, the flight analyzer: around October 14; by October 19.
- Release 0.3, accuracy and fault diagnosis: around October 23; by November 2.
- Release 0.4, the competition kit: around October 29; by November 12.
- Release 0.5, the app preview: code ready around November 3; by November 20. It is out once Neer has used it and any changes that turns up are made.
- Release 1.0, the app: code ready around November 13; by December 6. It is out, again, once Neer has used it.
- Everything else on the roadmap that is software: around December 5, 2026; by mid-January 2027 if the work grows.
- The one goal that is not only software, an avionics board built and flown, has no date. It follows Neer’s build and the launch calendar, so spring 2027 at the earliest.
How the estimate is made
Each milestone is counted in increments, then divided by the pace. An increment is one change with its own done when, the test the roadmap sets it: reviewed, tested on macOS, Windows and Linux, and merged. The roadmap lists the increments planned for each milestone. Each count below adds the growth that similar milestones showed once work began: little for well-defined work such as a file format, two to three times for open-ended work such as accuracy or a user interface.
The pace assumed is about 9 increments a day for release 0.1, 8 a day through release 0.4, and 7.5 a day after that, as the code grows and each check takes longer. Those rates already allow for time spent on bug reports. The first 20 days averaged 8.5 a day.
Each date comes in two forms. The likely date is the count divided by the pace. The slow case stretches every duration by 1.6, on top of the growth already in the counts. The 1.6 is a judgment from that history, not a statistical bound.
The releases
| release | what it adds | increments left | likely | slow case | also waits on |
|---|---|---|---|---|---|
| 0.1 the simulator | Monte Carlo from the command line and Python (M4.6; Monte Carlo flies many copies of a flight with its inputs scattered); logged apogees from real flights (M2.3c1); release builds and named fixes (M10.1) | about 25 | 2026-10-09 | 2026-10-11 | Neer publishing it |
| 0.2 the flight analyzer | flight-log importers (M7.1); readings and smoothing (M7.2); a flight against its simulation (M7.3) | about 45 | 2026-10-14 | 2026-10-19 | Neer publishing it |
| 0.3 accuracy and diagnosis | the accuracy campaign from Mach 0 to 2.5 (M1.14b to M1.14g); logged traces (M2.3c2); fault diagnosis (M7.4) | about 70 | 2026-10-23 | 2026-11-02 | Neer publishing it |
| 0.4 the competition kit | optimizing a Monte Carlo result (M6.2e); challenge presets (M6.3); airbrakes (M6.4); submission packs (M6.6); ejection charges (M6.7); RASAero and RocketPy files (M3.5, M3.6) | about 50 | 2026-10-29 | 2026-11-12 | Neer publishing it |
| 0.5 the app preview | C and WebAssembly bindings (M4.4); the user-interface choice (M9.0); 3D replay of a real flight beside its simulated ghost (M9.2) | about 35 | 2026-11-03 | 2026-11-20 | Neer using it, then publishing it |
| 1.0 the app | the desktop editor (M9.1); the web app that works offline (M9.3); the design assistant (M8.1); undo and edits (M8.2); RockSim files (M3.4) | about 75 | 2026-11-13 | 2026-12-06 | Neer using it, then publishing it |
| after 1.0 | canards, CAD files, phone apps, accounts, the extended Mach band, motor, parachute and avionics design | about 165 | 2026-12-05 | 2027-01-10 | see below |
The dates are for the code. A release is out when Neer publishes it, which takes minutes. For 0.5 and 1.0 it also takes his own use of the app, and any changes that use turns up. Each column is its own scenario: the slow case for 1.0 can fall after the likely date for the work after 1.0.
How feasible each goal is
| goal | outlook | why |
|---|---|---|
| A simulation library on par with RocketPy | high; mostly done | The physics, staging, pods, Monte Carlo, optimization and Python bindings have shipped. |
| Accuracy: 5% mean apogee error on real flights, at least as good as OpenRocket | medium | Against seven real flights, hpr’s apogees miss by 6.04% on average (Accuracy). Against 55 more from a private collection, hpr’s apogees are +9.83% above the logs on average and OpenRocket’s +9.00%: neither meets 5%, and hpr is close to OpenRocket (Accuracy). On real flights, the inputs limit accuracy too: motors vary in impulse, logged masses are off, the weather is uncertain. Matching OpenRocket is likely; the 5% mean may not hold everywhere. If the campaign stalls, its gaps are written down rather than hidden (the stopping rule). |
| Accuracy above Mach 1 | medium | Few real flights go supersonic. None of the seven public flights does. In the project’s private collection of flight logs (not published), 5 of the 42 flights that state a top speed reach about Mach 1 or more, and more may show up when the rest of its logs are read. Flights near Mach 2 are rare. |
| File interop: OpenRocket, RockSim, RASAero, RocketPy | high | OpenRocket’s files fly today. The others follow known formats and earlier work. |
| Competition design and submission packs | high | Mostly well-defined calculations from cited models. Testing that each safety number errs the safe way adds work, not risk. |
| Flight forensics: logs, fits, diagnosis | high; medium for diagnosis | Importers and fits are well defined. Diagnosis must name the right fault first for at least 80% of 200 simulated faulty flights; real anomalous flights depend on finding logs of them. |
| The app: editor, 3D replay, web app | medium | The code can be built steadily. Whether it is good to use is judged by people, starting with Neer, and that review sets the pace. |
| Phone apps and accounts | medium | They need an app-store account and a hosting provider, both Neer’s choices. Neither is part of 1.0. |
| CAD files | high for meshes and drawings; medium-low for STEP | Few permissively licensed libraries read or write STEP’s exact solids. STEP import may need a licensing decision. |
| Motor design | high for solid motors; medium for hybrids and liquids | Hybrid and liquid design waits first on a decision about US export rules for rocket propulsion. |
| Parachute design and avionics software | high | Each is checked against closed forms, published tables or exact round trips. |
| An avionics board | depends on Neer | It needs a board built, bench-tested and flown beside a commercial flight computer. |
What only Neer can do
- Publish each release.
- Use the 0.5 and 1.0 apps before they count as done.
- Choose an app-store account and a hosting provider, when phone apps and accounts come up.
- Decide how US export rules apply, before hybrid and liquid design.
- Build and fly the avionics board.
None of these blocks the work before release 0.5.
What could move the dates
- New goals. Each round of new goals so far has added weeks of work. The dates cover the roadmap as it stood on October 6, 2026.
- Bug reports. 96 issues were open that day, 29 of them high priority. A run of critical ones would delay milestone work.
- Hard milestones growing more than expected. Accuracy, diagnosis and the app are the most open-ended; the slow case allows for that.
- Slower checks as the code grows. The later pace already allows for some of this.
What 1.0 includes, and what comes after
Release 1.0 is the simulator, the flight analyzer, the competition kit and the desktop and web app. Phone apps, accounts, canards, CAD files and the Mach 2.5–3.5 band come after 1.0. Motor, parachute and avionics design come after that, one at a time (the suite decision record). Until 1.0, hpr flies only commercial solid motors.