rocketcal.cc (pronounced "rocket calc") is a tool I made for fun.

It costs about $5 per month, so I don't plan to ever use ads or logins or tracking or any of that crap.

Rocketcal.cc is a tool which allows you to build Factorio spaceships without wasting any rockets, while still leveraging auto-requests as much as possible.

It minimizes manual launches by generating a separate auto-request blueprint which includes only the items which fill whole rockets. The remaining manual launches are made more convenient via a circuit-driven silo loader.

When you paste a spaceship blueprint in rocketcal.cc, it generates a book with three blueprints:

The auto-request blueprint
- A copy of your blueprint modified to include only full rockets of items (if your ship uses 157 belts, only 150 of them will be included).
The manual-launches blueprint
- A full copy of your blueprint, but with auto-requests disabled.
The silo loader blueprint
- A constant combinator with groups for each of the manual launches, attached to an item-counting combinator which drives a requester chest.

Paste the auto-requests blueprint and wait for it to finish building. You'll need at least one silo with automatic requests enabled.

Next, paste the manual-launches blueprint, and connect a silo loader to a silo which has auto-requests disabled.

In the constant combinator, enable the first launch group, wait for the items to load, then launch the rocket.

Repeat for the rest of the launch groups, leaving the prior groups checked as you go (the combinator magic requires it).

You can use multiple silo loaders (each connected to its own silo) to divide up the work and speed up the manual launches.

See the demo video.

If you encounter a bug (or have a suggestion), please post in this factorio.com forum thread. The forum will send me an email.

TL;DR you can POST a blueprint string directly to /paste.

`GET /`

The text/html landing page, with a webform which accepts a space platform blueprint by sending a POST to /paste.

`POST /paste`

This endpoint accepts pasted blueprints strings.

The body can be one of two forms:

A blueprint string, or
A webform body of the form blueprint=:encoded-bp where :encoded-bp is the percent-encoded blueprint string.

It will respond with a 302 with a Location of /:md5, where :md5 is the MD5 sum of the blueprint string.

`GET /:md5`

The text/html page with the rocket plan for a blueprint.

`GET /:md5/:md5.txt`

A blueprint, returned as text/plain.

`GET /:md5/:md5.md`

The Markdown version of a rocket plan, returned as text/plain.

`GET /:md5/:md5.json`

The JSON representation of a rocket plan, returned as application/json.

`GET /:md5/:md5-book.txt`

The rocket plan as a construction blueprint book, returned as text/plain.

`GET /icons-32/:slug.png`

The 32x32px icon for a given item slug (e.g. fast-inserter), returned as image/png.

`GET /icons-64/:slug.png`

The 64x64px icon for a given item slug (e.g. fast-inserter), returned as image/png (for Retina/HiDPI displays).

`GET /recent`

A text/html page which lists all of the blueprints, sorted by submission date.

`GET /about`

This page.

`GET /weights.json`

An application/json table of all item slugs and weights known by rocketcal.cc (in kg).

`GET /200`

Returns the text/plain response "OK", which verifies the site is still up.

2025/1/9 sat

Fixed a bug where small blueprints could cause the tiles under the hub to not be populated in the auto-launch blueprint, which would result in a superfluous rocket launch (thanks Zulan!).

2024/12/14 sat

Fixed a bug in rockets which have an item of both quality and non-quality (thanks Deltaqyto!).

2024/12/11 wed

Added launch count and tags to /recent.

2024/12/10 tue

Fixed a foundation counting bug in the auto blueprint (thanks again DOSorDIE4Csp!). Regenerated all rocket manifests.

2024/12/7 sun

A separate "Auto launches" blueprint is generated which contains all items which fill whole rockets, minimizing the number of manual launches required.

2024/12/6 sat

Space platform foundations are now part of a separate blueprint which uses auto requests for construction.

2024/11/23 sat

Added construction blueprint book generation (/:md5/:md5-book.txt).
Tolerate trailing spaces and newlines when pasting a blueprint.
Fixed another module counting bug. Regenerated all rocket manifests.

2024/11/22 fri

Fixed that modules were missing (thanks DOSorDIE!). Regenerated all rocket manifests.
Added /:md5/:md5.json.
Added 2x icons to support Retina/HiDPI displays.

2024/11/18 mon

Added support for quality.
Fixed an off-by-one error (introduced by yesterday's performance improvements) which dropped the last item of the manifest. Regenerated all rocket manifests.

2024/11/17 sun

Fixed a weight parsing bug (thanks DOSorDIE!). Regenerated all rocket manifests.
Performance fix which reduced Lucrehulk processing time from 18 seconds to 330ms.

2024/11/11 mon

Added icons.
Added about.
Added weights.json.
Added support for Accept-Encoding: gzip.

2024/11/10 sun

Initial implementation.

rocketcal.cc

About

What is it?

How it works

How to use the book

Bugs

API