SpaceChem Bench: Right All Along

research_5 Hard Sensing Single-reactor Atropos Station · SpaceChem Bench report →

Inputs: α Carbon (C), β Fluorine (F). Output: ψ Polytetrafluoroethylene ((C2F4)n) ×10. Features: Bonders (4), Sensor, Large output (4×8).

In SpaceChem Bench, 16 LLMs each had one attempt at this SpaceChem puzzle, with 60 minutes to build a working solution and keep optimizing it, without seeing the community archive. 5 of 16 models solved it. Together they found 2 new Pareto-frontier points beyond the frozen community archive.

5 / 16models solved it
1,289best LLM cycles (672 community)
2new frontier points

Records

ScoreCommunity bestBest LLMModel
Cycles6721,289GPT-6 Astra · +92%
Reactors11GPT-6 Astra Ties record
Symbols1520GPT-6 Astra · +33%

Community records from the community archive when we froze it on October 18, 2026. A point counts only after fresh-game replay and SChem’s precognition check.

Pareto frontier

Pareto explorer

Lower is better ↙
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Community archiveModel frontier pointNew frontier point
Select a point with the mouse or keyboard to inspect its scores and reactor blueprint.

Search over time

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Every model

ModelSolvedBest cyclesBest reactorsBest symbolsNew frontier points
01Gemini 4 ArgonYes1,5001242
02GPT-6 AstraYes1,289120—
03Sonnet 5.5Yes1,518156—
04Opus 5.5Yes1,817123—
05GPT-6.1 SolYes2,019126—
06DeepSeek V4.1 FlashNo————
07Fable 5.1No————
08GLM-5.3No————
09GPT-6 LunaNo————
10Gemini 3.8 FlashNo————
11Grok 4.7No————
12Haiku 5.5No————
13Kimi K3.1 ProNo————
14MiMo-V2.6-ProNo————
15Muse Spark 1.3No————
16Muse Wonder 1.0No————

Best scores can come from different solutions. New frontier points are not matched or beaten on all three scores by any community solution.

Best model solutions

These solutions are in SpaceChem Community Edition export format and released under the MIT License. All of this puzzle’s model solutions are on GitHub and Hugging Face.

GPT-6 Astra Fewest cycles

1,289 cycles · 1 reactor · 34 symbolsresearch_5.1289-1-34.txt on GitHub

Layout

α β ψ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 → ↓ ↓ → ← ← ↑ ↓ → → ↑ → ↑ ↓ ← ↑ ↓ ← S↓ S← IN α GRAB IN β CW B+ DROP FLIP↑ CW GRAB IN α IN β ?C→ DROP DROP IN β OUT ψ

Running in the game

GPT-6 Astra solution running on research_5 in SpaceChem
SpaceChem Community Edition export (research_5.1289-1-34.txt)
SOLUTION:Right All Along,Player,0-0-0
COMPONENT:'drag-largeoutput-reactor',2,0,''
MEMBER:'instr-start',90,0,128,0,0,0,0
MEMBER:'instr-start',180,0,32,8,7,0,0
MEMBER:'feature-bonder',-1,0,1,1,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,5,0,0
MEMBER:'feature-bonder',-1,0,1,6,0,0,0
MEMBER:'feature-bonder',-1,0,1,6,1,0,0
MEMBER:'feature-sensor',-1,0,1,6,7,0,0
MEMBER:'instr-arrow',0,0,64,0,1,0,0
MEMBER:'instr-arrow',90,0,64,1,1,0,0
MEMBER:'instr-arrow',90,0,64,1,3,0,0
MEMBER:'instr-arrow',0,0,64,1,4,0,0
MEMBER:'instr-arrow',180,0,64,2,1,0,0
MEMBER:'instr-arrow',180,0,64,2,3,0,0
MEMBER:'instr-arrow',-90,0,64,2,4,0,0
MEMBER:'instr-input',-1,0,128,0,1,0,0
MEMBER:'instr-grab',-1,1,128,1,1,0,0
MEMBER:'instr-input',-1,1,128,1,2,0,0
MEMBER:'instr-rotate',-1,0,128,1,3,0,0
MEMBER:'instr-bond',-1,0,128,1,4,0,0
MEMBER:'instr-grab',-1,2,128,2,2,0,0
MEMBER:'instr-toggle',-90,0,128,2,3,0,0
MEMBER:'instr-rotate',-1,0,128,2,4,0,0
MEMBER:'instr-arrow',90,0,16,2,1,0,0
MEMBER:'instr-arrow',0,0,16,2,3,0,0
MEMBER:'instr-arrow',0,0,16,3,2,0,0
MEMBER:'instr-arrow',-90,0,16,3,3,0,0
MEMBER:'instr-arrow',0,0,16,4,0,0,0
MEMBER:'instr-arrow',-90,0,16,4,2,0,0
MEMBER:'instr-arrow',90,0,16,7,0,0,0
MEMBER:'instr-arrow',180,0,16,7,1,0,0
MEMBER:'instr-arrow',-90,0,16,7,7,0,0
MEMBER:'instr-arrow',90,0,16,8,0,0,0
MEMBER:'instr-arrow',180,0,16,8,3,0,0
MEMBER:'instr-grab',-1,1,32,3,2,0,0
MEMBER:'instr-input',-1,0,32,3,3,0,0
MEMBER:'instr-input',-1,1,32,6,1,0,0
MEMBER:'instr-sensor',0,0,32,7,0,0,6
MEMBER:'instr-grab',-1,2,32,7,1,0,0
MEMBER:'instr-grab',-1,2,32,8,0,0,0
MEMBER:'instr-input',-1,1,32,8,1,0,0
MEMBER:'instr-output',-1,0,32,8,2,0,0

GPT-6 Astra Fewest reactors

1,291 cycles · 1 reactor · 30 symbolsresearch_5.1291-1-30.txt on GitHub

Layout

α β ψ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 ↓ ↓ → ← ← ↑ ↓ → → ↑ → ↑ ↓ ← ↓ ← S↑ S← GRAB CW B+ DROP FLIP↑ CW GRAB IN α ?C→ DROP DROP IN β OUT ψ IN β

Running in the game

GPT-6 Astra solution running on research_5 in SpaceChem
SpaceChem Community Edition export (research_5.1291-1-30.txt)
SOLUTION:Right All Along,Player,0-0-0
COMPONENT:'drag-largeoutput-reactor',2,0,''
MEMBER:'instr-start',-90,0,32,3,4,0,0
MEMBER:'instr-start',180,0,128,5,1,0,0
MEMBER:'feature-bonder',-1,0,1,1,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,5,0,0
MEMBER:'feature-bonder',-1,0,1,6,0,0,0
MEMBER:'feature-bonder',-1,0,1,6,1,0,0
MEMBER:'feature-sensor',-1,0,1,6,7,0,0
MEMBER:'instr-arrow',90,0,64,1,1,0,0
MEMBER:'instr-arrow',90,0,64,1,3,0,0
MEMBER:'instr-arrow',0,0,64,1,4,0,0
MEMBER:'instr-arrow',180,0,64,2,1,0,0
MEMBER:'instr-arrow',180,0,64,2,3,0,0
MEMBER:'instr-arrow',-90,0,64,2,4,0,0
MEMBER:'instr-grab',-1,1,128,1,1,0,0
MEMBER:'instr-rotate',-1,0,128,1,3,0,0
MEMBER:'instr-bond',-1,0,128,1,4,0,0
MEMBER:'instr-grab',-1,2,128,2,2,0,0
MEMBER:'instr-toggle',-90,0,128,2,3,0,0
MEMBER:'instr-rotate',-1,0,128,2,4,0,0
MEMBER:'instr-arrow',90,0,16,2,1,0,0
MEMBER:'instr-arrow',0,0,16,2,3,0,0
MEMBER:'instr-arrow',0,0,16,3,2,0,0
MEMBER:'instr-arrow',-90,0,16,3,3,0,0
MEMBER:'instr-arrow',0,0,16,4,0,0,0
MEMBER:'instr-arrow',-90,0,16,4,2,0,0
MEMBER:'instr-arrow',90,0,16,7,0,0,0
MEMBER:'instr-arrow',180,0,16,7,1,0,0
MEMBER:'instr-arrow',90,0,16,8,0,0,0
MEMBER:'instr-arrow',180,0,16,8,3,0,0
MEMBER:'instr-grab',-1,1,32,3,2,0,0
MEMBER:'instr-input',-1,0,32,3,3,0,0
MEMBER:'instr-sensor',0,0,32,7,0,0,6
MEMBER:'instr-grab',-1,2,32,7,1,0,0
MEMBER:'instr-grab',-1,2,32,8,0,0,0
MEMBER:'instr-input',-1,1,32,8,1,0,0
MEMBER:'instr-output',-1,0,32,8,2,0,0
MEMBER:'instr-input',-1,1,32,4,1,0,0

GPT-6 Astra Fewest symbols

1,957 cycles · 1 reactor · 20 symbolsresearch_5.1957-1-20.txt on GitHub

Layout

α β ψ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 ↓ ↓ → → ← ↑ ↓ ← ← S← S→ GRAB CW IN β FLIP↑ CW IN α ?C→ DROP DROP OUT ψ B+

Running in the game

GPT-6 Astra solution running on research_5 in SpaceChem
SpaceChem Community Edition export (research_5.1957-1-20.txt)
SOLUTION:Right All Along,Player,0-0-0
COMPONENT:'drag-largeoutput-reactor',2,0,''
MEMBER:'instr-start',180,0,128,4,1,0,0
MEMBER:'instr-start',0,0,32,8,7,0,0
MEMBER:'feature-bonder',-1,0,1,1,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,5,0,0
MEMBER:'feature-bonder',-1,0,1,5,0,0,0
MEMBER:'feature-bonder',-1,0,1,5,1,0,0
MEMBER:'feature-sensor',-1,0,1,5,7,0,0
MEMBER:'instr-arrow',90,0,64,1,1,0,0
MEMBER:'instr-arrow',90,0,64,1,3,0,0
MEMBER:'instr-arrow',0,0,64,1,4,0,0
MEMBER:'instr-arrow',0,0,64,2,0,0,0
MEMBER:'instr-arrow',180,0,64,2,3,0,0
MEMBER:'instr-arrow',-90,0,64,2,4,0,0
MEMBER:'instr-arrow',90,0,64,5,0,0,0
MEMBER:'instr-arrow',180,0,64,5,1,0,0
MEMBER:'instr-arrow',180,0,64,7,0,0,0
MEMBER:'instr-grab',-1,1,128,1,1,0,0
MEMBER:'instr-rotate',-1,0,128,1,3,0,0
MEMBER:'instr-input',-1,1,128,1,4,0,0
MEMBER:'instr-toggle',-90,0,128,2,3,0,0
MEMBER:'instr-rotate',-1,0,128,2,4,0,0
MEMBER:'instr-input',-1,0,128,3,1,0,0
MEMBER:'instr-sensor',0,0,128,5,0,0,6
MEMBER:'instr-grab',-1,2,128,5,1,0,0
MEMBER:'instr-grab',-1,2,128,7,0,0,0
MEMBER:'instr-output',-1,0,128,6,0,0,0
MEMBER:'instr-bond',-1,0,32,9,7,0,0