Castelion vs Portal Space Systems
Which Aerospace AI tool is better in 2026?
Castelion
Mass-producing affordable hypersonic weapons for defense
Portal Space Systems
Rapidly maneuverable spacecraft powered by solar-thermal propulsion
Side-by-side
Castelion is the more established option (raised $469M); pricing is comparable on both sides.
| Metric | Castelion | Portal Space Systems |
|---|---|---|
| Taglinei | Mass-producing affordable hypersonic weapons for defense | Rapidly maneuverable spacecraft powered by solar-thermal propulsion |
| Foundedi | 2022🏆 | 2023 |
| HQi | El Segundo, US | — |
| Employeesi | 201-500🏆 | 11-50 |
| Neuron scorei | 76🏆 | 72 |
| Total fundingi | $469M🏆 | $67.5M |
| Latest roundi | Series B · Dec 2025 | Seed |
| Valuationi | — | — |
| Cheapest paid plani | Pricing not disclosed | Pricing not disclosed |
| Free plani | ✗ | ✓ |
| Free triali | ✗ | ✓ |
| Top tier pricei | Pricing not disclosed | Pricing not disclosed |
| Pricing summaryi | Enterprise · Contact sales | Free |
| Categoriesi |
Capability matrix
Developer-facing capabilities and access signals for Castelion and Portal Space Systems.
| Capability | Castelion | Portal Space Systems |
|---|---|---|
| MCP support | ✗ | ✗ |
| Public API | ✗ | ✗ |
| Webhooks | ✗ | ✗ |
| OAuth 2.0 | ✗ | ✗ |
| SDK languages | — | — |
| Free plan | ✗ | ✓ |
| Free trial | ✗ | ✓ |
| Verified | ✗ | ✗ |
| Active deal | ✗ | ✗ |
🟢 Strengths of Castelion
- Has raised more capital ($469M vs $67.5M)
- Higher Neuron score (76 vs 72)
- More mature (2022)
🔵 Strengths of Portal Space Systems
- Offers a free plan
- Offers a free trial
- Newer company (2023)
Which should you choose?
Choose Portal Space Systems if price matters most — it starts at Free, which is friendlier for teams watching burn. Both AI Aerospace tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Castelion if you want the most established option — it has raised $469M, suggesting more runway for enterprise features, support, and long-term roadmap. For mission-critical workflows or larger teams, that stability often outweighs a lower monthly price.
Frequently asked questions
Castelion vs Portal Space Systems — which is better?
It depends on your priority. Castelion has raised more capital and is the more established option; Portal Space Systems has broader feature depth. See the side-by-side table above.
Is Castelion cheaper than Portal Space Systems?
No — Portal Space Systems's cheapest paid plan is Free, while Castelion's is Enterprise · Contact sales.
Do Castelion and Portal Space Systems offer free plans?
Castelion: Paid only. Portal Space Systems: Yes, has a free plan.
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