# Project 645601 — Space Defense Capabilities

**Program element:** 1206427SF — Space Systems Prototype Transitions (SSPT)  
**Project:** 645601  
**Component:** U.S. Space Force  
**Appropriation:** 3620F — RDT&E, Space Force  
**Budget Activity:** 4 — Advanced Component Development & Prototypes  
**Vintage:** President's Budget PB2027  
**Canonical URL:** https://hitchintel.com/programs/1206427SF/645601  
**Parent:** https://hitchintel.com/programs/1206427SF

## Summary

Project 645601 — Space Defense Capabilities requests $87.7M in FY2027, 100% of the $87.7M requested for program element 1206427SF, down 16% on FY2026. 3 R-2A activities decompose the request. Axient is the largest named R-3 performer at $3.0M, 3.5% of the project's FY2027 R-3 total.

## Funding profile

| Fiscal Year | Estimate Type | Amount ($M) |
|---|---|---|
| FY2025 | Actual | 112.1 |
| FY2026 | Enacted | 104.9 |
| FY2027 | Request | 87.7 |
| FY2028 | Outyear | 68.7 |
| FY2029 | Outyear | 70.3 |
| FY2030 | Outyear | 71.7 |
| FY2031 | Outyear | 73.3 |

> Estimate types are not summed. This project is one leaf of PE 1206427SF; the PE total is the sum of its projects, never added to them.

## What project 645601 buys

The Space Defense Capabilities project prototypes technologies for insertion into programs of record and provides platforms to operate prototypes in space. The Rapid On-Orbit Space Technology Evaluation Ring (ROOSTER) provides a low-cost, rapid, and flexible on-orbit capability to host and deploy numerous prototypes and payloads in order to mature critical technologies and enable investment or divestment decisions. Each ROOSTER on-orbit platform is designed to fly multiple payloads per mission, thus fully utilizing launch potential and providing the only recurring rideshare option for prototypes, demonstrations, and experiments to geosynchronous orbit. The objectives of the ROOSTER program are to enable rapid and cost-effective technology insertion into operational programs of record through the on-orbit checkout and testing of prototypes, demonstrations, and experimental payloads. Additionally, ROOSTER will work to mature operational concepts and tactics, techniques, and procedures, such as on-obit refueling, for use within the United States Space Force space enterprise architecture. Tetra provides a pathfinder to define future system architectures and operational concepts for several Space Domain Awareness (SDA) and Space Control programs and other mission partners, as well as prove prototype and experiment technologies for the Air Force Research Laboratory (AFRL) and other Department of War labs. It serves as an additional platform to host prototype and experiment payloads that need to operate in concert with ROOSTERs. As a secondary mission, it provides a training platform for operators to develop and demonstrate tactics, techniques, and procedures for the evolution of operations and training in alignment with objectives from organizations such as the National Space Test and Training Complex and United States Space Force Space Training and Readiness Command. Quasi-Zenith Satellite System-Hosted Payload has dual goals of enhancing the US-Japan alliance and proving the feasibility and capability of a SDA sensor payload able to be proliferated and hosted on US and non-US satellites. In addition to prototyping such a capability, it will serve as a dedicated sensor in the Space Surveillance Network, enhancing SDA in Geostationary Earth Orbit over the Eurasian theater.

**R-3 lines of work:** Product Development; Support; Test and Evaluation.

## Named R-3 performers

| Performer | $M | Share of this project's FY2027 R-3 total |
|---|---|---|
| Axient | 3.0 | 3.5% |

> Budget-justification contract funding, not obligations. Shares need not reach 100% — unnamed and government work is in the denominator.

## Activities (R-2A) — 3

| Activity | FY2025 | FY2026 | FY2027 | Move | Page |
|---|---|---|---|---|---|
| Technology Maturation and Prototype Development | 36.3 | 36.2 | 46.1 | +27% | [a0](https://hitchintel.com/programs/1206427SF/645601/a0) |
| Prototype Integration, Test and On-Orbit Prototype Demonstration | 22.6 | 28.0 | 21.6 | −23% | [a1](https://hitchintel.com/programs/1206427SF/645601/a1) |
| Space-To-Space Communications | 53.3 | 40.7 | 20.1 | −51% | [a2](https://hitchintel.com/programs/1206427SF/645601/a2) |

> Activities carry the prior, current and budget year only — no five-year plan. In the request year they partition this project exactly; in earlier years they can under-cover it.

### Technology Maturation and Prototype Development

- ROOSTER: Support shipment and launch integration efforts for the ROOSTER-4 space vehicle, pending updated launch plans. For ROOSTER-5, complete platform development and factory testing of the ROOSTER-5 space vehicle and begin integrated test campaign. Prepare for shipment and launch integration efforts. Obtain security and policy…

Full year-by-year narrative: https://hitchintel.com/programs/1206427SF/645601/a0

### Prototype Integration, Test and On-Orbit Prototype Demonstration

- ROOSTER: For ROOSTER-4, finish payload integration; support launch integration and launch, pending updated launch plans. Begin the execution of the 12-month on-orbit prototype testing and demonstration phase. Conduct on-orbit tests and demonstrations to enable technology maturation. For ROOSTER-5, continue integrating manifested…

Full year-by-year narrative: https://hitchintel.com/programs/1206427SF/645601/a1

### Space-To-Space Communications

Complete development of the optical space terminals, conduct functional and performance testing of the terminals on the government testbed at MIT/LL, conduct environmental testing on the terminals, and continue development of the Space Data Network C2 System.

Full year-by-year narrative: https://hitchintel.com/programs/1206427SF/645601/a2

## What is NOT on this page

Congressional marks, the R-2 mission description and acquisition strategy, the industry vs government split of the whole request, and related program elements are recorded at **program-element** grain — an NDAA mark lands on a PE, never on a project. They are at https://hitchintel.com/programs/1206427SF.

## Source & machine access

- **Source:** FY2027 Department of the Air Force RDT&E Budget Justification, Exhibits R-2/R-2A/R-3, PE 1206427SF project 645601 (PB PB2027).
- **MCP:** `mcp.hitchintel.com` — `budget_get_program_element(pe="1206427SF")`.

*HitchAI is an independent intelligence service, not affiliated with the U.S. Department of Defense. Budget figures are requests/estimates, not obligations.*