Quick Takeaways
Table of Contents
- SpaceX launch of SDA’s Fourth Tranche‑1 mission
- Timeline and key milestones
- Space Development Agency’s Tranche‑1 program overview
- Technical specs of the 21 data transport satellites
- Future outlook and official statements
- Frequently Asked Questions
- When is the SpaceX launch of the SDA data satellites scheduled?
- How many satellites are included in SDA’s Fourth Tranche‑1 mission?
- What is the primary purpose of the SDA data transport satellites?
- Core Insight: SpaceX will attempt to launch 21 data transport satellites for the Space Development Agency (SDA) on Oct 12, 2026.
- Key Highlight: The payload marks SDA’s fourth Tranche‑1 mission, adding 21 satellites to a constellation aimed at low‑latency missile tracking.
- Actionable Advice: Defense contractors should monitor the launch schedule for potential integration windows and data‑link testing.
WASHINGTON, OCT 10 (Reuters) — SpaceX is slated to lift off 21 data‑transport satellites for the U.S. Space Development Agency on Oct 12, 2026. The mission, designated SDA’s Fourth Tranche‑1, will test the agency’s low‑Earth‑orbit (LEO) data‑relay architecture.
SpaceX launch of SDA’s Fourth Tranche‑1 mission
The launch will use a Falcon 9 Block 5 from Cape Canaveral Space Launch Complex 40. SDA contracts SpaceX under a Fixed‑Price‑Incentive‑Fee (FPIF) agreement that penalizes delays beyond the Oct 12 window. The launch window opens at 02:30 GMT and closes at 04:45 GMT, a 135‑minute slot chosen to align with the orbital plane of existing SDA satellites.Timeline and key milestones
| Date (UTC) | Event | Status | |------------|-------|--------| | Oct 10 2026 | Final payload integration check | Completed | | Oct 11 2026 | Wet dress rehearsal | Completed | | Oct 12 2026 02:30‑04:45 | Launch window | Pending | | Oct 12 2026 06:15 | First satellite separation | Expected | | Oct 12 2026 08:00‑10:00 | On‑orbit checkout of all 21 units | Planned |Space Development Agency’s Tranche‑1 program overview
SDA’s Tranche‑1 architecture consists of 126 data‑transport satellites split across four launches. The constellation is designed to provide sub‑second data latency for missile‑flight‑trajectory tracking, enabling the Integrated Air and Missile Defense (IAMD) system to fuse sensor data in near real time. The first three launches delivered 105 satellites; the upcoming batch brings the total to 126, meeting the agency’s 2027 operational target.Technical specs of the 21 data transport satellites
Each satellite weighs 225 kg, carries a phased‑array X‑band transceiver, and is powered by a 1.2 kW solar array. The bus is based on the proven LEO‑150 platform, offering a 10‑year design life with on‑orbit refueling capability. Key performance parameters include:| Parameter / Feature | Details / Specs | Recommendation |
|---|---|---|
| Mass | 225 kg per unit | Verify integration with launch adapter |
| Power | 1.2 kW solar array | Ensure ground‑station power budget accounts for peak load |
| Frequency band | X‑band (8–12 GHz) | Coordinate with existing NATO X‑band users |
| Propulsion | Hall‑effect electric thruster | Use for station‑keeping and de‑orbit maneuvers |
| Design life | 10 years (extendable) | Plan for mid‑life upgrades in 2032 |
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