Payload Integration Engineer - Level 4

## Job Description Sophia Space is hiring a Payload Integration Engineer to be the technical owner of the payload on our first TILE demonstration mission. The payload is an electro-optical imager built by an outside vendor.

You will be Sophia's technical lead with that vendor and its partners, own the interface between the imager and our spacecraft, write the software that runs on TILE to control the imager, and carry the payload from engineering model testing through integration and test on the spacecraft. This is a wide-ranging systems engineering role with hands-on software and electronics work.

You will review the vendor's mechanical, thermal, and electrical design. You don't need to be a specialist in each, but you need enough breadth to ask the right questions in a design review and to recognize when an answer doesn't hold up. You will also write and test real code, interfacing with the Sophia Space software engineering team, because the payload control application is yours to finish.

You will work closely with Sophia's avionics, software, mechanical, and mission operations engineers and with the spacecraft integrator. Future missions add more imaging modalities, science instruments, RF payloads, and optical communications terminals. The way you set up this payload becomes the template for those.

We use AI coding assistants where they help and expect you to as well. ## Location & Eligibility This position is primarily in-person in Pasadena, California, with occasional hybrid flexibility based on business needs. Travel is light: expect about one trip to the spacecraft integrator. This role is open as a full-time direct hire or as contract-to-hire. Start as soon as possible.

This position requires access to technology that is subject to U.S. export control laws. To comply with applicable ITAR and EAR regulations, applicants must qualify as a U.S. Person, as defined under those regulations. U.S.

Persons generally include U.S. citizens, lawful permanent residents (green card holders), and certain protected individuals as defined by applicable law. ## What the Next Year Looks Like - Vendor oversight and interface closure.

Lead technical work with the imager vendor and its partners: set up reviews of the vendor's mechanical and thermal design, run technical interchanges to close open requirements such as payload power, and finish the interface control document with an updated delivery schedule and updated top-level requirements.

In parallel, carry the payload control application forward from its preliminary version and refine the mission analysis of imaging opportunities and lighting. - Engineering model test planning. Write the test plan for the imager's engineering model and take it through review ahead of the test campaign. - Vendor integration and test.

Support the vendor as they integrate and test the imager, and confirm the results show it meets its requirements and interface agreement. - Spacecraft integration and test.

Take full technical responsibility for integrating and testing the imager with the spacecraft, then support pre-launch verification and on-orbit checkout. ## Vendor Technical Oversight - Serve as Sophia's technical lead with the imager vendor and its partners. - Set up and run design reviews of the vendor's mechanical, thermal, and electrical design so Sophia has visibility into how the imager is being built. - Run technical interchanges across the vendor and its partners to close open requirements, and work through partnership and contractual constraints to get the right engineers talking. - Hold the vendor to its schedule and requirement commitments, and raise technical and schedule risks early. ## Interfaces and Requirements - Own the payload-to-spacecraft interface control document across mechanical, electrical, thermal, data, and software interfaces, working with Sophia's discipline engineers on the details. - Negotiate and maintain the payload's top-level requirements, and flow them into verification. - Define and verify the end-to-end data path from the imager into TILE. ## Payload Control Software - Develop and test the application that runs on TILE to control the imager: sending commands, receiving and timestamping image and health data, managing operating modes, and handling faults. - Take the application from its preliminary version to flight: specify and implement the remaining interfaces from the vendor's interface documents, and test them against simulators and hardware. - Work directly with the vendor's firmware engineers on command and telemetry protocols, boot sequence, and fault behavior. - Debug at the bench with schematics, serial and Ethernet links, and a scope or logic analyzer. ## Mission Analysis - Use orbit analysis tools such as STK to predict what the imager can see and under what lighting conditions, and keep that analysis current as the mission design changes. ## Test Planning, Integration, and Test - Write test plans and procedures with pass/fail criteria for the engineering model and flight imager, and take them through review. - Support the vendor's integration and test of the imager, including witnessing key tests. - Lead integration and test of the imager on the spacecraft: procedures, anomaly investigation to root cause, and test evidence. - Support environmental testing (thermal vacuum, vibration, shock, EMI/EMC) run by others, pre-launch verification, and on-orbit checkout. ## Communication - Write clear technical memos, review packages, and status updates for Sophia leadership and customers. - Build consensus across Sophia engineering and external partners without direct management authority. ## Required Skills - B.S. in Electrical, Aerospace, Computer, or Mechanical Engineering, Physics, or a related discipline, or equivalent experience. - 3 to 5 years of experience in systems engineering, integration and test, or instrument development on spacecraft, aircraft, or other complex hardware. - Solid Python and C or C++ for hardware: talking to devices over serial or Ethernet, parsing data, and writing automated tests.

You don't need to be a career software developer. - Experience working directly with an external hardware vendor, supplier, or partner, such as running design reviews, negotiating requirements, or tracking deliveries. - Experience writing interface control documents or requirements, and verifying hardware against them. - Hands-on test experience: writing procedures with pass/fail criteria, running tests on real hardware, and investigating anomalies. - Enough mechanical, thermal, and electrical background to review a vendor's design and ask useful questions. - Strong written and verbal communication, and comfort pushing a partner for answers. ## Desired Skills - Electro-optical or imaging payload experience, including performance measures such as radiometry, MTF, and SNR. - Orbit and mission analysis with STK or similar tools. - Linux, embedded Linux, and containers. - Time synchronization: NTP or PTP, pulse-per-second signals, timestamping. - Reading schematics and pinouts, harness debugging, scope and logic analyzer. - Spacecraft command and telemetry standards such as CCSDS, and SpaceWire or CAN. - Spacecraft integration and test, environmental test, launch campaigns, and on-orbit commissioning. - Experience on rideshare, CubeSat, SmallSat, or rapid demonstration missions. - Experience with SWIR, MWIR, LWIR, hyperspectral, RF, or optical communications payloads. - Requirements and MBSE tools such as DOORS, Jama, Polarion, Cameo, or Innoslate. - Active or previous DoD security clearance.

Sophia Space is a venture-backed deep technology company building high-performance, energy-efficient computing systems designed to operate in orbit. Our work sits at the intersection of aerospace systems, advanced computing, artificial intelligence, and applied physics, enabling a new generation of distributed edge computing capabilities in space. Having successfull