Payload Integration Engineer - Level 4

Sophia Space Inc.; Pasadena, Northern (CA, KY); Hybrid; USD 127,000 - 193,000; Full time

Job summary

Sophia Space Inc. is hiring a senior software-focused engineer to build and verify the payload control software for the TILE demonstration mission. You will write the Linux application, develop simulators and testbeds, and lead verification campaigns from integration through on-orbit commissioning.

The role combines software with electrical and data-interface depth, requiring coordination with avionics, mission ops, and hardware teams. Occasional travel to Pasadena, CA is expected.

Qualifications

• BS in CS/CE or related field.
• 8+ years building software for hardware systems with HIL testing.
• Shipped software in fielded hardware environments.
• Python plus C/C++/Rust; Linux; Containers.
• Networking: implemented protocols from interface documents.
• Bench skills: Ethernet, serial, scope and logic analyzer.
• Time synchronization: NTP/PTP and timestamping.
• Experience creating and managing ICDs for software/data interfaces.
• Strong written and verbal communication; cross-disciplinary teamwork.

Responsibilities

• Design, build, and test the payload control software and interfaces.
• Work with vendor firmware on boot sequences, protocols, and timing.
• Deploy and operate the application on containerized onboard compute platform.
• Own payload-to-bus interfaces and end-to-end data path verification.
• Lead hardware-in-the-loop tests and verification campaigns.
• Drive consensus across avionics, software, mission ops, and partners.
• Prepare memos, reviews, and customer-facing technical content.

Skills

Python

C/C++

Rust

Linux

Containers

Networking

Time synchronization

Test engineering

ICD/Interface control documents

Communication

Education

B.S. in Computer Science / Computer Engineering / related

Tools

Kubernetes

Helm

SpaceDAQ / test rigs

Ethernet / CAN

Job description

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 successfully completed our Seed financing, Sophia is focused on scaling its team, products, and capabilities as we prepare for the next stage of growth. We are building a world-class engineering organization that combines expertise from aerospace, cloud computing, robotics, and AI to solve some of the most challenging problems in space infrastructure. As both a product company and an engineering-driven organization, we actively leverage modern AI tools throughout our development process to accelerate learning, improve productivity, and help deliver innovative, environmentally responsible computing platforms for the future.

Job Description

Build the software that operates the payload on Sophia's first TILE demonstration mission, and carry that payload through integration, verification, and delivery to the spacecraft. The payload is an electro-optical imager. The software is a Linux application: it commands the imager, receives and timestamps its data, manages operating modes and faults, and hands the data to Sophia's onboard compute platform. You will write it, build the simulators and engineering testbed used to prove it, run the verification campaigns, and support checkout once the payload is on the spacecraft.

This is a software-led role with electrical and data-interface depth. Mechanical and thermal integration are covered by others; you coordinate with them rather than own that work. You will work closely with avionics, software, mission operations, the spacecraft integrator, and the payload vendor's firmware team, and you will be the person who understands the payload end to end.

Future missions expand into additional imaging modalities, science instruments, RF payloads, and optical communications terminals. The patterns you establish here become the template for those.

We use AI coding assistants where they help and expect you to as well.

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.

Start as soon as possible. Contract-to-hire arrangements are welcome.

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

• First version against simulators. Stand up the payload control application and the simulators it talks to. Implement the command, telemetry, data, and timing interfaces from the interface documents, with tests.
• Engineering-unit campaign. Bring up the application against real hardware on the engineering testbed. Characterize the data path, timing, and fault behavior. Close out the interface documents against what the hardware actually does.
• Flight unit and delivery. Run the verification campaign on the flight unit, support environmental testing, and deliver the payload with its software, procedures, and test evidence to the spacecraft integrator.
• Checkout and commissioning. Support integration onto the spacecraft, pre-launch verification, and on-orbit payload commissioning.

Primary Responsibilities

Payload Control Software

• Design, build, and test the application that operates the payload: commanding, telemetry, data ingest, operating modes, timing, and fault handling.
• Implement the payload's software and data interfaces from interface documents, with tests that exercise the documented examples and edge cases.
• Work directly with the payload vendor's firmware team on boot sequences, command and telemetry protocols, frame timing, and fault behavior.
• Deploy and operate the application on Sophia's containerized onboard compute platform.

Electrical and Data Interfaces

• Own the payload-to-bus interface control documents for software and data interfaces; coordinate with the mechanical and thermal owners on theirs.
• Define and verify the end-to-end data path from the payload sensor into Sophia's onboard compute platform.
• Own time synchronization for the payload: reference clocks, pulse-per-second signals, timestamping, and correlation of payload data with spacecraft time.
• Debug at the bench: schematics and pinouts, harnesses, serial and Ethernet links, scope and logic analyzer.

Testbed and Verification

• Build the payload simulators and the engineering testbed: network, timing, power emulation, interface board, and harness.
• Write verification procedures with pass/fail criteria, automated tests, and hardware-in-the-loop test rigs.
• Take the measurements that prove the payload and its software meet their requirements, and keep the evidence.
• Lead anomaly investigation to root cause and disposition.
• Support environmental testing (thermal vacuum, vibration, shock, EMI/EMC) run by others.

Integration, Delivery, and Leadership

• Deliver the payload, software, procedures, and test evidence to the spacecraft integrator; support spacecraft integration, launch readiness, and on-orbit commissioning.
• Drive consensus across avionics, software, mission operations, and spacecraft partners without direct management authority.
• Prepare technical memos, review packages, and customer technical content; support proposal efforts and ROM estimates; partner with the Lead for Formulation & Customer Delivery on customer-facing activities.

Required Skills

• B.S. in Computer Science, Computer Engineering, Software Engineering, Electrical Engineering, Aerospace Engineering, Physics, or a related discipline, or equivalent experience.
• 8+ years building software for hardware systems (spacecraft, aircraft, robotics, instruments, autonomous systems), including hardware-in-the-loop testing and at least one delivery through a formal integration and test campaign.
• Shipped software that ran unattended in a fielded hardware system.
• Python plus at least one of C, C++, or Rust. Linux. Containers.
• Packet-level networking: you have written protocol code from an interface document and tested it against the document's examples.
• Electrical and data interface bench skills: Ethernet, serial, reading schematics and pinouts, scope and logic analyzer, harness debugging.
• Time synchronization: NTP or PTP, pulse-per-second signals, timestamping, clock correlation.
• Test engineering: hardware-in-the-loop rigs or simulators, automated tests, procedures with pass/fail criteria, root-cause investigation.
• Experience developing and managing interface control documents for software and data interfaces.
• Strong written and verbal communication, with a record of building consensus across engineering disciplines.

Desired Skills

• Imaging pipelines: frame capture, buffering, compression, storage, and downlink.
• Spacecraft command and telemetry standards such as CCSDS.
• SpaceWire or CAN.
• Kubernetes and Helm.
• Embedded GPU platforms.
• Spacecraft integration and test, environmental test, launch campaigns, LEOP, and on-orbit commissioning.
• Electro-optical performance verification: radiometry, MTF, SNR, pointing stability, alignment, calibration.
• Experience with SWIR, MWIR, LWIR, hyperspectral, RF, or optical communications payloads.
• Familiarity with optical communications terminal technologies and high-speed space data links.
• Experience supporting rideshare, CubeSat, SmallSat, or rapid demonstration missions.
• Familiarity with MBSE, SysML, DOORS, Jama, Polarion, Cameo, or Innoslate.
• Active or previous DoD security clearance.

The pay range for this role is:

127,000 - 193,000 USD per year (Pasadena, CA)