HIMARS Specialist

Why Castelion, Why Now

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

HIMARS Specialist

The HIMARS Specialist will serve as Castelion's internal subject matter expert (SME) on HIMARS employment, operations, and tactical integration. This individual will translate firsthand operational experience into actionable guidance for engineering, manufacturing, testing, and customer engagement teams.

You will play a critical role in ensuring our systems are intuitive, survivable, rapidly employable, and aligned with how warfighters actually operate.

Responsibilities

• Serve as the internal SME on HIMARS operations, tactics, techniques, and procedures (TTPs)
• Provide operator-informed input into system architecture, human-machine interface (HMI), mobility concepts, and reload workflows
• Advise engineering teams on real-world constraints including crew ergonomics, field maintenance, deployment timelines, and survivability considerations
• Support design reviews to ensure operational realism is embedded in system decisions
• Participate in field tests, live fire events, and mobility demonstrations to evaluate usability and mission flow
• Assist Business Development and Program teams with customer engagement, CONOPS development, and operational briefings
• Develop training concepts and documentation rooted in real operational experience
• Identify capability gaps and improvement opportunities based on firsthand system use

Basic Qualifications

• Prior experience operating the M142 HIMARS in an operational military environment
• Deep understanding of HIMARS crew operations, mission planning, reload procedures, and fire mission execution
• Experience in deployed, training, or live-fire environments
• Ability to communicate operational insights clearly to engineering and technical teams
• Active U.S. security clearance or ability to obtain one

Preferred Skills and Experience

• Experience serving as Section Chief, Platoon Sergeant, Fire Direction Specialist, or similar leadership role
• Instructor or evaluator experience within a HIMARS unit
• Exposure to joint fires integration and coordination with higher-echelon fire control systems
• Familiarity with modern digital fire control and targeting workflows
• Experience supporting acquisition, test, or modernization efforts

Additional Requirements

• Ability to put in extended hours, including evenings and weekends, when required to meet aggressive timelines
• This role is based in Torrance, CA and requires full-time onsite presence

Other Duties

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice.

Benefits and Perks

All full-time employees are granted meaningful long-term equity, sharing in the company's significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company-paid holidays, and comprehensive health benefits - including 100% employee-covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid

parental leave to support growing families, a $100 monthly fitness stipend to promote health and performance, and onsite EV charging for convenience. In addition, employees enjoy perks like catered meals, company-covered food during high-demand periods, and a fully stocked kitchen to stay fueled throughout the day.

Affirmative Action/EEO Statement

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.

ITAR Requirements

To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.