Full-Time

Senior Mechanical Design Engineer

Space

Antares Nuclear

Antares Nuclear

51-200 employees

Develops autonomous microreactors for remote power

Compensation Overview

$140k - $185k/yr

Carson, CA, USA

In Person

On-site in Torrance, California.

Category
Mechanical Engineering

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Requirements
  • Bachelor’s degree in mechanical or aerospace engineering, or a related physics-based field.
  • 3+ years of experience in space system/product mechanical design, system configuration and layout.
  • Expertise with CAD (e.g., NX, CATIA) and past experience with PLM and other manufacturing planning and management systems.
  • Ability to work long hours and weekends as necessary to support critical milestones
  • Willingness and ability to obtain and retain a security clearance
  • ITAR requirements: To conform to U.S. Government export regulations, applicant must be a US citizen or national, or a permanent resident, or be eligible to obtain the required authorizations from the U.S. Department of State.
Responsibilities
  • Own a subsystem and related hardware as part of the larger space nuclear system.
  • Drive system-level layout, requirements definition/decomposition, build/test cycles, defend decisions across all phases of design, take concept through CDR and onward.
  • Own CAD models, manage configurations, produce drawings, DFMEA, etc.
  • Drive cross-discipline alignment and trade studies.
  • Coordinate closely with other teams/people (nuclear, thermal, structures, manufacturing, quality) to ensure a system architecture that satisfies mission/product requirements.
  • Develop a clean sheet design through hardware procurement and dev/qual testing.
  • Support design reviews and integration/test planning for hardware, define manufacturing plan and generate work instructions as needed.
Desired Qualifications
  • Master’s or PhD in mechanical or aerospace engineering, or a related physics-based field.
  • Expertise in the design, analysis, and integration of nuclear or space nuclear systems.
  • Leadership experience on a project or research team.
  • Strong project management skills, cross discipline communication, and interpersonal and collaborative skills.
  • Exceptional communication skills to work effectively across teams and convey technical information to non-specialists.
  • Understanding of fundamental principles in fluid systems and solid mechanics.
  • Demonstrated track record of initiative and high impact / ROI contributions.
  • Broad knowledge of materials science and material selections, especially for nuclear applications.
  • Ability to conduct complex design trades, system sizing, and first-order engineering analyses while clearly identifying analysis limitations and associated design risks.
  • Very strong design skills and GD&T/ drawings experience; take a design into production.

Preparing company description.

Company Size

51-200

Company Stage

Series B

Total Funding

$126M

Headquarters

Los Angeles, California

Founded

2023

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Simplify Jobs

Simplify's Take

What believers are saying

  • Antares achieved zero-power criticality on June 4, 2026, a full month ahead of the July 4 deadline.
  • The company secured $96 million in Series B funding led by Shine Capital for uranium and factory build-out.
  • Urenco signed a long-term HALEU supply deal ensuring commercial fuel readiness beyond 2031.

What critics are saying

  • Urenco's UK HALEU facility opens in 2031, creating a 5-year gap before Antares' 2028 deployment target.
  • BWXT's limited TRISO fuel capacity for demos risks commercial production delays in 2027–2028.
  • Antares depends on Chinese reactor-grade graphite for its moderator, exposing supply chains to geopolitical disruption.

What makes Antares Nuclear unique

  • Antares R1 uses passive sodium heat pipes for zero-moving-part, high-reliability cooling.
  • The reactor operates autonomously for 6+ years on a single HALEU TRISO fuel core.
  • R1 fits standard military cargo platforms like 463L pallets for rapid global deployment.

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Benefits

Health Insurance

Dental Insurance

Vision Insurance

401(k) Retirement Plan

Flexible Work Hours

Remote Work Options

Paid Vacation

Paid Sick Leave

Paid Holidays

Hybrid Work Options

Wellness Program

Mental Health Support

Gym Membership

Phone/Internet Stipend

Home Office Stipend

Professional Development Budget

Conference Attendance Budget

Stock Options

Company Equity

Relocation Assistance

Parental Leave

Family Planning Benefits

Fertility Treatment Support

Adoption Assistance

Childcare Support

Elder Care Support

Pet Insurance

Bereavement Leave

Tuition Reimbursement

Professional Certification Support

Mentorship Program

Training Programs

Tuition Reimbursement

Growth & Insights and Company News

Headcount

6 month growth

0%

1 year growth

-1%

2 year growth

10%
Bloomberg L.P.
Apr 8th, 2026
Nuclear startup Antares wins key approval to complete demonstration reactor under US programme

Antares Nuclear Inc., a California-based startup developing small reactors, has become the first company to receive approval from federal regulators to complete its demonstration system under a US programme designed to accelerate new fission technologies. The approval from the Department of Energy marks a significant milestone for the nuclear startup as it works to advance small modular reactor technology.

Business Wire
Dec 3rd, 2025
Antares Raises $96 Million in Series B Funding to Accelerate Nuclear Microreactor Development

Antares, an advanced nuclear energy startup, today announced the close of its $96 million Series B funding round. The round was led by Shine Capital, with pa...

Startup Ecosystem Canada
Dec 3rd, 2025
Antares Raises $96M for Microreactor Development for Diverse Energy Applications

Antares raises $96M for microreactor development for diverse Energy applications. News summary. Antares, a nuclear startup, has successfully raised $96 million in a Series B funding round to advance its small modular reactor design, known as the R1 microreactor. This funding includes $71 million in equity and $25 million in debt, with participation from Shine Capital, Alt Capital, Caffeinated, FiftyThree Stations, and Industrious. The R1 microreactor is designed for commercial, defense, and space-based applications, producing between 100 kilowatts and 1 megawatt of electricity using TRISO fuel. The startup's progress follows a renewed interest in nuclear power, evidenced by significant investments in similar companies like X-energy, Deep Fission, Aalo Atomics, and TerraPower. Antares aims to demonstrate its reactor for the Department of Energy next year, with plans to activate its full-power reactor by 2027. Story coverage.

FinSMEs
Dec 2nd, 2025
Antares Raises $96M in Series B Funding

Antares raises $96M in Series B funding. Antares, a Torrence, CA-based nuclear energy startup, raised $96M in Series B funding. The round was led by Shine Capital, with participation from Alt Capital, Caffeinated, FiftyThree Stations, Industrious, and other investors, bringing its total amount to date to over $130M in funding. It consisted of $71M in new equity capital and $25M in debt for equipment, factory build-out, and uranium procurement. Led by CEO Jordan Bramble, Antares is building compact nuclear microreactors to deliver energy where it's needed most: * remote military bases, * austere industrial sites, * and, one day, deep space and underwater missions. With operations in Torrance, California; Idaho Falls, Idaho; and Aiken, South Carolina, and a team of 60, Antares is working to demonstrate a low-power test reactor before July 4, 2026, and to test its electricity-producing demonstration unit in 2027. Production units will be deployed as early as 2028.

Business Wire
Dec 2nd, 2025
Antares raises $96M Series B to accelerate nuclear microreactor development

Antares, an advanced nuclear energy startup, has closed a $96 million Series B funding round led by Shine Capital. The round includes $71 million in new equity and $25 million in debt for equipment, factory build-out and uranium procurement. Participants include Alt Capital, Caffeinated, FiftyThree Stations, Industrious and other investors. The Washington-based company is developing nuclear microreactors. CEO Jordan Bramble said the capital will accelerate the company's mission to deliver its technology, though specific deployment timelines were not disclosed.