The primary objectives of the Tianwen-4 mission are to achieve Jovian orbiting, as well as orbiting and landing exploration of Callisto, and to advance scientific research on the Jovian system. To leverage high-quality research capabilities from home and abroad and improve the mission's scientific detection capacity and research outcomes, an opportunity announcement for scientific payload development for the Tianwen-4 mission is open to institutions at home and abroad.

I. Scientific Payload Configuration

The Tianwen-4 mission spacecraft consists of an orbiter and a lander.

The orbiter is planned to accommodate 10 scientific payloads: Soft X-ray Spectrometer, Magnetometer and Wave Instrument, Jovian And Solar-wind Magnetospheric Investigation, Medium and High Energy Particle Detector, Far-Ultraviolet Imager, Wide Angle Camera, Medium Angle Camera, Callisto Laser Altimeter, Visible and Infrared Imaging Spectrometer, and Callisto Gamma-Ray Spectrometer.

The lander is planned to carry 2 scientific payloads: Callisto Surface Composition Analyzer and Callisto Lander Magnetometer. 

Functional and performance specifications are provided in the appendix.

II. Proposal Requirements

(I) Selection Criteria

Proposals shall satisfy mission-driven functional and performance requirements, feature advanced technical solutions, viable development plans, development schedules compatible with mission timelines, and manageable development risks.

(II) Application Requirements

1. Applicant Entity shall possess capabilities for developing spacecraft-related products and qualifications including quality management certification (ISO 9001). The principal investigator shall have sound research and academic competence.

2. Research institutions outside the Chinese Mainland are encouraged to participate in joint proposals for projects led by Chinese research institutions. All parties shall negotiate to formulate the technical and economic plan.

3. Research institutions outside the Chinese Mainland are encouraged to submit proposals as the lead applicant entity. In principle, development funds shall be self-funded.

4. Research institutions outside the Chinese Mainland undertaking development tasks shall comply with relevant laws and regulations of China and their home jurisdictions.

5. Applicant entity shall submit both Chinese and English PDF versions of the proposal to the China National Space Administration (CNSA) by 31 December 2026. The timeline for proposal selection will be informed separately.

III. Contact Information

WANG Wei, China National Space Administration

Tel: +86-010-88298230 | E-mail: clep@cnsa.gov.cn (For requirements of Proposal Outline)

DONG Shuai, China National Space Administration

E-mail: dongsh@cnsa.gov.cn

LIU Dawei, Chinese Academy of Sciences

E-mail: liudw@nao.cas.cn (Technical Specifications in Guidelines)

Appendix: Scientific Payload Guidelines for the Tianwen-4 Mission.docx