CHAPEEA Project

The Crew Health and Performance Exploration Analog (CHAPEA) is a NASA-led project designed to simulate long-duration human missions to Mars. Conducted on Earth under strictly controlled conditions, it provides scientists with a unique opportunity to study how humans adapt physically, psychologically, and operationally to the extreme isolation, limited resources, and communication delays that will characterise future missions to the Red Planet.
The project represents a crucial step in NASA’s long-term strategy to prepare for sustained human exploration beyond Earth’s orbit, particularly under the Artemis programme, which aims to establish a sustainable presence on the Moon as a precursor to Mars expeditions.

Background and Purpose

Future Mars missions will expose astronauts to extended isolation, confinement, and operational stress unlike any previous spaceflight experience. A round-trip to Mars could take two to three years, with each crew living on the planet’s surface for over a year in conditions of reduced gravity, limited communication with Earth, and strict resource constraints. Understanding how humans can live and work effectively in such conditions is essential for mission success.
To address these challenges, NASA developed the CHAPEA programme—an Earth-based analogue mission replicating many of the psychological, physical, and logistical aspects of life on Mars. These simulations help researchers refine habitat design, food systems, team operations, and health support mechanisms in preparation for future planetary exploration.

The Mars Dune Alpha Habitat

The CHAPEA missions take place inside a specially constructed habitat known as Mars Dune Alpha, located at NASA’s Johnson Space Center in Houston, Texas. The habitat measures approximately 1,700 square feet (about 158 square metres) and was built using 3D printing technology, which NASA envisions as a potential construction method for habitats on Mars or the Moon.
The structure is designed to imitate Martian living conditions as closely as possible. It includes:

• Private crew quarters for four participants.
• Workstations for scientific experiments, maintenance, and mission operations.
• A galley and food preparation area designed for shelf-stable meals similar to what astronauts will eat on Mars.
• A medical station, exercise area, and relaxation spaces.
• Crop-growing modules for testing small-scale food production and resource recycling.
• An adjoining external sandbox area that simulates Martian terrain for extravehicular activities (EVAs) using virtual and physical tools.

This environment allows researchers to observe how humans perform under realistic stressors—limited supplies, isolation, confinement, delayed communication with mission control (up to 20 minutes each way), and simulated equipment malfunctions.

Structure of the CHAPEA Missions

The CHAPEA project is planned as a series of three analogue missions:

1. CHAPEA 1 (2023–2024): The first mission began on 25 June 2023 and lasted 378 days. Four volunteer crew members lived and worked entirely inside the Mars Dune Alpha habitat, conducting daily experiments, simulated EVAs, and resource management tasks.
2. CHAPEA 2 (scheduled for 2025): The second mission will incorporate adjustments based on data from the first simulation, focusing on refining resource systems, crew workloads, and communication protocols.
3. CHAPEA 3 (scheduled for 2026): The final mission will aim to validate operational procedures for real Mars missions, including emergency response, food sustainability, and habitat efficiency.

Each mission involves continuous monitoring of the crew’s physical health, mental well-being, performance metrics, and social interactions. The goal is to identify potential problems early and develop countermeasures for future long-term spaceflight.

Research Objectives

The CHAPEA project addresses several key areas of study essential for human exploration of Mars:

1. Crew Health and Well-being: Researchers track sleep patterns, nutrition, exercise routines, stress levels, and immune responses. The aim is to understand how prolonged confinement affects human physiology and mental health.
2. Team Dynamics and Behaviour: The missions study interpersonal relationships, conflict resolution, teamwork, and leadership under isolation. Insights will guide astronaut selection, training, and psychological support systems.
3. Operational Efficiency: Simulated Mars tasks—such as habitat maintenance, scientific research, and surface exploration—are designed to test productivity and workload balance under real mission constraints.
4. Life Support and Resource Management: The CHAPEA missions test sustainable systems for water recycling, air purification, waste management, and crop cultivation, all vital for survival on Mars where resupply from Earth is not feasible.
5. Communication Delay Adaptation: Mars missions involve significant time delays in communication with Earth. CHAPEA introduces these delays into daily operations, forcing crews to rely on autonomy, pre-planned procedures, and internal decision-making.
6. Emergency Response and Resilience: The simulation includes randomised emergency scenarios such as equipment failures, medical incidents, or habitat malfunctions to assess problem-solving under stress.

Challenges Simulated in CHAPEA

While CHAPEA cannot fully reproduce Martian gravity, atmosphere, or radiation exposure, it successfully mimics the psychological and operational challenges of a Mars mission. These include:

• Isolation and confinement from the outside world for over a year.
• Limited personal space and privacy, which test patience and interpersonal tolerance.
• Delayed communication with mission control, requiring greater autonomy.
• Restricted diets consisting mainly of packaged or dehydrated foods.
• Simulated environmental stressors such as equipment breakdowns or power shortages.

The combination of these factors creates a demanding environment that tests the endurance, adaptability, and teamwork of the participants.

Early Findings and Observations

Preliminary insights from CHAPEA 1 highlight several factors that strongly influence mission success:

• Crew cohesion and psychological compatibility are as critical as technical competence.
• Structured daily routines and physical activity help maintain motivation and mental health.
• Autonomy and problem-solving skills are essential when communication with Earth is delayed.
• Nutritional diversity and occasional “comfort foods” contribute to morale and performance.
• Private spaces and recreation play an important role in preventing fatigue and interpersonal conflict.

These observations are helping NASA refine astronaut selection criteria, mission planning, and habitat design for future interplanetary expeditions.

Future Prospects and Significance

The CHAPEA missions form part of a broader set of NASA analogue programmes, such as underwater and Arctic simulations, that study how humans operate in isolated environments. The data from CHAPEA will feed directly into the planning of long-duration Artemis lunar missions and the eventual human Mars mission expected in the 2030s or 2040s.
Beyond space exploration, CHAPEA’s findings have practical applications on Earth as well. The research informs psychological support strategies for workers in remote or extreme environments such as polar research stations, submarines, and disaster-response teams. It also contributes to the design of sustainable living systems and closed-loop resource management technologies that can benefit future terrestrial habitats.