Through its "Moon to Mars" program, NASA plans to send the first crewed missions to Mars by the end of the next decade. This ambitious undertaking necessitates the implementation of advanced technologies through various programs. Among the critical areas of focus include propulsion technologies, which aim to minimize transit times to Mars, significantly reducing astronauts' exposure to microgravity and cosmic radiation. Additional technologies under investigation encompass methods for waste management, water extraction and recycling, crew health and safety, and achieving self-sufficiency in resources.
A Technology Gap in Space Propulsion
NASA is also exploring essential technologies that would facilitate cost-effective exploratory missions to Mars and beyond. Among these technologies, sub-kilowatt electric propulsion systems stand out as a primary focus for small spacecraft (those weighing 500 kg or less). A recent paper, presented at the 56th Lunar and Planetary Science Conference, outlines a novel program: the Commercial Hall Propulsion for Mars Payload Services (CHAMPS).
The research was led by a team of NASA engineers including Gabriel F. Benavides, Steven R. Oleson, and Alain S.J. Khayat. Benavides works at NASA Glenn Research Center as an in-space electric propulsion engineer, while Oleson leads the Compact Fission Reactor Design Team at Los Alamos National Laboratory and heads the Compass team at NASA GRC. This multidisciplinary group is tasked with conducting integrated vehicle systems analyses.
Foundation on Past Research
The CHAMPS initiative is grounded in previous investigations such as the Planetary Science Deep Space SmallSat Studies (PSDS3) and the Small, Innovative Missions for Planetary Exploration (SIMPLEx) program. These foundational studies have shown the significance of utilizing low-power, high-throughput electrostatic Hall Effect Thrusters (HET) optimized with magnetic shielding. These propulsion systems utilize solar energy (or another energy source) to ionize inert gas propellants like xenon. The resulting ions are then steered via magnetic fields to generate thrust.
The Role of Solar Electric Propulsion Systems
Aligned with the goals of the Artemis Program, these propulsion systems will be integral in launching the initial two components of the Lunar Gateway—the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO). Anticipated to launch in 2027, this mission involves the deployment of both modules utilizing a Falcon Heavy rocket to reach lunar orbit. Upon arrival, the modules will leverage their high-power solar-electric propulsion (SEP) systems to attain a near-rectilinear halo orbit (NRHO) around the moon.
This propulsion technology faces limitations, prompting NASA to initiate the Small Spacecraft Electric Propulsion (SSEP) project in 2017. The objective is to create miniaturized counterparts of NASA's advanced high-power solar-electric propulsion units. The current model, the H71M, is designed to provide a propellant throughput exceeding 140 kg (310 lbs) while accommodating the propulsion needs of a spacecraft weighing up to 450 kg (990 lbs).
Collaborative Development for Future Missions
In collaboration with commercial partners, NASA is licensing the H71M technology to guarantee its availability for forthcoming small spacecraft missions. This partnership has led to the development of the CHAMPS concept, projecting spacecraft that utilize the commercial variant of H71M called the NGHT-1X system, devised by Northrop Grumman. Missions aligned with this framework will prioritize economical and frequent launch opportunities instead of adhering strictly to direct transfer orbits to Mars.
Conceptualizing the CHAMPS Mission
One of the critical obstacles in executing economically viable scientific operations with small spacecraft is determining optimal launch opportunities to Mars. Launching primarily as the main payload introduces significant costs, while being a secondary payload may complicate the mission due to the primary payload’s requirements dictating launch parameters. Moreover, rescheduling a launch to accommodate different dates can be a logistical challenge.
The CHAMPS framework proposes to mitigate these issues by scheduling secondary payload launches associated with a Commercial Lunar Payload Services (CLPS) mission. These missions, expected to bring various payloads to the moon over the coming years, will leverage well-understood launch trajectories with multiple alternatives available. During the mission, instrument checks will occur while the spacecraft performs a gravitational assist maneuver to increase its velocity. This maneuver enables the craft to briefly enter a moon-centered NHRO until it aligns favorably for a Mars transfer.
Mission Timeline and Objectives
The initial low-thrust maneuver is projected to span approximately three months, succeeded by a four-month cruise phase and a subsequent seven-month low-thrust operation. Upon reaching Mars, the spacecraft will assume an orbit positioned 15 km (approximately 9.32 mi) above the planet's surface, ensuring comprehensive equatorial coverage every five sols (or 5.137 Earth days). Concurrently, it will address secondary scientific objectives by examining Deimos, one of Mars's moons. After approximately two years, the mission will transition to an aerosychronous orbit of 17 km (10.5 mi) altitude.
This strategic orbital position will facilitate continuous observations of the Martian atmosphere above critical surface features while also functioning as a data relay system for various surface operations.
Scientific Instruments and Research Goals
The CHAMPS mission is designed to conduct multiple scientific investigations using various instruments. According to the proposal, this will entail:
- A Visible/UV imager, akin to the Mars Color Imager (MARCI) employed during the Mars Climate Orbiter (MCO) and Mars Reconnaissance Orbiter (MRO).
- A thermal infrared (TIR) radiometer comparable to the mini-Mars Climate Sounder (MCS) utilized by the Mars Reconnaissance Orbiter (MRO).
- A near-infrared (NIR) spectrometer similar to the Argus device used in atmospheric investigations on Earth.
Through these instruments, the CHAMPS mission aims to:
| Objectives | Description |
|---|---|
| Atmospheric Measurements | Analyze the three-dimensional structure of the Martian atmosphere to gauge its pressure, temperature, aerosol distribution, water vapor, and ozone content. |
| Dust and Ice Studies | Monitor the development and behavior of Martian dust and water ice clouds, yielding insight into climate patterns and dust storm interactions. |
| Magnetospheric Evaluation | Investigate plasma conditions and magnetic field configurations around Mars, assessing interactions with solar radiation. |
These studies will empower scientists to tackle pivotal climate-related questions regarding Mars, including:
- How volatiles are exchanged between the Martian surface and atmosphere.
- The responses of the lower and middle atmosphere to regional and global solar heating.
- The coupling dynamics across various atmospheric levels.
- The effects of space weather on the Martian atmospheric conditions.
"Establishing a consistent pattern of scientifically driven, cost-efficient mission opportunities is vital to addressing unresolved questions about Mars, enabling swift responses to new discoveries, and increasing collaborative opportunities within the Mars science community." – NASA Mars Exploration Program Initiative 1
Conclusion
As NASA progresses with its initiatives aimed at lunar and Martian exploration, the CHAMPS program embodies a critical leap toward overcoming ongoing challenges in space propulsion and mission logistics. By leveraging advanced technologies and fostering collaborations, NASA is poised to expand our understanding of Mars while enhancing the prospects for future scientific inquiry throughout the solar system.
For further reading, refer to the full details of the CHAMPS proposal in the linked paper: CHAMPS Overview.
