NASA is charting a course for the stars with a groundbreaking ambition: to launch the first nuclear reactor-powered interplanetary spacecraft by the end of 2028, with Mars as its initial destination. This ambitious endeavor, revealed just as the Artemis II mission embarked on its lunar journey, signals a potential paradigm shift in space exploration, potentially offering the United States a decisive advantage in the burgeoning space race against China. While the specifics of this pioneering project remain largely under wraps, MIT Technology Review has consulted with leading experts in nuclear power and propulsion to illuminate the potential mechanisms behind this revolutionary spacecraft.

The prospect of a nuclear-powered vessel capable of traversing the vast distances between planets opens up a universe of possibilities. Unlike conventional chemical rockets, which are limited by the amount of fuel they can carry, a nuclear reactor could provide a continuous and potent source of energy. This would dramatically reduce transit times to distant celestial bodies, enabling more frequent and complex scientific missions. For Mars, a nuclear propulsion system could cut travel time significantly, from the current six to nine months down to potentially just a few, thereby minimizing astronaut exposure to the harsh conditions of deep space, such as radiation and microgravity.

Experts suggest several potential configurations for such a spacecraft. One prominent concept is Nuclear Thermal Propulsion (NTP). In an NTP system, a nuclear reactor heats a propellant, typically hydrogen, to extremely high temperatures. This superheated gas is then expelled through a nozzle at high velocity, generating thrust. NTP systems are significantly more efficient than chemical rockets, offering a much higher specific impulse, which is a measure of propellant efficiency. This means that for the same amount of propellant, NTP can generate more thrust over a longer period.

Another possibility is Nuclear Electric Propulsion (NEP). In this scenario, the nuclear reactor generates electricity, which then powers electric thrusters. These thrusters, such as ion engines or Hall thrusters, accelerate charged particles to very high speeds. While NEP systems typically produce lower thrust than NTP, they are even more efficient and can operate for extended periods, making them ideal for long-duration missions where speed is less critical than sustained propulsion. The choice between NTP and NEP, or even a hybrid approach, will depend on the specific mission objectives, the required thrust levels, and the technological maturity of each system.

The development of a nuclear spacecraft faces significant technical hurdles. Ensuring the safety and reliability of a nuclear reactor operating in the extreme environment of space is paramount. This includes developing robust shielding to protect the spacecraft’s systems and potential crew from radiation, as well as designing a reactor that can withstand the rigors of launch and space operations. Furthermore, the logistical challenges of handling nuclear materials for space missions, including their transport and assembly, will require careful planning and adherence to strict international regulations.

Despite these challenges, the potential rewards are immense. A nuclear-powered spacecraft could not only facilitate human missions to Mars but also open up possibilities for exploring the outer solar system and beyond. It could enable rapid response missions to asteroids or comets, and provide the power needed for advanced scientific instruments on long-duration probes. The competitive imperative is also a strong motivator. As China continues to advance its space program, including its own plans for lunar and Martian exploration, the United States is keen to maintain its leadership in space. A successful nuclear spacecraft program would be a powerful demonstration of technological prowess and a significant geopolitical statement.

This exploration into NASA’s nuclear spacecraft initiative is part of MIT Technology Review‘s "MIT Technology Review Explains" series, dedicated to demystifying complex technological landscapes and anticipating future developments.

Meanwhile, the world of Artificial Intelligence is on the cusp of a major unveiling: MIT Technology Review is set to release its highly anticipated "10 Things That Matter in AI Right Now" list. This new compilation arises from the overwhelming number of groundbreaking AI advancements that nearly made it onto the publication’s flagship "10 Breakthrough Technologies" list for 2026. The sheer volume of significant AI developments necessitated a dedicated focus, leading to the creation of this specialized AI-centric report.

The "10 Things That Matter in AI Right Now" will be officially revealed on stage at the signature EmTech AI conference on April 21st, with a full online publication following later that day. For those eager to be among the first to access this curated insight into the AI landscape, attending EmTech AI or subscribing to MIT Technology Review for livestream access are the key avenues. This list promises to distill the most impactful and transformative trends within the rapidly evolving field of artificial intelligence, offering readers a clear understanding of what’s shaping the future. The methodology and aims behind this crucial list are available for further exploration.

Adding another dimension to technological advancements, MIT Technology Review is also presenting a narrated feature on a company pioneering gene therapies with radical ambitions. Unlimited Bio is developing experimental gene therapies aimed at enhancing muscle growth, treating erectile dysfunction, and pursuing what they term "radical longevity." The company has already initiated a clinical trial involving volunteers receiving two such therapies, with the long-term goal of significantly extending human lifespan. Beyond muscle support, Unlimited Bio has plans to apply similar therapies to address hair loss and erectile dysfunction. However, these ambitious plans have sparked concern among some experts, raising questions about the ethical implications and potential unforeseen consequences of such interventions. The debate surrounding these gene therapies and their divided opinions is detailed in a recent report. This narrative is part of MIT Technology Review Narrated, a weekly podcast series available on Spotify and Apple Podcasts, offering an auditory exploration of significant technological stories.

In the realm of "must-read" technology news, a critical audit has revealed that major tech giants Google, Microsoft, and Meta are continuing to track user data even when individuals have opted out of such tracking. This practice could lead to billions of dollars in potential fines, highlighting a significant privacy concern. The broader implications of how our digital devices compromise our privacy are also under scrutiny, with a growing recognition that AI’s ability to retain and process information presents the next frontier for privacy protection, particularly concerning AI "memories" and what they retain about individuals.

OpenAI has introduced a new cybersecurity model, GPT-5.4-Cyber, specifically designed for defensive cybersecurity operations. This move follows a trend of AI companies focusing on cybersecurity, with OpenAI joining Anthropic in this endeavor. Like Anthropic’s recent offerings, OpenAI’s new model is currently accessible only to verified testers, underscoring the sensitive nature of AI applications in security. This development arrives at a time when AI is already demonstrably making online crimes easier, raising concerns about a potential escalation of cyber threats.

Amazon is making a significant play in the satellite internet market with its $11.6 billion acquisition of Globalstar. This move positions Amazon as a direct competitor to Elon Musk’s Starlink and aims to capitalize on the lucrative satellite broadband sector. Notably, Apple has already partnered with Amazon’s satellite network to provide emergency connectivity for iPhones, further integrating satellite technology into consumer devices.

Early users of experimental brain-computer interfaces (BCIs) are sharing their experiences, detailing both the benefits and drawbacks of living with these implants. The emotional toll of wearing Meta’s AI-powered sunglasses is also being reported, with users experiencing sadness due to the devices’ shortcomings. This follows a report where a patient with a Neuralink implant reportedly received a boost from generative AI, showcasing the evolving capabilities of brain-machine interfaces.

A concerning revelation indicates that dozens of AI disease-prediction models were trained on questionable data, with the possibility that some may have already been deployed in clinical settings. This raises serious questions about the reliability and safety of AI in healthcare.

Uber is proactively adapting to the threat of robotaxi disruption by shifting away from its traditional gig economy model. The company is investing $10 billion to acquire a substantial fleet of autonomous vehicles, signaling a strategic pivot to embrace the future of ride-sharing.

Elon Musk’s AI venture, xAI, is facing a lawsuit from the NAACP concerning alleged pollution from its data centers, with accusations of violating the Clean Air Act. This legal challenge reflects a growing concern about the environmental impact of data centers, a sentiment shared by communities that often oppose their construction in their backyards.

Apple is being discussed as a potential winner in the AI race, not necessarily through direct innovation, but by strategically benefiting from the substantial investments made by its competitors.

The notorious online forum 4chan has played an unexpected role in the development of AI’s reasoning abilities, having served as an early testing ground for a feature known as "chain of thought" reasoning.

The "Quote of the Day" comes from a copywriter who shared with The Guardian that "Everything got a whole lot worse once they rolled out AI," lamenting being overwhelmed by "workslop"—AI-generated content that appears polished but contains significant flaws.

Finally, in "One More Thing," a surprising perspective suggests that refrigeration, while seemingly a boon for food preservation, has actually "ruined" our food system. While fruits like bananas are now global commodities thanks to thermal control networks, and even a simple salad bag is a sophisticated respiratory apparatus, the long-term consequences of widespread refrigeration are being re-examined. Promising alternative preservation methods are being explored to address these concerns.