Trump Claims NASA Will Send a Nuclear-Powered Ship to Mars by 2028 — Is It Technically Feasible?

A Mars Proclamation That Sparked Heated Debate

Recently, former U.S. President Donald Trump claimed that NASA is building a "nuclear-powered starship" and plans to carry out a Mars mission by 2028. The news quickly went viral on platforms like Reddit, sparking polarized reactions among space enthusiasts and industry professionals — some were inspired by the grand vision, while others raised serious doubts about the timeline and technical feasibility.

Before diving into the analysis, we need to clarify several key questions: What exactly does "nuclear-powered" mean? Is "starship" referring to SpaceX's proprietary vehicle or a generic term? And is the 2028 timeline remotely realistic? This article will provide a rational breakdown of the claim based on the current state of space technology.

The Technical Reality Behind Nuclear-Powered Spacecraft

The Difference Between Nuclear Thermal and Nuclear Electric Propulsion

In aerospace, "nuclear power" generally falls into two categories:

• Nuclear Thermal Propulsion (NTP): Uses a nuclear reactor to heat propellant and generate thrust, with a specific impulse roughly twice that of chemical rockets
• Nuclear Electric Propulsion (NEP): Uses a nuclear reactor to generate electricity that drives ion thrusters — more efficient but with lower thrust

Nuclear thermal propulsion is not a new concept. Its history dates back to the late 1950s with the U.S. NERVA program (Nuclear Engine for Rocket Vehicle Application). The program conducted extensive ground-based hot-fire tests from the 1960s to early 1970s and successfully demonstrated the basic feasibility of nuclear thermal rocket engines, but was shelved as the Apollo program wound down and federal budgets were cut. The core principle of NTP is to pass a low-molecular-weight propellant like liquid hydrogen through a nuclear fission reactor core, heating it to extremely high temperatures (typically above 2500K) before expelling it at high velocity through a nozzle to generate thrust. Because hydrogen's molecular weight is far lower than the combustion products of chemical rockets, the exhaust velocity is higher, yielding a specific impulse of approximately 900 seconds — roughly double that of a conventional liquid oxygen/liquid hydrogen engine (~450 seconds). Nuclear electric propulsion takes a different approach — it uses a nuclear reactor to generate electricity that powers electric propulsion devices such as Hall-effect thrusters or ion thrusters. NEP can achieve specific impulses of several thousand to even tens of thousands of seconds, but thrust is typically on the order of just a few newtons, making it better suited for long-duration continuous acceleration in deep-space cruise scenarios rather than maneuvers requiring rapid orbit changes.

Both technologies are considered ideal candidates for deep-space exploration, particularly crewed Mars missions, because they can significantly shorten travel time — compressing the Earth-to-Mars transfer from roughly 9 months to 3–4 months — thereby reducing astronauts' radiation exposure in space.

NASA's DRACO Project: Nuclear Thermal Propulsion Is Underway

NASA is indeed advancing research into nuclear propulsion. The DRACO project (Demonstration Rocket for Agile Cislunar Operations), a joint effort between NASA and the Defense Advanced Research Projects Agency (DARPA), is specifically aimed at in-orbit demonstration and verification of nuclear thermal propulsion technology. The project's goal is to validate the ability of a nuclear thermal rocket engine to operate in space.

DRACO was officially launched in 2021. In July 2023, Lockheed Martin was awarded a contract worth approximately $499 million to build the experimental spacecraft (named ARIES) that will carry the nuclear thermal rocket engine. The nuclear fission reactor at the engine's core is being designed and manufactured by BWX Technologies, using High-Assay Low-Enriched Uranium (HALEU) fuel. The in-orbit demonstration was initially targeted for around 2027, though the timeline remains subject to adjustment. It's important to note that DRACO's design thrust level and scale are far smaller than what would be required for a crewed Mars mission propulsion system — it is fundamentally a technology demonstration mission, designed to prove that a nuclear thermal propulsion engine can safely start and operate in the vacuum of space, and to validate critical subsystems such as reactor control, propellant flow management, and radiation shielding.

However, DRACO is still in the technology verification phase. Its goal is to complete a single in-orbit demonstration, and it remains a very long way from actually supporting a crewed Mars mission. The leap from a single technology demonstration to a reliable crewed flight system typically requires multiple iterations and over a decade of engineering development. Bridging the gap from demonstration to operational application still requires solving a series of major challenges, including engine lifespan, reliable restart capability after repeated shutdown cycles, and engineering scale-up to higher thrust levels.

The Naming Confusion Around "Starship"

"Starship" as a name is inherently prone to causing confusion. In public discourse, SpaceX's Starship is currently the most well-known candidate for a crewed Mars transport system, but SpaceX's Starship uses liquid oxygen/methane chemical propulsion, not nuclear power.

The SpaceX Starship system consists of two stages: the Super Heavy booster at the bottom and the Starship spacecraft on top, with a total height of approximately 121 meters — making it the largest launch vehicle ever designed by humans. The entire system uses SpaceX's proprietary Raptor full-flow staged combustion cycle engines, burning liquid oxygen and liquid methane as propellants. An important strategic reason for choosing methane as fuel points directly to Mars: Mars's atmosphere contains approximately 95% carbon dioxide, and subsurface ice deposits contain water. In theory, the Sabatier reaction can convert carbon dioxide and water into methane and oxygen, enabling In-Situ Resource Utilization (ISRU) for propellant production to fuel the return trip. This concept is one of the technological cornerstones of Musk's Mars colonization plan, but the ISRU system itself has never been validated at scale on the Martian surface. As of 2025, Starship has undergone multiple test flights and achieved notable progress in booster recovery and ship reentry, but it still requires extensive test flights before achieving crewed certification.

Therefore, Trump's "nuclear-powered starship" is more likely a conceptual catch-all term, or a conflation of different technology paths, rather than a reference to any specifically approved spacecraft. This ambiguity in phrasing is a major source of public confusion.

Crewed Mars Landing by 2028: Ambition or Fantasy?

The Multifaceted Challenges of a Crewed Mars Mission

Setting a crewed mission timeline of 2028 is considered extremely aggressive by most space experts. The challenges of a crewed Mars mission extend far beyond the propulsion system:

1. Radiation Protection: Shielding against cosmic rays and solar particle events during months of deep-space travel

The deep-space radiation environment is fundamentally different from low Earth orbit. On the International Space Station (ISS) in low Earth orbit, Earth's magnetic field still provides significant radiation shielding, with astronauts receiving a daily radiation dose roughly ten times that at ground level. But once outside the protection of Earth's magnetosphere in deep space, astronauts are directly exposed to two primary radiation threats: Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE). GCR consists of high-energy protons and heavy ions with extremely high energies that cannot be fully blocked by any reasonably thick passive shielding layer. Heavy ions create dense ionization tracks in biological tissue, significantly increasing the risk of cancer and central nervous system degeneration. SPE events are high-flux streams of charged particles released by solar flares or coronal mass ejections, capable of causing acute radiation injury within hours. NASA has set a career radiation exposure limit for astronauts of approximately 600 millisieverts, while the estimated radiation dose for a round-trip Mars mission (including surface stay) could reach 900–1200 millisieverts — far exceeding the safety limit. Current protective strategies under investigation include hydrogen-rich material shielding, water-wall designs, pharmaceutical countermeasures, and reducing flight time through nuclear propulsion.

2. Life Support Systems: Must operate reliably for years without resupply
3. Mars Entry and Landing: Decelerating and soft-landing large-mass payloads in Mars's thin atmosphere

Mars EDL (Entry, Descent, and Landing) is referred to by aerospace engineers as the "seven minutes of terror" and is one of the most technically challenging phases of a crewed Mars mission. Mars's atmospheric density is only about 1% that of Earth's, creating a fundamental dilemma: the atmosphere is thick enough to generate severe aerodynamic heating during high-speed entry (entry velocity typically exceeds 5.5 km/s), but not thick enough to slow large-mass payloads to safe landing speeds using parachutes alone, as Earth's atmosphere can. To date, the heaviest payloads NASA has successfully landed on Mars are the Curiosity and Perseverance rovers, on the order of 1 ton, using a combination of heat shields, supersonic parachutes, and a sky crane system. A crewed mission would require landing masses of 20–40 tons or more — a gap of one to two orders of magnitude from existing experience. NASA has explored large-mass landing solutions through projects like LDSD (Low-Density Supersonic Decelerator) and HIAD (Hypersonic Inflatable Aerodynamic Decelerator), but these technologies are still in early verification stages. SpaceX's approach relies on Starship's own Raptor engines for powered retro-propulsion landing, but this requires verifying reliable engine restart capability in the Martian environment after extended coast phases.

4. Return Capability: Producing fuel on the Martian surface or carrying sufficient return propellant
5. Astronaut Health: Bone loss, muscle atrophy, and psychological issues from prolonged microgravity exposure

The Cautionary Tale of the Artemis Program

Even the relatively mature Artemis lunar program has seen its crewed landing goals repeatedly delayed. Artemis I, the uncrewed lunar flyby test flight, was successfully completed in November 2022, with the Orion spacecraft spending approximately 25 days in lunar orbit before safely returning to Earth. But subsequent crewed mission timelines have been under persistent pressure: Artemis II (crewed lunar flyby) was originally scheduled for a 2024 launch, then postponed to September 2025, and postponed again to April 2026; Artemis III (crewed lunar landing, using SpaceX's Starship as the lunar lander) is currently scheduled no earlier than 2027. The delays stem from multiple causes: the Orion spacecraft's heat shield experienced unexpected char layer spallation during the Artemis I reentry, requiring in-depth investigation and engineering modifications; the Space Launch System (SLS) rocket's production schedule and costs have consistently exceeded expectations; and the Starship lunar lander's development faces its own technical challenges, including orbital refueling and long-duration cryogenic propellant storage.

These delays highlight a fundamental truth: even returning to the Moon — a destination humans reached 50 years ago — remains enormously difficult under modern safety standards and system complexity. Against the backdrop of not having returned to the Moon yet, leaping directly to a crewed Mars landing by 2028 lacks a reasonable technological progression path to support it. By the general conventions of aerospace engineering, the most optimistic estimates for a crewed Mars mission place it in the late 2030s to 2040s.

The Gulf Between Political Declarations and Engineering Reality

Grand proclamations in the space sector often carry a strong political flavor. Successive U.S. administrations have proposed ambitious space goals, but actual implementation is frequently constrained by:

• Uncertainty in Congressional budget approvals
• Objective limitations of technology maturity
• Strategic shifts caused by political administration changes

Compressing complex systems engineering into a politically convenient timeframe has rarely succeeded in history. Looking back, President George H.W. Bush's Space Exploration Initiative (SEI) in 1989 set a goal of landing on Mars before 2019; President George W. Bush's Constellation Program in 2004 envisioned returning to the Moon as a stepping stone to Mars; President Obama set a goal in 2010 of sending humans into Mars orbit by the mid-2030s — all of these grand narratives were ultimately significantly adjusted or canceled due to insufficient funding, technical bottlenecks, or policy changes. This cycle of "declaration — delay — reset" represents a structural dilemma that has long plagued America's crewed deep-space exploration efforts.

How to Rationally Evaluate Space News Like This

Distinguishing Vision from Executable Plans

When encountering news like this, the public should learn to distinguish between "visionary statements" and "executable engineering plans." A technology direction receiving policy attention is a positive thing — it may bring more R&D investment — but this is not the same as that technology being mature enough to support a mission on a specific date. In aerospace engineering, technology maturity is typically measured using TRL (Technology Readiness Level), which ranges from levels 1 to 9, from basic principle observation (TRL 1) to flight-proven systems (TRL 9). Nuclear thermal propulsion is currently at roughly TRL 4–5 (laboratory environment validation to relevant environment validation), still a long engineering development road away from the TRL 8–9 required for crewed flight.

Follow Authoritative Information Sources

Reliable references for assessing the feasibility of space developments include:

• NASA's official technology roadmaps and budget documents
• Peer-reviewed academic research
• Independent assessment reports from the GAO (Government Accountability Office)

Secondhand accounts on social media platforms often lose critical technical context during dissemination, easily leading to exaggeration or misinterpretation.

Conclusion: Balancing Enthusiasm with Rationality

Nuclear propulsion is indeed an important technology option for humanity's journey to Mars, and NASA and DARPA's related exploration efforts are very real. However, locking a crewed Mars mission to 2028 lacks a realistic foundation from the standpoints of both technology maturity and engineering complexity. This proclamation reflects political-level space ambition more than an engineering-level firm commitment.

For readers who genuinely care about space progress, the more prudent approach is to maintain enthusiasm for grand visions while scrutinizing every timeline and promise through a rigorous technical lens. Nuclear propulsion will ultimately play a pivotal role in humanity's deep-space exploration — but that day will arrive through solid engineering accumulation, not a mark on a political calendar.