NASA Administrator Jim Bridenstine testifying at an April 2, 2019 House Science, Space, and Technology Committee hearing holding a “Mars 2033” bumper sticker.

The Science and Technology Policy Institute’s (STPI’s) independent analysis of the possibility of sending humans to Mars in 2033 concludes that it is “infeasible under all budget scenarios and technology development and testing schedules.”  It might be possible for such a mission to depart Earth in 2037, but 2039 is more realistic, the report says.  “Mars 2033” became a rallying cry for some human spaceflight enthusiasts during the Obama Administration and although NASA’s plans have changed quite a bit since then, a sizable Mars-or-bust community remains.


Sec. 435 of the 2017 NASA Transition Authorization Act required NASA to contract with an “independent, non-governmental systems engineering and technical assistance organization to study a Mars human space flight mission to be launched in 2033.”  In August 2017, NASA chose STPI, part of the Institute for Defense Analyses (IDA), to conduct that analysis.

At the time the law was written, NASA was following Obama Administration policy to get humans into orbit around Mars in the 2030s.  Landing on Mars was envisioned at an unspecified time in the future. The Obama policy eschewed lunar landings as unnecessary and a distraction from the real goal, Mars.

Mars advocates, including members of NASA’s congressional authorization committees, wanted humans to land on Mars in the 2030s, not just orbit.

Section 432 of the law required NASA to develop “a human exploration roadmap, including a critical decision plan, to expand human presence beyond low-Earth orbit to the surface of Mars and beyond, considering potential interim destinations such as cislunar space and the moons of Mars.”  The initial roadmap was supposed to be sent to Congress by December 1, 2017, with periodic updates at least every two years.

NASA missed the deadline largely because in December 2017, President Trump issued Space Policy Directive-1 (SPD-1) restoring the George W. Bush Administration’s plan to return astronauts to the surface of the Moon before going to Mars.  NASA submitted the Section 432 roadmap — National Space Exploration Campaign Report — in September 2018.

In the meantime, STPI completed a draft of its Mars 2033 report in December 2017 and was asked to update it after SPD-1.  The final report was recently submitted to Congress and was referenced during the April 2 House Science, Space, and Technology (SS&T) hearing on NASA’s FY2020 budget request, although STPI’s role was not mentioned.   It was made public yesterday.  It incorporates research through January 2019, including NASA’s plans for human lunar landings by 2028.  However, it does not reflect the most recent upheaval — Vice President Pence’s March 26 directive that NASA accelerate that date to 2024.

In assessing the possibility of sending humans to Mars in 2033, STPI used NASA’s Campaign report, interviews and other documents from NASA, and other sources.  It noted that Section 432 called for NASA to provide a “roadmap,” but that the Campaign report instead is a “high-level strategy” and a “plan for a plan” to get to Mars.

Even getting humans to orbit Mars, never mind land, anytime in the 2030s will be a challenge, STPI concluded, and 2033 is not feasible at all.

STPI found that a 2033 departure date for a Mars orbital mission is infeasible under all budget scenarios and technology development and testing schedules, given NASA’s current and notional plans. 2035 may be possible under budgets that match 1.9 percent real growth, but carries high risks of schedule delays due to complex technology development, testing, and fabrication schedules for the [Deep Space Transport] DST; may require reducing the scope of lunar missions; and reduces NASA’s ability to mitigate risks to human health. We find that 2037 is the earliest the DST could feasibly depart for Mars assuming a small budget increase or smoothing budgets over two time periods in the 2030s, with 2039 being a more realistic timeframe if there are delays or budget shortfalls affecting the acquisition or testing of the DST. — STPI

Earth and Mars are correctly aligned every 26 months to permit direct travel between the two planets, hence the two-year “windows” for launch.  STPI assumed a three-year total trip duration based on the sources used for its report.

STPI estimated the cost for a Mars orbital mission launching in 2037 at $87 billion ($FY2017), with the caveat that if NASA continues to invest in SLS, Orion and the Gateway for lunar missions, the additive cost for the Mars mission is less — $45 billion.

What impact Pence’s Moon-by-2024 directive will have on plans for human Mars exploration is unknown.  He and NASA Administrator Jim Bridenstine continually stress that Mars is the “horizon goal,” with the Moon serving as  a “proving ground.” Bridenstine plans to create a “Moon to Mars” mission directorate at NASA headquarters to focus that effort and emphasize that they are joint goals.

Appearing before the House SS&T Committee on April 2, Bridenstine insisted that accelerating the return to the Moon as directed by the White House would also accelerate trips to Mars because the lunar missions are needed first.  That is a debatable premise, however.  The whole concept of the Obama-era plan was that missions to the lunar surface are an unnecessary waste of time and money; whatever technology and human testing is needed can be done in lunar orbit instead.

Reacting to Pence’s directive, a spokesperson for Sen. Ted Cruz (R-TX) told that while Cruz supports a return to the Moon, “he believes reaching Mars in the 2030s should be the focal point of our national space program and it should be American boots that are the first to step foot on the surface of the Red Planet.”  Cruz chairs the space subcommittee of the Senate Commerce, Science, and Transportation Committee that oversees NASA.

House SS&T committee chairwoman Rep. Eddie Bernice Johnson (D-TX) said much the same thing at the April 2 hearing: “we want our nation to achieve challenging exploration goals like landing humans on Mars.” She said the committee might support lunar missions if the Moon is a “useful and necessary waypoint,” but criticized the agency for not providing a “meaningful” roadmap as required by the law.  Rep. Kendra Horn (D-OK), who chairs the House SS&T space subcommittee, offered a similar rebuke and asked what proposal the committee was being asked to consider — the budget proposal that calls for landing on the Moon by 2028, Pence’s directive to land on the Moon by 2024, or, referring to the STPI report, “as of just last Friday, we have a substantive analysis that raises numerous questions about NASA’s Exploration Campaign and the extent to which the Moon program will get us to Mars.”

Rep. Ed Perlmutter (D-CO), the most ardent Mars 2033 advocate, expressed disappointment with the conclusions of the STPI report.  He almost always brings a “Mars 2033” bumper sticker to NASA hearings, but did not in this case.  Bridenstine is a former Congressman from Oklahoma, was a member of the committee, and is a close friend of Perlmutter’s.  This time it was Bridenstine who brought the bumper sticker and reassured Perlmutter that Mars remains the goal.

Getting there in 2033, however, does not appear realistic based on STPI’s analysis.