A NASA advisory committee on human space flight is recommending NASA seriously consider flight testing its new lunar landing system with an uncrewed Moon mission before a mission with astronauts on board.

“Serious consideration should be given to demonstrating through flight test the ability to deorbit, land on and ascend from the lunar surface under the expected physical and environmental conditions,” the Human Exploration and Operations (HEO) committee of the NASA Advisory Council says in a new report.

Skipping an uncrewed mission could risk the first astronauts who attempt to meet President Trump’s goal of Americans back on the Moon by 2024, the committee says. “Inadequate design may not be uncovered prior to human use,” it warns. The lander program is being managed by NASA in Alabama at the Marshall Space Flight Center in Huntsville.

The recommendations come from the Oct. 29-30 meeting of the HEO committee. The committee, which met at Kennedy Space Center to hear agency briefings, includes former astronauts, former and current NASA officials and civilians including Alabama attorney Mark McDaniel of Huntsville.

NASA typically requires systems that fly humans to be “human rated,” which means the probability of a loss on takeoff or landing not exceed 1 in 500. “While there may not be a single correct or acceptable approach,” the HEO committee said, “systems developed for human space flight in the past have found that uncrewed end-to-end flight tests have been extremely valuable. Partial or ground testing may be options but the HEO committee strongly recommend flight testing.”

The committee also said it thinks NASA is on track with its estimates of the cost to land on the Moon in 2024 in the program dubbed Artemis. “$1.6 billion is considered a reasonable estimate of first-year costs toward the 2024 landing,” the committee said. The Senate NASA budget for 2020 gives NASA an extra $1.2 billion overall.

Even with a steady flow of funding, the committee said meeting Trump’s deadline will be “challenging and difficult.” Without the funding, the result will be “significant risk to schedule.” Setting the goal for lunar return, as Trump did, has been good for NASA, the committee said. It has led to a “change in the (NASA) culture and streamlined decision-making, new acquisition methods, etc.”

McDaniel said he agrees. “From what I have seen and heard, I am confident that the mission can be accomplished,” McDaniel said. “The policy is in place, the leadership is in place and the right NASA team is in place.”