NASA offered new details Friday about a mad dash to get two lunar landers — built by competing companies Blue Origin and SpaceX — and the space agency’s own rocket and spacecraft ready for a crucial test mission next year.

“We will not delude ourselves into believing that more time, more money, and flying less will somehow make our work safer or more achievable,” NASA chief Jared Isaacman said Friday in a press conference reaffirming the agency’s commitment to launching a low-Earth orbit test mission next year before a crewed lunar landing in 2028.

Blue Origin and SpaceX each have multibillion-dollar contracts with the US space agency to develop vehicles capable of ferrying astronauts from NASA’s Orion spacecraft down to the lunar surface.

“Every vendor and partner should understand that when a schedule is broken, NASA personnel will be knocking on the door, and not to observe, not to write a paper or convene a committee, but to roll up their sleeves and solve problems,” said Isaacman.

In February, Isaacman, then a newly appointed NASA administrator, shook up the agency’s road map for a moon landing by adding a 2027 test mission. Called Artemis III, this mission would see vehicles from both Blue Origin and SpaceX practice docking with Orion in low-Earth orbit, or just a few hundred miles above our planet — far closer to home than the moon that’s 238,855 miles (384,400 kilometers) away.

The estimated 14-day test mission will involve the launch of three massive rockets and will involve docking and undocking the crewed Orion spacecraft multiple times with experimental vehicles.

It’s “likely the most complicated launch campaign ever undertaken,” said Jeremy Parsons, manager of NASA’s Artemis Program.

Artemis III is designed to help vet which lander NASA might use for Artemis IV, which is slated to mark the first time astronauts have landed on the surface of the moon since the agency’s Apollo program concluded in 1972.

Blue Origin and SpaceX are developing vastly different vehicles. SpaceX, which was the first to cinch a lunar landing contract in 2021, intends to use its gargantuan Starship launch vehicle — which is under development but recently completed its first orbital test flight.

Starship is a two-part launch system that includes the Super Heavy rocket booster and the upper Starship spacecraft, a 171-foot-tall vehicle packed with six rocket engines of its own. The Starship spacecraft would serve both as the lunar lander and the upper stage of the rocket itself. The vehicle is unlike anything ever flown in the history of spaceflight.

Blue Origin’s Blue Moon Mark 2, however, harkens much closer to legacy lunar lander designs. Blue Moon is expected to launch within the cargo bay of Blue Origin’s New Glenn rocket and, at 52 feet tall, is visually reminiscent of a scaled-up version of NASA’s Apollo-era landers. Blue Moon has not yet flown a test flight.

The company intended to launch a scaled-down, cargo version, called Blue Moon Mark 1, this year. But those plans were put on hold after a New Glenn rocket exploded in May during routine ground tests and destroyed the company’s Florida launch site.

Both Blue Origin’s and SpaceX’s vehicles have a long series of tests and technology demonstrations ahead — before Artemis III or Artemis IV. Neither vehicle has flown with crew on board or docked with a spacecraft carrying astronauts, as they will do during Artemis III.

In Friday’s meeting, NASA also acknowledged a series of changes it’s made to other aspects of the Artemis program, including efforts to speed up production and design changes for the agency’s Space Launch System rocket and Orion spacecraft as well as greenlighting a simplified, lighter-weight version of moonwalking spacesuits designed by Houston-based company Axiom.

The simplified suits are meant to be quicker to bring to fruition for early moon landing missions, including Artemis IV, but Axiom will continue building the more advanced version for more difficult lunar excursions later in the Artemis program.

Almost across the board, NASA is “looking to simplify, remove difficult requirements,” Parsons said. But it’s the lunar lander vehicles, Parsons added, that are currently driving NASA’s schedule.

Under a newly released timeline for the Artemis Program, within the coming months, SpaceX will need to finish building the Starship prototype that will fly the Artemis III mission and complete several demonstrations to test the vehicle’s landing legs and airlock. Meanwhile, it will continue its Starship test flight campaign — including by expanding operations to two new launchpads in Florida and carrying out the first practice run at transferring fuel between two Starship vehicle in orbit.

Such a propellant transfer will be necessary to get the hefty Starship to the moon. Transferring super-chilled cryogenic propellants between two vehicles in Earth orbit has never been done before. SpaceX’s first demonstration is expected in early 2027.

For a moon landing, SpaceX will need to launch multiple refueling flights. Previously, experts had estimated the number could be between 10 and 40. CEO Elon Musk said on social media this week, however, that a moon landing would require six to eight launches.

NASA officials confirmed Musk’s estimate Friday but noted a final figure likely cannot be known until after propellant transfer testing is done.

Blue Origin’s Blue Moon Mark 2 will also require some complicated prep work in low-Earth orbit before heading to the moon. NASA said Friday that the lander would need to dock with at least three boost stages.

The company also has a long to-do list. Blue Origin must get its New Glenn flying again, which could happen by the end of the year, and get its overdue Blue Moon Mark 1 test flight off the ground early next year.

The Blue Moon Mark 2 lander used on Artemis III will also need to be outfitted with life support systems. The crew of four astronauts that will be onboard Orion during the mission are expected to climb aboard the Mark 2 vehicle while docked with the spacecraft.

NASA is not expecting to attempt the same with Starship. Citing SpaceX’s past experience flying crewed Dragon vehicles, the agency said it believes it can adequately vet the company’s life support systems outside the Artemis III mission.

After Artemis III, both Blue Moon Mark 2 and Starship are expected to make uncrewed trips to the moon to practice landing.

NASA has not yet determined which of the two vehicles will be used for its Artemis IV mission after pulling its commitment to SpaceX last year and pledging to use whichever vehicle was ready first. The agency cited a desire to assure its mission timeline amid a race with China.

Artemis IV is currently slated for early 2028, with a second astronaut landing, Artemis V, coming later that year. That timeline is widely expected to shift.

China has for years been working to land its taikonauts on the lunar surface for the first time by 2030. Experts believe the nation will more than likely hit or exceed that deadline.