Near the Moon’s eastern limb lies Mare Crisium — the Sea of Crises — a low basalt plain embayed by rugged mountains. Carved by a colossal impact some 3.9 billion years ago, the 460-mile-wide (740 kilometers) mare appears largely flat and featureless. But lingering whispers of a volcanic past are everywhere, from its ubiquitous darkness to craters flooded and semi-obliterated by ancient basalt lavas — and a curious, solitary landmark near its center: the four-mile wide (6.4 km) Mons Latreille.
Soon, a robotic craft called Blue Ghost will land here, carrying 10 science instruments and technology tests as part of NASA’s Commercial Lunar Payload Services (CLPS) program. Also known as Blue Ghost Mission 1 and nicknamed Ghost Riders in the Sky, the lander is targeting a six-day launch window in mid-January.
An active past
Mare Crisium bears witness to an active past: long, sinuous ridges snaking across its eastern hinterlands, ghostly shadows of ancient craters and the capelike spit of Promontorium Agarum abutting its southeastern rim. Wider than the state of Arizona, the mare boasts a land area of 68,000 square miles (176,000 square km) — on par with Oklahoma.
Six decades ago, even as Russia lost its space race with the U.S. when Neil Armstrong and Buzz Aldrin triumphantly walked at Tranquillity Base in July 1969, the Soviets entertained a last-ditch gasp for glory by bringing a lunar sample back to Earth first.
As Armstrong and Aldrin slept in the hours after their historic moonwalk, Russia’s Luna 15 robotic probe attempted to land in Crisium, 344 miles (554 km) northeast of their landing site. But it hit a mountain during descent and was destroyed.
Another try in 1974 saw Luna 23 land too fast and topple over. But in 1976, Luna 24 safely returned 0.37 pound (170 grams) of Crisium soil to the eager hands of Russian scientists. Those samples inconclusively hinted at the presence of 0.1 percent water by mass.
In 2018, NASA began hiring private firms to send small robotic landers and rovers to the Moon through its CLPS program. One of those firms is Firefly Aerospace. Headquartered in Cedar Park, Texas, it was founded in 2017 and began flying its Firefly Alpha orbital rockets in 2021. It is also building the first stage of Northrop Grumman’s new Antares 330 booster.
Firefly won its first CLPS contract in February 2021: a $93.3 million task order to land on the Moon with Blue Ghost, a four-legged craft named after the rare Phausis reticulata firefly, whose eerie, bluish-white glow is native to the eastern U.S.
Lofted into orbit by SpaceX’s Falcon 9 rocket, Blue Ghost will be the first U.S. mission to Crisium. Standing 6.6 feet (2 meters) tall and 11.5 feet (3.5 m) wide, the Blue Ghost lander can carry about 330 pounds (150 kg) of payload to the Moon. One X-band and three S-band antennas furnish communications and HD video. And body-mounted solar panels will afford 300 watts of power for missions up to 60 days.
The lander passed its critical design review in October 2021 and integration readiness review in April 2022. Assembly was complete by October 2023, by which time the mission’s launch had slipped a year, to late 2024. According to NASA, the mission’s current launch window opens no earlier than the middle of this month, and will last six days.
Journey to the Moon
Once launched, the lander’s voyage to the Moon will take several weeks — giving Firefly time to validate Blue Ghost’s health and collect data.
After 25 days circling Earth, it will head for the Moon and enter lunar orbit for an additional 16 days of testing. Then, day 45 will mark the mission’s trickiest feat — a nail-biting descent from its 60-mile (100 km) orbit to the surface.
About an hour before landing, Blue Ghost’s 1,000-newton main engine will ignite. The lander will then coast for 50 minutes as its terrain-relative navigation system calculates altitude, rate of descent, and selects a suitable landing spot. Twelve miles (20 km) above the surface, it will pitch over, slowing from 3,800 mph (6,100 km/h) to 90 mph (145 km/h) to position itself over the selected touchdown zone. The main engine will shut off at an altitude of 500 feet (1,600 m) as Blue Ghost’s eight reaction control thrusters pulse periodically to fine-tune the descent.
That descent has been meticulously practiced on Earth. Firefly performed dozens of drop tests on various surfaces (such as sand, simulated lunar soil, and even concrete) to prove Blue Ghost’s shock-absorbing footpads can handle difficult landing conditions.
Alighting at 2.2 mph (3.5 km/h), contact sensors in the footpads will signal touchdown. And the past hour’s drama will be supplanted by the silence and serenity of a landscape unaltered for millions of years.
Tons of tech
Then the Blue Ghost Mission 1 can truly begin. For 14 days, Blue Ghost’s instruments will scour their environs and test technologies that may benefit future human explorers. Southwest Research Institute’s Magnetotelluric Sounder, a magnetometer atop an 8-foot (2.5 m) mast, will probe the lunar mantle to a depth of 700 miles (1,100 km) — two-thirds of the way to the Moon’s core. And Texas Tech University’s Lunar Instrumentation for Subsurface Thermal Exploration with Rapidity will drill 7 to 10 feet (2.1 to 3.3 m) into the ground, measuring heat flow in the interior.
The University of Maryland’s Next Generation Lunar Retroreflector will help measure the Earth-Moon distance with submillimeter precision, offering clues about the lunar interior and addressing questions about general relativity and dark matter. The Lunar Environment Heliospheric X-ray Imager — provided by NASA, Boston University, and Johns Hopkins University — will observe interactions between Earth’s magnetosphere and the solar wind.
Aegis Aerospace’s Regolith Adherence Characterization will assess how abrasive lunar soil affects different materials—including solar cells, optics, and spacesuit coatings. And Montana State University’s Radiation Tolerant Computer will test hardened computing electronics on the Moon’s airless, radiation-drenched surface.
NASA’s Stereo Cameras for Lunar Plume Surface Studies will gather still and video images to reveal how Blue Ghost’s rocket exhaust displaces soil, rocks, and dust. Data from its six tiny cameras will provide 3D surface views before and after touchdown, offering insights into how heavy landers and large habitats can be landed safely.
Honeybee Robotics’ Lunar PlanetVac will employ pressurized gas to pneumatically suck pebble-sized soil specimens into a collection chamber as a precursor for future sample-return missions. And NASA’s Electrodynamic Dust Shield will use electric fields to remove lunar dust from the lander, testing possible future use to clean solar panels, radiators, camera lenses, and astronauts’ spacesuits, boots, and visors of the damaging material.
Finally, the U.S./Italian Lunar GNSS Receiver Experiment aims to discern faint Global Navigation Satellite System signals from lunar distance for the first time — potentially allowing Earth-based GPS-type sensors to be used on future Moon missions.
More on the horizon
Even as it counts down to Mission 1, Firefly already is planning Mission 2 as well as yearly Blue Ghost flights beyond. In March 2023, it won a $112 million CLPS task order for a 2026 mission to land three payloads on the lunar farside, including an Australian-built seismometer and a NASA astrophysics experiment.
Mission 2 also debuts Firefly’s Elytra Dark transfer vehicle. After sending a Blue Ghost lander to the Moon’s farside — beyond direct line-of-sight with Earth — Elytra Dark will release Europe’s Lunar Pathfinder satellite as a data-relay for the lander.
