SpaceX launches Intuitive Machines IM-1 mission from Florida

by John Sharp

A SpaceX Falcon 9 launched a lunar lander for Intuitive Machines (IM) of Houston, Texas. The mission, IM-1, saw the launch of the first of the IM Nova-C class landers from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida on Feb. 15 at 1:05 AM ET (06:05 UTC). The first launch attempt was scrubbed on Feb. 14 due to off-nominal methane temperatures prior to loading. If the mission successfully lands on the Moon, IM will become the first commercial organization, and the first American spacecraft in over 50 years, to successfully land on the surface of the Moon.

IM-1 is the first of three flights for the Nova-C class lander, which is designed and developed under NASA’s Commercial Lunar Payload Services (CLPS) contract to help support NASA’s Artemis campaign and commercial development on the Moon.

Falcon 9 booster B1060-18 was selected for IM-1’s launch and was rolled out to LC-39A on Feb. 7 with the spacecraft encapsulated in the fairing in preparation for a wet dress rehearsal. The booster hasn’t flown since its 17th flight, during which it launched the Starlink Group 6-18 mission in September 2023. It first flew on June 30, 2020, carrying a GPS satellite and bears the earliest serial number still in active use.  Following launch, B1060 performed a return-to-launch-site landing at Landing Zone 1 (LZ-1), which is just a few miles south of LC-39A at the Cape Canaveral Space Force Station.

While SpaceX is targeting Feb. 14 for the launch, there are further launch windows available on the following two days. The launch windows are calculated to ensure that the spacecraft arrives at the Moon at the beginning of the lunar day. Landing is expected to take place on Feb. 22, regardless of which of the available launch windows is used.

The Nova-C class lunar lander for this mission has been aptly named Odysseus after the mythical Greek character renowned for his long, epic journey and his intellectual brilliance, guile, and versatility. The naming is appropriate as Nova-C has been designed with state-of-the-art technology, including the first cryogenic liquid methane and liquid oxygen propulsion, also known as methalox, system to attempt a lunar landing. 

The use of methalox to fuel the lander has complicated the well-tuned Falcon 9 “load-and-go” procedure, during which fueling takes place immediately prior to launch to maintain optimal conditioning of the liquid propellants. Cryogenic propellants for the spacecraft within the fairing also have to be loaded as late as possible, and SpaceX has, therefore, designed and built additional connections to the lander from the transporter-erector, which provides ground connections to the Falcon 9. IM has indicated that two wet dress rehearsals were carried out to ensure the new connections function correctly. Fueling of the spacecraft is due to commence approximately two and a half hours prior to liftoff, according to SpaceX.


Innovative Machine Nova-C ready for encapsulation. (Credit: Innovative Machines)

Following liftoff, Falcon 9 will steer onto an easterly trajectory out over the Atlantic Ocean. Two minutes and 17 seconds after launch, the booster will separate from the second stage, reorient itself, and return to land at LZ-1. The fairings will separate three minutes and six seconds into the flight and splash down in the Atlantic Ocean, where they will be collected by a SpaceX support vessel.

Falcon 9’s second stage will burn for five and a half minutes to take the spacecraft into a 185 x 60,000 kilometer Earth orbit. Following about 35 minutes of coasting,  the second stage will then perform a further short burn to propel Odysseus into a Trans-Lunar Orbit (TLO) — a trajectory that will send the lander to intercept the Moon’s orbit. Deployment of the spacecraft will occur 48 minutes and 24 seconds after launch when the second stage will use spring force to gently push the lander away.

Odysseus will now perform autonomous commissioning tasks and orient its top platform solar cells toward the Sun. Once “power positive,” the craft will make first contact with the flight controllers at IM’s Nova Control, the company’s center for lunar mission operations in Houston, Texas. It will also determine its precise location by using star field navigation.

IM controllers will then commission the cryogenic engine systems and make a small adjustment to the lander’s trajectory to confirm that the engine is performing as expected, and make any calibration adjustments needed. The main engine is able to both throttle and gimbal inside a two-axis ring and is supplemented by cold-gas helium reaction control system thrusters.

Odysseus will make three small adjustment burns on the way to the Moon, each requiring the spacecraft to re-orient into thrust attitude prior to each burn, subsequently returning to the default power attitude.

The TLO trajectory will take IM-1 behind the Moon, where the main engine will perform an autonomous Lunar Orbit Injection burn to place Odysseus into an almost circular 100-kilometer Low-Lunar Orbit. Here, throughout 12 lunar orbits, each lasting approximately two hours, the controllers will perform detailed checks of all the spacecraft’s systems before committing to a lunar descent. 

The Descent Orbit Burn also takes place autonomously, on the far side of the Moon, and will reduce the craft’s orbit to 10 kilometers above the landing site. The craft then coasts for an hour before the powered descent commences.

The Nova-C’s main engine is designed to burn continuously throughout the powered descent. Throttling and gimbaling are used to slow the lander by 1,800 meters per second, pitching the lander over to assume landing attitude at 30 meters above the lunar surface before bringing the craft to a soft landing. 

Missions success criteria for IM-1. (Credit: Intuitive Machines)

During descent, Odysseus is guided by hazard sensors to pinpoint the landing zone and select a safe, level, and unimpeded landing site. Inertial measurement units guide the craft through the last 10 meters of descent, as visual systems are rendered blind by dust kicked up by the engine’s exhaust. 

The mission’s landing site is a crater known as Malapert A, located some 300 kilometers from the Moon’s south pole and close to the Malapert Massif, a candidate landing zone for NASA’s Artemis III mission.

The Nova-C lander is a hexagonal cylinder that stands four meters tall and 1.57 meters wide on six landing legs with a launch mass of 1,908 kilograms. It is capable of carrying approximately 100 kilograms of payload to the lunar surface and uses solar panels to generate 200 watts of power. 

The payloads onboard are expected to function only for as long as the spacecraft receives sunlight, which it converts into power via solar cells. It is expected that the extreme cold of the lunar night will render the electronics inoperable, so it is not anticipated that these instruments will wake up when the Sun again.

IM-1 carries payloads for several customers — six for NASA under CLPS and a further six for commercial partners. One of the commercial payloads is the Embry-Riddle Eaglecam, which is a free-flying device designed to capture the first third-person images of a lunar landing. Eaglecam will be deployed at 30 meters above the lunar surface and photograph the lander as they both descend toward the surface. This device was designed and built in response to a challenge by IM founder Steve Altemus during a 2019 visit to the Embry-Riddle Aeronautical University, his alma mater.

NASA’s Glenn Research Center has provided one of the payloads under CLPS, the Radio Frequency Mass Gauge (RFMG). An important factor of spaceflight is determining exactly how much fuel remains in each tank of your spacecraft. This is particularly difficult in microgravity, where, unless thrust is provided, cryogenic liquids tend to coat all of the internal surfaces of the tanks. RFMG seeks to provide an accurate estimate of fuel levels in spacecraft tanks using radio frequencies passed through the tanks and received via an external antenna. This technology has been tested on the ground during parabolic flights and on the International Space Station, but this is the first integrated test performed on a spacecraft operating and landing in microgravity.

Another NASA CLPS payload will photograph and measure the plume-surface interactions as Odysseus lands, informing future landing vehicle designs, including those for Artemis. The commercial payload Eaglecam will also trial an experimental electrostatic dust removal system for spacesuit design.

Other NASA science payloads include navigational instrument and radio astronomy trials, and the Radio wave Observation at the Lunar Surface of the photoElectron Sheath (ROLSES) instrument, which will measure plasma levels on the lunar surface around the lander, providing further environmental data to inform the future design of landers, habitats, and space suits.

NASA and IM are hoping that the Nova-C will succeed where others have failed, with recent lunar landing attempts either having failed — India’s Chandrayaan, Israel’s Beresheet, and Astrobotic’s Peregrine — or having suffered major issues on landing — Japan’s SLIM. 

IM-1 is the first of three Nova-C flights under the CLPS contract, with planning for the next two missions already well underway.

This was the 300th Falcon 9 mission, the 18th flight of this booster, and SpaceX’s 14th mission of 2024.

(Lead image: Falcon 9 launches from LC-39A with the IM-1 mission atop it. Credit: Max Evans for NSF)

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