Zitat von January 21, 2025 3:52 pmBlue Ghost Conducts First Burn, Science Operations, Captures Eclipse
Firefly’s Blue Ghost continues its journey to the Moon carrying 10 NASA science and technology instruments. Four days into the mission, the lunar lander completed its first main engine burn. This milestone is the first of several maneuvers that will position the lander in a trajectory towards the Moon. After 25 days orbiting Earth, Blue Ghost will continue its four-day journey to lunar orbit and orbit the Moon for 16 days before it begins descent operations to the lunar surface as part of NASA’s Artemis campaign.
Jointly developed by NASA and the Italian Space Agency, the Lunar GNSS Receiver Experiment (LuGRE) technology demonstration acquired Global Navigation Satellite System (GNSS) signals, and calculated a navigation fix at nearly 52 Earth radii: more than 205,674 miles (331,000 kilometers) from Earth’s surface. This achievement suggests that Earth-based GNSS constellations can be used for navigation at nearly 90% of the distance to the Moon, an Earth-Moon signal distance record. It also demonstrates the power of using multiple GNSS constellations together, such as GPS and Galileo, to perform navigation. Throughout its journey, LuGRE will continue expanding our knowledge of Earth-based navigation systems in space as it acquires and tracks signals on its way to the Moon, during lunar orbit, and for up to two weeks on the lunar surface.
During this Earth transit phase, the Firefly mission team has continued to ensure the spacecraft remains healthy. The most recent visuals from space include footage of Earth eclipsing the Sun.
Zitat von 11 minutes agoIntuitive Machines Delivers Second Lunar Mission Lander to Cape Canaveral, Florida
Intuitive Machines, Inc. (Nasdaq: LUNR, LUNRW) (“Intuitive Machines” or the “Company”), a space exploration, infrastructure, and services company, announced that it has delivered its IM-2 mission lunar lander, named Athena, to Cape Canaveral, Florida following a historic southeast Texas snowfall.
In coordination with SpaceX, the liftoff of the IM-2 lunar mission is targeted for a four-day launch window that opens no earlier than February 26. In case of unfavorable launch conditions, such as inclement weather, backup opportunities will be determined based on the lunar blackout window and other factors.
Commanded using Intuitive Machines’ commercial Lunar Data Network, IM-2 will be the Company’s second of four manifested lunar missions as part of NASA’s Commercial Lunar Payload Services (“CLPS”) initiative. ... Athena’s mission is designed to validate resource prospecting, mobility, and communications infrastructure in the Moon’s Mons Mouton region, one of nine potential Artemis III landing sites.
"Mons Mouton" war mir als topographische Bezeichnung auf dem Mond bislang unbekannt; ich sehe, daß die offizielle Benennung durch die IAU erst im Mai 2022 erfolgt ist. Es handelt sich um die höchste Erhebung auf dem Mond, was auf der Lewone mangels eines Normalnull als Höhe über dem durchschnittlichen umgebenden Mare-Boden gerechnet wird (die hohe Anzahl der sogenannten Mascons, der verbliebenden Impaktorkerne, die für die Entstehung der Mare verantwortlich sind, hat zu einer ziemlich "verbeulten" Verteilung geführt), das ist in diesem Fall das South Pole-Aitken-Basin; der Berg selbst liegt 6 km höher. Als potenzieller Landungsort ist die Gegend aufgrund zahlreicher Areale im "ewigen Mondschatten" ausgewählt worden, an denen man auf Eisvorkommen auch an der Oberfläche hofft.
"Les hommes seront toujours fous; et ceux qui croient les guérir sont les plus fous de la bande." - Voltaire
Zitat Firefly Aerospace@Firefly_Space Another payload milestone achieved on our way to the Moon! Our #GhostRiders began calibrating the LEXI X-ray imager to maximize its performance levels and prepare for operations on the lunar surface. Developed by @BU_Tweets, @NASA, and @JohnsHopkins, LEXI will be calibrated daily until we land on the Moon. The payload will then capture a series of X-ray images to study the interaction of solar wind and the Earth’s magnetic field that drives geomagnetic disturbances and storms on our home planet. #BGM1 9:28 PM · Jan 28, 2025
Seitenstück. Die XB-1 von Boom Supersonic hat heute auf ihrem Testflug zum ersten Mal die Schallmauer durchbrochen.
Zitat Plans to revive supersonic air travel have taken a leap forward after a test plane broke the sound barrier above the Mojave Desert in California.
A demonstrator aircraft, known as the XB-1, surged past Mach 1.1 (850 mph) in three high-speed runs spanning 35 minutes on Tuesday.
Boom Supersonic, the company behind the test, said the flight represented the most significant milestone yet in its efforts to return to the golden age of supersonic air travel.
The US company is seeking to revive the technology more than two decades after Concorde was retired by British Airways amid struggles to make the finances add up.
The test plane, flown by chief test pilot Tristan `Geppetto’ Brandenburg, pushed through the sound barrier at around 8:30am local time in a four-minute high speed run through a specially designated supersonic corridor close to Edwards Air Force base.
Boom plans to launch passenger flights cruising at Mach 1.7, or twice the speed of the fastest commercial aircraft today. Supersonic travel could cut the journey time between Paris and New York in half to around four hours.
The Overture plane, which would carry about 65 passengers and cost around £200m, according to Boom, has received outline orders from airlines including United and American.
Boom aims to produce 33 aircraft a year at its factory in North Carolina, which was completed in June, and double that number when a second assembly line is added.
Mr Scholl said the market for Boom’s plans was more than 1,000 aircraft, based on the number of people flying business class today on routes where demand for supersonic travel would be sufficient to boost profits.
Taking the project from the first supersonic test flight through to service entry will be a formidable task at a time when even regular flights are being challenged by climate campaigners as an unnecessary luxury.
4:34pm Concorde successor breaks the speed of sound The XB-1 demonstrator has broken the speed of sound, hitting Mach 1.1. It is the first civil supersonic aircraft in US history and the first to do so since Concorde was retired in 2003.
4:39pm Plane breaks sound barrier for second time during flight The XB-1 demonstrator swiftly achieved a second supersonic flight in an effort to secure more data for owner Boom Supersonic. It has eased back down to Mach 8, which ex-Concorde pilot Mike Bannister pointed out is about the maximum speed achievable by today’s airliners. (Ein offensichtlicher Tippfehler für "Mach 0.8")
4:44pm XB-1 demonstrator goes supersonic for third time The plane is back up to Mach 1.09 as Boom Supersonic aims to gather as much data as possible during this test flight.
4:46pm Make that Mach 1.12 The plane is now decelerating and descending back to the runway in the Mojave Desert after its third surge into supersonic speed, where it hit Mach 1.12.
4:56PM Plane lands safely The plane has landed on what ex-Concorde pilot Mike Bannister has called a “really successful day”.
Zitat Firefly Aerospace's Blue Ghost lunar lander snaps its 1st photos of the moon (images)
irefly Aerospace's Blue Ghost moon lander has snapped its first photos of its distant target.
On Monday (Jan. 27), Texas-based Firefly released two photos of the moon that Blue Ghost captured from Earth orbit. One shows the natural satellite all alone, a small grayish dot in an empty black sea; the other is a selfie, showing the moon glowing above some of Blue Ghost's golden hardware.
Everything seems to be going well for Blue Ghost so far. The lander remains healthy in orbit and has completed two engine burns on schedule, according to Firefly. In about 10 days, the spacecraft will conduct its most important engine firing yet — a translunar injection burn, which will set it on course for the moon.
Zitat Firefly Aerospace@Firefly_Space T-5 days until Blue Ghost says goodbye to Earth! With the accuracy we achieved on our first two burns, we were able to skip the third Earth orbit maneuver. Blue Ghost is already in a good position to perform our trans-lunar injection in just under a week. Our #GhostRiders continue to capture some incredible shots of our home planet along the way. #BGM1 5:00 PM · Feb 3, 2025
Zitat Firefly Aerospace@Firefly_Space Blue Ghost has "merged" onto the highway to the Moon! After a successful Trans Lunar Injection burn, our lander has left Earth's orbit and begun its 4 day transit to the Moon's orbit. We'll then spend approximately 16 days in lunar orbit before we begin Blue Ghost's descent. This gives us plenty of time to calibrate our navigation system and continue payload science operations for @NASA. #BGM1 3:18 PM · Feb 9, 2025
Zitat Firefly Aerospace@Firefly_Space Blue Ghost has already downlinked nearly 13 GB of data during our journey to the Moon, including some incredible payload science for @NASA! The latest payload successes include radiation tolerant computing through the Van Allen Belts with @montanastate's RadPC, measuring changes in the magnetic field with @SwRI's Lunar Magnetotelluric Sounder, and ongoing health checks for @HB_Robotics's Lunar PlanetVac.
Zitat After a successful Trans Lunar Injection burn on Saturday, Feb. 8, Firefly’s spacecraft carrying NASA science and tech to the Moon has departed Earth’s orbit and begun its four-day transit to the Moon’s orbit. Blue Ghost will then spend approximately 16 days in lunar orbit before beginning its descent operations. Since launching more than three weeks ago, Blue Ghost has performed dozens of health tests generating 13 gigabytes of data. All 10 NASA payloads onboard are currently healthy and ready for surface operations on the Moon.
NASA’s Radiation Tolerant Computer (RadPC), developed by Montana State University, successfully operated while passing through the Earth’s Van Allen radiation belts, providing insight on how to mitigate the effects of radiation on computers. This helps improve our understanding of the radiation environment that future astronauts may experience on Artemis missions.
During an on-orbit health check, NASA’s Lunar Magnetotelluric Sounder (LMS), developed by the Southwest Research Institute, accurately detected a change in magnetic fields. This is a positive sign that LMS will be able to measure the Moon’s magnetic and electrical fields, shedding light on the Moon’s interior temperature and composition on the lunar surface.
Also during a health check, Firefly and NASA teams captured data and an interior image of the sample container a from NASA’s Lunar PlanetVac (LPV), indicating the payload is operational in advance of surface operations on the Moon. The LPV payload is a technology demonstration that is designed to efficiently collect and transfer lunar soil from the surface to other science instruments or sample return containers without reliance on gravity.
Launch Date: January 15, 2025 Landing Date: March 2, 2025 Landing Time: TBA Landing Site: Mare Crisium near Mons Latreille
Stichwort Mare Crisium. Realiter ist die Lokalität in den Annalen der Raumfahrt verzeichnet als Einschlagstelle der sowjetischen Mondsonde Luna 15 am 21. Juli 1969 um 10 Uhr 51 Weltzeit, während Armstrong und Aldrin 554 km weiter im Südwesten gelandet waren, auf die Minute genau 13 Stunden, nachdem Neil Armstrong seinen Satz von "kleinen Schritt für einen Menschen" gesagt hatte und zehn Minuten bevor der "Eagle" wieder vom Mare Tranquilitatis abhob und als Landeplatz von Luna 24 1976, die 170 g Mondgestein mit zur Erde zurückbrachte (die Landeplätze der vergleichbaren russischen Missionen Luna 16 (1970) und Luna 20 (1972) - mit je 101 und 55 Gramm - lagen im Mare Fecunditatis).
Im Sachen Literatur spielten dort Arthur C. Clarkes Erzählung "The Sentinel" (1951), Keimzelle für den Monolithen aus "2001 - A Space Odyssey", natürlich Arno Schmidts "KAFF auch Mare Crisium" von 1960 und last but not least Robert A. Heinleins Roman "The Moon is a Harsh Mistress" von 1966.
Zitat Alex Lightman
Have met Elon Musk, written about space business since 1996
Originally Answered: what did Elon Musk get out of reading The Moon Is a Harsh Mistress?
I asked him in person what science fiction he had read or watched and how it influenced him. The first work he mentioned was The Moon Is a Harsh Mistress. Elon expressed – with some emotion and awe still visible – how stunned he was to have The Moon, which he had thought of as barren and lifeless, being inhabited by many people who were living their lives there, and this altered his thinking. He also mentioned being impressed that there were people who could make money doing business from getting people to the moon and building things there and owning real estate there.
Zitat "These 3 science fiction authors inspired Elon Musk’s creation of SpaceX, fascination with AI, and quest to colonize Mars"
Musk found that sci-fi addressed a curiosity brewing during his teen years in a way that religion and science alone couldn’t. Neither gave satisfactory answers to his questions about where the universe came from and why it exists, Walter Isaacson wrote in his new biography of the CEO, titled Elon Musk.
“When he reached his teens, it began to gnaw at him that something was missing,” Isaacson wrote. That feeling led to an “adolescent existential crisis” that Musk tried to solve with books.
“I began trying to figure out what the meaning of life and the universe was,” Musk said. “And I got real depressed about it, like maybe life may have no meaning.” He turned to existential philosophers like Nietzsche, but they left him feeling more adrift (he doesn’t recommend this as teenage reading material). He found solace in the supernatural world instead.
Three authors and books, Isaacson wrote, guided Musk through this phase and to the other side of trying to colonize Mars and bringing robots to life in a way that benefits, rather than harms, humanity.
The Moon Is a Harsh Mistress by Robert Heinlein
A favorite of Musk’s, this novel takes place on a lunar penal colony ruled by a supercomputer called Mike. The AI surpasses its robot state “with self-awareness and a sense of humor,” Isaacson writes, which leads to its self-sacrifice during a rebellion.
Zitat A SpaceX launch later this month will send a new type of lunar explorer to the moon.
IM-2, the second moon mission by Houston company Intuitive Machines, will lift off from Florida's Space Coast during a four-day window that opens on Feb. 26.
If all goes to plan, Athena will land on a plateau just 100 miles (160 kilometers) from the moon's south pole. This region is thought to be rich in water ice, and IM-2 will prospect for the precious resource with the help of some ride-along robots, including a pioneering hopper nicknamed Gracie. ... Gracie will deploy from Athena and perform a total of five hops, using its thrusters to launch itself across the lunar surface. These leaps will get progressively higher; the first will reach a maximum of 65 feet (20 meters), for example, and the second will get up to 165 ft (50 m), said Trent Martin, senior vice president of space systems at Intuitive Machines.
"And on the third hop, we go about 100 meters [330 feet] in altitude," Martin said in a NASA press conference on Friday (Feb. 7). "We'll hop down into a permanently shadowed crater."
That target crater, known as Crater H, lies about 1,650 ft (500 m) from Athena's landing site and is about 65 ft (20 m) deep, he added. Intuitive Machines hopes to maintain communications with the hopper while it's on the crater floor using another IM-2 payload, Nokia's Lunar Surface Communication System, which will set up the first-ever 4G/LTE network on the moon. Even if Gracie goes as dark as its surroundings, however, it should still be able to hop back out into the light: It's designed to do so after 45 minutes, or when surrounding temperatures reach a certain minimum, Martin said.
No hopper has ever explored the moon before (though China also intends to launch one next year, on its Chang'e 7 lunar mission). So, Gracie is mainly a technology demonstration, which aims "to show that we can reach extreme environments with technologies other than rovers," Martin said.
More serious prospecting work will be performed by IM-2's primary payload, NASA's Polar Resources Ice Mining Experiment 1, or PRIME-1 for short. (The IM-2 mission is part of the agency's Commercial Lunar Payload Services program, or CLPS, which puts NASA science gear on private moon landers.)
PRIME-1 consists of two instruments: a drill that will grab samples from up to 3.3 feet (1 m) underground and a mass spectrometer, which will analyze those samples for the presence of water and other interesting compounds.
Also flying to the moon on Athena is MAPP ("Mobile Autonomous Prospecting Platform"), a 22-pound (10-kg) rover built by the Colorado company Lunar Outpost. MAPP will carry payloads of its own — for example, high-resolution optical and thermal cameras, which scientists will use to create detailed 3D imagery of the polar region that MAPP will explore.
If all goes to plan, Athena will touch down on March 6 and operate on the lunar surface for about 10 Earth days. Its operational life will end shortly after the sun sets at its polar locale, depriving the solar-powered lander of life-giving light.
Zitat Firefly Aerospace@Firefly_Space Way to go #GhostRiders! The team confirmed Blue Ghost's first trajectory correction maneuver was performed with such accuracy we are skipping the next one. With Earth in the rearview mirror, we're on cruise control until we reach the Moon's orbit and perform a Lunar Orbit Insertion in just a couple days. So long, and thanks for all the fish! #BGM1 10:17 PM · Feb 11, 2025
Zitat Scott Tilley 🇺🇦@coastal8049 BLUE GHOST @Firefly_Space initial lunar orbit:
Measured period ~28440s, Semi-Major Axis ~4649km, Based on arrival vector, I estimate perilune ~150km, From SMA & perilune, ecc ~0.5940 & apolune ~5673km Inc ~100° from arrival angle. The entire orbit is visible from Earth now. 🧵⬇️
BLUE GHOST's first perilune was observed here allowing the orbital period to be estimated. I'll fit up the full pass Doppler to compare it to the initial orbital estimate tomorrow.
Zitat AMSAT-DL@amsatdl For those who missed the #BGM1 @Firefly_Space LOI (Lunar Orbit Insertion) burn last night (closest approach to the Moon at 01:53 UTC), here a time-laps video showing the events. 9:20 AM · Feb 14, 2025
"Firefly's Blue Ghost Mission 1 (BGM1) Lunar Orbit Insertion (LOI) burn on 2025-02-14 (closest approach to the Moon at 01:53 UTC) as a time-laps video showing the events. It's a critical maneuver to enter lunar orbit."
Nachtrag.
Zitat Firefly Aerospace@Firefly_Space "I love you to the Moon, but not back - I'm staying there," 💙 Blue Ghost. We captured our first shots of the Moon following a successful Lunar Orbit Insertion. The lander will soon begin to circularize its orbit in preparation for landing on March 2. #BGM1 6:59 PM · Feb 14, 2025
Hier mal etwas journalistisch aufbereiteter. Mittlerweile gibt es auch eine Zeitangabe für die Landung, die bisher noch ausstand.
Zitat Blue Ghost will spend the next 16 days in lunar orbit, if all goes to plan. It will conduct additional engine burns to circularize its path around Earth's nearest neighbor, then attempt a landing in the Mare Crisium ("Sea of Crises") region of the moon's near side on March 2.
Zitat A robotic lander from Texas-based Firefly Aerospace is now in orbit around the Moon and going through its final preparations to land in the coming weeks.
On Thursday, the company announced that its Blue Ghost lander fired its main engine and thrusters for four minutes and 15 seconds in a maneuver called the Lunar Orbit Insertion, which put it in an elliptical orbit around the Moon.
Its arrival comes nearly a month after the spacecraft launched onboard a Falcon 9 rocket from pad 39A at NASA’s Kennedy Space Center. This is the third mission launched as part of the agency’s Commercial Lunar Payload Services (CLPS) program, an initiative designed to bring science and technology demonstrations to the Moon at a cheaper cost.
With its arrival in lunar orbit, it will spend the next 16 days performing some additional checkouts as well as maneuvers to circularize its orbit. Landing on the Moon at Mare Crisium near Mons Latreille is targeting 3:45 a.m. EDT (0745 UTC).
Zitat Firefly Aerospace@Firefly_Space Our #GhostRiders completed another lunar orbit maneuver with a 3 minute, 18 second burn early this morning. This maneuver moved the lander from a high elliptical orbit to a much lower elliptical orbit around the Moon. Shortly after the burn, Blue Ghost captured incredible footage of the Moon's far side, about 120 km above the surface.
In this orbit, the team will experience planned rolling comms blackouts as Blue Ghost goes around the far side of the Moon. When on the near side, the team will continue to downlink data and finalize the plan for our next maneuver that will get Blue Ghost even closer to the lunar surface and keep us right on track for landing on March 2. #BGM1 3:59 PM · Feb 18, 2025
Zitat Scott Tilley 🇺🇦 🇨🇦@coastal8049 True to their word @Firefly_Space has successfully completed BLUE GHOST's LOI2 burn a day later than originally planned.
T=~7200s w/ eclipse timings conforming to ~100x150km orbit which was their target per FCC filings.
Congrats team Firefly and welcome to low lunar orbit! 🧵⬇️
BLUE GHOST's LOI2 burn was likely the biggest delta-V burn of the mission thus far and needed to be carefully time to avoid crashing into the Moon. The doomed LUNA 25 performing the same type of burn fired too long and crashed into the Moon as a result.
Zitat Firefly Aerospace@Firefly_Space The beauty of taking the scenic route is we have time to adjust our maneuvers based on real flight data along the way! For our third and final lunar orbit maneuver scheduled early Monday morning, we'll perform a 16 second burn that inserts Blue Ghost into a near-circular low lunar orbit with a 100-km perilune (the closest point to the Moon's surface). This will put us in prime position to perform a Descent Orbit Insertion as planned on March 2! Stay tuned for more. #BGM1 6:33 PM · Feb 21, 2025
Zitat Firefly Aerospace@Firefly_Space Earth rise, Earth set, repeat! Blue Ghost's third and final lunar orbit maneuver is complete! Early this morning, our #GhostRiders performed a 16-second burn with our RCS thrusters to enter a near-circular low lunar orbit. Up next, we'll perform a 19-second Descent Orbit Insertion at our 100-km perilune to begin our descent to Blue Ghost's final destination, Mare Crisium, on March 2.
Footage below captured by Blue Ghost shortly after our second lunar orbit maneuver. More to come soon! #BGM1 Last edited 4:20 PM · Feb 24, 2025
Zitat Firefly Aerospace@Firefly_Space That feeling you get when you look out the window and realize you’re almost home! T-4 days until we land in the Moon. Blue Ghost will reach her final destination no earlier than 2:34 am CST on March 2. We’ll start the joint livestream with @NASA at 1:20 am CST, approximately 75 minutes before we touch down on the surface.
Zitat Toby Li@tobyliiiiiiiiii Next week will be HUGE for Moon exploration.
Starting Feb 26, an unprecedented three lunar landers will be en route to land on the Moon. Read about all three of the exciting missions:
@Firefly_Space’s Blue Ghost is expected to touch down on March 2 which includes payloads like landing plume investigation.
@Int_Machines’s Nova-C scheduled to launch tomorrow and land on March 6, is headed for the Lunar South Pole to investigate the amount of water ice on the Moon with NASA’s PRIME-1 drill & mass spectrometer. Also onboard is the Micro Nova hopper. A propulsive drone that will hop around the lunar surface, including permanently shadowed regions, to expand the exploration footprint to up to 25 km. Also hitching a ride, @LunarOutpostInc’s tiny MAPP rover will collect regolith samples and NASA’s Lunar Trailblazer orbiter to detect and map water on the Moon.
@ispace_inc’s Hakuto-R lander, already en route to the Moon, is expected to land in April will deploy the small Tenacious rover to collect lunar regolith samples.
Lunar exploration is on the rise as we prepare to send astronauts back to the Moon later this decade! 9:45 PM · Feb 25, 2025
01:16 MEZ. Liftoff. 2:43. Stufentrennung. 3:38. Fairing separation. 8:34. B1083 zum 10. Mal sicher gelandet, auf der A Shortfall of Gravitas. 36:31. Zweite Zündung des Triebwerks der 2. Stufe; Dauer etwas über eine Minute. 34:47. Brennschluß. "Nominal orbital insertion." 43:45. Freisetzen des Mondlanders Nova-C, "Athena." Höhe 1290 km. 47:45. AstraForge, Sonde "Odin" freigesetzt, auf Vorbeiflug an einem Asteroiden.
"Les hommes seront toujours fous; et ceux qui croient les guérir sont les plus fous de la bande." - Voltaire
Zitat Intuitive Machines@Int_Machines After liftoff on February 26, Athena established a stable attitude, solar charging, and radio communications contact with our mission operations center in Houston. The lander is in excellent health, sending selfies, and preparing for a series of planned main engine firings to refine her trajectory ahead of lunar orbit insertion, planned on March 3. Intuitive Machines is targeting a lunar landing opportunity on March 6. 📸: #Athena 👀@spaceX
Zitat Dr. Phil Metzger@DrPhiltill I’m excited since I had a small role in one of the payloads: PRIME-1. It will measure the ice in the lunar soil that gets drilled up by the Trident Drill. Originally this payload was only going to verify the presence of ice, not measure how much ice there is. 🧵/1
2/ People at NASA told me they were showing the instruments to @Dr_ThomasZ, and he asked if it would quantify the ice in the soil. When they said “no”, he told them he wanted it to make the measurement. So NASA gave me a contract to solve the physics and write software to do it.
3/ The video in the prior post in this thread shows how the drill takes one “bite” at a time and dumps the cuttings onto a pile. The cone of light in that video represents the look-angle of the mass spectrometer, MSOLO. It sees water molecules coming off the drill cuttings pile.
4/ The drill cuttings are warmed by the cutting action of the drill, so the thermal energy causes the ice to sublimate into vapor. It flies off the cuttings pile into the vacuum of space. MSOLO measures the rate that water molecules randomly fly into its inlet.
5/ The physics and geology that affect the rate of vapor coming out of the cuttings pile are complicated. The rate depends on the physical state of the ice. Is it coating the sand grains? Ir is it separate grains mixed between the sand grains? Does it bridge between grains? Etc.
6/ This matters because the surface area per mass of ice is different for each physical form that the ice might be in. We want to know what fraction of the mass of the lunar soil is ice, but the rate the vapor comes off is proportional to the surface area of the ice.
7/ We don’t know the geological history of the ice well enough yet to know its surface-area-to-mass relationship. This introduces an unknown in the measurement that we will be making, which increases the measurement error.
8/ Second, it turns out that lunar ice can be amorphous or crystalline, and there are multiple crystalline states that are stable for ice in the range of temperatures that are possible in the lunar craters. It is super cold — like 40 to 70 degrees Kelvin (above absolute zero).
9/ Fortunately, the heat needed to vaporize the ice is not very different for the different crystalline forms, so this introduces only a negligible error. (But I had to check to be sure.)
10/ The biggest problem is the extreme sensitivity on temperature. Just a few degrees increase in temperature will increase the vaporization rate of the ice by a factor of 10. Estimating the temperature of the cuttings pile is crucial. It will require deep post-mission analysis. (Image credit: Andreas, Icarus 186[1]: 24-30.)
11/ How fast does the cuttings pile cool down or heat up as it sits on the surface? Will sunlight shine on it? Will radiative heat from the spacecraft warm it? Will sublimating water ice cool it significantly (latent heat of sublimation)? Will heat conduct into the cooler ground?
12/ While it will take very in-depth post-mission analysis to get super accurate estimates of all these effects, the goal is to make a real-time measurement of the ice that we can tell the public during the mission. So I did my best to make it estimable in realtime.
13/ Next, as the ice inside the sand pile turns into vapor, how fast does it squirt out between the sand grains into space? This process is called diffusion, and there are different types of diffusion depending on how dense the vapor is between the sand grains. (Image: Ratnakar and Dindoruk, Processes 10[6]: 1194.)
14/ Each type of diffusion follows a different equation and has a different rate.
Finally, all three processes are coupled together and affect each other: sublimation, temperature changes, and diffusion. So the physics has to be written in a fully coupled set of equations.
4/ A) Sublimation cools the temperature and increases the pressure which changes the rate that heat flows, and it changes the gas pressure which changes the type and rate of diffusion. B) Heat flow changes the temperature which changes the sublimation rate and the gas density which changes the summer diffusion. C) Diffusion changes the pressure which changes the sublimation rate and it changes the heat transfer rate.
All three affect all three.
15/ Fortunately I found some simplifications that make it much easier and faster to solve. The most important is that sublimation is so fast that it reaches equilibrium with the vapor pressure in just microseconds. So we can treat it as an equilibrium process.
16/ The second is that, at these temperatures, the equilibrium vapor pressure is extremely low — usually less than 1 pascal. For comparison, atmospheric pressure at sea level on Earth is 101,325 pascals. We are talking about 0.00001 atmosphere of pressure.
17/ Because the pressure is so low, the gradient (change of pressure) within the cuttings pile is minuscule and unable to drive any diffusion. The only place where diffusion happens is the outer 200 micron “skin” of the cuttings pile. Just the thickness of one sand grain.
18/ This dramatically simplifies the math and turns it into a problem that can be solved in just minutes on a laptop computer instead of many hours on a supercomputer. It also (mostly) decouples the problem from the size and shape of the cuttings pile.
19/ But it also tells us that the rate vapor will come out of the cuttings pile will be very low. It will be a difficult measurement to make, and we really want the sunlight to fall on the drill cuttings to warm them more to increase the sublimation rate.
20/ I delivered software to NASA that does the calculations. See the word “concentration” on this info sheet? That means the concentration of ice in the soil, which we can now calculate after we measure the rate that vapor comes off the drill cuttings. 🥳 However…
21/ it will be a difficult measurement, and the first estimate of ice concentration that the team announces will need further improvement by post-mission analysis to tighten up the temperature estimate. And we need to learn more about the area-to-mass ratio of the ice.
22/ That’s how all planetary science is. The measurements are brutally hard and the complex environments of other worlds require time to sort.
So, I’m super excited about this mission which should be the first to get ground-truth of lunar ice. /end🧵
Zitat von Ulrich Elkmann im Beitrag #121Intuitive Machines is targeting a lunar landing opportunity on March 6.
Zitat Watch live: Ariane 6 second flight
27/02/2025
Ariane 6 is scheduled to launch from Europe’s Spaceport in French Guiana at 13:24 local time on 3 March 2025 (16:24 GMT, 17:24 CET). This is the first commercial flight for Ariane 6, flight number VA263, operated by Arianespace, carrying the CSO-3 satellite for the French Procurement Agency (DGA) and the French space agency (CNES) on behalf of the French Air and Space Force’s Space Command (CDE).
Zitat Felix Space Time@Space_Time3 SpaceX has been GRANTED their Starship flight 8 FAA Launch License. Launch is currently NET March 3rd. 5:13 PM · Feb 27, 2025
Zitat Intuitive Machines@Int_Machines Athena is approximately halfway to the Moon and continues to communicate with our flight controllers in Houston. Our flight controllers are preparing for the mission’s next milestones, Trajectory Correction Maneuvers (TCM). TCMs are intended to refine Athena’s trajectory ahead of lunar orbit insertion. #AdLunam #Athena #IM2 (28FEB2025 0807 CT) 3:07 PM · Feb 28, 2025
Zitat Intuitive Machines@Int_Machines Our flight controllers used the Company’s Lunar Data Network to command Athena’s first planned Trajectory Correction maneuver (TCM) at 11:00 a.m. CT on February 28, 2025, to refine the lander’s trajectory ahead of Lunar Orbit Insertion (LOI).
Data from the 6-second full-thrust mainstage engine burn confirmed Athena hit her 9.5 m/s target with approximately .38 m/s accuracy. Propulsion mixture ratios, mass flow rate, and temperature were as predicted. The TCM was nominal per expectations. Athena continues to be in excellent health and is closer to the Moon now than the Earth. (28FEB2025 1630 CT) 11:30 PM · Feb 28, 2025
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