Every 10 years, the National Academies convene a panel of planetary scientists to set priorities for Solar System exploration. These decadal surveys help NASA decide where to send missions and what scientific questions they should seek to answer. None of the results from Artemis II are likely to answer these big questions.
“Is there going to be decadal-level science out of Artemis II? Probably not,” Neal told Ars in an interview this week. “This is a technology demonstration mission… This is primarily to have a crew there to check out the engineering and make sure that things are working.”
From a scientific perspective, what’s most intriguing about Artemis II is figuring out how to incorporate humans into planetary exploration. For more than 50 years, generations of scientists have learned to explore other worlds only through the electronic eyes of robots. With NASA’s return to the Moon, they must learn to take advantage of human observations.
This requires a shift in how ground teams design instruments, plan science campaigns, and select targets for their observations. It also necessitates a change in culture. Astronauts on the lunar surface or in lunar orbit will provide a real-time feedback loop for the army of scientists looking over their shoulders from Earth. During the Apollo program, it took multiple landings to fine-tune how this works.
Should we take a closer look at this rock? Should we go see that outcrop? Humans can make these key decisions in seconds or minutes rather than days, weeks, months, or in some cases, years.
The experience of the Artemis II flyby also informed spacecraft engineers about the utility of the Orion spacecraft as an observation platform and the optical quality of the capsule’s windows. The astronauts reported some issues with glare from the Sun and the Earth. They MacGyvered a makeshift window shroud using a T-shirt to help overcome the glare so they could better see the lunar surface.
“We confirmed that we can achieve science through orbital observations and through integrating science into flight operations,” said Kelsey Young, NASA’s science lead for the Artemis II mission.
Human eyes are remarkably good at sensing color gradients and brightness changes. “Right away, they started describing the green around Aristarchus plateau and different brown hues, and these colors really help tell us nuances about the chemistry of lunar material,” Young said after the flyby.
Glover, Artemis II’s pilot, noted his perception of the Moon’s three-dimensionality during the flyby: “You really get a sense that we’re flying over something with elevation and terrain.” The astronauts were able to glimpse craters, mountains, and ridges at different angles as the Orion capsule arced behind the Moon. “Every vantage point is different,” Young said. //
“You might think that, after looking at hundreds of images taken of the lunar surface, I would get sick of it,” Young said. “I have not, nor do I anticipate getting sick of it.”
“It was quite infectious,” Neal said. “The Earthrise image that they took is one for the ages.”
One of my favorite Apollo astronauts is the late Jim Lovell. He flew in two missions yet never walked on the moon. His unflappable leadership during the ill-fated Apollo 13 mission helped make it what some called a “successful failure.”
Lovell also flew on Apollo 8, the mission that first flew around the moon. It was Christmas Eve 1968, and Lovell, William Anders, and Frank Borman delivered a Christmas message to the world from their orbit around the moon, which included a reading from Genesis 1: //
Lovell passed away at the age of 97 in August of last year, but a couple of months before he died, he recorded a message for Artemis II. NASA kept Lovell’s message a secret, but mission control played it to wake the crew up on Monday.
Hello Artemis II! This is Apollo astronaut Jim Lovell. Welcome to my old neighborhood. When Frank Borman and Bill Anders and I orbited the moon on Apollo 8, we got humanity's first up close look at the moon and got a view of the home planet that inspired and united people around the world. I'm proud to pass that torch on to you as you swing around the moon and lay the groundwork for missions to Mars, for the benefit of all. It's a historic day, and I know how busy you'll be, but don't forget to enjoy the view. So, Reid and Victor and Christina and Jeremy, and all the great teams supporting you, good luck and Godspeed from all of us here on the good earth.
As the Artemis II crew came close to passing behind the Moon and experiencing a planned loss of signal, they captured this image of a crescent Earth setting on the Moon’s limb.
Jet Propulsion Laboratory and California Institute of Technology
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Excors Ars Centurion
12y
365
Subscriptor++
Resistance said:
I thought the current trajectory has the spacecraft and everything near it returning to Earth?
Yes - NASA says the translunar injection burn was also the deorbit burn. It's a very long deorbit trajectory, and there's six opportunities for correction burns to ensure a safe reentry angle and splashdown location, but they're already on their way to Earth. And they've skipped the first two correction burns because the trajectory is close enough to optimal.
If I'm interpreting this paper right, the requirement is to reach the entry interface with a max downrange error of 25.6km (figure 4), with up to 20 m/s delta-v of corrections, so this is just about fine-tuning. I presume that means anything that's still floating near the spacecraft, and not flying off at many m/s, is close enough to the optimal trajectory that it's still going to impact the Earth.
One can get away with “roughing it” when using the bathroom during trips to the Moon. Going to Mars, requiring months in space, is a different matter. If the toilet breaks on the way to Mars, there is a non-zero chance the crew is dying. So it’s great to try out these systems now, on Orion. This really is the purpose of this test flight, to make sure life support systems work for the crew, to identify problems, and to implement fixes in the future.
In the big picture, the Artemis II mission continues to go splendidly. The deputy manager of the Orion program for NASA, Debbie Korth, said Saturday that the spacecraft is performing “remarkably well,” and that the vehicle’s overall performance has “pleasantly surprised” the engineers working on the program.
Everything is going so well, in fact, that much of the focus has been on frozen urine. And considering all of the things that could go wrong with a dangerous deep space journey like this, a wee problem like this seems like a big win. //
Zapfenzieher Wise, Aged Ars Veteran
15y
137
Go, Artemis, go!
Oh, wait ... 😋
As NASA prepares to send four astronauts around the moon for the 10-day Artemis II mission, a veteran space flier's unexplained illness in orbit is spotlighting one of the biggest risks of deep-space travel: the need for medical systems in case of emergencies.
NASA astronaut Michael Fincke said a sudden episode aboard the International Space Station (ISS) in January left him unable to speak and forced NASA's first-ever medical evacuation from the orbiting laboratory. Doctors have ruled out a heart attack, Fincke told the Associated Press, but they still don't know what caused the medical issue.
NASA was able to get Fincke (along with the three other members of the crew) back to Earth relatively quickly from the ISS. But that may not be the case for the longer lunar missions the agency envisions under the Artemis program.
Robert Goddard, a Massachusetts-born physicist, launched the world’s first liquid-fueled rocket on this date 100 years ago.
It was not an overly impressive flight. The rocket, fueled by gasoline and liquid oxygen, rose just 41 feet into the air, and the flight lasted 2.5 seconds before it struck ice and snow.
Nevertheless, this rocket, named “Nell,” represented a historic achievement that would help launch the modern age of spaceflight. Three decades later, the first objects would begin to ride liquid-fueled rockets into space, followed shortly by humans. A little more than 40 years would pass before humans walked on the Moon.
To mark this historic moment, a few Ars staffers are sharing some of their most memorable launches. Please add yours in the comments below.
Recorded during 2017, timelapse sequences from the International Space Station are compiled in this serene video of planet Earth at Night. Fans of low Earth orbit can start by enjoying the view as green and red aurora borealis slather up the sky. The night scene tracks from northwest to southeast across North America, toward the Gulf of Mexico and the Florida coast. A second sequence follows European city lights, crosses the Mediterranean Sea, and passes over a bright Nile river in northern Africa.
This page lists various fan-made tools that can help calculations related to the gameplay of Kerbal Space Program. Unlike addons, they do not directly influence the game, as they are run separately.
Performing a transfer from an orbit of one body directly to an orbit of another one seems like serious business. A few guides published on the forums have a lot of maths and stuff, you may think this is too complicated to figure out.
Well, it is rocket science, but: it's not complicated.
In the basic orbiting tutorial, you were introduced to the concept of orbiting, and basic orbit stabilization, as well as an orbital table to help you along. Now, what if you want an orbit that isn't on that table? What if you want to have an orbit with a specific period? That's where these formulae come in.
In the basic orbiting tutorial, you were introduced to the concept of orbiting, and basic orbit stabilization, as well as an orbital table to help you along. Now, what if you want an orbit that isn't on that table? What if you want to have an orbit with a specific period? That's where these formulae come in.
The blue circle is Kerbin itself, the light blue circle around it is the top of the atmosphere. You can click+drag on the left of Kerbin to set periapsis, or on the right of Kerbin for apoapsis. You can also use the text boxes to enter altitudes and velocities numerically.
You need to specify two values in all: either altitudes of periapsis and apoapsis, velocities at periapsis and apoapsis, or both altitude and velocity at either periapsis or apoapsis. You select the values you want to enter with the Parameters menu, the remainder of the information will be computed from the values you put in. If you enter altitude and a velocity above escape velocity, it'll give you excess velocity at infinity. The apoapsis and periapsis textboxes are altitudes above mean sea level (AMSL), the text report below has both altitudes AMSL and distances from the center of Kerbin. Note that if you specify values that lead to an apoapsis lower than periapsis, the plotted orbit and contents of the text fields will be swapped automatically.
This online tool calculates delta-v and CommNet requirements in KSP (a video game, Kerbal Space Program). It helps KSP players plan and solve complex missions. Just like the game, these calculators are made to be interactive and visual to help new players quickly grasp the mechanics of rocket science.
How to Use: Simply select the body you wish to perform orbital synchronization calculations on from the drop-down list, then pick the resonance you wish to place your craft in. Example: If you wanted a 2:3 resonance, enter 2 into Numerator and 3 into Denominator.
Launch Window Planner for Kerbal Space Program
On September 26, 2022, NASA’s Double Asteroid Redirection Test (DART) spacecraft crashed into a binary asteroid system. By intentionally ramming a probe into the 160-meter-wide moonlet named Dimorphos, the smaller of the two asteroids, humanity demonstrated that the kinetic impact method of planetary defense actually works. The immediate result was that Dimorphos’ orbital period around Didymos, its larger parent body, was slashed by 33 minutes.
Of course, altering a moonlet’s local orbit doesn’t seem like enough to safeguard Earth from civilization-ending impacts. But now, as long-term observational data has come in, it seems we accomplished more than that. DART actually changed the trajectory of the entire Didymos binary system, altering its orbit around the Sun. //
Because Dimorphos orbits Didymos, some of the ejecta remained trapped in the system, where it altered the mutual orbit between the two rocks. But a crucial fraction of the ejecta achieved escape velocity from the entire binary system. The momentum carried away by the system-escaping debris is what ultimately contributed to shoving the center of mass of the whole Didymos-Dimorphos pair. “In our case, we found that the beta parameter due to DART impact was around two,” Makadia explained.
The debris blasted completely out of the Didymos system gave the asteroids a push roughly equal to the initial impact of the spacecraft itself. //
The goal of DART was primarily to take our planetary defense out of the realm of computer models and get us some hands-on, practical experience, and Makadia thinks we succeeded in doing that. “Our work proves that hitting the secondary asteroid is a viable path for deflecting a binary system away as long as the push is large enough,” he said. “This wasn’t the goal of DART, but we can always design a bigger spacecraft.”
Statistical Ars Legatus Legionis
15y
54,490
pseudonomous said:
I will presume that both you and the NASA guys got the math right and that for a polar landing NRHO makes sense. But if they are really going to "question all requirements", we have to admit the possibility that they might fly Artemis IV or V as an equatorial region landing, do we not?
For Orion as a crew vehicle it doesn't matter. Orion has 1,300 m/s of DeltaV of which 300 m/s is allocated for docking, station keeping, and course corrections. So it is limited to orbits which require <1000 m/s to enter AND exit (NRHO is about 900 m/s). Even equatorial LLO with a 3.5 day loiter (13 days + surface time for total mission time) is a minimum of 835 m/s * 2= 1670 m/s. Loiters improve the worst case scenario but only make a small impact on the best case ones. Even if you could modify the Centaur V to have 3 day endurance and cryocoolers and use it for part of LOI (which we shouldn't that will end up being a $5B 10 year boondoggle) it has in the ballpark of 500 m/s excess DeltaV so you are likely still short unless you dip into your reserves.
Longer term with a better crew vehicle you might have the option to go to LLO Direct via fast insertion but it still isn't a slam dunk option with reusable landers as your example bring up. If you have reusable crew landers LLO as a staging point is made worse if you change landing locations. There isn't one LLO and as such to move between LLOs you need to do a plane change. The only cost effective way to make a plane change is to burn to a highly elliptical orbit you know like how NRHO is highly elipitcal. Every mission requires more prop, has more boiloff, and when changing landing sites you also pay a plane change tax. One feature of NRHO is due to its high perilune you can reach every spot on the moon with a consistent DeltaV cost. This makes mission planning a lot easier. You could land near Apollo 11 on the 70th anniversary if you wanted to. It is no harder (or easier) from NRHO than the poles or any other landing site.
To be clear these nuanced challenges mostly apply to the staging point for a crewed mission. If you are fine with adding 15+ day loiter time you can drop heavy cargo on the south pole by going LLO quite cheaply. If it is an expendable cargo lander efficiency doesn't really matter because it is a one way trip so Direct LLO without a loiter becomes viable.
The reality though is it is complicated and it depends on exactly what mission, to exactly where, how long you are willing to loiter, is the lander reusable and is it crewed. Another wrinkle is if it is crewed are the crew in their own vehicle or pushed there by the tanker. If the crew is riding on the tanker than fast insertion is required which means your crew made the thousands of tons of prop more expensive as well. Likely to the dismay of people in NASA doing this kind of analysis the public discourse though has largely been "NRHO is stupid derp derp derp".
Ajax81611 Wise, Aged Ars Veteran
5y
166
Subscriptor
NASA missed a huge soft drink sponsorship opportunity here by not naming it the Perfect Elliptical Polar Stable Insertion with Coplanar Line of Apsides.