Orion enters retrograde lunar orbit
Engineers today successfully completed an engine burn that put Orion into the retrograde lunar orbit in which it will remain for the next week.
Due to the distance of the orbit, it will take Orion nearly a week to complete half an orbit around the Moon, where it will exit the orbit for the return journey home. About four days later, the spacecraft will harness the Moon’s gravitational force once again, combined with a precisely timed lunar flyby burn to slingshot Orion onto its return course to Earth ahead of splashdown in the Pacific Ocean on Sunday, Dec. 11.
As of now all systems seem to be working as intended.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Engineers today successfully completed an engine burn that put Orion into the retrograde lunar orbit in which it will remain for the next week.
Due to the distance of the orbit, it will take Orion nearly a week to complete half an orbit around the Moon, where it will exit the orbit for the return journey home. About four days later, the spacecraft will harness the Moon’s gravitational force once again, combined with a precisely timed lunar flyby burn to slingshot Orion onto its return course to Earth ahead of splashdown in the Pacific Ocean on Sunday, Dec. 11.
As of now all systems seem to be working as intended.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I understand that the mission is primarily an engineering and operational evaluation of the system, but why such a wide Lunar orbit? It seems opportunities are not being exploited.
This is what I asked about a few days ago. It appears it will only make half an orbit before returning to Earth. Why the big rush? Why not let it stay in orbit longer? It is not designed to operate that long?
Thanks
This is all my opinion:
The “wide” orbit is designed to maximize line-of-sight time between the Orion (and ultimately the Lunar Gateway) and the lunar south pole area. Since its apogee is to the south, it will spend more time over that area. The lunar south pole is expected to be the site of early landings.
Remember the orbit “stands on end” as seen from Earth, and is “rectilinear”, circling the lunar disk, but never going behind the moon as seen from Earth, again to maximize Earth / Orion line-of-sight time.
As to why not a longer flight, my guess is that the systems on Orion could not support it at this stage of development. The life-support system is supposedly pretty bare-bones on this flight, leading many to question whether this is a sufficiently meaningful test prior to the next flight, which is manned.
That all makes sense. Thanks for the explanation
It’s as meaningful as any Dragon test. The solar arrays will allow longer missions, especially as a lifeboat:
https://m.youtube.com/watch?v=gMxQjao-Fug
From Jeff Foust’s story at Space News this weekend:
The use of DRO is unique to Artemis 1. The Artemis 2 mission will fly a free return trajectory around the moon, while Artemis 3 and later missions will go into a near-rectilinear halo orbit around the moon, which will also be used by the lunar Gateway. NASA chose DRO for this mission since it is a stable orbit that enables testing of the spacecraft without requiring much fuel to maintain the orbit.
Orion, though, will not remain in DRO for long. The spacecraft will perform a maneuver Dec. 1 to depart DRO, heading back towards the moon. The spacecraft will conduct another burn during a lunar flyby Dec. 5 to put the spacecraft on track for a reentry Dec. 11, splashing down in the Pacific Ocean off the California coast.
https://spacenews.com/orion-enters-lunar-distant-retrograde-orbit/
It’s amusing that Artemis I, Artemis II, and Artemis III will each have very radically different flight profiles.
Hello Ray,
As to why not a longer flight, my guess is that the systems on Orion could not support it at this stage of development. The life-support system is supposedly pretty bare-bones on this flight, leading many to question whether this is a sufficiently meaningful test prior to the next flight, which is manned.
It *could* last longer; in fact, the profiles for some of the launch windows this fall would have been considerably longer. It just ended up launching on a window with one of the shorter mission profiles.
Philip Sloss (as always) had a nice piece on NSF last year explaining some of this:
“The mission does vary between what we generally term a ‘short-class mission’ which is about a 25, 26, 28 days or what we’ve generically termed a ‘long-class mission’ which is somewhere between 38 and 42 days,” [Artemis 1 Mission Manager Mike] Sarafin explained. “Within a launch period, we will switch based on the day that we launch from long class mission to short class mission, so it’s really dependent on the day that we go whether we’re short class or long class. And it all has to do with that three-body problem and the alignment [of the Sun, Earth, and Moon].”
The orbital period of the DRO is about 12 days, which dictates the length of Orion’s stay at the Moon. The overall mission duration will be between four and six weeks. Notably, both mission durations are longer than the spacecraft’s maximum limit with a full crew of four onboard – 21 days. Orion’s systems are capable of operating up to around 210 days in an uncrewed configuration, such as on Artemis 1.
https://www.nasaspaceflight.com/2021/11/artemis-1-launch-periods/
Just curious, Mr Z.
Was posting that Orion was entering the orbit, followed by the “Halleluiah” on purpose.
sippin_bourbon: Heh. This was purely by accident. And even if the entire Artemis-1 mission is a success I will not be celebrating. It is a very flawed rocket launching a very overpriced capsule. There is little to cheer.
Going back to the Moon is little to cheer. I’m sure some folks hated Apollo/Saturn as well.
Jeff Wright wrote: “I’m sure some folks hated Apollo/Saturn as well.”
Many people complained that we were spending money on the Moon when there were so many poor people here on Earth.
Well, we stopped going to the Moon, and we went from 2 billion poor people to 5 billion to 6 billion poor people. America started spending fortunes on welfare and other anti-poverty programs, yet we still have the same proportion of the population in poverty. Welfare only encouraged people to remain poor, because they didn’t have to work (be productive) in order to live off the largess of the government.
Apollo-Saturn was designed for the mission of going to the Moon. SLS was not, but a lunar mission was kluged together from parts and pieces that were — or will be — available.
The good news is that the push to go to Mars and the push to commercialize space for the benefit of we Earthlings is funded with private money, not government money. It is too bad that government is trying to relive the heyday of half a century ago, but it is good that there are people funding the forward thinking commercial space companies, who intend to bring us a better tomorrow through goods and services that we will be willing to pay for. There are valid reasons to complain about government space projects, as few of them directly provide visible benefits to us on Earth. Many commercial space projects do provide such visible benefits, such as communications, internet access to remote areas, and publicly available Earth observation photographs, data, and analysis.
As a rocket, SLS performed as intended. Unfortunately, it was not designed to perform its new mission: to provide a sustainable presence on the Moon. Had its mission been to keep the Space Shuttle contractors employed, then it would be performing its mission very well, and it seems to have been designed specifically for this mission.
Oil well firefighter Red Adair may have said, “I can do it well, I can do it fast, and I can do it cheap. Choose two.” It appears that when Congress designed SLS for NASA, they, as a group, chose only one. SLS was tasked with putting around 100 tonnes into low Earth orbit, and it does that well. However, it does not do it cheap, and it might be able to ramp up to doing it once annually rather than the current expectation of once biennially. This makes it much less useful for space exploration than Congress may have intended.
It got the job done and employees people—good.
A seven to one return is good.
https://www.thespacereview.com/article/3737/1
https://space.nss.org/settlement/nasa/spaceresvol4/newspace3.html
Mr. Z made money off a book on that first circumlunar thump—as well as the author of the more disgusting “Whitey on the Moon.” Same with Lehrer.
Strange how the very critics of government space programs seem to profit from them, in’it?
I on the other hand, haven’t made one dime on SLS…but for as many years I’ve been advocating it, Boeing should have flown me out for the first launch :)
Oil well firefighter Red Adair may have said, “I can do it well, I can do it fast, and I can do it cheap. Choose two.”
Edward, so he’s the one who first discerned that primary law of applied science, that I have referred to on many occasions.
Jeff, call me when the government gets out of the way of Starship launches; their obstructions are akin to mercantilist protectionism for a Big Space sector that can profit ONLY when they have monopoly protection – not in the face of competition.
Ray Van Dunne observed: “The life-support system is supposedly pretty bare-bones on this flight, leading many to question whether this is a sufficiently meaningful test prior to the next flight, . . ”
If the next flight will have people on board, I am surprised that NASA had no biologicals on the mission: is nothing stirring, not even a mouse?
Jeff Wright questioned: “Strange how the very critics of government space programs seem to profit from them, in’it?”
I would be strange if there had been a commercial space industry to provide an alternative. However, government had a lock on the market, and even forbade commercial launches when the Space Shuttle came out, giving government complete control over what missions are launched into space.
The Space Shuttle, instead of thrusting us faster into the exploration and exploitation of space, set us back at least two decades.
Jeff’s complaint mischaracterizes Robert’s book Genesis, as the point of the book was to point out that Apollo 11 was not mankind’s first foray into deep space and to point out some of the affects causing it and effects resulting from it, especially the irony that the free market capitalist country got to the Moon through centralized control of the project that did it.
Robert keeps pointing out that government faltered in space, after Apollo, not returning to the Moon for more than half a century, yet commercial space companies began planning manned missions to Mars (not dreaming, not giving Power
Point presentations, but planning and developing the hardware to do it).
Advocating for an expensive system that rarely flies is not the admirable activity that Jeff seems to think it is, explaining why he wasn’t offered a trip for its maiden voyage.