Lovell was the first person to fly to the Moon twice.
Robert Pearlman – Aug 8, 2025 9:28 PM | 85
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.
Statistical Ars Legatus Legionis
15y
54,490
michaeltherobot said:
You clearly know what you are talking about, so could you ELI5 why polar LLO costs more than equatorial LLO? My intuition that they are the same comes from KSP, in which, soon after leaving Earth orbit, you plan a miniscule burn to adjust lunar insertion from coming around the side to coming over the top.
Of course, in both those cases I then have to decelerate hard at perilune to be captured. Perhaps the flight paths NASA is considering have some way to save dV vs my hard deceleration, which don't work for polar orbits?
The added cost comes from the plane change and plane change at high velocity (low orbit) are expensive. You CAN do something similar to what you describe it just takes longer potentially much longer. The higher the perilune the cheaper the plane change becomes but the longer it takes to reach the perilune. You drop yourself into a highly elliptical orbit around the moon at the same plane as the initial orbit. You then ride up to the perlune, raise the plane to 90 degrees and lower the perilune to circular (decelerate hard).
NASA wouldn't consider doing a plane change in Earth orbit because then you can have a free return trajectory which is a risk reduction factor.
So the tradeoff of DeltaV vs time.
Compare this map to the one in the previous post.
https://arstechnica.com/civis/attachments/1772816223709-png.129833/
1772816223709.png
Significant cheaper but it adds a 3.5 day loiter riding up to the vey high perilune to become as cheap as NRHO (including the transit). To have insertion and exit cost that are 2x this you would need the same loiter on the way back. In KSP things like mission duration are quite cheap and excessive risk doesn't matter but yeah same basic concept and math.
To be clear this is really only an issue for an occupied crew vehicle. If you add a 15 day loiter then the phase change becomes essentially free. For prestaging the lander or the tanker to refuel it after a sortie neither would be harmed by a 30 day longer mission. So if LLO was used as a staging point, which I don't think it will, then there would be mission choices by SpaceX and BO on how much LLO loiter vs round trip DeltaV for sending that tanker to meet lander with the prop it needs.
Statistical Ars Legatus Legionis
15y
54,490
Polar LLO is really hard to get into. Even with a less dumpy crew vehicle bringing it all the way day to Polar LLO and back is dubious. I know know it runs against the popular trend of everything NASA does is stupid but the math doesn't lie.
I got this some years ago when NASA removed the sensitive restriction. Not sure it is available anymore. NASA is pretty bad about maintaining public access to old reports. It was created in the analysis requirements for Constellation.
A direct LLO requires a huge amount of DeltaV to enter and leave when talking about polar landing sites. This is because you need to do an up to 85 degree plane change Exactly how much depends on where exactly you are landing.
https://arstechnica.com/civis/attachments/1772812012884-png.129830/
1772812012884.png
It is at max of 1,313 m/s for the LOI and the south pole landing sites are in those 1,000+ m/s circles. There is a reason Apollo landed in equatorial regions. The LOI for Apollo 11 was 900 m/s.
Now if it takes 1313 m/s to get into LLO then it will take 1313 m/s to get back out. So we are talking 2,626 m/s. Throw in a couple hundred m/s for docking, course corrections (burns are never perfect) and safety margin and 3,000 m/s is a reasonable budget. You can reduce DeltaV somewhat by having a long loiter in LLO which reduces the prohibitive cost of a plane change by coasting up to the apolune (the same way GEO sats coast up to apogee in a GTO orbit but you now largely erased the big advantage of LLO over NRHO in that it is faster for crew missions.
Apollo did consider a polar landing for one of the late Apollo missions but it was canceled due to the higher risk of LoM and LoC. To get the margins needed the Apollo CSM would need to dwell in an intermediate orbit for an extra 2.8 days on the LOI and 1.6 days on the TEI. So an extra four days to the mission timeline. Technically Orion with its 1.3 km/s DeltaV "could" get to Polar LLO but it would require a loiter time of ... 6 days. That is 6 days on the way in and another 6 on the way out. You could make it asymmetrical to reduce risk like Apollo did but it would still be around 12 days loiter on top of 6 days transit on top of 6+ days surface mission.
For reusable landers LLO has another issue. It is so deep in the moon gravity well that while the lander itself uses less propellant you have to bring propellant to the lander. The propellant you bring to the lander requires more DeltaV so that propellant is requiring more propellant. So your lander uses less prop but yout tug/tanker uses more. Total prop usage per mission increases not decreases. A crew landing is essentially all propellant on a first order simplification.
TLDR: NASA knows what they are doing. NRHO got maligned by its association with porkish SLS & Orion (even by me in the past). NRHO is not a terrible orbit for a reusable architecture. It has numerous advantages to include that it is very cold. That is important if you have reusable cryogenic landers trying to minimize boiloff waiting months for crews to arrive. Your lander will point its nose at the sun to reduce thermal load. However in LLO like LEO the moon is a thermal mirror. Thermal load is substantially worse. Using NRHO as a staging point does not require a gateway station.
Even in the analysis above the alternate orbit is all around worse except saving 3% to 6% prop.
Regarding NASA’s support for the development of commercial space stations, the bill mandates the following, within specified periods, of passage of the law:
- Within 60 days, publicly release the requirements for commercial space stations in low-Earth orbit
- Within 90 days, release the final “request for proposals” to solicit industry responses
- Within 180 days, enter into contracts with “two or more” commercial providers for such stations
Cruz is trying to inject urgency into NASA as several private companies—including Axiom Space, Blue Origin, Vast, and Voyager—are finalizing designs for space stations. All have expressed a desire for clarity from NASA on how long the space agency would like its astronauts to stay on board, the types of scientific equipment needed, and much more. These are known as “requirements” in NASA parlance.
“Accessing and remediating any of these issues can only be performed in the VAB.” //
normally butters Ars Praefectus
19y
5,319
georges said:
It's amazing to me that there isn't a retractable maintenance arm on the launch stand. The ground hardware all cost sooooo much money but no one though to add this?
Apollo had a Mobile Service Structure at each pad.
Shuttle had a Rotating Service Structure at each pad.
Ares/SLS were based on the Clean Pad concept. NASA wanted commercial launch providers to agree to use the pads at LC-39 (as well as the VAB, crawler-transporters, and crawlerway infrastructure) between NASA exploration missions. Each launch vehicle type from each launch provider would have its own Mobile Launcher Platform including the umbilical tower. There weren't going to be any vehicle-specific support structures, just a clean pad to share.
During Ares V development, rollout weight became a major concern. Unlike Saturn V, Ares V and SLS have huge SRBs loaded with massive amounts of solid propellant. The weight of the stack including the launch platform, umbilical tower, and crawler was pushing the limits of what the crawlerway foundations can support. They were worried it would be so heavy that it would sink into the Florida swamp on the way to the pad.
These factors contributed to the (poor) design choice to minimize the scope of the umbilical tower and rely heavily on the VAB for service access. //
aggressive-trail Smack-Fu Master, in training
1m
85
woodbourne said:
Time to cancel the program. There's nothing on the moon that we need right now. Let the Chinese waste the money on useless rockets and wait for there to be an economic reason for going there. We're basically using technology from the 1940's to accomplish something that has no economic payback using the same corrupt defense contractors and the same stupid procurement rules that we had 60 years ago. Enough, please stop this project.
And here I was, thinking that these arguments from the 60s would have been settled by now. Beyond the fact that the economic case for Luna can be quantifiably justified today, I’d argue the biggest argument is what it provides us in terms of science.
The far side of the moon is shielded from Earth’s radio interference, making it the most valuable real estate in the solar system for radio astronomy and deep space communication infrastructure.
Scientists want to build LF radio telescopes there to detect signals from the "Dark Ages", the period after the Big Bang but before the first stars formed. These signals are blocked by Earth’s ionosphere. This environment is also perfect for tracking deep-space objects without local interference.
If you don’t care about anything else, at least care about that. //
rhgedaly Ars Scholae Palatinae
8y
1,290
First hydrogen, then helium. Hope the batteries that will need recharging aren't lithium. Damn the periodic table! //
Chuckstar Ars Legatus Legionis
23y
37,070
Subscriptor
dehildum said:
That table gives them 100+ reasons for launch delays and more profits for the contractors.I don’t remember any Apollo, Gemini, or Mercury vehicle needing to be returned to the VAB….
Apollo 16 was moved back to the VAB, after a fuel tank in the service module was damaged during testing (over-pressurized).
But the reason that was the only time they had to do that in Apollo was not because the Saturn was so much better designed, but because the Mobile Service Structure provided access to the full stack, and they only needed the VAB if a repair required taking the stack apart, which was necessary for the Apollo 16 repair.
All the assembly/integration at the Cape for Gemini and Mercury were done on the launch stand. The VAB was purpose-built for Apollo-Saturn. //
MilesArcher Ars Centurion
5y
294
Subscriptor
BCGeiger said:
🎼Hanger Queen, 🎶
🎼Should’a cancelled it back in ‘17🎶
🎼Hanger Queen🎶
🎼They keep pouring cash into this bad machinee🎶
Man, you had the opportunity to rhyme hydrazine and missed it.
Yui Smack-Fu Master, in training
5m
81
The most astonishing part of Jared's letter is that while Butch and Suni were on station they were advocating for NASA to show leadership, and yet disagreements on the ground had "deteriorated into unprofessional conduct".
Yikes. //
Wickwick Ars Legatus Legionis
15y
39,338
dangle said:
Yeah, but we remember that at the time, after we were still blinking in disbelief at our screens after formal coverage of the test flight finished, and after an hour delay to the presser in order to get their stories straight, that when the feed returned, Jim Bridenstine stared into the camera and confidently announced that "Today, a lot of things went right."
I will react today exactly as I did in the comments of that the article that covered that: Taht was Bridenstine being a good politician and saving as much face for a valued contractor as he could. His words didn't matter. What would matter was his (and NASA's) actions. And as it turns out, the actions were spot-on. NASA forced Boeing to refly OFT-1.
Unfortunately, Ballast Bill Nelson was the Administrator after the OFT-1 repeat and he has a long history with Boeing and Old Space in general. And it was under his watch that the OFT-1 repeat was accepted as sufficient even though there were thruster issues again.
NASA owned up to not monitoring Boeing closely enough prior to the OFT-1 launch. However, they at least did the right thing and made Boeing repeat the test. NASA performed far more poorly when human life was on the line for OFT-2. //
https://planet4589.org/space/misc/starliner26.ji.pdf
https://planet4589.org/space/misc/starliner26.pdf
“The most troubling failure revealed by this investigation is not hardware.”
NASA on Thursday announced it has formally classified the 2024 crewed flight of the Starliner spacecraft as a “Type A” mishap, an acknowledgement that the test flight was a serious failure. //
The letter and a subsequent news conference on Thursday afternoon were remarkable for the amount of accountability taken by NASA. Moreover, at Isaacman’s direction, the space agency released an internal report, comprising 311 pages, that details findings from the Program Investigation Team that looked into the Starliner flight.
“Starliner has design and engineering deficiencies that must be corrected, but the most troubling failure revealed by this investigation is not hardware,” Isaacman wrote in his letter to the NASA workforce. “It is decision-making and leadership that, if left unchecked, could create a culture incompatible with human spaceflight.”
Isaacman said there would be “leadership accountability” as a result of the decisions surrounding the Starliner program, but did not say which actions would be taken. //
The true danger the astronauts faced on board Starliner was not publicly revealed until after they landed and flew back to Houston. In an interview with Ars, Wilmore described the tense minutes when he had to take control of Starliner as its thrusters began to fail, one after the other.
Essentially, Wilmore could not fully control Starliner any longer. But simply abandoning the docking attempt was not a palatable solution.
NASA shall evaluate the “viability of transferring the ISS to a safe orbital harbor” after retirement. //
The most recent NASA authorization act, passed in 2022, extended the US government’s support for the ISS program until 2030. The amendment tacked onto this year’s bill would not change the timeline for ending operations on the ISS, but it asks NASA to reconsider its decision about what to do with the complex after retirement.
The amendment would direct NASA to “carry out an engineering analysis to evaluate the technical, operational, and logistical viability of transferring the ISS to a safe orbital harbor and storing the ISS in such harbor after the end of the operational low-Earth orbit lifetime of the ISS to preserve the ISS for potential reuse and satisfy the objectives of NASA.” //
In 2024, NASA awarded SpaceX a nearly $1 billion contract to develop a souped-up version of its Dragon spacecraft, which would be equipped with additional thrusters and propellant tanks to provide the impulse required to steer the space station toward a targeted reentry. The deorbit maneuvers will slow the station’s velocity enough for Earth’s gravity to pull it back into the atmosphere. //
Artist’s illustration of SpaceX’s deorbit vehicle, based on the design of the company’s Dragon spacecraft. The modified spacecraft will have 46 Draco thrusters—30 for the deorbit maneuvers and 16 for attitude control. Credit: SpaceX //
The deorbit vehicle needs to slow the station’s speed by about 127 mph (57 meters per second), a tiny fraction of the spacecraft’s orbital velocity of more than 17,000 mph (7.7 kilometers per second). But the station mass is around 450 tons (400 metric tons), equivalent to two freight train locomotives, and measures about the length of a football field. Changing its speed by just 127 mph will consume about 10 tons (9 metric tons) of propellant, according to a NASA analysis released in 2024.
The analysis document shows that NASA considered alternatives to discarding the space station through reentry. One option NASA studied involved moving the station into a higher orbit. At its current altitude, roughly 260 miles (420 kilometers) above the Earth, the ISS would take one to two years to reenter the atmosphere due to aerodynamic drag if reboosts weren’t performed. NASA does not want the space station to make an uncontrolled reentry because of the risk of fatalities, injuries, and property damage from debris reaching the ground.
Boosting the space station’s orbit to somewhere between 400 and 420 miles (640 to 680 kilometers) would require a little more than twice the propellant (18.9 to 22.3 metric tons) needed for deorbit maneuvers, according to NASA’s analysis. At that altitude, without any additional boosts, NASA says the space station would likely remain in orbit for 100 years before succumbing to atmospheric drag and burning up. Going higher still, the space station could be placed in a 1,200-mile-high (2,000-kilometer) orbit, stable for more than 10,000 years, with about 146 tons (133 metric tons) of propellant.
There are two problems with sending the ISS to higher altitudes. One is that it would require the development of new propulsive and tanker vehicles that do not currently exist, according to NASA. //
BobDole11 Ars Centurion
4y
290
I think everyone would love to see the ISS saved for posterity. I would imagine the grand kids of today's generation, when space flight may perhaps be common, visiting and touring a monument ISS and learning how primitive it was (compared to a +50'ish years future) and the bravery of the souls that ventured forth for the expansion of humanity's knowledge, science, exploration, cooperation, and greatness.
I've had those feelings and thoughts myself when viewing Apollo era hardware long ago. Standing by a Saturn 5 dwarfing my 8yr old stature filled me with inspiration to learn about spaceflight, science, and engineering.
But - the ramifications of a collision (or collisions) with space junk yielding 450 tons of more space junk, yielding further collisions and more and smaller junk, and on and on is just too great. The debris at a higher orbit takes too long to deorbit. The thought of our orbitals becoming impassable for centuries is terrifying. //
Veritas super omens Ars Legatus Legionis
13y
26,080
Subscriptor++
What would it take? Based on the history of the SLS I would predict it would take an order of magnitude more money than whatever NASA says and 20 to 30 years longer. There are many laudable goals for space missions, this isn't one of them!. //
fl4Ksh Ars Tribunus Militum
8y
1,518
Subscriptor
NASA is paying SpaceX $2.9B to develop a Starship lunar lander. That work has been ongoing since late 2021 and is scheduled to launch in late 2028.
That lunar lander design could be a pattern for a Starship LEO space station, which would have 1000 cubic meters of pressurized volume (ISS has 913), would support a crew of 10 (ISS supports 7), would be deployed to LEO in a single Starship launch (ISS required 12 years [1999 to 2011] and 35 launches), and would cost ~$10B (ISS cost $150B to build and deploy to LEO and $3B to $4B per year to operate, in today's money). Like the ISS, that Starship LEO space station would use cargo Dragon and crew Dragon spacecraft for resupply of consumables and for crew rotation.
That Starship LEO space station could be built in 36 months and launched in 2030.
Slow Launch System
“You know, you’re right, the flight rate—three years is a long time.”
jack1983 Smack-Fu Master, in training
12y
93
The Lurker Beneath said:
Do it on a windy day?
There are risks with too high wind speeds as well. High airflow causes static buildup and turbulence. Hydrogen requires very little ignition energy (well below 1mJ at stoichiometric conditions). So even a gust of wind can set off a combustible mixture.
Cryogenic hydrogen is an absolute nightmare to work with.
paulfdietz Ars Scholae Palatinae
7y
1,168
Using hydrogen as the fuel in the first stage was never a good idea. The density is just terrible, making the first stage much larger. Because the first stage is disposed of so quickly, Isp is less important; what's more important is "density impulse" (density x Isp), and LoX/LH2 is inferior to LOX/hydrocarbon by that metric.
Low density also makes the engines more expensive, as more pumping power is needed for a given thrust. //
paulfdietz Ars Scholae Palatinae
7y
1,168
pokrface said:
Right, but the "first stage" of SLS (and STS) is properly the SRBs.
It's more like the first "half stage". What matters for the argument is the velocity at which a stage is done. Even with the SRBs there, that's not that high (although higher than say the Falcon 9, which ends the stage 1 burn at an unusually low velocity so it can be recovered.)
The SRBs do allow the thrust of those LH2 engines to be somewhat lower, since they don't have to lift the fully fueled stack off the pad themselves. By the time the SRBs drop some propellant is gone. This ameliorates to some extent the relatively poor thrust/weight ratio of the engines (73.1 vs 184 for the Merlin 1D.)
What everyone agrees on is that NASA needs a new spacecraft capable of relaying communications from Mars to Earth. This issue has become especially acute with the recent loss of NASA’s MAVEN spacecraft. NASA’s best communications relay remains the Mars Reconnaissance Orbiter, which has now been there for 20 years.
Congress cared enough about this issue to add $700 million in funding for a “Mars Telecommunications Orbiter” in the supplemental funding for NASA provided by the “One Big Beautiful Bill” passed by the US Congress last year.
The advertisement on the auction website was titled “Space Shuttle Remove Before Flight Flags Lot of 18.” They were listed with an opening bid of $3.99. On January 12, 2010, I paid $5.50 as the winner.
At that point, my interest in the 3-inch-wide by 12-inch-long (7.6 by 30.5 cm) tags was as handouts for kids and other attendees at future events. Whether it was at an astronaut autograph convention, a space memorabilia show, a classroom visit, or a conference talk, having “swag” was a great way to foster interest in space history. At first glance, these flags seemed to be a perfect fit.
So I didn’t pay much attention when they first arrived. The eBay listing had promoted them only as generic examples of “KSC Form 4-226 (6/77)"—the ID the Kennedy Space Center assigned to the tags. //
It was about a year later when I first noticed the ink stamps at the bottom of each tag. They were marked “ET-26” followed by a number. For example, the first tag in the clipped-together stack was stamped “ET-26-000006.” //
A fact sheet prepared by Lockheed Martin provided the answer. The company operated at the Michoud Assembly Facility near New Orleans, where the external tanks were built before being barged to the Kennedy Space Center for launch. Part of the sheet listed each launch with its date and numbered external tank. As my finger traced down the page, it came to STS 61-B, 11/26/85, ET-22; STS 61-C, 1/12/86, ET-30; and then STS 51-L, 1/28/86… ET-26. //
Once the tags’ association with STS-51L was confirmed, it no longer felt right to use them as giveaways. At least, not to individuals.
There are very few items directly connected to Challenger‘s last flight that museums and other public centers can use to connect their visitors to what transpired 40 years ago. NASA has placed only one piece of Challenger on public display, and that is in the exhibition “Forever Remembered” at the Kennedy Space Center Visitor Complex. //
digital.rain Smack-Fu Master, in training
2y
34
Sarty said:
It is such an extremely NASA thing to do to mark items so mundane and interchangeable as remove-before-flight tags with individually traceable serial numbers.
It has to be one of the quality control check points … you know you placed, say, 56 tags for a specific mission. After removal, you can check that all the 56 tags for that mission have been properly removed.
Harrison Schmitt, speaking with a NASA interviewer in 2000, said his productivity in the Apollo suit “couldn’t have been much more than 10 percent of what you would do normally here on Earth.”
“You take the human brain, the human eyes, and the human hands into space. That’s the only justification you have for having human beings in space,” Schmitt said. “It’s a massive justification, but that’s what you want to use, and all three have distinct benefits in productivity and in gathering new information and infusing data over any automated system. Unfortunately, we have discarded one of those, and that is the hands.”
Schmitt singled out the gloves as the “biggest problem” with the Apollo suits. “The gloves are balloons, and they’re made to fit,” he said. Picking something up with a firm grip requires squeezing against the pressure inside the suit. The gloves can also damage astronauts’ fingernails.
“That squeezing against that pressure causes these forearm muscles to fatigue very rapidly,” Schmitt said. “Just imagine squeezing a tennis ball continuously for eight hours or 10 hours, and that’s what you’re talking about.”
Barratt recounted a conversation in which Schmitt, now 90, said he wouldn’t have wanted to do another spacewalk after his three excursions with commander Gene Cernan on Apollo 17.
“Physically, and from a suit-maintenance standpoint, he thought that that was probably the limit, what they did,” Barratt said. “They were embedded with dust. The visors were abraded. Every time they brushed the dust off the visors, they lost visibility.”
Getting the Artemis spacesuit right is vital to the program’s success. You don’t want to travel all the way to the Moon and stop exploring because of sore fingers or an injured knee.
“If you look at what we’re spending on suits versus what we’re spending on the rocket, this is a pretty small amount,” Rubins said. “Obviously, the rocket can kill you very quickly. That needs to be done right. But the continuous improvement in the suit will get us that much more efficiency. Saving 30 minutes or an hour on the Moon, that gives you that much more science.”
“Once you have safely landed on the lunar surface, this is where you’ve got to put your money,” Barratt said.
NASA has never before cut short a human spaceflight mission for medical reasons. “It’s the first time we’ve done a controlled medical evacuation from the vehicle, so that is unusual,” Kshatriya said.
The Soviet Union called an early end for an expedition to the Salyut 7 space station in 1985 after the mission’s commander fell ill in orbit.
In a sense, it is surprising that it took this long. Polk said predictive models suggested the ISS would have a medical evacuation about once every three years. It ended up taking 25 years. In that time, NASA has improved astronauts’ abilities to treat aches and pains, minor injuries, and routine illnesses.
Crews in orbit can now self-treat ailments that might have prompted a crew to return to Earth in the past. One astronaut was diagnosed with deep vein thrombosis, or a blood clot, in 2018 without requiring an early departure from the space station. Another astronaut suffered a pinched nerve in 2021 and remained in orbit for another seven months.
One of the more compelling reasons for the space station’s existence is its ability to act as a testbed for learning how to live and work off the planet. The station has served as a laboratory for studying how spaceflight affects the human body, and as a platform to test life support systems necessary for long-duration voyages to deep space.
FranzJoseph Wise, Aged Ars Veteran
11m
1,581
DavidEmami said:
Hope the everything turns out well for the crew member. It does make me wonder, though -- how would they deal with something life threatening? And have any medical procedures been done in space before? Did some searching and the closest I can find is a post-splashdown injury on Apollo 12 that the crew treated before egress, but that wasn't in free-fall. In particular, I assume the medical concept of the "golden hour" has to be abandoned.
First, obviously IANAD, so take it with a big grain of salt.
"Golden hour" is usually talked in the context of massive traumatic injuries and/or massive haemorrhaging. Even there it's a bit controversial, as it might be more useful only in the context of triage of massively multiple casualties with limited medevac resources down here.
IOTW, if any massive traumatic injury happens on the ISS (say a micrometeorite going through an astronaut or a pressurised cylinder failure resulting in an open fracture and haemorrhaging), the casualty is likely to be fucked anyway.
For things that develop over a longer time (appendicitis ‑‑> septicaemia), the astronauts are hopefully so well monitored that it would be caught early on.
You can find a full equipment list in the CHeCS onboard here (PDF, 2011 link). https://ntrs.nasa.gov/api/citations/20110022379/downloads/20110022379.pdf
Includes BP/ECG, AED, basic dental & surgery stuff (nothing quite major, scalpel and forceps etc), detox kit, airways kit, ambu bag and low‑flow mask and endotracheal oxygen supply, IV with pump and IV solutions, chest drain valve for pneumothorax, dressings, sutures and splints. Plus medicines, obviously.
Not really sure what the survival rate of somebody with a tension pneumothorax would be, even if quickly drained with the drain valve and intubated. I presume NASA has some procedures for getting an intubated or IV'd astronaut back home, even if it might mean not wearing their suit?
What's the max acceleration experienced during re‑entry and chute deployment? Not Soyuz, hopefully something gentler like CrewDragon (I assume Soyuz's retrorockets are less gentle here)?
henryhbk Ars Tribunus Militum
12y
1,891
Subscriptor++
FranzJoseph said:
First, obviously IANAD, so take it with a big grain of salt.
"Golden hour" is usually talked in the context of massive traumatic injuries and/or massive haemorrhaging. Even there it's a bit controversial, as it might be more useful only in the context of triage of massively multiple casualties with limited medevac resources down here.
IOTW, if any massive traumatic injury happens on the ISS (say a micrometeorite going through an astronaut or a pressurised cylinder failure resulting in an open fracture and haemorrhaging), the casualty is likely to be fucked anyway.
For things that develop over a longer time (appendicitis ‑‑> septicaemia), the astronauts are hopefully so well monitored that it would be caught early on.
You can find a full equipment list in the CHeCS onboard here (PDF, 2011 link).
Includes BP/ECG, AED, basic dental & surgery stuff (nothing quite major, scalpel and forceps etc), detox kit, airways kit, ambu bag and low‑flow mask and endotracheal oxygen supply, IV with pump and IV solutions, chest drain valve for pneumothorax, dressings, sutures and splints. Plus medicines, obviously.
Not really sure what the survival rate of somebody with a tension pneumothorax would be, even if quickly drained with the drain valve and intubated. I presume NASA has some procedures for getting an intubated or IV'd astronaut back home, even if it might mean not wearing their suit?
What's the max acceleration experienced during re‑entry and chute deployment? Not Soyuz, hopefully something gentler like CrewDragon (I assume Soyuz's retrorockets are less gentle here)?
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IAAD, most of the survivable emergencies require only a critical but generally simple procedure to buy time. Often I am faced with surgical emergencies in the hospital overnight, and while on paper we have at least one trauma and one cardiac OR on hot standby, it's not like surgeons are standing there in stasis waiting to operate, and often will be several hours until they can formally operate on someone (or we need some test to complete). So for instance for the appendicitis above we use broad spectrum IV antibiotics, then figure it out later, Broken bones easy - splint and transport, pneumothorax (particularly tension) you can do a needle decompression (all it takes is a 20ga IV catheter and a stopcock) and again you've bought plenty of time for surgeons to get ready to do a definitive thoracostomy (chest) tube, most bleeding can be stopped with pressure.
Things where this isn't true would be a stroke or intracranial bleeding. Not 100% sure if the aircraft carriers that picked up Apollo astronauts even have the ability to treat that onboard. depending where the bleed is. If it is an epidural (in the skull, outside the brain but hydraulically crushing the brain) then the answer is simply we drill a hole and relieve the pressure (trepanning) and then some actual neurosurgeon can fix the issue, and when I was the intern, that's who did the burr hole, a 4 minute procedure that bought you hours to the OR. But if the bleed is deeper (such as a sub-arachnoid bleed or interparenchymal bleed) well not much you are doing outside an interventional neuroradiology suite, and those patients often have a poor prognosis on land. Not sure if they screen for berry aneurysms in the astronaut core with a head angiogram? Penetrating trauma management is battlefield medic level care to buy time to get to surgery, and a lot can be done to stall exsanguination within reason without much clinical skill or equipment. There are military medic deployed pro-coagulants that can be put into a wound to form instant clot, and of course the tried and true tampon in the hole. In a penetrating wound something like a tampon works by absorbing blood and expanding to put pressure on the bleeding vessels, which works surprisingly well in the absence of definitive medical care.
As for g-forces anyone who has ridden in an ambulance on our pothole strewn streets in the northeast knows you subject you patient to a surprising number of shock loads, but I worry more about needing to put a critically ill patient into a chair for the descent when bleeding has stopped while lying prone or on their back. Does crew dragon have a stretcher capability?
While Rocketdyne’s ownership merry-go-round kept spinning, the company’s competitors pushed forward. SpaceX and Blue Origin, backed by wealthy owners, took a fresh approach to designing rockets. Apart from the technical innovations that led to reusable rockets, these newer companies emphasized vertical integration to cut costs and minimize reliance on outside supply chains. They wanted to design and build their own rocket engines and were not interested in outsourcing propulsion. Rocketdyne’s business was—and still is—entirely focused on selling ready-made engines to customers.
The launch startups that followed in the footsteps of SpaceX and Blue Origin have largely imitated their approach to insourcing. There are at least nine medium to large liquid-fueled rocket engines in production or in advanced development in the United States today, and just one of them is from the enterprise once known as Rocketdyne: the RS-25 engine used to power the core stage of NASA’s Space Launch System (SLS) rocket. //
The RS-25 engine, by far the largest in L3Harris’ portfolio and a former Rocketdyne product, is not part of the sale. The RS-25 was initially known as the Space Shuttle Main Engine and was designed for reusability. The expendable heavy-lift SLS rocket uses four of the engines, and NASA is burning through the 16 leftover shuttle-era RS-25 engines on the first four SLS flights for the agency’s Artemis Moon program. The second SLS flight is set to launch in the coming months on a mission carrying four astronauts beyond the Moon.
L3Harris will retain total ownership of the RS-25 program. The company has a contract with NASA to build new RS-25 engines for SLS flights beyond Artemis IV. But the new RS-25s will come at an expense of about $100 million per engine, significantly more than SpaceX sells an entire launch on a Falcon 9 rocket. The engine contract is structured as a cost-plus contract, with award and incentive fees paid by the government to L3Harris.
Sending astronauts to the red planet will be a decades-long activity and cost many billions of dollars. So why should NASA undertake such a bold mission?
A new report published Tuesday, titled “A Science Strategy for the Human Exploration of Mars,” represents the answer from leading scientists and engineers in the United States: finding whether life exists, or once did, beyond Earth.
“We’re searching for life on Mars,” said Dava Newman, a professor in the Department of Aeronautics and Astronautics at Massachusetts Institute of Technology and co-chair of the committee that wrote the report, in an interview with Ars. “The answer to the question ‘are we alone‘ is always going to be ‘maybe,’ unless it becomes yes.”
The damage will therefore test the current leaders of Russia. How committed are they to the International Space Station partnership with NASA? Before, they were willing to play out the string to 2030 and the end of the station’s lifetime, but that required minimal investment in new capabilities. In fact, Russia recently cut the number of crewed Soyuz missions to the station from four every two years down to three, to save money. Now they must devote significant resources to the Soyuz program critical to the ISS.
“This is a real-life test of their resilience,” Jeff Manber, a senior Voyager official and former Nanoracks chief executive with long-time expertise in Russia’s space program, told Ars. “We are going to learn just how important the ISS is to leadership there.” //
The at least temporary loss of Site 31 will only place further pressure on SpaceX. The company currently flies NASA’s only operational crewed vehicle capable of reaching the space station, and the space agency recently announced that Boeing’s Starliner vehicle needs to fly an uncrewed mission before potentially carrying crew again. Moreover, due to rocket issues, SpaceX’s Falcon 9 vehicle is the only rocket currently available to launch both Dragon and Cygnus supply missions to the space station. For a time, SpaceX may also now be called upon to backstop Russia as well.