You are not logged in.
There are two very serious problems with the Gateway station in this odd halo orbit. One is quite literally fatal to its crew.
The delta-vee to reach it from Earth is actually a bit lower than the delta-vee to reach a low lunar orbit similar to Apollo, especially one oriented polar. That puts Gateway within reach of SLS Block 1 with the (overweight) Orion and (underpowered) service module it has. SLS-block1/Orion cannot successfully reach the low lunar orbit used by Apollo, much less a polar-oriented low lunar orbit.
From low lunar orbit, the theoretical delta-vee required to land is comparable to the low orbit velocity: about 1.6-something km/s. Actual is a tad higher due to gravity losses and propellant safety margins. This is true whether the orbit is equatorial or polar.
From the halo orbit, you have a trivial burn of a few m/s at apolune to put you onto a surface-grazing transfer ellipse, BUT, the perilune velocity is what you have to "kill" to land! From that orbit, the perilune velocity is trivially-less than lunar escape velocity: 2.5-something km/s. That's 41% higher than from low lunar orbit!
That's NOT the fatal problem, it is just added difficulties designing lunar landers with a lot more mass ratio than they should otherwise need, all because SLSblock-1/Orion is a faulty moon rocket design, with enormous sunk costs that NASA is unwilling to write off. They couldn't write it off, even if they wanted to, because Congress, not NASA, controls ALL of NASA's money. Congress has micromanaged NASA for decades, and they are NOT competent to do so! They never have been. It is really starting to show, too!
The fatal problem is sudden solar flare events of large magnitude. Not all are lethally large, but some are. The Gateway station design does NOT have a radiation shelter for its crew, but in that (or any) orbit about (or even near) the moon, it has no effective shielding from Earth's magnetosphere.
The Apollo data show that typically spacecraft hulls can cut that kind of radiation roughly in half, but that's not good enough for a big event, not by a very long shot! You might be looking at as much as 5-to-10 THOUSAND REM accumulated over 5-10 hours.
This is not galactic cosmic rays I am talking about; that's a thin drizzle of far higher-energy particles, difficult to shield. But there's actually very little of it: some 24 to 60 REM accumulated over a year. Supposedly, accumulating 400 REM over a career in space increases your risk of late-in-life cancer by something like 3%.
300 REM accumulated in a "short time" (hours to days) is lethal to 50% of those exposed, the other 50% very-nearly dying of severe radiation sickness. Extremely severe. 500 REM is lethal to 100% of those so exposed. It is a very, very ugly death.
There was indeed an event of that magnitude, between the last two Apollo missions to the moon in 1972.
As it says in the quote beneath my byline, there is nothing as expensive as a dead crew, especially one dead because of a bad management decision. This is a TERRIBLY BAD management decision! It WILL kill a crew!
GW
Last edited by GW Johnson (2021-09-13 08:56:23)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
GW-
Here is a repost of my original opener for this thread:
"Ever since NASA announced their latest workfare program for their favored contractors, I've been wondering exactly who came up with this terrible idea. It sounds like a bad medical experiment designed by Josef Mengele for the residents of a concentration camp!
The idea of placing a long-term habitat in cis-lunar space with no provision for shielding from solar flare radiation and GCR, and which makes no attempts made to alleviate the effects of microgravity, makes me wonder just what they hope to achieve other than killing or seriously injuring the astronauts involved. First proposed by NASA, and now we have the ESA jumping on board the idea along with the Russians. Other than providing something to justify the enormous amount of capital expended on the SLS, it seems to serve no truly useful purpose. It's another NASA let's all get on board and go...nowhere."
Offline
you could blame that on the prime contractors that used an ISS for a model....
Offline
I think the design for the Japan car looks great, the Japanese 'Lunar Cruiser'
The strange Lunar orbit habitat seems to have bureaucracy coming along with it
However there will also be stations in LEO
Building A Space Station In A Weird Orbit. Here’s Why
https://hackaday.com/2019/02/25/nasa-is … heres-why/
NASA reveals the 3 contenders to replace the International Space Station
https://www.slashgear.com/nasa-reveals- … -03701144/
A Mars space station is an interesting idea but this with the CGI and presenations this Moon kind of one is sometimes like a poorly done epsiode of Deep Space 9? I hope they know what they are doing!
Looks like we are going to need a different partner for getting to the moon.
Might be good news since the USA never needed Russia to get to the Moon.
more space politics
'Russia Legally Threatens NASA Astronaut for Allegedly Sabotaging Space Station'
https://futurism.com/the-byte/russia-th … t-sabotage
NASA and Russia negotiating to dock vehicles in the Russian ‘node’
https://techstory.in/nasa-and-russia-ne … sian-node/
Last edited by Mars_B4_Moon (2021-12-03 11:09:00)
Online
While I think a station for the moon is a poor idea its not going to get all that much use from starships unless its layout changes dramatically so as to get it dock able to the docking ports.
Offline
What can the Moon or the ISS or Gateway truly tell of a Manned Mars Station or Mars Biodome or Manned Mars Excursion Module, some argue that more must be tested on the station and on the Moon. It seems the Moon will be an international efforst to make a Moon base and the revised Japanese plan includes landing a Japanese astronaut on the Moon in the latter half of the 2020s. Others wonder about the cost justification of lunar Gateway, what if for example the Chinese were to put major effort in Mars while NASA remained focused on trying to turn the Moon into some kind of base or launch pad or manufacturing plant? Mars could one day have exports and perhaps could be used as a base to ship other low tech products to other colony sites across the solar system for example the asteroids but shipping "commodity stuff" from Mars to Earth does not make any sense economically.
NASA's "sustained" lunar presence.
https://twitter.com/wingod/status/1474254134320582657ISS Operations Extended To 2030
http://spaceref.com/international-space … -2030.htmlNASA updates Artemis I integrated testing schedule
https://www.aerotechnews.com/blog/2021/ … -schedule/The wiki entry on the Gateway
NASA officials promote the Gateway as a "reusable command module" that could direct activities on the lunar surface. However, the Gateway has received both positive and negative reactions from space professionals.
Formerly known as the Deep Space Gateway (DSG), the station was renamed Lunar Orbital Platform-Gateway (LOP-G) in NASA's 2018 proposal for the 2019 United States federal budget. When the budgeting process was complete, US$332 million had been committed by Congress to preliminary studies.
https://en.wikipedia.org/wiki/Lunar_Gateway
Gateway will be the first modular space station to be both human-rated, and autonomously operating most of the time in its early years, as well as being the first deep-space station, far from low Earth orbit. This will be enabled by more sophisticated executive control software than on any prior space station, which will monitor and control all systems. The high-level architecture is provided by the Robotics and Intelligence for Human Spaceflight lab at NASA, and implemented at NASA facilities. The Gateway could conceivably also support in-situ resource utilization (ISRU) development and testing from lunar and asteroid sources, and would offer the opportunity for gradual buildup of capabilities for more complex missions over time.
Offline
As the title indicates its a bad idea one from the stand point of radiation protection circling the moon and acting as a way station.
Offline
The main purpose of the Gateway is generation of jobs for "Old Space."
The radiation protection from Solar Flare emissions in the designs I've seen is totally non-existent. No provision for any artificial gravity--which is absent all NASA designs. No provision for any Cosmic Ray shielding, either, which is the least of the worries for the inhabitants.
Offline
I concur fully with OF's assessment in post 208.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
The Deep Space Gateway may be morphing into an equipment site, instead of a location for habitation. There would seem to (me at least) to be some value in having a fully featured Lunar Orbiter with sufficient heft to maintain itself in orbit.
Such a facility could serve as a temporary emergency-only shelter for a spacecraft carrying passengers, and it could even serve as an orbiting supply point, again for emergencies.
That would be a useful role, and potentially worth all the billions that have been invested in the save-old-space jobs over many years now.
(th)
Offline
I'm still in absolute agreement with Robert Zubrin, who referred to it as a "Lunar Tollbooth."
"Ya ain't goin' to the Moon, unless ya pay Old Space a hefty toll."
Offline
I have noticed recently that the highly-elongated orbit of Gateway is about one of the Lagrange points, not the moon itself. My analysis presumed a 3000 km x 14,000 km ellipse about the moon, so I was wrong. That weird orbit makes it easiest for SLS to reach, with usable payload. But the one-way trip to or from the moon now exceeds lunar escape delta-vee, plus a lunar gravity loss.
That choice made the lander design problem worse from a mass ratio standpoint, but it makes landing anywhere on the moon easier than from low lunar orbit with an expensive plane change. Just like in my analysis, even from the Lagrange point, while way out there at low speed, that's when you do the least-cost plane change. Plane change delta-vee is directly proportional to the sine of the angle change, and to the speed at which you are moving.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
It became a 2 rocket launch for the moon when the gateway came about but then again that is what was slated even back when we had Ares 1 for Orion on the roman candle srb launch system. Its also why we need the block 2 rocket with the higher payload capability.
Offline
Meet the Lunar Gateway’s Robot Caretakers
Offline
Setting Up a Moon Base – But Where?
https://www.leonarddavid.com/setting-up … but-where/
NASA is eying an Artemis Base Camp, calling it “our first foothold on the lunar frontier.” The ingredients for that encampment are a Lunar Terrain Vehicle – an unpressurized rover – to transport suited astronauts around the site; a habitable mobility platform – a pressurized rover – to enable long-duration treks away from Artemis Base Camp. Lastly there would be the surface habitat itself, capable of housing four humans at a lunar south pole locale.
Negative Article
'It’s time for NASA to cancel the Lunar Gateway'
https://thehill.com/opinion/technology/ … r-gateway/
A recently leaked NASA document shows there is bad news and some good news for the Artemis return to the moon program, according to a recent article in Ars Technica. The bad news is, largely because of costs associated with building the Lunar Gateway, the pace of Artemis missions to the moon slows to an unsustainable crawl, with years between flights and the establishment of a lunar base pushed off to the 2030s. The good news is that many of these problems might be solved by canceling the Lunar Gateway.
The Lunar Gateway, once known as the Deep Space Gateway when it was first envisioned in the Obama administration and then the Lunar Orbital Platform-Gateway, is planned for an elliptical lunar orbit and would, as the name implies, serve as a gateway to the lunar surface. Astronauts on board the Orion would dock at the Lunar Gateway and transfer to a Human Landing System (HLS) to travel the rest of the way to the lunar surface.
and
NASA chose to keep the Gateway and repurpose it for Artemis primarily because the Orion cannot enter low-lunar orbit or depart after completing its mission. The Orion can dock with the Lunar Gateway in a higher elliptical polar orbit, passing 3,000 kilometers (about 1,865 miles) above the lunar north pole and 70,000 kilometers (about 43,500 miles) above the lunar south pole. The HLS would depart from the Lunar Gateway and then land on the lunar surface. After the surface mission is completed, the HLS would lift off, dock with the Gateway, and the crew would transfer back to the Orion to return to Earth. Meanwhile, the Lunar Gateway would be a base where the HLS would be refurbished and refueled.
However, as the Ars Technica article suggests, while the initial elements of the Lunar Gateway will launch on the commercial rocket, SpaceX’s Falcon Heavy, much of it will have to use the SLS in the late 2020s and early 2030s, which because of costs, can only launch once a year at best. As a result, “Such an effort, according to NASA’s revised schedules, will require most or all of the capability of the SLS rocket during that time frame, and they could preclude the agency from developing a greater focus on lunar surface activities.” That means expeditions to the lunar surface, including the buildup of a lunar base, simply slow to a crawl for several years.
Ars Technica goes on to say, “The problem with this solution is that, last April, NASA selected SpaceX’s Starship to serve as a lunar lander. Starship is already larger than the proposed Gateway, and it replicates many of its power and propulsion capabilities. So if you already have Starship as part of your lunar architecture, and if NASA is really interested in activities on the lunar surface, why spend a decade and tens of billions of dollars building the Gateway?”
Other issues in the Artemis program could delay its progress. They include space suits and the SLS itself, which recently had a less than optimal wet dress rehearsal. But concerning the Lunar Gateway, we need to paraphrase the question once asked by John Houbolt, the engineer who developed the lunar orbit rendezvous that took Americans to the moon during the Apollo program: Do we want to return to the moon or not? If we do want to return to the moon, then it is time that NASA cancel or at least defer the Lunar Gateway and get on with it.
Some at NASA argue that the Lunar Gateway, which would serve as a human-tended space station in orbit around the moon, is needed to test technologies that would sustain astronauts on the long voyage to Mars. Considering that the International Space Station exists, and several commercial space stations are being planned, this argument seems dubious at best...
Unable to achieve the goal using existing hardware has lead to the bumbled steps to go back to the moon for sure.
Offline
If they want to put money and resources into putting a human city on the Moon instead of Mars then so be it.
I try to be impartial and positive about Gateway, it was reported the new spacecraft would be attached to the launch vehicle for 6 days.
but this time I will post news in the 'Bad Joke' thread
mission was largely meant to test the orbit Gateway might occupy.
CAPSTONE suffers communications problem
https://spacenews.com/capstone-suffers- … s-problem/
In a July 5 statement, NASA said the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) cubesat “experienced communications issues” during its second pass with the Deep Space Network (DSN) after its July 4 deployment from Rocket Lab’s Lunar Photon kick stage. Amateur satellite observers had noticed a lack of transmissions from the spacecraft, prompting speculation something had gone wrong with it.
Last edited by Mars_B4_Moon (2022-07-05 16:22:25)
Online
Back to normal
MISSION UPDATE: Communications are back!
https://twitter.com/NASAAmes/status/1544706636882796545
Operators have successfully re-established contact with our CAPSTONE spacecraft.
CAPSTONE (Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) is a lunar orbiter that will test and verify the calculated orbital stability planned for the Lunar Gateway space station. The spacecraft is a 12-unit CubeSat that will also test a navigation system that will measure its position relative to NASA's Lunar Reconnaissance Orbiter (LRO) without relying on ground stations. It was launched in 2022, and will spend over 6 months flying around the Moon.
https://spacenews.com/nasa-cubesat-to-t … way-orbit/
Computer simulations indicate that this particular orbit — a near-rectilinear halo orbit (NRHO) — offers long-term stability with low propellant requirements for orbital station-keeping, by using a precise balance point in the gravities of Earth and the Moon that offers a stable trajectory.
https://www.esa.int/Enabling_Support/Op … ar_outpost
Following a three-month trip to the Moon after launch, the CAPSTONE lunar satellite will spend six months collecting data during this demonstration, flying within 1,000 miles of the Moon’s North Pole on its near pass (1609 km) and 43,500 miles from the South Pole (70,006 km) at its farthest.
A near-rectilinear halo orbit (NRHO) is a halo orbit with slightly curved or nearly straight sides between close passes with an orbiting body.
Such a non-elliptical orbit would require at least two other bodies (e.g. the Earth and Moon), and thus NRHO orbits are one theoretical solution to the classic three-body problem in gravitational mechanics. Of the three bodies, one is taken to be of negligible mass (the spacecraft).
https://westeastspace.com/encyclopedia/ … alo-orbit/
https://newatlas.com/orbit-halo-gateway/60657/
Last edited by Mars_B4_Moon (2022-07-06 12:47:32)
Online
Politics and the invasion of Ukraine has now made sure Russia will not be involved with Gateway
Zubrin called it a "lunar orbital tollbooth”
Huge sunspot pointed straight at Earth has developed a delta magnetic field
https://www.newsweek.com/sunspot-growin … th-1738900
and if this was Artemis or a Lunar Space Station in its way? X-class flare messing with satellites, the Carrington Event was the most intense geomagnetic storm in recorded history back in 1859 recorded during solar cycle 10. It created strong auroral displays that were reported globally and caused sparking and even fires in multiple telegraph stations. Geomagnetic storms of this magnitude occurring today would cause widespread electrical disruptions, blackouts, and damage due to extended outages of the electrical power grid https://science.nasa.gov/science-news/s … uperstorm/ The solar storm of 2012 was an unusually large and strong coronal mass ejection (CME) event that occurred on July 23 that year. It missed Earth with a margin of approximately nine days, as the equator of the Sun rotates around its own axis with a period of about 25 days. Earth research looked for signatures of large solar flares and CMEs in carbon-14 in tree rings and beryllium-10 (among other isotopes) in ice cores. The signature of a large solar storm has been found for 774–775 CE and for 993–994 CE. Carbon-14 levels stored in 775 suggest an event about 20 times greater the sun's usual activity, and 10 or more times the size of the Carrington Event. The Bastille Day solar storm was a powerful solar storm on 14-16 July 2000 during the solar maximum of solar cycle 23. The storm began on the national day of France, Bastille Day. It involved a solar flare, a solar particle event, and a coronal mass ejection which caused a severe geomagnetic storm. The Halloween solar storms were a series of solar storms involving solar flares and coronal mass ejections that occurred from mid-October to early November 2003, peaking around October 28–29. This series of storms generated the largest solar flare ever recorded by the GOES system, modeled as strong as X45 (initially estimated at X28 due to saturation of GOES' detectors). Satellite-based systems and communications were affected, aircraft were advised to avoid high altitudes near the polar regions, and a one-hour-long power outage occurred in Sweden as a result of the solar activity. Aurorae were observed at latitudes as far south as Texas and the Mediterranean countries of Europe. Twelve transformers in South Africa were disabled and had to be replaced, despite the country's low geomagnetic latitude.
Another Sun discussion
Heliopolis *2*
https://newmars.com/forums/viewtopic.php?id=2961
Last edited by Mars_B4_Moon (2022-09-02 03:58:36)
Online
It was said that they would rather go with China for such a goal and station during talks about the ISS cooperation.
Offline
Whip-cracking burst of energy from sun could explain solar wind
https://www.livescience.com/solar-wind- … ck-spotted
NASA Capstone Spacecraft Suffers Anomaly on Way to the Moon
https://www.cnet.com/science/space/nasa … -the-moon/
Giant Sunspot With Unstable Magnetic Field Quadruples in Size in 24 Hours
https://www.newsweek.com/sunspot-unstab … th-1741986
Sun spot AR3085 grew to the size of Earth
https://www.space.com/sun-fast-growing- … ugust-2022
Online
It's events like this that are the reason I say NASA is going to kill a crew on Gateway.
The larger of such could be a 10,000+ REM event over the course of only several hours. That's a "short" exposure. Lethal dose 50 is 300 REM, and lethal dose 100 is 500 REM, for "short" exposures.
A spacecraft or station module hull will only knock that space exposure down by around a factor of 10, to around 1000+ REM over several hours! It's still quite lethal, and a very ugly death.
Please look again at the tag line on my postings!
GW
Last edited by GW Johnson (2022-09-22 15:48:57)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
All you need to do is look at how many starlink satellites are dropping out of orbit from these storms...
Offline
Some say NASA is lost with Gateway
but Mars colonies
I say 'Direct' but that does not mean avoiding some test runs like using Robots to set up a colony and maybe sending something alive first, maybe not like a Laika space dog or Ham the first space chimpanzee, but there might be a way to test farming before humans arrive, they say France put a a stray Parisian cat in space and a rabbit rode inside the Chinese Shenzhou as a test of the spacecraft's life support systems.
in other relevant news
SpaceX's Starship has 50% chance of success on 1st orbital Elon Musk says
'Elon Musk hints at a crewed mission to Mars in 2029'
https://www.npr.org/2022/03/17/10871678 … -mars-2029Russia returns to the Moon (maybe)
https://www.thespacereview.com/article/4548/1
What it could do is provide a steppingstone to pushing outward with proper shielding.
Offline