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SlavaUkrainiFTW t1_jc7469a wrote

Didn’t realize the end was that close… Would love to see a new station at some point that could be used as a jump-off point for solar system travel.

IIRC the concessions made with the ISS to make the orbit favorable for Russia made it practically unusable for launching trips to other places in the solar system. Someone correct me if that’s wrong.

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Various-Air-1398 t1_jc771n3 wrote

Just attach boosters to it to send it into deep space.

edit: Geez, I wasn't being serious, actually found the whole "deorbit tug" idea rather humorous.

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PandaKing185 t1_jc78hje wrote

Just a hypothesis, but the core technology on the ISS is over 20 years old at this point, and I'm sure we have learned a lot ways in which we can improve upon the basic design and systems. There are standards used in the ISS design that any incremental update (think replacing one module at a time) would have to be backwards compatible with as it transitions, thus limiting any major overhauls. I imagine it would be more cost effective and allow for more improvements to just start from scratch using everything we've learned and create new standards

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link2edition t1_jc7agic wrote

Yeah there is a Saturn V stage orbiting the sun right now, swings by the earth every 40 years, its supposed to actually hit us in 2000 years or so, which I am sure will be amusing for the astronomers of the day.

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urmomaisjabbathehutt t1_jc7b1c9 wrote

i want people to keep adding modules of every kind to make a rebel space achipielago

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jftitan t1_jc7b6b2 wrote

He never watched Futurama where the space trash ball returns to earth.

You see, humans tried to send our trash to the sun... problem solved.

But then again the trash ball took orbit and then eventually returned to earth.

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nursenavigator t1_jc7bsmf wrote

Yup. And the cool part about "let's take our trash and ship it to the sun!" is that hitting the sun is very difficult. Lot less fuel is needed and easier aiming if you blast out to, say, Jupiters orbit, slow down , and then let the sun pull it in.

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ImpulseAfterthought t1_jc7c2ol wrote

Another problem already solved in Kerbal Space Program. ;)

Seriously, though, this is a fascinating subject. So many complexities to consider.

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Ratstail91 t1_jc7c5td wrote

I personally think the space station needs to be preserved as a historical monument somehow, and it's really sad that they're planning to bring it down.

I'm fully aware that I'm not an expert though - so I'd delegate decision to people who are... I just wish there was another way.

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Alan_Smithee_ t1_jc7kdr7 wrote

Why can’t they just use a Cygnus to do it?

Personally, I’d prefer that they leave it up, and perhaps let private space companies operate it if NASA and partners won’t.

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BufferTheOverflow t1_jc7ksw4 wrote

Sad to see it go. It will be interesting to see what survives the descent.

2

maxcorrice t1_jc7m1go wrote

It takes a lot of delta V to do it, definitely not impossible but best bet would be to keep a schedule similar to the current one but the boosts go for much longer to get it into a slightly higher orbit each time, it’ll cost less total but for longer and it’ll give us time to get better more efficient engines, or it could be used as a testbed for things like ion engines where they have low thrust but high efficiency

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fernibble t1_jc7n8tp wrote

> The deorbit vehicle shall be capable of providing at least 47 m/s of delta-v for the ISS at 450,000 kg mass.

Very interesting that only 47 m/s of delta-v, at a minimum, is needed. The orbital speed of the ISS is about 7660 m/s.

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LukeNukeEm243 t1_jc7oitd wrote

Axiom is planning to use the ISS as a starting point for their new space station. Axiom's first module is planned to launch in late 2025 and will dock to the forward port of the Harmony module of the ISS. The second, third, and fourth modules are planned to launch in 2026, 2027 and 2028 respectively. Then the Axiom segment will separate from the ISS and become its own modular space station.

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not_that_planet t1_jc7oqx4 wrote

Indeed. If NASA accepts (is allowed to accept???) this as a project, this will be a big deal.

I'm not going to say propulsion in space is easy, but it is relatively straightforward. Getting into and out of orbit is something we really aren't very good at.

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rocketsocks t1_jc7pahe wrote

I really hope we don't half-ass a transition from the ISS to the next generation of space stations. One of the best things about the ISS currently is that every crew has a roughly 3 month overlap with the previous crew, which allows a tremendous amount of transfer of knowledge. That's continued for about two decades, it'd be a shame to let that operational expertise die.

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drc84 t1_jc7qzpm wrote

I like to think that a deorbit tug is when you get a hand job as you are coming back from a long space mission.

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JayR_97 t1_jc7r97l wrote

Couldn't we just boost it to a safe orbit? Seems a shame to just burn it up

3

Pharisaeus t1_jc7rbal wrote

This is because atmosphere does most of the job, you just need to drop the perigee low enough.

Consider that the Space Shuttle had around 300 m/s of delta-v available for their orbital operations. Deorbit burn of visiting spacecraft to the ISS are around 130-150 m/s.

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Pharisaeus t1_jc7sg48 wrote

> Why can’t they just use a Cygnus to do it?

To small. You'd need something like fully loaded ESA ATV to deliver enough delta-v. Single biggest push ISS ever got was from https://en.wikipedia.org/wiki/Johannes_Kepler_ATV and with 4.5t of fuel (total theoretical payload capacity was 7.5t, but part of that was fuel for ISS, water and dry cargo allocation) it delivered less than 30m/s delta-v, raising orbit form 350 to 400km. Here you need about 50% more. So theoretically fully loaded with fuel it could make it. But that was the biggest resupply craft flying to the ISS.

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rocketmonkee t1_jc7spqi wrote

> Why can’t they just use a Cygnus to do it?

Basically, that is what the Request for Information (RFI) is asking. NASA is proposing the idea to use natural orbital decay or propulsion from the Russian Segment, then use the "space tug" to take over for the final de-orbit burn, plus any attitude and Delta-V adjustments during the final de-orbit events.

This announcement is NASA's mechanism to ask the aerospace industry what it thinks, and for the aerospace industry to give ideas.

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Decronym t1_jc7tcye wrote

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

|Fewer Letters|More Letters| |-------|---------|---| |CoM|Center of Mass| |EDL|Entry/Descent/Landing| |KSP|Kerbal Space Program, the rocketry simulator| |LEO|Low Earth Orbit (180-2000km)| | |Law Enforcement Officer (most often mentioned during transport operations)| |LOX|Liquid Oxygen| |MECO|Main Engine Cut-Off| | |MainEngineCutOff podcast| |MRO|Mars Reconnaisance Orbiter| | |Maintenance, Repair and/or Overhaul| |SLS|Space Launch System heavy-lift|

|Jargon|Definition| |-------|---------|---| |Starlink|SpaceX's world-wide satellite broadband constellation| |cislunar|Between the Earth and Moon; within the Moon's orbit| |perigee|Lowest point in an elliptical orbit around the Earth (when the orbiter is fastest)|


^(11 acronyms in this thread; )^(the most compressed thread commented on today)^( has 14 acronyms.)
^([Thread #8688 for this sub, first seen 14th Mar 2023, 17:48]) ^[FAQ] ^([Full list]) ^[Contact] ^([Source code])

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r_not_me t1_jc7thqc wrote

Wasn’t there a botanist stuck on Mars that used a hole in his glove to “Ironman” his way to the rescue ship?

Seems like we have this whole thrust thing figured out to me /s

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Winjin t1_jc7uu6r wrote

I saw a great argument that Passengers were released the same year and suffered from miscast too.

Hilariously, if you swapped Chris Pratt with DeHaan both movies would be elevated. The scripts and directing would still be a major pain, but DeHaan as a sad creepy passenger and Pratt the Superhero Chad would work way better.

Also the recut Passengers would've been way better. And Rihanna scenes weren't needed.

Well, overall, both movies could be better, but the miscast idea still stands.

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ClioBitcoinBank t1_jc7vjvv wrote

Waste of money, the station can be deorbited without an expensive "tug".

−7

dragonlax t1_jc7w155 wrote

That would require the invention of new heat shield tech, getting it up to space (it will be very heavy and horribly expensive to lift), then install it, add parachutes, flotation devices, etc. You’re talking tens of manned flights costing $100m+ each just to recycle 20+ year old tech, no use for it at all.

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DeNoodle t1_jc80ovm wrote

Sounds like relying on Russia is not a strategy to rely on.

0

ioncloud9 t1_jc819fr wrote

It would have to be moved really far up. Like around 1000km up to last decades without needing a reboost. And it would be out of control. It needs constant fuel to desaturate the reaction wheels and maintain orientation. Without that it would be spinning out of control until it broke apart. Then its a massive liability.

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GatoNanashi t1_jc82vao wrote

There's no real way to do it. Nothing exists that can bring the segments down intact so the only option is to try and boost it into a parking orbit somewhere. At that point it's basically just more abandoned crap in space.

I get you, but it's just not practical in any way even taking money out of the equation.

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Northwindlowlander t1_jc8a6oc wrote

For quite a while it was assumed that using the old ISS as the building site for a new one was the best way to do it- without the shuttle, assembling was going to be harder. But the chinese station pretty much shows that time's past, especially considering that you don't necessarily want the new station in the same orbit

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Northwindlowlander t1_jc8adtp wrote

Yeah, it really doesn't take a lot. TBH it does seem a little oversimple to me, just because the drag on the station isn't a constant- bringing it down is easy, bringing it down exactly where and when you want it to is not so simple, being able to brute force that could be very useful.

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Overcriticalengineer t1_jc8akgj wrote

There is, but not in the way people would normally think. Usually, there’s two of each module made in case something happens. Take all of the spares, make an ISS on the ground.

Edit: I need to do some research if spares were made for the main modules. Kinda want to see how much of this would be possible for a full list. At the least, there’s a list of some spares that might be used.

0

quaderrordemonstand t1_jc8atk7 wrote

Why bring the whole thing down like that? I always assumed the plan would be to dismantle it and send each piece down to burn up in the atmosphere? Would that not happen?

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afraid_of_zombies t1_jc8b8so wrote

I really hope we decide to keep it going instead of killing it off. At least until some other system takes her place. Like two starships docked together.

0

Northwindlowlander t1_jc8cka3 wrote

It still seems to me that even though the useful life of the ISS is limited, and its value as a building site for a new station has diminished, that 420 tons of pretty much <anything> in LEO is a useful resource. Reconfiguring the thing for less cross-section then firing up something like a dragon with nothing but fuel, seems like a fairly small investment even if you have no specific plans for it in the future.

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doctor_strangecode t1_jc8f5d3 wrote

Let's not tear down the publicly funded station until there's an existing alternative that we like.

Given that we just bailed out Silicon valley bank for around $100B, that should be their free handout for the next decade, and let's build it with public money, as a public resource.

−3

whoamvv t1_jc8gkf4 wrote

By the way, do not ever ask your partner for a "deorbit tug" in bed.

1

rocketsocks t1_jc8gy7r wrote

First off, SVB wasn't "bailed out". SVB has always had plenty of assets to cover deposits, they just fucked up their liquidity and management and caused a bank run. The FDIC stepped in and is going to make sure it's run properly, but realistically there won't end up being a single dollar of tax payer funds that goes into SVB for a "bail out".

Regardless, that is mostly besides the point. Yes, there should be a larger commitment to ongoing space station operations. Unfortunately, the way these things work is with specific projects and there hasn't yet been an "ISS 2" project that has been able to congeal political support. There is both half-assed commitment to next generation fully commercial stations and also to the Lunar Gateway, but these are not the same things. For Congress something like Lunar Gateway seems like a perfect replacement, it's a sink for federal aerospace dollars and it allows for international cooperation, but operationally it's apples and oranges.

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rocketsocks t1_jc8h3a1 wrote

Yes, that will for sure happen, but in order for it to happen safely we need something with a lot of propulsive capability. The original plan was to use 3 Progress vehicles, but that puts Russia in the critical path.

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rocketsocks t1_jc8jpnb wrote

So you're proposing they just build a propulsion system on the station as a DIY project?

The whole purpose of this is to build a system that works reliably. And one can be developed, but not for zero dollars. Very likely this will end up being a variant of a cargo spacecraft (Cygnus or Dragon) optimized for propulsion. None of those vehicles have enough thrust to do the job in one go right now, the station weighs 400 tonnes after all.

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bookers555 t1_jc8jz04 wrote

Nah, thats just going to be used in conjuction with Lunar missions.

Besides, it would be a huge waste of money to put our "main" space station orbiting the Moon since the requirements to get people there would go from a medium sized rocket like the Falcon 9 to a super heavy lift one like the SLS.

Each crew transfer would cost 2-3 billion dollars, which is absurd.

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ClioBitcoinBank t1_jc8kddg wrote

Use a cargo mission with a modified upper stage, grab it with Canada arm, and attach to station, the crew lander can carry extra fuel going up and refill before evac. Not exactly this but something similar and simpler.

−1

bookers555 t1_jc8ko8l wrote

Its travelling at almost 30.000 km/h and at a height of 400km.

If you reduce its speed, it just falls to the ground, if you just reduce height, it burns up.

So unless you have some sci fi anti-gravity tech, its just impossible to bring it back.

And if its kept in space there's the risk of it crashing with something and becoming a huge swarm of junk.

Its sad to see it go, but deorbiting it is the safest thing.

No matter, the next one will be bigger and better.

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kittyrocket t1_jc8ltk6 wrote

Huh, I'm suddenly wondering if Axiom could take a module or two with them when they bud off of the ISS. Those could be their 'historical wing' where a billionaire adventurer could get an 'authentic ISS experience. More marketing copy blah blah blah.'

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miemcc t1_jc8t006 wrote

The main problem with ISS is that it was never designed to last this long. What started as a nice neat science module has become a rats nest of cables and pipework. At least it hasn't gone as far as Mir, where they threaded cables and air con through throttle interconnecting doors.

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mauore11 t1_jc8x9kr wrote

Is there a way to sell it to a private sector and keep it in orbit?

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Northwindlowlander t1_jc91tct wrote

Safety isn't that much of a concern, it's a simplification but all of the places we're likely to put an orbiting station for the forseeable future are in the same ballbark of risk in terms of ease of access and return, obstacles, etc.

You can't separate physics and dollar cost since dollar cost is directly related to payload, quite simply delta v costs money.

Launches play a big part... Like, the ISS is low enough that it suffers a lot from atmospheric drag and its orbit needs frequent boosts (and that'll get worse as the atmosphere warms). But obviously higher up = harder to get to. So that's just a plain old compromise, but it's ultimately one that can be handled within a really wide range- raising it occasionally is just a question of fuel, so that's meant that the low-ish orbit has worked well and that's probably still true.

The other being the orbital path of course, since you have to have the launches intersect with the orbit. And that's simple phyics really but not simple human-stuff. Where will we be launching from in 2040, and how will we be launching? Will we have equatorial stations, or more mobile floating launchers? Will be still be using chemical rockets for everything with no other options in sight, or will we be kettling stuff up, or have a big railgun up an equatorial mountain, or be launching payloads from the moon, or getting close to any of those? It all gets insanely complicated, right down to "which US politicians want to keep launching from their state" or "which countries will be friendly and stable enough to invest this stuff in"

An ISS replacement in the short to medium term, I bet 20 scottish pence would end up at a similar orbital height, but with a different track to suit current US launch sites and less or no thought to Russian cosmodromes. In the longer term I'd expect payload delivery to get easier and therefore a higher altitude to become more desirable, especially with a warming atmosphere, but for now it's almost certainly still better to be lower and to get mass there easier

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Northwindlowlander t1_jc9282w wrote

Putting into a parking or graveyard orbit would be a ton of effort. But pruning it a bit to reduce drag once it's unmanned, and lifting it somewhat higher would be pretty easy. At this point, literally just a matter of cost.

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thx1138- t1_jc955zx wrote

Yeah at first I was bummed to hear it had a deorbit date, but it looks like the new thing is all the spacefaring nations are going to start building their own space stations. The US is looking at several solutions and may do more than one of them at once. It sucks that it's time has come, but the biggest achievement of the ISS was building it in the first place. We all worked together and learned a lot, now the next phase is going to be ground-up rebuilds using everything we learned. It's still progress!

Also unless someone else builds a Starship they're going to have a really hard time keeping up with the US in the future.

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thatwasacrapname123 t1_jc98jg6 wrote

I read a proposed alternate ending to Passengers that I thought was great. Instead of he saves the ship, she forgives him, they live out the rest of their lives happily..She never forgives him, he dies saving the ship and now she is stranded alone on the ship..Final scene you see her finish a drink at the bar, say goodnight to the robot barman. Then you see an anguished look on her face as she stands over a cryopod looking down at a young man, realising she is about to make the same terrible decision to wake someone up.

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jawshoeaw t1_jc9clnv wrote

Hey if you guys don’t want it I’ll take it off your hands. Just need it boost its orbit a bunch no prob

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Dianesuus t1_jc9eih5 wrote

That would've been a way better ending, especially if they included some kind of "days alone" counter to show whether she holds out longer/by how much. it would've added so much weight to fishburne's comment about how pratt was drowning alone.

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Anderopolis t1_jc9v7q4 wrote

It will be 30 years old at the time of decommissioning, it already has several permanent leaks.

We totally should fund commercial leo though so that replacements are up by 2030, but this budget request asks for no additional funding for that.

3

swissiws t1_jc9zv45 wrote

I wonder if a pair or more of non-reusable Starship boosters bodies could be welded together to make a new ISS? Once removed the inside plumbing, the room inside the tanks is gigantic. Lots of work to do but a possibility.

1

FullOfStarships t1_jca2mo6 wrote

Don't you just make a bomb out of sugar and liquid oxygen? Problem solved.

0

FullOfStarships t1_jca45ks wrote

Agreed.

You could build an ion engine to do this with a tiny amount of propellant, but that would take years which completely misses the point.

Sort of like taking foot off the gas and letting a car drift to a stop.

Instead, ISS needs something like brakes. Press the pedal and the whole thing slows down. Just like modulating the brake pedal so that you stop at the lights. In this case, you apply just the right amount of brakes at just the right time to splashdown in the Southern Pacific (Point Nemo, as it's known).

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stefanSfermat t1_jca5ahl wrote

I've been saying we need these capabilities for years. Shuttle was excellent LEO utility vehicle. We have no equivalent at the moment.

1

Pharisaeus t1_jcaa43m wrote

  1. There are safety risks because modules are old and degraded
  2. Costs are pretty high, it takes a couple of billions to keep it flying each year. Why would private sector do it? Cost is high and return prospects not great.
1

Pharisaeus t1_jcaacjp wrote

> recycle the parts/materials

That's completely pointless. It's not a solid block of aluminium or something else which can easily be recycled. Consider that ever on Earth we don't "recycle" things like cars, because it's just not practical - it would be more expensive than making a new thing from scratch.

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FullOfStarships t1_jcabdpw wrote

NASA needs to build on their own previous research on electromagnetic EDL - "Magnetoshell Aero Capture":

https://www.nasa.gov/directorates/spacetech/niac/2012_Phase_I_magnetoshell/

Click through to the PDF for detailed info on their modelling, EG aerocapture of a 60t spaceship at Mars replaced a 20t heatshield with a 1t magnetic system. Also 20km/s aerocapture at Neptune.

"This means that for any given breaking drag forces on the Magnetoshell will be three orders of magnitude larger than the aerodynamic forces on the spacecraft. With the ability to rapidly and precisely modify the drag in varying atmospheric conditions, much larger braking forces can now be contemplated at low risk, enabling very aggressive aerocapture maneuvers."

The thing that makes this suitable is that when you turn the system on it basically kicks in the atmospheric reentry much higher than normal. You then adjust the magnetic field strength to accurately target the deceleration that you have pre-planned.

Some concepts that I've seen literally put the system on a tether behind the spacecraft, and it acts like the parachute behind a drag racer or a plane landing on a short runway. Nice feature of this is that it's a dynamically stable system - it just brakes in a straight line.

Just what this needs.

I'm honestly disappointed that SpaceX aren't testing this. Not because it's their patriotic duty to do everything interesting in spaceflight, but because they're launching 100 F9US this year alone, and every Starlink mission should be testing this during U/S disposal post mission (after all payloads have deployed).

Exactly like they tested reentry of the first stage long after MECO / stage separation / payload in its way to orbit. Zero risk to mission success.

First target should be to slow down FH core stages so they can survive F9-style reentry and recovery.

Also, those simulations were based on "room temperature" copper coils to reduce the technical complexity of the system during testing phase.

There are now very low mass / high performance thin film superconducting tapes which would be perfect for this job, I think. There will be LOX residuals to provide the cryocooling.

I'd love to see a world where every Starship uses this to reduce the performance requirements on the heatshield. Starship docks behind ISS, switches on the MAC, targets the reentry, then un-docks, reboosts itself, and lands safely.

(Before you say "why Starship"? ISS is about 4x the dry mass of Starship. If MAC is in regular use in Starship EDL, then it will work on a combined Starship / ISS system by just running the MAC for 5x longer than normal.

If any other provider is going to be in a position where they have 100t+ spaceships in regular use, ground control teams with years of experience with ISS rendezvous, MAC built into the system [I can dream], etc, etc, then perfect. But I'm not seeing it.)

1

Pharisaeus t1_jcacr2a wrote

I have no idea what point you're trying to make. The article discusses de-orbiting the ISS, which requires pushing a 500t object to a transfer orbit with 150km lower perigee than what it is right now. The space shuttle had nowhere near the delta-v to do that. Yes it was used few times to reboost ISS orbit, but only a tiny bit.

Yes, Shuttle was used to construct some parts of the ISS, but in 36 flights in total. Are you suggesting an idea to de-assemble ISS and take it back to the ground piece by piece? It's a completely crazy idea and even if the Shuttle was still operational it would never be considered.

2

stefanSfermat t1_jcadpix wrote

Some parts? 🤣

I am discussing the need for a general-purpose LEO utility vehicle. It is extremely unlikely that we would ever attempt to bring the ISS in its entirety, fully assembled, back to ground.

You can't move a house with a pickup truck, but a pickup truck is definitely an asset on a job site.

0

Pharisaeus t1_jcaecu7 wrote

> Some parts? 🤣

Yes. Large part of the ISS was not launched on the Shuttle. Zarya, Zvezda, Pirs, Poisk, Nauka, Prichal were not. And Mir and recently Tiangong proved you don't need a Shuttle to construct a modular space station.

> the need for a general-purpose LEO utility vehicle

No such need ever existed, and history showed how stupid idea this was. It was bad as a launcher because you needed a crew, which made it extremely expensive and dangerous. It was also bad as a manned craft, because you had a huge vehicle with a tiny manned part. The only scenarios where it was useful was Hubble refurbishing and SpaceLab missions. Everything else, including ISS construction, could have been done much cheaper by regular rockets.

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toby_gray t1_jcaidd7 wrote

There’s also the alternate cut that someone made where the movie starts when she wakes up and it suddenly becomes a horror film. Without an hour of him endearing himself and making the audience feel sorry for him, it’s a lot fucking creepier.

9

Martianspirit t1_jcaiski wrote

I wonder what exactly is the plan. Just get it down enough that the atmosphere will do the rest of the braking?

I guess they will want a targeted deorbit, which means they need to brake with propulsion until it deorbits.

1

Sojoez t1_jcakdjr wrote

If people would stop fucking focusing on the two characters and judged the movie more on where the director excels then more people would enjoy the movie. The world building is absolutely gorgeous.

1

Raspberry-Famous t1_jcaubzw wrote

Yeah, absolutely, you'd solve most of the really hard parts of this problem that way. The downside is that it would pretty difficult at a pure technical level and also that you'd have to coordinate everything around the station being taken apart vs. having everything else drive the decommissioning timeline and then the actual deorbiting basically just being a button you push.

3

Northwindlowlander t1_jcavf3f wrote

What I was getting at is that parking/graveyard orbits aren't realyl practical, and people tend to react as if that makes any sort of preservation impossible, and that can obscure the fact that it doesn't need to be permanent, it just needs to be sustainable.

Anyone that knows that lifting it to a permanent orbit isn't practical, should also know what the alternatives are, but that doesn't seem to stop it... Tell you what, you book the Dragon, I'll get some jerrycans of rocket fuel

3

Jaws12 t1_jcb1sbp wrote

Perhaps, but this might also be an underestimation of the future capabilities of advanced AI/simulation systems trained on the entire body of an actor’s work to recreate their potential performance in different roles.

3

Raspberry-Famous t1_jcbcasy wrote

The plan is to gradually put it into an elliptical orbit where the perigee is as low as it can go and then to do one big burn that will put it into a steep enough final descent that all of the debris will end up in more or less the same place.

2

Winjin t1_jcbkk6o wrote

I mean, it's not just the face, or the body. The whole scenes have no charisma. It means that you also need to redraw Delevigne as if she's actually interested, rather than... what was going on.

2

ClioBitcoinBank t1_jcbncm8 wrote

By ground based solution I mean you accomplish 99% of the deorbit construction phase of the mission on the ground instead of sending up parts in the cargo missions and slowly building a deorbiter system or whatever you want to call it. Those same missions could siphon off fuel from the resupply mission upper stages, but a ground based solution might be to send a dedicated vehicle, purpose built for this mission. Imagine your going on a camping trip, you wouldnt assemble the tent and then walk it into the woods, you would take the tent into the woods in pieces, and assemble it there. I like the idea of Nasa sending a simply single mission vehicle to solve this problem, I jsut dont like that it would cost a ton of extra money for what basically boils down to a demolition job, demolition should be the cheapest and least reliably type of mission Nasa has ever conducted, ladies and gentlemen, it's time to cheap out.

1

BufferTheOverflow t1_jcbpsqo wrote

I’m not familiar with logistics of surface recovery at Point Nemo, but surely we have to at least try? The prospect of taking such an important milestone, tugging it into the Pacific, and letting debris (if any) sink is disheartening.

1

Chairboy t1_jcbrckq wrote

Whatever little chunks survive re-entering at those speeds (which will be very little, it will be mostly powder and little bits of confetti-like pieces of metal falling out of the sky) will hit the water and sink because the kinds of things that would float will probably burn up.

Just to make sure we're on the same page here, that it's understood there isn't a space station touching down.

1

ClioBitcoinBank t1_jccgblp wrote

You can control the landing area and deorbit the station using a modified upper stage, the kind that are constantly flying upto the station, canada arm it to the station and then have station residents finish the system. This should be a quick cheap demolition, not an excuse to design a mission vehicle from the ground up as a "deorbit tug".

1

Fellowearthling16 t1_jcch72w wrote

That’s not off the table. Nothing is. The only reason it’s in the news right now is because Biden set aside money specifically for NASA to start working on a finalized plan.

NASA’s existing plan is pretty much putting some undecided propulsion system somewhere near the middle of the truss. It’s a whole lot of nothing.

1

Polygnom t1_jcfkaoi wrote

And then instead of one problem, you have half a dozen or more problems.

Currently, the problem is somewhat simple:

Attach to Node 2 forward, and be able to produce 47m/s of delta-v attacked to a station of 450 tons.

Boost-de-boost maneuvers of the whole station are well researched at this point, so we know the force vectors and what happens to the station when doing so. The station itself can also help with attitude control.

If you break it up in pieces, you would need to find out where to attach, what the force vectors need to be to properly boost of module through its CoM without spinning out of control. Most pieces won't be able to support the burn with attitude control.

You'd also have to disassemble the station, which in itself might take months or longer. All while diminishing the capabilities of the station further and further while doing so.

Honestly, keeping it as one piece looks a lot simpler. You basically just need to do a stronger de-boost burn. So basically business as usual, just more fuel.

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Polygnom t1_jcfky2m wrote

The earth equatorial radius is ~6378km. The ISS is just 400km above that, or less than 6%.

99% of the energy is expended just to get into a suborbital trajectory. Its only the last couple of seconds in any spaceflight that raise the perigee from being below ground to being above the atmosphere.

In order to deorbit the station, they just need to lower the perigee enough so that drag does the rest. And a huge space station with huge solar panels has much more drag then a small, cylinder shaped capsule.

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thx1138- t1_jcgj0wd wrote

Yeah I guess my thought was that CoM on a rather asymmetrical structure such as the ISS may be hard to control from... but then again they have actual rocket scientists so maybe it's not :D

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doctor_strangecode t1_jcha6kw wrote

A lot of money is being spent to fill in a hole. $200B / 300M population is $600 per American man woman and child. That's a lot.

It's not taxpayers that get hurt, it's "bank customers" that will pay for it, which I'll argue is the same group of people as taxpayers. Hard to pay taxes without a bank.

The money came from FDIC, which backed the bank beyond the limits they apply to other banks. FDIC is funded by a tax/fee on banking, and banks will pass those costs on their customers. And those customers are everyone.

For ISS, we should look at the space shuttle. When the shuttle program ended, congress replaced it with nothing. We had to ride to space with the Russians.

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rocketsocks t1_jchkes8 wrote

https://www.fdic.gov/news/press-releases/2023/pr23019.html

> No losses associated with the resolution of Silicon Valley Bank will be borne by taxpayers. Shareholders and certain unsecured debt holders will not be protected. Senior management has also been removed. Any losses to the Deposit Insurance Fund to support uninsured depositors will be recovered by a special assessment on banks, as required by law.

As for Shuttle, it was not ended and replaced with nothing. It was replaced with what became SLS and Orion (plus some other stuff that didn't continue), which has so far made use of over $40 billion in funding. On top of that the commercial crew program was started. All of these things started before the last Shuttle flight.

That doesn't necessarily change the main point, but accuracy is important.

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