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[Starver]

The false argument behind it (also Aldrin's idea of the Mars Cycler) is that it makes the trip easier because "all you have to do" is to reach it and that saves you fuel as you then link up with it and ride until you want to get off. Because to dock with the hardware (then undock and continue) takes no less capability than to be in that orbit, then leave it after an arbitrary time (of maybe less than a cycle).

On the other hand, if you've set up such a station, over a number of missions (and/or via unmanned heavy-lift capabilities) then you've likely got a proper refuge rather than a cramped 3ish-man capsule and (accounting for the necessity of docking with it, which is a risk beyond "attaining any equivalent transfer[1] orbit" if you're forced to rely on meeting this one (or one of a few alternates) location in ballistic space-time but you only need to build in 'local' abort-to-last-base capabilities, and can have the next step (back off the station) serviced by a pre-placed bit of kit that's designed for your next step better than what got you there.

(i.e., we can get to the ISS fairly routinely, with kit that isn't rated to get us to Lunar Orbit. But we can get one of those up there (tested in orbital conditions, fully refuelled and majntained by the guys already up there), use that to get to the LG where there is a lander descent/ascent stage[2] waiting in a similar manner. A form of this was one of the early considerations for the Apollo program, before the need to rush things (it being a race, and all) led to the conclusion they'd just push everything for every stage up with one massive Saturn V, including the 'temporary Lunar Gateway' that Collins ended up manning.)

Failure modes are different (i.e., if you're expecting to meet something that goes wrong while you're on route, you need the capability to get back again, and you can miss your rendezvous too) but there's potentially more resilience than Apollo 13 had to work with (even assuming they might have had problems trying to match orbits).

Plus, it sets your store. We're there. And that would count for something (and harder for the legacy to be abandoned than without there being something physical to abandon, one of the oft unmentioned qualitites about the ISS).


ETA: I hope that made sense. It was tapped in while on a short walk, knowing I wouldn't get immediate leave to reply once I'd gotten to my destination. And I need to add that this is how I see it, safe and snug in my expertise armchair.


[1] By which I don't mean Transfer Orbit in the normal sense. "Stepping Stone" orbit as well, such as ISS might be in at the top of our air-column.
[2] Later, with a moonbase, just one equipped/fuelled for safe descent, arrangements made down there to get a ride back up again.

[Madman198237]

The LOP-G is basically, as one expert said (Sorry, I can't remember who.), a tax on anyone going to the Moon or Mars. It won't have any real benefits until such time as we're actually mining water from the surface of the Moon and can therefore refuel spacecraft and need a holding tank in lunar orbit, at which point having a gigantic propellant tank in orbit becomes a good idea.

To be fair, a certain configuration of equipment CAN make it more efficient to dock with something else, i.e. if you've got a highly efficient propulsion system (ion or plasma or nuclear [I wish]) on an orbital module, then all you need is to bring up something akin to Orion with its service module, dock with that unit in LEO, then the unit handles all the transfers and delivers the crew to the destination, preferably without bringing along the capsule. Something similar was, I think, used in the Martian, at least in the book.

However, rendezvousing with a fixed-in-one-orbit installation makes just about zero sense unless you can, as mentioned, use it as a depot for things like fuel. In this case, you save the fuel needed for the ship to descend to the lunar surface and come back up, at the expense of needing a single tanker capable of moving fuel from the surface to orbit, and an orbiting fuel depot to hold that fuel. Alternatively, the same tanker could (theoretically) rendezvous with the ship you're trying to refuel, but then you can only refuel any given mission with one tanker's worth of fuel, which might preclude larger missions from being refueled in that manner (unless you're using some massive thing as a tanker). At that point, having the fixed installation with a lot more tank space but no need to move the entire dry mass of the larger fuel tank to and from the surface becomes more efficient.

But all these arguments rely on having some serious surface and orbital infrastructure which we aren't going to have until either NASA gets its usual contractors moving (hahahahahahaha yeah right) or SpaceX gets Starship and Super Heavy up and running. I highly doubt the Elon Time prediction of "later this year" is going to happen for Super Heavy, but we might, maybe, hopefully see it under construction/under testing next year.

[Starver]

It's not just fuel. It's other consumables, plus a (theoritical) one-time cost for infrastructure specific for the orbital environment (solar storm shelter8ng?).

When the Shuttle was hoiking up its lab every time it launched it reduced its capability to send up other things, including consumables and things to launch or otherwise work with. With the ISS (and Mir and Skylab before) consumables for the residents (between supply visits) are up what they are for day-trips, but productivity and the running of long-term projects were raised.

Sending a couple of tin cans to the Moon, each time, was expedient at the time, but it was then too easy to say "Apollo 18? Naw, that's enough...", and even though Skylab tried to make "a destination" it ended up being a holiday-home in the back-of-beyond that eventually nobody wanted to repaint for half the 'holiday'. The Mirs did very well at it, long after the whole thing might have been shelved, and the ISS has built on that (also, no single government can quietly drop it, without others raising eyebrows or even now claiming that they at least are still in it for the purest of pure science and aren't being political about it... even if this means they are being political about it, but their own way).

The organisation (gov/non-gov/Hugo Drax) or consortium of such that gets to the point of getting a Gateway (preferably perma-manned[1]) does not just commit to the first mission to use it to complete the task but has invested in enough more missions. This investment costs more than the two-tin-can method, initially, and may cost more than the TTC version ends up doing once it's been stopped again a handful of iterations down the line. But amortising across a (hopefully) sustained lifetime of the project, dovetailing with other relevent projects to make its legacy outlive its actual operation and carry even across setbacks[2], make it less of a moneypit than initially you would assume.

Still a moneypit, but few alternatives (other than not bothering with any) come out much cheaper, and of all the vanity projects it's at least got a potential to be longer lasting in both the physical and heritage senses.


(That's how I would defend Gateway against that argument. Yes, there are problems. I mentioned earlier the problem with having to rendezvous to do what's needed, or else you're relegated to your free-return trajectory (or whatever you can/must do once the rendezvous is shelved, if it's a last minute thing), but these things will get worked out/stumbled over if we're serious about the things we're trying to do. Quitting is an option, but not a very satisfactory one.)


[1] Because the documentaries we see about docking with unmanned space-stations often end up not going very well for the visitors.

[2] If there had not been the number of Shuttles that there were then, for better or worse, NASA would have been out of the Manned Flight market for far longer. Had there been more then they could have had Challenger/Colombia (or whichever other ones were in the wrong place in the cycle at the wrong time) and still been able to continue. Still learning, each time, and having other incidents along the way, but even if you think it was a non-optimal idea (too much of an omnibus to do any space-task as good as other platforms might) and good money sent after bad, it would have fulfilled more dreams along the way.

[Madman198237]

The Space Shuttle is a really unfortunate story. It is a categorically unsuitable vehicle for every purpose, bar one, and that one being "looking really cool and iconic". It is far too dangerous for manned missions, yet it has no capability to be run without humans onboard. It hauled three of the most amazing engines ever constructed around in space....as dead weight, because it carries no fuel for them on its own. Its thermal protection system had no backup, and the most minor damage could destroy the entire vehicle. Its goal of rapid reuse slipped so far that it was only barely refurbishable by any reasonable metric. It could not escape should anything go wrong, because the SRBs are far too dangerous. The Loss-Of-Crew Metric (a fraction representing how often the crew would be lost in the event of a failure of a certain danger or above) was 1/12, ten times worse than the original (And already higher than what NASA wanted for human-rated vehicles) LOC of 1/120 or so.


I agree that there are definite benefits to a physical place that needs to be maintained, though they're almost exclusively non-material benefits and thus harder to justify before you've got it started. Also, I believe it makes more sense to produce a manned outpost on the surface of the Moon for your "well, we've already built [thing], can't stop now" effect. Other consumables lack the benefit of being produced in-situ, though maybe if you're running an amazing number of large missions through a lunar outpost then yeah, maybe other consumables being shipped separately to the Moon via more efficient (and slower) propulsion methods using an established framework might just be viable.

[Bralbaard]

 
Anyhow, today will be the first launch attempt for launcherone, from a converted 747. Plane is expected to take of at 16:30 UTC, with the launch window opening half an hour later.

Launch scrubbed for today.

The attempt was moved to today, but the rocket failed shortly after it was dropped from the plane.
Radar images from the debris cloud: https://twitter.com/wxmeddler/status/1265022819458580480?s=21
Luckily the plane and crew are fine.

[McTraveller]

A nice "learning experience" day for SpaceX today. 

Rockets are still unforgiving...

[Madman198237]

A nice "learning experience" day for SpaceX today. 

Rockets are still unforgiving...

What exactly are you talking about?

[McTraveller]

https://www.youtube.com/watch?v=7YaFsUWgN3s&feature=youtu.be

Starship SN4 had an "anomaly" after static fire.

It's an interesting stream - a mix of technical detail plus a surprising amount of - casual? - banter.  A little unprofessional at times, but interesting.

[Starver]

(@ninja(#1), I had to search for the news, it hadn't crossed my usual newsfeeds - the non-Dragon prototype, that looks more like a Dan Dare/Flash Gordon craft than the Dragon one, apparently exploded on live-streaming - as ninja#2 has just linked to, I think.)

Last time I heard mention of this craft, ISTR it being mentioned that they'd be testing this 'alpha' version of the hardware to destruction. I take it that wasn't the plan today, though?

Fingers crossed for Hurley and Behnken (sp?), though. It's a more mature and more tested system, but probably not what they want to see the day before the next attempt to loft them up.

[Madman198237]

Darn, the one time Everyday Astronaut isn't covering it. I was wondering how something happened that didn't pop up immediately in my YouTube feed

They must've filled the tanks almost completely, given the size of that fireball. I don't believe they were planning on blowing this one up, no. It was supposed to take the 150 meter hop, hopefully SN5 is going to be able to take its place here soon.

[Iduno]

Spoiler (click to show/hide)

[Kagus]

--snip--

I giggled.

[Starver]

So, because we aint going to be in the EU, the UK is now looking to make it's own satellite system, rather than relying on being in the Galileo club as a locally-controlled backup to GPS (and GLONASS, and now BeiDou), and all at at a cost of £2.5Billion (20% from the UK government, who have no better things to splash the cash on, obviously, given the guaranteed Brexit dividend and absolutely no health emergencies at the moment).

It's going to be called OneWeb, apparently, but that either sounds rather pathetic or Evil Overlord speak for a Planetary Subjugation Project launched under the guise of something far more innocent and philanthropic. And Elon/Jeff have already bagged stakes in the latter, in the general field of orbital domination, with local lad Branson who is part of OneWeb with his LauncherOne project still currently far behind.


So, I was wondering what it should be called. British 'counterpart' to Galileo, so something like Newton? Maybe not.. Actual less-diverse astronomers would be better, so Herschel? (German-born, both of them). Halley? (Lost your signal, just wait 76 years to reacquire...). Lovell? (Already honoured with a radio-telescope.) Recent names like Couper or Moore?  Branching out again, Hawking, Pillinger, May (living) or Cox (ditto)?


Actually, from that selection I'd go for May. Because it May happen. It could be over in a Flash if we find ourselves Under Pressure, but it would be Heaven For Everyone if The Miracle happens and we Break Free with our One Vision to be Princes Of The Universe  No, no, Don't Stop Me Now, though I know I'm Going Slightly Mad...


Of course, it's as likely to end up as Satellitey McSatelliteface, if left up to the British public to name it, but (mostly, but not exclusively, aimed at non-Brit forumites) what do you think fits our doubtless not-going-to-overrun-and/or-get-cancelled attempt to paint a Union Jack in the heavens with yet more satellite tracks?  Who[1] should we name the system after?

Asking for a Boris...

[1] Or what... BeiDou is named for the Big Dipper, an actual inspired choice given the asterism is used as a guide to find the Pole Star in actual feats of navigation by the stars. (n.b., "Polaris" is already in use, and it would be unfortunate to talk of "Britain's Polaris Satellites". Especially if that's their true secret...)


edit, while I'm correcting some trivial but bad phraseology: vvv Oh yes, I like that one... Good start!! vvv

[Il Palazzo]

Lucy in the Sky with Diamonds?

[martinuzz]

Those satellites will be so very autonomous that they will vote to leave the solar system.
Solexit would be a good name