14 thoughts on “NASA’s “Inability” To Do Space Assembly”

1. Regarding lunar mission architectures and LEO refueling.

   I think there is a sweet spot to launch vehicle sizing.

   Larger launch vehicles are more operationally efficient, up to a point. Once you get up to something of about 25t payload to LEO, you’ve reached takeoff and you can get to the moon pretty easily. Which is a reason why I keep my eye on China, because of the Chinese Long March 5.

   Now if you keep increasing vehicle size (beyond the minimum 25t to LEO payload), eventually its size gets in its own way as is obvious with the SLS program. But what is the point of diminishing returns vs size?

   One way to exploit larger vehicle size, is if you could land the 1st stage for reuse and still manage that 25t payload to LEO. And we have that vehicle today with the Falcon Heavy which can do better than 25t to LEO and still recover all the lower stages for reuse.

   1. New Glenn will be an interesting test of the limits of size. Larger than Falcon Heavy yet smaller than SLS.

      If Blue Orion pulls it off, and does it soon, that would be fantastic. 45t to LEO with 1st stage reuse could really accelerate a lunar program.

      If New Glenn flew in fully expendable mode, what would be its payload to LEO?

      1. If New Glenn flew in fully expendable mode, what would be its payload to LEO?

         Really expensive.

      2. Ack! Blue Origin, not Blue Orion.

2. I’m sure I once calculate what a Falcon Heavy might do with four side boosters instead of two, and even what would happen if you used an array of nine first stages.

   *does some simple additive math that doesn’t try any fancy staging or fuel transfer*

   5 cores should lift 5/3rds as much as 3, and 9 cores should lift three times as much. Assuming booster recovery, the borderline obese 5 core would put 95 tonnes into LEO (210,000 lbs), the same as SLS Block 1. A 9 core variant would put up 171 tonnes (378,000 lbs), which is 30% more than SLS block 2.

   The Falcon 9H is already flying as is, and they can already stick the landings, so it’s probably not a big leap except in payload to orbit.

   But I don’t think SpaceX would have an interest in it because it would just be an alternative to their BFR, and a poke directly in NASA’s eye. There might be a point where NASA is interested, though, especially if the $90 million Falcon Heavy launch price scaled up linearly to $150 million for the 5 core and $270 million for the nine core, but that would require a financial rethink on the Congressional side.

   1. What payload would need a launcher that big? It would have to be something that must be launched in one piece. The biggest payloads I’ve seen proposed have been the 50000 lb BA 3300 and the Nautilus-X core module.

      1. Well, I’m not sure what payloads other than Orion on the 5 core version, which would make SLS Block 1 redundant. The 9 core would just be to tell NASA “Whatever you were thinking you needed to build that thing for can fly vastly cheaper on this slapped-together Falcon Obese.”

         As I recall, with a payload, the current Falcon 9 can launch itself into orbit as an SSTO. Such a stage would be kind of useful for building a spinning barbell to study partial-G, and for that the longer the better.

         If a Falcon Heavy was launched without a payload, how long could they make the center-core section to achieve something similar, with a docking port at the center of mass (on orbit) and perhaps some outfitted living spaces on the end opposite the engine?

3. NASA’s own SLS-based Evolvable Mars requires multiple rendezvous events in lunar orbit. How ironic.

4. I’ve long thought that politicians should value what an expanding industry could do for their state as opposed to a stagnant government agency but how to persuade them? Persuading the general public that SLS/Orion is the wrong route to take is easy and it doesn’t even require sensationalism or lying. There are a lot of people whose interests didn’t lead to being a space nerd but that doesn’t mean they are bumbling idiots, like some of the twitter responses say.

   I am not certain there is a breaking point coming. I thought the domestic crew launch gap would draw attention but it didn’t, not even now that it is almost over! I think it is just up to people like Musk to keep plugging along and doing what they can with and without government help/interference. It doesn’t look like congress will change until alternatives exist or get snookered into supporting a separate development track along side SLS/Orion/Gateway.

   Everything SLS is wanted to do requires docking. Why can’t Orion dock with an upper stage, does it have something to do with how it needs to be oriented?

   I feel bad for Dr Metzger. Didn’t he have a lunar rover that was cancelled? I hope that he, and others, will be able to take advantage of the lunar path that doesn’t rely on SLS and that this dual track isn’t sabotaged. We really need a lot of prospecting missions to prepare for SH/S.

5. Isn’t mating two payloads something we already knew how to do in both Earth orbit and Lunar orbit before the ISS? That’s as hard as getting to skylab or the Apollo 11 astronauts getting back to the Command Module.

   1. I’d think that everyone was more worried about getting the Apollo 11 astronauts back to the lunar module.

6. The NASA position has been disgusting.
   (1) We have a glorious future ahead of us in space!
   (2) Oh no, space assembly! (wets panties)

   How do you get a government agency out this sort of situation? You let it (and its political hack supporters) know in no uncertain terms that if it continues to be this way, if achievement via risk continues to be someone else’s job, it will die. Nothing concentrates the bureaucratic mind like the looming loss of their bureau. Alas, the predatory Proxmires and Mondales, who served that sort of function in the past, are not to be found now.

   1. How do you get a government agency out of this sort of situation?
      By placing its budget authority under another agency either directly or by breaking it up and doing so piecemeal. This seems to be the fate of NASA. Question is who’ll bid for what’s left at the various centers? Some centers might have interesting gear to sell, others not so much.

      1. This isn’t NASA’s fault; it’s Congress’s.

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