Recent Posts

Pages: [1] 2 3 ... 10 Next
1
The suggestion I would make to your thoughts Ron would be to change of the word "need" to "want"... As do we really "want" human missions to the Moon or Mars..? It's the lack of "want" on the public's side and you can't make someone "want" something unless you're Madison Avenue...
2
I think the practicalities of painting the name on the deck played a role too.  The ships are *named for* ships in the culture series, they are not supposed to *be* the ships in the culture series. "A Shortfall of Gravitas" is a perfectly intelligible tribute to the Culture ship "Experiencing A Significant Gravitas Shortfall"...and is much more likely to read well when painted on deck, etc.

ASoG is also much more pronouncible than EaSGS, if you're going to go that way.  And they both work equally well as a meta comment on the "seriousness" of SpaceX endeavors.
4
It should be possible to accelerate fine regolith to a few 1000m/s somehow. E.g. a bucket full of regolith driven by a linear electric motor. Why wouldn't it work? It would probably benefit from being very long, but remember that we are talking about "settlement scale" here, not small space probes like dawn.
If we're talking about "settlement scale" then it seems like electric propulsion can consider beamed power to remove some of the sun's constraints. A laser can provide more than the sun's 1.4 kw/m2 at 1 AU, and it can provide it at a specific wavelength rather than black body, which is potentially much more efficient for photovoltaics provided the band gap and wavelength are well optimized for each other. We've seen this demonstrated with eg lasermotive.

If this approach could, say, temporarily turn a 5 MW solar array into a 500 MW solar array, not only is that sufficient for high power ion propulsion, but it might even be easier to switch to thermal. The thrust would potentially be high enough for an oberth burn.

Earth departure could be handled by infrastructure near or perhaps even on Earth, and we would be able to use that to send solar laser arrays anywhere else we wanted to do lots of round trips like Mars or Ceres.

I don't think this is mutually exclusive with BFR/BFS, it probably enabled by BFS because it's the kind of infrastructure nobody would invest in without demand for space transportation that's created by BFS and others like New Glenn. Getting to orbit is still hard, there's still limits, and increasing ISP still increases the possible missions. Even if BFS offers quick transits to Mars inside transfer windows it's not like better ISP wouldn't offer improvements like quick transits without waiting for a window.
5
HMXHMX, would you say this lot are serious and plausible then, according to your knowledge and experience?

My issue with this approach is that, however you do it, the g-forces involved are going to be order(s) of magnitude higher than in a conventional launch (someone correct me if I'm wrong). This would require specific builds for anyone planning to launch with them. For instance, my assumption would be that a conventional cubesat wouldn't work. This creates a chicked-and-egg problem. Why would anybody change they design and build practices for a specific launcher like this, and on the other hand, why would this launcher be build if there aren't any suitable payloads going for it?

Two ways to sort this problem that I see is that either they offer launches so much cheaper than any other alternative that people are willing to custom build for them, or that the launch isn't anywhere near as high-g as I'm thinking it'll be. Either seems unlikely to me, but lets hope I'm proven wrong.

I would say they are as serious as any of the other one or two dozen small launch vehicle start-ups that have raised >$5m seed funding.  I've not spent any time analyzing their approach, so I can't speak to plausibility.  Seriousness alone is no measure of likelihood of success, of course, either technically or in the marketplace.  I know that from personal experience.  ;)
6
https://www.nasaspaceflight.com/2018/02/spacexs-mr-steven-fsv-fairing-catcher/

- By Micheal Baylor

It includes an interview with Brian Herbert, a Senior Dynamic Positioning Officer who interacted with Mr. Steven before SpaceX leased her. Mr. Steven is a very capable ship!
7
SpaceX Reusable Rockets Section / Re: Fairing reuse
« Last post by Chris Bergin on Today at 06:05 PM »
FEATURE ARTICLE: SpaceX's Mr. Steven, the FSV fairing catcher -

https://www.nasaspaceflight.com/2018/02/spacexs-mr-steven-fsv-fairing-catcher/

- By Micheal Baylor

It includes an interview with Brian Herbert, a Senior Dynamic Positioning Officer who interacted with Mr. Steven before SpaceX leased her. Mr. Steven is a very capable ship!
8
Someone commented that A Shortfall of Gravitas isn't an 'official' Culture ship name. This seems to be covered by Iain M. Banks's Q&A in 2000:

https://www.theguardian.com/books/2000/sep/11/iainbanks-science-fiction
Quote
MattB242
Somebody once told me that the ships 'Very Little Gravitas Indeed' and 'Zero Gravitas' were a response to a scathing review. Is this true?

IainMBanks
Yes. But it was a scathing review of Culture ship-naming policy delivered by another Involved civilisation. They suggested that such enormously powerful and intellectually refined entities ought to have names with a little more gravitas, to reflect their near-god-like status; the immediate and sustained reaction of one of the Culture's ship manufacturies was to name all its subsequent vessels things like: Stood Far Back When The Gravitas Was Handed Out; Gravitas, What Gravitas?; Gravitas... Gravitas... No, Don't Help Me, I'll Get It In A Moment; Gravitas Free Zone; Low Gravitas Warning Signal, etc etc (including the Zen-like Absolutely No You-No-What). I am so sad I have a separate list of the Gravitas ships at home. It currently runs to about 20, I think.
9
Thought I remembered this page and how it looked like this video.

Observe the wave actions through the neck of the bottle, it acts like impedance matching tapered section in the video you linked.

Vibrational Behavior of an Empty Beer Bottle
http://www.acs.psu.edu/drussell/Demos/BeerBottle/beerbottle.html

Shell
At 14:05, there's an almost perfect representation of what a mechanical version of an EMdrive can be represented as, the big difference is, to be truly an accurate mechanical analogue, I think the length of the rods should become shorter along the length.


10
All sorts of claims of enhanced productivity have been made if the communications delays associated with Mars operation are eliminated, but nothing has been proved.
I beg to differ.
Lunokhod 2 had 'video' at 3.2 seconds per frame and a driving speed of around 1mph, and managed 40km in four months.

100m/day - while constrained by day, and presumably line of sight to some soviet site.

Opportunity and Curiosity did about a tenth of this. (while not constrained by earth rotation)

This is with comms that at best I can understand amounts to 21s/frame for high resolution planning, and 3.2s/frame while driving.

For any plausible rover design today, there would be essentially live video, and most of the driving could be very, very easy in comparison to what lunakhod did, even retaining its 'high speed' of 2km/h

A relay satellite over next to DSCOVR means you can drive (or operate) most of the time the sun is up, and get even at 2km/h for the easy bits, thousands of kilometers in a six month mission.

Teleoperation with lunar delays is very, very easy at 2km/h, for simple 'drive there, put that instrument there' type tasks.
It's lots harder if you want to juggle.
Pages: [1] 2 3 ... 10 Next