Recent Posts

Pages: [1] 2 3 ... 10 Next
1
Missions To The Moon (HSF) / Re: 25 Good Reasons To Go To The Moon
« Last post by Lunadyne on Today at 06:04 PM »
I agree with Tulse in that an initial facility on the Moon would be unlikely to be a geriatric facility, however it has long been speculated that older folks moving to the Moon could get a new lease on life through a combination of the significantly lower gravity (aiding the heart, among other things) and a controlled environment.  Don't think that people aren't thinking about it.  I was interviewed a number of years ago by an Israeli newspaper about the Moon and the journalist mentioned that the reason they contacted me was because people were asking about the validity of retirement communities on the Moon.  My guess is that some fraudster was trying to sell rich Jews on investing in Lunar retirement homes.  I pointed out that it was unlikely to happen quickly, but is nevertheless an interesting concept worth exploring.  The most likely phrase to be uttered at Earthlight Acres is "I've fallen and I can't get...oh wait, yes I can get up.  Never mind!"  Plus the heightened levels of radiation are less of an issue for them.  Still an issue, but less of one.

Totally disagree about self-sufficiency.  There are few communities on Earth that are entirely self-sufficient; if they are they've likely stagnated technologically.  Trade brings benefits, and the Moon is going to be a much better trading partner than Mars.  If only from a capital investment perspective.  If I have a cargo vessel, I'll have a choice between the Moon run and the Mars Run.  The Moon is less than a week each way, while Mars is -at best- 6 months away each way.  Let's say 15 months round trip for this example.  In the time it takes to run a cargo load to Mars, I could have run 30+ trips to the Moon.  30 monetized cargo loads (plus deadheading lunar regolith, Moonshine and lunajuanaô) compared with one.  Throw in some asset depreciation accounting tricks and you're talking some real money.

An initial Mars colony is absolutely not going to be self-sufficient in anything even remotely resembling the near term.  There will absolutely be supply chains braving six plus months of collision risk to run supplies to the settlers.  To assume otherwise is imprudent.

Glad for the clarification on AG and Rx.  My first thought was Agriculture and Pharmaceuticals (derived from plants), which, when considered in the unique terroir of the the Moon, is actually kind of interesting.  Hmmm, the trace elements are going to allow for genetic expression you won't normally see here on Earth, which combined with epigenetics...hmmm.  I need to cogitate on this one a bit more.

ThereIWas3 pointed to several more recent articles on Lunar radio astronomy, from which I identified three scientists interviewed (plus team members).  I decided not to contact one of them because their webpage indicated a dual teaching focus in Physics & Astronomy and Women's Gender Studies.  Call me sexist, but I consider the latter to be an unserious 'science' when compared with Physics or Chemistry or even Biology.  Of the two I did contact one is semi-retired, the other active.  Both have been aware of the issue.  They don't really see the regular comms as being an issue because they're going to be at wavelengths well, well beyond where the radio telescopes will be looking.  I even noted to them that NASA is probably going to announce laser comms as the silver bullet solution to the issue. 

The issue is going to be the RFI generated by the equipment used to broadcast the comms.  That is probably going to have to be shielded in some way, and the active scientist indicated that they are about to start a study with LockMart on the topic.  This would likely be the case even if lasers were used.  Which brings me back to my initial question: Is the slight delta-V advantage of staging from EML-2 for MARS! as compared with EML-1 worth the likely opportunity cost of the quietest and potentially most significant radio telescope location in the Solar System?  Call me a sciencephile, but I've got to lean towards the telescopes; just stage from EML-1 for crying out loud.

On the jewelry angle - one idea I had (that I've probably already mentioned but will do so again) was for a pendant that would incorporate a circular thin section of a lunar breccia mounted above a polarized LED.  One or the other would rotate (probably the thin section), and as it did so the colors of the different minerals in the sample would be changing in a constant cycle.  It would definitely be an eye-catching piece, and is something different from the usual watch faces, cuff links, earrings, bracelets, &c. that are offered up as jewelry options for lunar rocks.

Which now has me wondering: What if you could assemble watch mechanisms in a vacuum environment?  It's unlikely to be able to be entirely sealed (wait, magnets?...) but would it allow the mechanism to function more efficiently over longer periods?

See, this is why cislunar space needs to be developed as an economic sphere.  Human creativity will make it an enriching part of our lives in innumerable ways that we cannot possibly imagine from our current perspective.  It's not until we're out there in a robust way, leveraging off of infrastructure that has been emplaced to enable such things, especially, primarily, can we just get it done already, transport of crews to orbit, and then throughout cislunar space, that the value of the efforts will start revealing themselves.
2
That's how good engineering works.  Going through it right now myself.  It's fine to have initial architecture choices and assumptions.  But if you find that you're not meeting cost or performance targets, rigidly holding on to dogma only ends in pain, tears and cancelled projects.

This is a rocket ship, it's design is driven by physics.  If the aero sim says 4 control surfaces, that's what it gets.  Physics doesn't care about what Musk tweeted out years ago.
I agree with you Norm as that's what I teach. By the same token I tell my wanna be engineers that if you are not "what iffing enough, people die..." That being said at some point you must "freeze" the design, begin building and flight testing..
3
This is a rocket ship, it's design is driven by physics.  If the aero sim says 4 control surfaces, that's what it gets.  Physics doesn't care about what Musk tweeted out years ago.

To be fair, he also said there were a lot of different paths they could have taken and had a viable solution, so it must have been some combo of factors that led to them liking this one over the others.  I imagine they had a few competing designs on the drawing board, it would be neat to see them all.
4
http://www.arianespace.com/press-release/kompsat-7-vega-c/
Quote
September 20, 2018
Arianespace to launch KOMPSAT-7 for the Korea Aerospace Research Institute (KARI) using a Vega C launch vehicle

Arianespace has been selected by the Korea Aerospace Research Institute to launch KOMPSAT-7. Stephane IsraŽl, Arianespace CEO, and Lim Cheol-Ho, President of the Korea Aerospace Research Institute (KARI), signed the KOMPSAT-7 launch contract today.

Using a Vega C launcher, the mission will be conducted from the Guiana Space Center in Kourou, French Guiana, from December 2021.
5
Blue Origin / Re: Blue Origin Space Capsule/Spacecraft
« Last post by Lar on Today at 05:55 PM »
Take general discussion of Blue (and of Blue vs SpaceX) to the general thread for Blue:
https://forum.nasaspaceflight.com/index.php?topic=43998

Not here.
6
Blue Origin / Re: Blue Origin General Discussion Thread 2
« Last post by Lar on Today at 05:52 PM »
In 2000 (or 2002) Musk was not as rich as Bezos. He still isn't. But he parlayed basically nothing into multiple multibillion dollar businesses.

In particular SpaceX has blown past Blue. Anyone who tries to claim differently is blowing smoke. I suspect the theoretical IPO value of SpaceX is 10x or more that of Blue.

Blue is a hobby. SpaceX is Musk's lifework.

When you evaluate it as a hobby, it's not done too bad. But aside from a few experiments (and I'm not even sure they were allowed to charge for that) and some deposits, zero revenue.

I stand by my earlier comments in particular the patent trolling part. I wish them well and I think it would be awesome if they actually turned into a non powerpoint competitor that was launching payloads for actual pay. So far, not so much.

As for who benefited from what contracts? Luck is 90% preparation and 10%  being ready to move when the chance appears. Blue could have been the big winner here and gotten contracts. But it's a hobby.
7
Space Science Coverage / Re: Proposed Europa Missions
« Last post by Star One on Today at 05:50 PM »
How did this topic morph into a discussion of the Federalist Papers? With a side order of snark in both directions?

I am glad it morphed back. Let's try to keep it that way, thanks.

It felt like it had become more of a space policy thread than anything else of late.
8
SpaceX BFR - Earth to Deep Space / Re: BFS Engineering Thread
« Last post by Lar on Today at 05:44 PM »
Lastly, you would lose the advantage of using the BFB to transfer prop up to the BFS, so you'd need a taller transporter/erector, (but I'm assuming you'd need that anyway to get the passengers onboard).

There was never any option to transfer fuel up from BFB to BFS.

All the mechanical forces go against it.

In flight? Agree.

But ISTR conops has the BFB fueled from a TSM at the bottom, (ala F9 S1) and the BFS fueled from a connection to the BFB. (unlike F9 S2 which uses umbilicals from the TE) Those would be used in tail to tail on orbit BFS to BFS refueling.
9
I made no assumptions other than that they were speaking standard English, and not some code where words don't represent their dictionary definitions. Their statement was the embodiment of the fallacy I referenced. I have explained repeatedly why that is the case, but you seem to continue ignoring the words I am saying.

In his most recent post spupeng7 changed what he said to something completely different, which avoids the fallacy, but which would make the make the original question pointless, because the relevant theories already meet the looser criteria he stated.

This is getting really confusing because how can you claim you made no assumption when your OP was couched in terms of an assumption, and yes I have read what you posted several times?
It really sounds like you are responding to something unrelated to my posts. Again, there is no assumption in my original post. I did use the word "sounds like" to soften the statement, mostly so that spupeng7 could rephrase, which he did, and in a way that negates any relevant meaning in the original question.

Rather than stating that you have read my posts, you could instead demonstrate some comprehension of them by making a post that actually addresses the content.

(For example, you could state an assumption I made rather than blindly accusing me of making assumptions, or you could actually make a comment related to the specific fallacy I mentioned.)

I have repeatedly made comments as to what you said but for some reason you donít seem able to grasp this and just keep accusing me of not addressing your content. Maybe if I said I am not so much interested in what you said but the way you said it would be clearer. Itís the tone of your post I have an issue with really, surely that must be clear by now?

This whole issue has taken up far too much time on this thread because we keep seeming to be talking past each other.
10

So obviously these large moving fins is a massive design change.  The two previous iterations of ITS/BFR did not have moving aero bits, and they showed re-entry landing scenarios with those vehicles.  So the question is, what happened between then and now that caused them to so completely lose confidence in their prior design that they decided to add not 1, not 2, but 4 moving control surfaces?  That must have been an interesting meeting...

The 2017 version of BFS did have "moving aero bits." That's why SpaceX added the "delta wing" thing. The moving bits were mounted on the back of the wing.

2016 BFS: "We don't need aerodynamic control surfaces."

2017 BFS: "Looks like we need some aerodynamic control surfaces."

2018 BFS: "Wow, we need a lot of aerodynamic control surfaces."
If you think of those three points in the more formal "gov" design review points:

2016 IAC - Concept presentation - Shows what technologies needed and determines if possible, probable timelines/schedules, and possible costs.

2017 IAC - PDR (preliminary design review) - more detail on hardware design, identification of actual requirements of all hardware needed, more detail on schedules, and revision of costs models.

2018 Reveal - CDR (critical design review) - detailed hardware designs for build to specs, all hardware has fairly well defined designs, some hardware in production, most hardware has already gone through prototyping, fairly well defined schedules with high likelihood of achieving, and costs well defined with high likelihood of being correct

If you compare to SLS program the dates would be 2012 Concpet, 2013 PDR, and 2014 CDR. SLS events were in actuality at a much slower rate 2012, 2014, 2016. So expect this program to be generally taking half the development time from concept to first flight test.
SLS 2012 to 2020 = 8 years.
BFR 2016 to 2020 = 4 years.

Costs
SLS -> >$24B (2012 - 2020)   - Total for full development from Constellation used parts thru 2025 estimated $60B
BFR -> <$2B (2016 -2020)      - Total for full development from previously designed prototyping efforts such as engine development and tank technologies development thru full commercial operational status 2023 estimated at $5B.

Added:
The costs ratio 12X also seems to hold up for the incremental costs of new vehilces:

SLS build rate .5/year at $2.5 per flight
BFR build rate initially 1/yr in a tent to 6/yr inside the final manufacturing facility building at $200M per flight

The key issues here is that SpaceX can afford to loose vehicles in an aggressive test program NASA cannot. BFR is fully reusable so if SpaceX successfully recovers a vehicle then the costs per test drops to a few $10s millions but the SLS is not reusable at all. This increases SpaceX's affordability for a aggressive testing schedule. Once SpaceX can reliably recover vehicles the test program will greatly accelerate since it will not need new build vehicles to do tests.
Pages: [1] 2 3 ... 10 Next