Comments on: Investing in a Spacefaring Future

By: Tim

Tim — Fri, 12 Dec 2008 05:55:04 +0000

Whoops, turns out that TPs thing I mentioned is actually because something used to make the ablative material is unavailable due to environmental restrictions, not because info on it has been lost. The source I originally heard that from made it seem like an information problem. Sorry about that.

By: Investing in a Spacefaring Future « The Four Part Land

Investing in a Spacefaring Future « The Four Part Land — Thu, 04 Dec 2008 17:29:51 +0000

[...] in a Spacefaring Future Investing in a Spacefaring Future is an interesting article based on the application of money, and where it could be spent. It is the [...]

By: Roderick Reilly

Roderick Reilly — Tue, 02 Dec 2008 23:22:12 +0000

Tim brings up an excellent point about what can be termed “Institutional Memory.”

“IM” if you will, is one of several Achilles Heels in NASA R&D efforts, especially when there are such huge time lags between new major programs. back in the 80’s I heard a lot of complaints from old-time rocket people about poor documentation, and encountered the problem with a vengeance when I was the Documentation Services Supervisor at the first iteration of what is now the ISS. With huge time lags combined with a lack of continuity, valuable personnel retire — and even die — before similar efforts are gain revived.

This lack of IM even, if inadvertantly, affects private efforts. It would appear, for instance, that in its first three (and abortive) launches of Falcon 1, SpaceX repeated mistakes and oversights that had been made by American rocket pioneers decades ago.

On a related note, a conflated view of space age history tends to imply that most early programs suffered high degrees of failure. Not necessarily. The image was distorted from early on by the misguided and misidirected Vanguard effort of the late 50’s. A number of venerable American launch vehicles were developed in an astonishingly short time and within budget back in the 50’s and 60’s, AND had succesful first launches.

By: Jonathan Goff

Jonathan Goff — Tue, 02 Dec 2008 07:31:11 +0000

Tim,
I agree that making sure that the gathered knowledge is preserved is very important. One of the best ways to preserve knowledge is by making sure it gets used. Putting effort into commercializing space technologies is one part of the challenge. Also, making sure that government programs implement the new technologies is also important. Sure, if there’s some technology we’re not going to be able to use for 30 years, that’s probably a bit early to spend a lot of money on. But a lot of the technologies that I’m talking about (prox ops, tugs, better orbital construction techniques, propellant depots and handling, high reliability aerobraking, etc) are things that should be useful on the nearer term. Especially if NASA can find ways to encourage their commercial adoption.

~Jon

By: Tim

Tim — Tue, 02 Dec 2008 05:16:18 +0000

Saving money for the future only works if you can get to that money later on. The same is true for the things you learn from R&D. For tech development to work, you need some way of recording, documenting, and storing the data -and more importantly, knowledge- you get from it. I suspect that archiving its past work is something NASA hasn’t been very good at. As I recall when VSE was announced there was trouble accessing old Saturn V documentation, and the folks working on the CEV haven’t been able to replicate the ablative TPS (?) used on Apollo.

By: Jonathan Goff

Jonathan Goff — Mon, 01 Dec 2008 14:26:34 +0000

Bill,
It’s true that you get fewer launch windows. Once we get to the point where biweekly launches aren’t doing it for us, we can always build more than one depot. Sure, if depots are tens of billions of dollars each, it could be a show stopper. But if they’re commercially operated and less expensive (which I think will be the case), if the demand ramps up, you just build two or three of them, and put them far enough out of phase so that you’re getting a launch opportunity from at least one of them every few days (you’re also more effectively using launch capacity, since you’ll get more launch opportunities per launch site per day).

~Jon

By: Bill White

Bill White — Mon, 01 Dec 2008 03:41:21 +0000

Here is an AIAA paper from 1964:

http://pdf.aiaa.org/jaPreview/AIAAJ/1964/PVJAPRE2339.pdf

It would seem that a vessel docked at a LEO propellant depot shall face significant launch window restrictions for travel to the Moon.

This is certainly not any sort of show stopper however PD based architecture proposals will need to address this issue.

By: Bill White

Bill White — Mon, 01 Dec 2008 02:41:10 +0000

Elsewhere I read that if a vessel is already in a LEO parking orbit (docked to a propellant depot for example) then launch windows that permit an outbound lunar trajectory only occur once every two weeks. Approximately.

On the other hand, when launching from the Earth’s surface the Earth’s rotation will place the launch pad on the correct plane for a lunar destination trajectory at least once per day.

Can anyone confirm or refute this as a matter of orbital mechanics?

If true, wouldn’t that add significant operational restrictions on to any lunar architecture that incorporated a LEO fuel depot as part of the critical path?

By: Brock

Brock — Mon, 01 Dec 2008 00:40:31 +0000

It seems to me that if you can’t afford project planning, you’ve got no business starting the project in the first place. Not just in the NASA context either.

By: Jonathan Goff

Jonathan Goff — Sun, 30 Nov 2008 02:06:52 +0000

Kevin,
Oh, I agree that NASA has and still does fund some technology development. It’s just that I think it should be a more sizeable chunk of the overall NASA budget. I agree also that it’s human nature to raid savings/future-investments to pay for current pleasure. That’s a large part of why the economy is now in the tank. But just because it’s human nature, doesn’t mean it should be encouraged or even tolerated.

~Jon