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Archive for the ‘NASA’ Category

NASA of the sixties reminds me of the Armadillo Aerospace of today.
Drop tests, I think an F-111 model and various parachute, parawing and Rogallo wing things.

Airbags, landing rockets, landing gears (Dyna-Soar like rig)

Thank you NASA CRgis for another video blog day, one of many more to come!

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From NASA Langley – they did wind tunnel tests on a model. Lots more pictures of various aerospace projects there too, some of them are quite weird. Thanks to Secret Projects forum for the info!

Rockwell X-33 wind tunnell model front view

Rockwell X-33 wind tunnell model side view

Naturally since Rockwell built the orbiter, this one looks like the orbiter too. With an SSME and RL-10:s (so Rand.org says) and cylindrical tanks, it would have been far lower risk than the Lockheed version that won.

In a sense, the “almost pure rocket” cone, the “flies a little better than a rock” lifting body and the “almost flies like a dangerous plane” winged vehicle are the three main paradigms to reusable vehicles.

Though, with SHARP (or like McD did with active cooling), your lifting body can be sharp edged and have vastly superior L/D compared to blunt ones.

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Rand Simberg talks about impedance matching. So I’d like to make a post of my comment there (I’ve always wondered why this obvious alternative gets mentioned so little…)

What to do when you arrive at Mars or Earth with your solar electric propelled vessel?

So, the problem with most low fuel demand velocity change schemes is that they only give slow accelerations. Low fuel high velocity change means solar or nuclear electric propulsion and aerocapture mainly.

High delta vee aerobraking is hard to do in one pass – it gets dangerous because of atmospheric variability and potentially other reasons.

Simple: detach a small capsule with the humans that goes directly to the surface (with only days of life support) and leave the untended craft to do multi-pass aerobraking. Hitting van Allen belts a few more times or taking a long time doesn’t matter that much with no humans onboard.

You could also potentially ultimately leave the long distance craft at some Lagrange point instead of LEO. (Cue some clever and complex maneuvers to save fuel – maneuvers that take long.)

Something similar could also be done when a long distance stack is assembled in LEO: send the humans there only after it’s through the belts. They can go with a smallish capsule again. Potentially at some Lagrange point, or in space without any fixed reference, just along the way. It could be dangerous though if the capsule doesn’t have much life support.

Many of these things have potential delta vee penalties as well as timing inflexibilities, but they could have enough other benefits that they should be considered.

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NASA Flight Controllers

Apollo 11 JSC KSC Flight Control, pre-launch

All these people had to get paid. Even when there wasn’t a launch. Well, to be exact: until the money was spent and there weren’t gonna be any more launches, which was a few years from this photo.

From the new NASA Flickr database.

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For the ISS. The shuttle would transfer unused hypergolics to the ISS propulsion module. ATV as well.

ISS Propulsion Module CAD

http://en.wikipedia.org/wiki/ISS_Propulsion_Module

It was canceled and instead Progress and ATV are used directly for most boosting. Nevertheless the technology could be useful in developing hypergolic propellant depots.

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He who controls the [Earth-Moon Lagrange points/Phobos/Deimos/Lunar North Pole], controls the solar system.

Why?

Because in space, it is not the tyranny of distance that sets the rules – it’s delta vee instead.

Since there’s no resistance, traveling large distances just takes longer, but doesn’t necessarily require more propellant. Unmanned craft can take this long trip time just fine. This is completely different from the implicit mental models of everyday life or historical exploration, travels and colonization. Even places that are far away in distance can be close in delta vee, and vice versa.

The Earth-Moon Lagrange (EML) points have really low energy trajectories to all the other places, including low Earth orbit (or Earth re-entry). They’re the crossroads. They’re probably not controllable though, like you can’t control low Earth orbit either, it’s just a figure of speech* to stress their significance.

For example, Phobos and Deimos have really low delta vee needs from EML2. And they have really low gravity. This means that it’s cheap to send stuff to them, but perhaps more importantly, it’s cheap to bring stuff from them. Since a lot of space faring is limited by mass that can be brought to locations, a low energy source of material is a real paradigm changer.

The Lunar north pole’s peaks of eternal light are much closer to Earth, but the Moon is so heavy that it takes quite a lot of propellant to descend to and ascend from the surface. The good constant sunlight is an asset though. The area is limited so this is the best incentive so far for a “race”, though I’m skeptical of that.

This post was written partly inspired by Paul Spudis’ and Clark Lindsey’s talking about the importance of the Moon as an enabler for other stuff – I am somewhat less certain. (On VASIMR and JIMO I can refer to Kirk Sorensen who has good reasons for skepticality – the power to mass ratio needed is huge and that’s the really hard part, yet it’s rarely talked about. Space reactors are much harder than Earth ones because of the cooling problem.)

We must dismiss analogies that do not work, since space is a different medium. We must use completely different planning than for exploration on land or the seas, because of the completely different role distance plays. And we must also plan on advancing from exploration ultimately to infrastructure, colonization and self sufficiency.

*: From Frank Herbert’s Dune of course.

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I do appreciate that the model is so different from Apollo that it takes time and thought to understand what it is about; I did not see it at first myself — but once I got past my preconceptions, I found the logic of this approach overwhelming. This is simply what exploration looks like in a world where the budget doesn’t double for a few years and then halve again. You build a piece at a time and as soon as you can start doing things with the pieces, you do so.

Jeff Greason about the Flexible Path, commenting on Rand Simberg’s superiorly excellent Popular Mechanics piece.

Rand Simberg in the article:

I would claim that in fact, this is the most visionary space policy that the nation has ever had, including Apollo. It finally, forthrightly declares a national goal of large numbers of humanity living off planet, with many of them going on excursions into the solar system, and it harnesses the vital element of private enterprise and competition to make it happen in a way that will drive costs down instead of up.

May I add that yours truly proposed something of a flexible path of his own in 2006, though only for launching.

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