[Mongoose]

Atlantis just reached wheel stop a few minutes ago.  Here's to over thirty years of fantastic service from the Shuttle fleet, and to the two that never made it back home.

Something struck me while watching the video of the final approach.  No other spacecraft has ever looked that graceful when returning to Earth.  Capsules plummet like a stone and then have to dangle from parachutes until they're unceremoniously dumped in an ocean or on a plain.  But the Shuttles were able to come in of their own accord, performing a great sweeping turn over the runway before performing a controlled landing.  Whatever the benefits of the new capsule systems that are in the works, they won't have that going for them.

[Thaeris]

Gorrammit, where's my SABRE engine!!???

[Nuke]

its likely gonna take a dozen years to fully develop it, then you got to build the skylon on top of that. though i think the engine, if successful, might be used on other designs. i can imagine some being bought for use on an american made spacecraft. sabre is far superior to anything weve ever tried to build. scram and aerospike engine suck in comparison, at least on paper. they cant be used during all phases of flight either. dragon will likely happen first.

[Thaeris]

That's indeed all and good - Dragon will be a critical asset in ensuring that the US can maintain manned space operations. Indeed, private industry should further distribute the technical knowledge base of spaceflight operations across the aerospace industry. This then will lower development and launch costs.

Scramjets aren't too much of a draw to me, but as I do more research, I have very high hopes for plug engines and aerospike engines. Merging an aerospike with a partial fixed bell might be a real winner with a system like SABRE if you can get a combination of good materials and a favorable logistics scenario. In other words, a high turnaround rate matched with economical operational costs. I see the annular aerospike engine with a replaceable ceramic exhaust cone as an ideal fixture on a future version of the SABRE.

[NGTM-1R]

I demand the immediate construction of the SuperOrion.

[Nuke]

That's indeed all and good - Dragon will be a critical asset in ensuring that the US can maintain manned space operations. Indeed, private industry should further distribute the technical knowledge base of spaceflight operations across the aerospace industry. This then will lower development and launch costs.

Scramjets aren't too much of a draw to me, but as I do more research, I have very high hopes for plug engines and aerospike engines. Merging an aerospike with a partial fixed bell might be a real winner with a system like SABRE if you can get a combination of good materials and a favorable logistics scenario. In other words, a high turnaround rate matched with economical operational costs. I see the annular aerospike engine with a replaceable ceramic exhaust cone as an ideal fixture on a future version of the SABRE.

i rather like the aerospike and plug engines that ive read about, sabre uses an expansion-deflection nozzle which is also capable of automatic compensation. im not entirely clear on which is the best one we have so far, but the reserch has been going on for decades. any atmospheric compensating nozzle should mesh well with the rest of the sabre design. you essentially want a nozzle that will be efficient at all altitudes. one of the reason you stage rockets (other than to get rid of dead weight) is because an effective nozzle at sea level will not be as effective at zero pressure and vise versa.

for an ssto design like skylon you need to have engines that work at all stages of flight. then it is only necessary to carry one set of engines instead of several. this makes the problem of dead weight a lesser concern, only empty tankage which in comparison to multiple sets of engines are fairly light. though skylon doesn't seem to require it it would be possible to use drop tanks for larger spacecraft/payloads.

[watsisname]

Atlantis re-entering the atmosphere, taken from ISS.  This was over the earth's nightside so you can also see the greenish bubble effect of airglow.  Very cool.

[Mongoose]

Yeah, my jaw dropped when I saw that shot.  The ISS apparently passed directly over Cape Canaveral about ten minutes before the landing, which seems appropriate.

[Luis Dias]

It almost seems as if they timed it!

[Nuke]

they did, space operations have to be timed perfectly to work.

[watsisname]

I think he means it seems they timed it so that the ISS would be able to view the re-entry.  Not sure if that's the case, but if not then it certainly is a nice coincidence.  Hell of a shot to to end the shuttle missions with.

[Luis Dias]

You guys must volume up your sarcasm detectors!

BTW, another article pointing out the sheer ludicrousness of the shuttle program:

How to Avoid Repeating the Debacle That Was the Space Shuttle

The most important thing to realize about the space shuttle program is that it is objectively a failure. The shuttle was billed as a reusable craft that could frequently, safely, and cheaply bring people and payloads to low Earth orbit. NASA originally said the shuttles could handle 65 launches per year; the most launches it actually did in a year was nine; over the life of the program, it averaged five per year. NASA predicted each shuttle launch would cost $50 million; they actually averaged $450 million. NASA administrators said the risk of catastrophic failure was around one in 100,000; NASA engineers put the number closer to one in a hundred; a more recent report from NASA said the risk on early flights was one in nine. The failure rate was two out of 135 in the tests that matter most.

It even includes FEYNMAN!

According to reports after the Challenger disaster, the ship exploded because of a faulty joint that included an O-ring hardened by especially cold conditions before launch. More importantly, this was far from an isolated problem, as illustrated by a report by Richard Feynman. Feynman slammed not only the O-ring error but the entire process of building and testing the shuttle, plus the management style and decision-making of NASA, for good measure. When he wrote, “Let us make recommendations to ensure that NASA officials deal in a world of reality,” and, “They must live in reality in comparing the costs and utility of the Shuttle to other methods of entering space,”

Finishes exactly where my feelings are:

So as we prepare to mothball the shuttles and send them off to their dotage at various museums, don’t be sad about the end of the program; instead think of where could have been now if we’d cancelled the thing 25 years ago. And make sure our future spaceships are based in and judged from this spot called reality.

http://discovermagazine.com/2011/jul-aug/22-how-to-avoid-repeating-debacle-of-space-shuttle