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Posted by: jabe Jan 4 2007, 02:47 AM

http://public.blueorigin.com/index.html update..
go Bezos go
BTW hate the web page but neat videos.. From http://www.spaceref.com/news/viewnews.html?id=1184 resource

Posted by: helvick Jan 4 2007, 09:42 AM

I was always a fan of the DC-X concept so this really warms the cockles of my heart. I worry though that the ultra coolness factor of a VTOL rocket is clouding practicality somewhat - I thought that the better\more informed opinion is that SSTO is too inefficient using current chemical rocket engines. I'd welcome some informed opinion to the contrary though.

Posted by: djellison Jan 4 2007, 10:04 AM

Well - consider the Atlas-Mercury flights. That was very very nearly SSTO

And that was a long time ago.

Doug

Posted by: tty Jan 4 2007, 11:16 AM

The first stage of Titan I had genuine SSTO capability back in 1960, though with a negligible payload. With modern structural materials building a throwaway SSTO would be fairly simple. What is difficult is making a reusable one.

tty

Posted by: edstrick Jan 4 2007, 12:53 PM

With adequate heat shielding, a vehicle derived from the current shell design for this test vehicle could make a very nice reusable orbital vehicle when put on top of a reusable DC-X style first stage.

One of the fundamental advantages of a VTVL vehicle <vertical take off vertical landing> is you can have a structurally efficient vehicle, structually efficient tanks (unlike the horrific X33 from Lockmart) minimal landing leg mass, no wings, use your flight rocket engines at very low thrust and only carry a little extra fuel for landing.. and you can land (as DC-X did) on unimproved reasonably flat terrain.

Posted by: climber Jan 4 2007, 08:19 PM

The goal here is "only" to get to 100 km altitude and back... and I think they'll be able to make it.
When you and me will be able (I mean financialy) to get a ride on one of these commercial vehicules, what will you prefer, feeling to go in a rocket or in an airplane? I guess Blue Origins looks more like a Space vehicule than SS1 but if I'm offered a ride on SS1, I'll go tomorrow

Posted by: Bob Shaw Jan 4 2007, 08:27 PM

Back in the 1960s there were a number of paper studies by Philip Bono at Douglas Aircraft Company, Inc looking at future launchers. Notable was SASSTO, an S-!VB derived single stage to orbit design. SASSTO had a payload capability of 3,629kg to a 185km orbit. Many excellent colour paintings of this and other projects were included in the 1974 'Frontiers of Space' book he co-authored with BIS stalwart Kenneth Gatland.

http://www.astronautix.com/lvs/sassto.htm

Wings won in the first serious stab at RLV technology, but the economics of VTVL remain attractive. Bono's beloved plug-nozzle rocket engine design has still not been flight tested on a large scale, though the X33 and VentureStar would have used such propulsion.


Bob Shaw

Posted by: nprev Jan 5 2007, 01:36 AM

As a side note, this test is getting a lot of media attention...it's been reported on CNN, and right now it's the top sci/tech hit on Google News. As jabe said, go, Bezos, go!

Posted by: edstrick Jan 5 2007, 09:50 AM

X33 was a good idea to follow up the DC-X with, but a lot of space activists think NASA picked "the wrong horse" for bad internal and political reasons, then badly mismanaged the program. The "Space Access Society" had a long series of Space Access Updates during the sad course of X-33 and was pretty consistent in pointing out things NASA was doing wrong, explaining why, and predicting what they were going to blow next. I'd ***REALLY*** like to see a post mortem on the program, both technical and political/bureaucratic.

I'd like, for example to see a final predict based on test stand results of the flight weight and specific impulse of the linear aerospike engine vs a bell-nozzle design with the same turbopumps and related hardware.

Posted by: nprev Jan 6 2007, 12:52 AM

With respect to Blue Origin, a friend of mine & I were speculating on what uses other than tourism a reuseable "rapid-turn" suborbital capability might have. We thought about a Hohmann-style rendezvous with a vehicle in LEO, and from our calculations you could get about 90 seconds of proximity (<1 km) to an orbiter with relative (although variable, depending on specific times) velocities of just a few meters per second during the apogee (provided inclinations, etc. were matched). This was based on a notional 200 km ASL orbit for the target vehicle.

What do the experts here think? Could something very like Blue be used to inexpensively resupply LEO space stations if a cargo capsule jettisoned at apogee had its own trim motor to increase "hang time" near such stations (or execute a rapid hard rendezvous)?

Posted by: Bob Shaw Jan 6 2007, 01:32 AM

Sorry, no. There's much more than altitude involved in being in orbit. You'd simply destroy the target vehicle with a 25,000 KPH collision!


Bob Shaw

Posted by: nprev Jan 6 2007, 02:58 AM

Wellll....I'm not much of an orbitsmith yet, Bob (still learning), but my buddy is an active-duty Air Force orbital analyst, and the trajectory he plotted gave a pretty good solution as described with minimal relative velocity.

Not saying here that he couldn't have been flat wrong (in the USAF you don't become infallable till you make Brigadier General or Chief Master Sergeant , and I was frankly skeptical from the beginning of our discussion), but we'll re-crunch the numbers sometime next week & I'll post the results.

Posted by: remcook Jan 6 2007, 11:55 AM

if you do a Hohmann-style rendezvous, you mean that you get there at apogee? Then your speed will be much smaller than a LEO station/satellite. In order to rendezvous you need to match speed as well, which basically means you need to be in LEO as well in this case, so it won't be suborbital anymore. You could drop something which has its own engines to get to LEO of course, but I think that won't be a very efficient way of getting stuff to LEO.

Posted by: Bob Shaw Jan 6 2007, 01:50 PM

Absolutely!

Going straight up with a VTVL first stage, then ejecting an upper stage which blasts sideways until it's in orbit, could just just about be done. It might even be 'efficient' insofar as the first stage would return to it's launch site with no down-range infrastructure, but in energy terms it would be far from efficient (so much so that even for a large first stage the orbital payload might be of trivial size).

Bob Shaw

Posted by: nprev Jan 7 2007, 03:47 AM

Yeah (sigh), that's probably quite true; a useful payload in all likelihood cannot be delivered via this method. Again, I'll speak to him next week & we'll play with the numbers some more; he's considering this as a thesis topic. Thanks Bob & remcook for your valuable critical commentary!

Posted by: edstrick Jan 7 2007, 09:51 AM

I have wondered if a 2 stage double DC-X type might be able to launch from Texas and land the first stage in Florida, but I think that's decidedly too long a hop for even a long-throw first stage. I'd like to see some calculations. A DC-X type first stage could do a partially fueled reverse hop from a downrange landing site to get back to it's primary launch site.

Posted by: Bob Shaw Jan 7 2007, 01:48 PM

I think the word you're looking for is 'Kistler'!


Bob Shaw

Posted by: edstrick Jan 8 2007, 12:22 PM

The Kstler vehicles are being soft <parachute and airbag?> landed, but not as VTVL vehicles. I don't know good details on their design, especially first stage landing and second stage re-entry and landing, but I wish them success.

Posted by: djellison Jan 8 2007, 01:03 PM

With such high gravity to fight against, and a nice thick atmosphere that's screaming out for chutes, parafoils etc.... landing with rockets on Earth just doesn't make a lot of sense to me.

Doug

Posted by: AndyG Jan 8 2007, 02:55 PM

I agree.

Using one of the fresh envelope-backs I got for Christmas, I see that retro-rocket-landing an Apollo CM from the drogue release altitude and speed, for example, would require something like a beefed-up AJ10-137 engine (massing around 4000kg), 31 seconds' thrust (1450 kg of fuel and oxidiser), all crammed into a 5800 kg mass capsule (!!). Naturally the engine would have to poke through the heat shield, which additionally complicates matters.

Comparing that to the (original) 245kg parachutes-and-drogues-and-deployment package, it's an absolute no-brainer.

<long pause>

...though, in its favour <whispering> it would look rather Heinleinian.

Andy

Posted by: mcaplinger Jan 8 2007, 04:35 PM

If you're never going to use the vehicle again, absolutely.

The arguments for VTVL all revolve around reusability and rapid turnaround. See, for example, http://www.thespacereview.com/article/412/1

I'm agnostic on the topic; like most engineering, there is no clear best solution. It's very dependent on the mission profile and on the logistical/economic assumptions.

Posted by: climber Jan 8 2007, 07:48 PM

I agree but I also wonder if a Soyouz-like last seconds hard brake retro-rocket solution could be used. There's no need here to have a "smooth" hard-brake since there's nobody inside. Is they can get the retro rocket working in the good force vector and then inflate air bags so the stage doen't hit too hard, I bet it'll not be too much of an extra weight as compared to reusability. And it'll be an elegant solution.

Posted by: Bob Shaw Jan 8 2007, 10:22 PM

Or there's the scheme for the Energia boosters, which would have landed under parachutes on Rogallo Gemini-style outriggers (you know what I mean!) and with the final impact cushioned by solid rockets. That gear is what all the square lumps were on the side of the Energia boosters - sadly, of course, never to be used in anger. So a liquid fuel first-stage land recovery system for *big* vehicles has already been built (and the boosters continue to fly in the form of Tsyklon). I was told years ago by Gerry Webb (at that time he was very cosy with the ex-Soviet rocketeers) that the core stage could also be recovered, but I've never found any references to that elsewhere.

Bob Shaw

Posted by: mchan Jan 9 2007, 03:53 AM

Ahh, Zenit?

Posted by: Bob Shaw Jan 9 2007, 08:37 AM

Absolutely. My rocketry database hit a nadir!

Nil Points!


Bob Shaw

Posted by: Jim from NSF.com Jan 9 2007, 06:35 PM

Thesis? The idea shouldn't have even got past the back of the envelope, much less an idea for a thesis. Somebody's engineering education is severely lacking. If this is the type of people in AFSPACECOM, then our military space cadre is in worse shape than in the 90's (which was worse than any point in history)

This proposal is similar to the "transfer" in the movie "Mission to Mars", where the crew "jumped" from the "MTV" to the a vehicle in Mars orbit. Both are impossible

Posted by: nprev Jan 11 2007, 02:07 AM

Well, it actually was just a back-of-the envelope exercise, Jim; it wasn't submitted for consideration or anything like that. He's still fishing for a topic & hadn't heard of the Blue Origin project, so we spent about ten minutes talking about it.

Of course, anything's possible if enough energy is available (admittedly a purely academic assumption). Whether it's affordable, practical, or desirable, aye, there's the rub!

Posted by: edstrick Jan 11 2007, 12:21 PM

Landing an Apollo like capsule on rockets is -- of course -- an idiot idea, unless it's a final impact softening like Soyuz does. But for a VTVL vehicle, it's a different story. The vehicle has a much lower mass-per-square-meter of surface (lot of empty tankage), so atmosphere drag will be more effective in slowing it down. It's already got tanks, and rocket engines and vehicle structural support strength enough to be able to sit fuelly fueled for launch. All you need is landing legs, radar, throttleable engines, and fuel. Certainly, a parachute brake system could help. That boils down to design tradeoffs.