Blue Origins, update Options

[jabe]

Blue origins update..
go Bezos go
BTW hate the web page but neat videos.. From nasawatch resource

[helvick]

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.

[djellison]

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

And that was a long time ago.

Doug

[tty]

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

[edstrick]

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.

[climber]

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

[Bob Shaw]

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

[nprev]

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!

[edstrick]

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.

[nprev]

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)?

[Bob Shaw]

un-needed quote removed

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

[nprev]

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.

[remcook]

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.

[Bob Shaw]

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

[nprev]

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!