Quote from: vt_hokie on 12/14/2010 02:10 amQuote from: Lars_J on 12/14/2010 12:18 amVery interesting. I wonder what kind of lifting body they are planning - and if it is based on any previous work. It is HL-20-ish, or like the LM lifting body CEV concept, or something more minimal like the Russian Kliper concept? It will be interesting to see. Recall that Orbital had a conceptual design for a lifting body craft back in the OSP days, though I don't know far along into the design process they were.Very perceptive; the shape shown in our proposal is a "fifth-generation" one that started with X-34 (whose DNA, by the way, made it into X-37 by the way of Rockwell/Boeing who was our partner on "X-34A"), then proceeded to Kliper/HL-10/HL-20 derivatives, and culminated in the BLB shape shown in the above-mentioned OSP picture.During the 1997-2003 time period we burned thousands of CFD hours and hundreds of physical wind tunnel hours developing a useable shape. The main challenge was to acheive reasonable landing speeds (the topic warrants a discussion of its own) at sizes compatible with a 4 to 6 person crew (it is easier with smaller vehicles like X-37 because wing area scales as the square of size but weight more like the cube) AND with a reasonable internal fuselage volume.Particularily troublesome was the increase in base drag if you wanted the cylindrical fuselage shape to extend all the way to the back for volume and hatch locationpurposes (the current design, like BLB, has two hatches for a number of reasons, including crew emergency egress.)With large base drag you get a low approach and landing L/D which in turn has all sorts of nasty consequences. The BLB/5th gen trick was to shape the trailing edge of the delta (not straight, like X-37) wing and the blending of the wing root with the body in order to create interference between the wing airflow and the body airflow at approach and landing conditions that DECRESED the base drag. Not impossible, but very hard - we checked it in real wind tunnel testing.
Quote from: Lars_J on 12/14/2010 12:18 amVery interesting. I wonder what kind of lifting body they are planning - and if it is based on any previous work. It is HL-20-ish, or like the LM lifting body CEV concept, or something more minimal like the Russian Kliper concept? It will be interesting to see. Recall that Orbital had a conceptual design for a lifting body craft back in the OSP days, though I don't know far along into the design process they were.
Very interesting. I wonder what kind of lifting body they are planning - and if it is based on any previous work. It is HL-20-ish, or like the LM lifting body CEV concept, or something more minimal like the Russian Kliper concept?
Any ETA on a snazzy name for this vehicle?
Yah it needs a snazzy name as that seems very important to sell a concept.
Ho-GAN!!! He "noes nut-hing, NUT-HING!!!"
During the 1997-2003 time period we burned thousands of CFD hours and hundreds of physical wind tunnel hours developing a useable shape. The main challenge was to acheive reasonable landing speeds (the topic warrants a discussion of its own) at sizes compatible with a 4 to 6 person crew (it is easier with smaller vehicles like X-37 because wing area scales as the square of size but weight more like the cube) AND with a reasonable internal fuselage volume.Particularily troublesome was the increase in base drag if you wanted the cylindrical fuselage shape to extend all the way to the back for volume and hatch locationpurposes (the current design, like BLB, has two hatches for a number of reasons, including crew emergency egress.)With large base drag you get a low approach and landing L/D which in turn has all sorts of nasty consequences. The BLB/5th gen trick was to shape the trailing edge of the delta (not straight, like X-37) wing and the blending of the wing root with the body in order to create interference between the wing airflow and the body airflow at approach and landing conditions that DECRESED the base drag. Not impossible, but very hard - we checked it in real wind tunnel testing.
Quote from: antonioe on 12/15/2010 05:08 pmDuring the 1997-2003 time period we burned thousands of CFD hours and hundreds of physical wind tunnel hours developing a useable shape. The main challenge was to acheive reasonable landing speeds (the topic warrants a discussion of its own) at sizes compatible with a 4 to 6 person crew (it is easier with smaller vehicles like X-37 because wing area scales as the square of size but weight more like the cube) AND with a reasonable internal fuselage volume.Particularily troublesome was the increase in base drag if you wanted the cylindrical fuselage shape to extend all the way to the back for volume and hatch locationpurposes (the current design, like BLB, has two hatches for a number of reasons, including crew emergency egress.)With large base drag you get a low approach and landing L/D which in turn has all sorts of nasty consequences. The BLB/5th gen trick was to shape the trailing edge of the delta (not straight, like X-37) wing and the blending of the wing root with the body in order to create interference between the wing airflow and the body airflow at approach and landing conditions that DECRESED the base drag. Not impossible, but very hard - we checked it in real wind tunnel testing.How does Shuttle deal with this issue? It is even bigger than OSP and has a big blunt rear.
Quote from: zaitcev on 12/17/2010 02:15 amHow does Shuttle deal with this issue? It is even bigger than OSP and has a big blunt rear.Larger wings, hence higher subsonic L/D. The shuttle isn't a lifting-body.
How does Shuttle deal with this issue? It is even bigger than OSP and has a big blunt rear.
Mr. Frank Culbertson, Orbital Science’s Senior Vice President and former NASA astronaut stated: Virgin Galactic is clearly breaking new ground in the commercial space market, and we are now very excited to have them on our team. This partnership for marketing and supporting our innovative and affordable design carries a great deal of promise for achieving the kind of growth in commercial spaceflight that will help to make this a sustainable market in the future.”
Upon hearing this, Arnie Aldrich exclaimed indignantly "you mean, if we loose an APU, we loose the bird?"Before the presenter had a chance to answer, a voice from the back of the room - which to this day will remain anonymous - shouted, in reference to the subsonic L/D of the orbiter:"What do you mean "bird?" You must mean "brick"!"
Somewhere it was written that the SR-71, after suffering double engine unstart (before they worked out an effective automatic control system for the inlet cones), "glides about as well as a manhole cover".
How do you know it "integrates all of the service module functions into the reentry vehicle"? All we have seen is early CG renderings of a landed vehicle.
But even if it does include all of it - isn't that a good thing? It should improve re usability.
Quote from: Lars_J on 12/19/2010 09:02 pmHow do you know it "integrates all of the service module functions into the reentry vehicle"? All we have seen is early CG renderings of a landed vehicle.the attached image shows the artwork for the spacecraft in orbit, without any expendable service module. Say what you want to about the quality of the ISS model, one would expect an image of one's product to be as accurate about one's product to the fullest extent possible.