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13 years ago @ The Space Review: essa... - The Space Review: Shou... · 0 replies · +2 points
In 1964, work in the US suggested 30% payload mass fraction for airbreathing SSTO aerospaceplanes that collect their entire lox requirements in high speed flight while ascending to orbit. This contention was independently verified and published in India since 1989, with emergence of the "Hyperplane" concept. India's concept studies on SSP centre on this type of "aerobic" reusable launch vehicle.
High temperature light weight front-end heat exchangers for flight to Mach 7 is a critical technology. Japan reported development of such HEX tubes in 1987 or '88, tested to Mach 9. Materials for uncooled scramjet combustors is another. NASA reported studies in this area..
"Silo-mentalities" within and between nations are a severe constraint to progress. An integrated , cooperative, global approach to an SSP-RLV system-of-systems design and mission is inescapable.
14 years ago @ Change.gov - Space Solar Power (SSP... · 0 replies · +2 points
--- On Thu, 18/12/08, IntenseDebate Notifications <firstname.lastname@example.org> wrote:
14 years ago @ Change.gov - Space Solar Power (SSP... · 1 reply · +2 points
Unfortunately, this error in thinking in choice of flight regime for ACES persisted for several years until 1995 Reference Vandenkerchove J and Czysz P “ SSTO Performance Assessment with In-flight LOX Collection”, Acta Astronautica Volume 37, 1995, Pages 167-178, brought out the need for US to redirect work on lox collection to hypersonic speed regimes. This US paper referred to our work as well.
14 years ago @ Change.gov - Space Solar Power (SSP... · 2 replies · +2 points
14 years ago @ Change.gov - Space Solar Power (SSP... · 3 replies · +2 points
The authors bring out here that propulsive efficiency, dry weight, and thrust-to-drag ration dominate the trade-offs in aerospaceplane design. Their work clearly bring out that it is mathematically impossible to attain orbital velocity of 8 kms per sec directly in a single stage unless the propulsive efficiency exceeds 40%, thrust-to-drag ratio exceeds 3.0, and the dry weight at take-off exceeds 56% of take-off weight.
14 years ago @ Change.gov - Space Solar Power (SSP... · 2 replies · +3 points
6. Gopalaswami R et al “Spaceplanes with Aerobic Propulsion – Key to Low Cost Access to Space”, AIAA 2001-3699, 37th, AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, July 8-11, 2001. Payload in the neighborhood of 5 % of take-off weight placed in orbit with a 25-tonne aerospacevehicle carrying 56% liquid hydrogen and no lox at take-off
14 years ago @ Change.gov - Space Solar Power (SSP... · 3 replies · +3 points
2.Gopalaswami R et al “Concept Definition & Design of a Single Stage-to-Orbit-Vehicle Hyperplane” International Astronautical Federation Paper IAF-88-194 8-10 October 1988. Payload in the neighborhood of 15% of take-off weight placed in orbit with a 100-tonne aerospacevehicle carrying 56% liquid hydrogen and no lox at take-off
3.Balepin V Vand Tjurikov EV “Integrated Air Separation and Propulsion System for Aerospace Plane with Atmospheric Air Collection”, SAE Technical Series Paper 920974, SAE Aerospace Atlantic, Dayton, Ohio, April 7-10, 1992
4.Vandenkerchove J and Czysz P “ SSTO Performance Assessment with In-flight LOX Collection”, Acta Astronautica Volume 37, 1995, Pages 167-178,
14 years ago @ Change.gov - Space Solar Power (SSP... · 4 replies · +2 points
I am the person you would have (understandably) forgotten who tried to speak to you, but did not succeed in capturing your attention, even when I came up to you immediately after you presented your paper at Salt Lake City for the 37th, AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, July 8-11, 2001,
“AIAA-2001-3702 Air Collection and Enrichment System (ACES) for advanced 2nd generation RLV's“
You may now recall that I had also just presented a paper, AIAA 2001-3699, “Spaceplanes with Aerobic Propulsion – Key to Low Cost Access to Space”.
Here are the references you seek on high payload efficiency aerospacevehicles:
14 years ago @ Change.gov - Space Solar Power (SSP... · 0 replies · +7 points
Several attempts were made in this direction in 1990’s. These initiatives, including a private sector attempt to set up an US-Japan-India venture, did not take-off because of restrictions imposed by the US Government on transfer of information and technology in dual-use areas. I heard that even Burt Rutan faced this problem even when Virgin Atlantic a British company was to be their Spaceship II venture as a commercial partner.
Many countries now reflect US restrictions on dual-use technology. So it’s unlikely any international SSP venture can happen unless the proposed UN sponsored Outer Space Treaty to outlaw space weapons is put in place with provision for such internationally safeguarded ventures. Partner countries can then make laws to operate within this safeguarded framework.
14 years ago @ Change.gov - Space Solar Power (SSP... · 7 replies · +4 points
a)Propulsion systems that increased the mission average fuel efficiency, and
b)For increasing the vehicle’s mission average mass ratio by extracting as much as 65% of vehicle mass while in atmospheric flight.
Please read that part as :
(a)Propulsion systems that substantially increased the mission average fuel efficiency, and
(b) By extracting up to 65% of vehicle mass while in atmospheric flight the overall mission average mission mass ratio is altered.
Put together, the product of (a) x natural logarithm of (b) the orbital velocity. This is higher and such aerospacevehicles deliver payload efficiency 15% to 30% according to later studies. This is as much as ten-to-twenty times higher than the proven Shuttle and 3 to 6 times higher than Dr. Koelle's Neptune rocket design
I’m not a mathematics man, just an aerospace engineer. The inconvenience cause by the error is regretted!!