Put some small wings on that second stage and land once around...
1) We know from Shuttle/X-37B ops.2) We know from X-15 re-usability.3&4) Is basically SSTO which in all the years talked about has yet to fly including the interesting Skylon. Thus not flying would be a step backwards IMO...Go with whats proven if you want to fly now...
Quote from: Rocket Science on 05/23/2016 09:24 pm1) We know from Shuttle/X-37B ops.2) We know from X-15 re-usability.3&4) Is basically SSTO which in all the years talked about has yet to fly including the interesting Skylon. Thus not flying would be a step backwards IMO...Go with whats proven if you want to fly now...Well, can TSTO be done with scramjets on the lower stage?
You would still need a rocket to get the scramjet up to speed so why bother thus Skylon does away with that... Just stick with a proven rocket design. Still waiting for the verdict on Falcon9R...
I have to admit India has an interesting twist on winged spaceflight in essentially having the vehicle's nose separate. I've never seen that suggested in a NASA configuration before, one with wings that is. No need to incorporate a cargo bay or one winged vehicle piggybacking another.
Quote from: redliox on 05/23/2016 09:40 pmI have to admit India has an interesting twist on winged spaceflight in essentially having the vehicle's nose separate. I've never seen that suggested in a NASA configuration before, one with wings that is. No need to incorporate a cargo bay or one winged vehicle piggybacking another.Well, the inter-stage gets lost as part of that - but hopefully it's not terribly expensive to replace.
Quote from: Rocket Science on 05/23/2016 09:35 pmYou would still need a rocket to get the scramjet up to speed so why bother thus Skylon does away with that... Just stick with a proven rocket design. Still waiting for the verdict on Falcon9R...I thought the US has already flight-tested a vehicle with a combined-cycle engines.How scalable are scramjets, for pushing against the rocket equation?Quote from: redliox on 05/23/2016 09:40 pmI have to admit India has an interesting twist on winged spaceflight in essentially having the vehicle's nose separate. I've never seen that suggested in a NASA configuration before, one with wings that is. No need to incorporate a cargo bay or one winged vehicle piggybacking another.Well, the inter-stage gets lost as part of that - but hopefully it's not terribly expensive to replace.
Well, according to this article, ISRO may even be looking at how to recover rocket stages the SpaceX way:http://www.ndtv.com/india-news/isro-to-look-at-possibility-of-recovering-rocket-stage-1409084
In addition, ISRO was “very seriously” thinking of retrieving and reusing the core boosters of the GSLV and GSLV Mk-III in a SpaceX-like manner, according to him. The next generation Heavy Lift Launch Vehicle could also be designed with such reuse in mind.The GSLV’s first stage, along with the four liquid-propellant strap-on boosters attached to it, account for almost three-fourths of the launch vehicle’s costs. “If we are able to recover and reuse [it], our reduction in cost will be maximum,” he said.
RLV-TD HEX was flown up to 70KM altitude which is about as near as possibly safe within Mesosphere (85 KM) -- which is about the altitude range limit for scramjets (because air density falls off significantly after Mesopause) Seems to me Scramjets are more for assisted flight (to an extent) and to save on fuel. Is my understanding inaccurate?
After successfully testing a technology demonstrator of a reusable launch vehicle, Indian Space Research Organisation (ISRO) is planning to test an air-breathing propulsion system, which aims to capitalise on the oxygen in the atmosphere instead of liquefied oxygen while in flight.“The mission to test the technology would be launched either in the last week of June or early July from Satish Dhawan Space Centre at Sriharikota. The mission would be on a sounding rocket,” K. Sivan, Director of the Thiruvananthapuram-based Vikram Sarabhai Space Centre told The Hindu.
The new propulsion system, once mastered, would complement ISRO’s aim to develop a reusable launch vehicle, which would have longer flight duration. The system, involving the scramjet engine, would become crucial while sending up the spacecraft.
According to ISRO, the Dual Mode Ramjet (DMRJ), the ramjet-scramjet combination, “is currently under development, which will operate during the crucial Mach 3 to Mach 9 ascend flight of the launch vehicle.”