Design a realistic SSTO rocket.
Budget: $1,500 – $3,000 USD
The mathematics suggest Single-Stage-To-Orbit rockets are possible using altitude compensating nozzles. But no analysis of the trajectory followed by a vehicle on such a flight has been published. The purpose of this project is produce such an analysis.
Need an aerospace engineer with high level understanding of the NASA trajectory analysis programs Post or Oasis. The problem with estimating the payload possible is that you need to calculate the Isp according to altitude. But this is done in a different way for an adaptive nozzle than for a fixed nozzle.
Info on the project can be found here:
https://www.researchgate.net/project/Single-stage-to-orbit-SSTO
I attached an image of the what the Vulcain engine used on the Ariane 5 core Isp profile by altitude would look like given an adaptive nozzle. Note that the graph for the RS-68 engine used on the Delta IV rocket would be similar since they both use hydrogen fuel at similar mixture ratios and combustion chamber pressures.
A surprising conclusion you can draw from this is that the Isp profile of these mid-level performance engines exceeds that of the high performance SSME's. This means the payloads of both the Delta IV and the Ariane 5 not only can be improved over their current values using adaptive nozzles but can even exceed that of the case where the engines were replaced by the high performance SSME's.
So this allows us to at least put a lower bound estimate of the payload possible both as an SSTO or multistage vehicle by comparing to estimates using fixed nozzle SSME's. That is to say, if you imagine replacing the engines in the Ariane 5 core or Delta IV core with SSME's then you can get reasonably accurate estimates of what the payload would be by using the rocket equation or a payload estimator such as on SilverbirdAstronautics.com. But this is only appropriate for fixed nozzles. It would not be accurate for our adaptive nozzle scenario.
That's the case for the hydrogen fueled engines used on the Ariane 5 core and Delta IV core, where we at least have this Isp profile for adaptive nozzles. But surprisingly we don't even have that for dense propellant engines such as using kerosene or methane. I rather suspect that surprising fact about hydrogen engines will also be true here: the performance of a mid-level performance engine such as the Merlin or BE-4 given adaptive nozzles will exceed that of a high performance engine such as the RD-180 or Raptor.
These facts about adaptive nozzles mean we can achieve high payload for SSTO's and increased payload for TSTO's simply be giving existing mid-level performance engines adaptive nozzles.
Robert Clark
Dept. of Mathematics
Widener Univeristy
Need an aerospace engineer with high level understanding of the NASA trajectory analysis programs Post or Oasis. The problem with estimating the payload possible is that you need to calculate the Isp according to altitude. But this is done in a different way for an adaptive nozzle than for a fixed nozzle.
Info on the project can be found here:
https://www.researchgate.net/project/Single-stage-to-orbit-SSTO
I attached an image of the what the Vulcain engine used on the Ariane 5 core Isp profile by altitude would look like given an adaptive nozzle. Note that the graph for the RS-68 engine used on the Delta IV rocket would be similar since they both use hydrogen fuel at similar mixture ratios and combustion chamber pressures.
A surprising conclusion you can draw from this is that the Isp profile of these mid-level performance engines exceeds that of the high performance SSME's. This means the payloads of both the Delta IV and the Ariane 5 not only can be improved over their current values using adaptive nozzles but can even exceed that of the case where the engines were replaced by the high performance SSME's.
So this allows us to at least put a lower bound estimate of the payload possible both as an SSTO or multistage vehicle by comparing to estimates using fixed nozzle SSME's. That is to say, if you imagine replacing the engines in the Ariane 5 core or Delta IV core with SSME's then you can get reasonably accurate estimates of what the payload would be by using the rocket equation or a payload estimator such as on SilverbirdAstronautics.com. But this is only appropriate for fixed nozzles. It would not be accurate for our adaptive nozzle scenario.
That's the case for the hydrogen fueled engines used on the Ariane 5 core and Delta IV core, where we at least have this Isp profile for adaptive nozzles. But surprisingly we don't even have that for dense propellant engines such as using kerosene or methane. I rather suspect that surprising fact about hydrogen engines will also be true here: the performance of a mid-level performance engine such as the Merlin or BE-4 given adaptive nozzles will exceed that of a high performance engine such as the RD-180 or Raptor.
These facts about adaptive nozzles mean we can achieve high payload for SSTO's and increased payload for TSTO's simply be giving existing mid-level performance engines adaptive nozzles.
Robert Clark
Dept. of Mathematics
Widener Univeristy