It has been suggested that suborbital space-planes could preform a kind of Bounce/Skip on re-entry repeatedly extending the range of the vehicle and perhaps more interestingly the time in Zero Gravity.I imagine such a capability would be an interesting growth on Suborbital Tourism, extending the time in weightlessness without needing to go all the way to orbit.http://www.risacher.org/bh/analog.htmlThe idea even goes back to WW2 with the Silverbird
It is apparent that to keep the insertion velocity from exceeding orbital velocities, ricochet trajectories are the only option to transport passengers across distances between 7,000 km and 20,000 km (where maximum altitude is limited to 500 km), and for cargo transport acrossdistances between 12,000 km and 20,000 km (no maximum altitude). In particular, for flights between opposite points of the Earth’s surface (antipodal flight), ricochet is the only suborbitaloption.There are two limiting distances: 7,000 km and 12,000 km; for distances close to these numbers,ballistic and ricochet trajectories require the same amount of ΔV. For two major routes, London-New York (5,585 km) and New York-Tokyo (10,858 km), the distances are close to these numbers.
I'm pretty dubious about the concept; it seems to me that net delta-V comes awfully close to full orbital velocities and that one might as well just design the craft to go all the way to orbit at a modest altitude, say 300 km, and then deorbit to approach one's final destination, avoiding all need to have intermediate skip encounters.
What would be the most durable or useful wing design for atmospheric ricochet?
...All-rocket vehicles are flying ballistic trajectories, and they are somewhat unflexible; a certain speed command a certain height, all this plotting against horizontal distance. http://isulibrary.isunet.edu/opac/doc_num.php?explnum_id=95 Page 28 QuoteIt is apparent that to keep the insertion velocity from exceeding orbital velocities, ricochet trajectories are the only option to transport passengers across distances between 7,000 km and 20,000 km (where maximum altitude is limited to 500 km), and for cargo transport acrossdistances between 12,000 km and 20,000 km (no maximum altitude). In particular, for flights between opposite points of the Earth’s surface (antipodal flight), ricochet is the only suborbitaloption. ...
It is apparent that to keep the insertion velocity from exceeding orbital velocities, ricochet trajectories are the only option to transport passengers across distances between 7,000 km and 20,000 km (where maximum altitude is limited to 500 km), and for cargo transport acrossdistances between 12,000 km and 20,000 km (no maximum altitude). In particular, for flights between opposite points of the Earth’s surface (antipodal flight), ricochet is the only suborbitaloption. ...
I want to thank Archibald for that reference; there's all kinds of useful information there....Skip trajectories require one to launch at considerably lower angles than minimum-energy single arc suborbital paths, this means they have to be at higher velocities to achieve a given distance. Of course the idea is to lower the distance per arc. Coming into the effective top of the atmosphere at a lower angle allows the craft to redirect itself onto another arc with a minimum of both vertical acceleration and thus air drag. Essentially one has to reverse the vertical component of the velocity; a shallow angle is necessary to keep that minimized....For any great distance, going to full orbit and then deorbiting seems to be the smart thing to do to me.
...So you reach 300 km orbit, and immediately begin to deorbit, and if using minimal delta-v, you will re-enter on opposite side of the planet- a 20,000 km distance traveled. And if using more delta-v to deorbit you can land a shorter distance traveled.Now, one doesn't need to go to 300 km orbit, one can go to orbit at 50 km height- there more orbital drag at 50 km, but this isn't a problem if the plan is to return immediately to Earth.It seems to me the advantage of sub-orbital is you can have a lower re-enter velocity, but for long travel distance [+10,000 km distance] the suborbital would be a similar delta-v as something going into orbit....
SkipFlight - I sense the makings of a good movie title. Now all I need is a script. Time to call George Kennedy.
Author in the house!Ah, the techno-thriller -- my favorite kind of science fiction.Chilly, just make sure you get nice fanfare theme music for it. It makes all the difference.Meanwhile, more towards the topic - I'd wonder if this kind of aerospace craft would require special exemptions under existing missile international treaties. Would the sale of such aircraft constitute a violation of MTCR?After all, this type of vehicle could be a pretty rapid delivery system if you packed it with a destructive payload.
Author in the house!Ah, the techno-thriller -- my favorite kind of science fiction.Chilly, just make sure you get nice fanfare theme music for it. It makes all the difference....Would the sale of such aircraft constitute a violation of MTCR?After all, this type of vehicle could be a pretty rapid delivery system if you packed it with a destructive payload.