In article ,
sanman wrote:
So you've all probably read that the latest Mach10 flight was
successful. The statements from NASA's O'Keefe seem to indicate that
this technology will be used to advance commercial flight, as well as
cheaper access to space.

Those are standard fantasies, but both fairly unlikely.

Commercial flight simply does not see substantial payoffs between about
Mach 5 and near-orbital speeds. Mach 5 cruise gets you anywhere on the
planet in four hours, assuming a direct route. Beyond that, incremental
benefits fall off sharply as preflight/takeoff/landing/postflight time
overheads swamp the further time savings, and costs rise sharply as the
aircraft and their maintenance get more expensive, new fuel infrastructure
becomes necessary, and traffic-control problems multiply.

And the idea that it makes sense for launchers to trade simple, cheap,
lightweight, well-understood LOX tanks for complex, technically
problematic, heavy, and poorly developed scramjets is utterly ludicrous.
It would be difficult to find a *stupider* design change.

So in light of these post-Nov16 statements from NASA, will there be a
future for scram?

For military applications, perhaps. They're the only real customers.
Hint: the detailed design of the X-43 scramjet is classified.

Some of you have said it's easier to get into space with a rocket, but
some of the news coverage I was reading said scram could at least be
used for a lower-stage booster.

If somebody else builds a large scramjet aircraft for some other purpose,
using it to carry an air-launched rocket up to speed and altitude would be
interesting. There's no way that *developing* it could possibly be
justified as part of a launcher project.

Could scram be suitable for heavy payloads in particular?

Contrariwise: almost any air-launch scheme will have quite limited
payload because of the limitations of the launch aircraft. For getting
big payloads into orbit, brute force using rockets is far superior: they
scale much better.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |