Hand-Flying Reentry

Reading a book about the X-15 program. Says that the pilots
hand-flew the reentry on the missions to space, the highest
mission was 67 miles and several minutes outside of the
atmosphere. Initial planning was for missions as high as
180 miles; that would obviously have been a much longer and
higher speed reentry, I wonder if the pilot could hand-fly
it? Don't think there was any automated way to do it back
in the 1960s.

Would it be possible for the pilots to hand-fly a space
shuttle reentry? Or would an automatic system be required
given the exacting parameters on a reentry from orbit?

In article ,
says...

Reading a book about the X-15 program. Says that the pilots
hand-flew the reentry on the missions to space, the highest
mission was 67 miles and several minutes outside of the
atmosphere. Initial planning was for missions as high as
180 miles; that would obviously have been a much longer and
higher speed reentry, I wonder if the pilot could hand-fly
it? Don't think there was any automated way to do it back
in the 1960s.

Actually there were electronics to help fly the aircraft. I Believe
these were all analog (you can actually do a lot with analog control
systems). But, there was no "modern" digital autopilot that would fly
the entire reentry for them.

Cite:

Experience with the X-15 Adaptive Flight Control System
https://www.nasa.gov/centers/dryden/...main_H-618.pdf

Would it be possible for the pilots to hand-fly a space
shuttle reentry? Or would an automatic system be required
given the exacting parameters on a reentry from orbit?

The pilot was trained to fly the shuttle manually during pretty much all
stages of flight. But you can't fly a space shuttle with zero
computers. The space shuttle has a digital control system (i.e. fly by
wire). There were no cables connecting the flight controls directly to
the control surfaces. Control surfaces were hydraulic and powered by
the shuttle's APUs.

That's why the shuttle had 4 redundant computers to control it (in case
of hardware failure). It also had a fifth computer with completely
different, but minimal, flight control software in case a software
failure caused the 4 main computers to fail.

Jeff
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On Tuesday, January 16, 2018 at 6:32:51 AM UTC-5, Jeff Findley wrote:
In article ,
says...

Reading a book about the X-15 program. Says that the pilots
hand-flew the reentry on the missions to space, the highest
mission was 67 miles and several minutes outside of the
atmosphere. Initial planning was for missions as high as
180 miles; that would obviously have been a much longer and
higher speed reentry, I wonder if the pilot could hand-fly
it? Don't think there was any automated way to do it back
in the 1960s.

Actually there were electronics to help fly the aircraft. I Believe
these were all analog (you can actually do a lot with analog control
systems). But, there was no "modern" digital autopilot that would fly
the entire reentry for them.

Cite:

Experience with the X-15 Adaptive Flight Control System
https://www.nasa.gov/centers/dryden/...main_H-618.pdf

Would it be possible for the pilots to hand-fly a space
shuttle reentry? Or would an automatic system be required
given the exacting parameters on a reentry from orbit?

The pilot was trained to fly the shuttle manually during pretty much all
stages of flight. But you can't fly a space shuttle with zero
computers. The space shuttle has a digital control system (i.e. fly by
wire). There were no cables connecting the flight controls directly to
the control surfaces. Control surfaces were hydraulic and powered by
the shuttle's APUs.

That's why the shuttle had 4 redundant computers to control it (in case
of hardware failure). It also had a fifth computer with completely
different, but minimal, flight control software in case a software
failure caused the 4 main computers to fail.

One of the books about the X-15 said that reentry had to be flown
very precisely, as even at the best, it was close to the limits for
heating on the airframe, g-forces on the airframe, aerodynamic
forces on the airframe, and g-forces on the pilot. A small amount
of miscalculation could push one or more of them beyond the danger
point.

That is why the limited the altitude flights to around 350,000 feet
or 67 miles.