NASA changing opinion on the Direct HLV launcher.

VTOL aircraft exist today. They've always had their detractors and
supporters. The programs that were not purchased says more about the
politics and less about the technology involved in each.

Of the 2 aircraft you mention only one has roots in the period we're
talking about in the 1950s. The other is a modern derivative of the
earlier successful design.

The Hawker P.1127 was a British design began an 1957 and evolved into
the Kestrel which led to units that were evaluated.

Hawker's design was the only type of VSTOL aircraft to survive the
loss of interest by the US DOD in this technology throughout this
period, although tilt-fan systems did make a comeback much later. The
survival of the Hawker design was due to enthusiastic support by the
builder, and RAF. Later, it was the Marine Corps that took the lead
in bringing the Harrier into service in the 1970s for the USA - well
after the period we're talking about.

The British-built Kestrel was designed with vertical/short takeoff and
landing capabilities, making it possible to operate from grass or semi-
prepared surfaces offering great operational flexibility. A feature
of all VTOL aircraft. In the Hawker design four adjustable exhaust
nozzles beneath the wing roots could be rotated to provide thrust for
vertical, backward or hovering flight as well as conventional forward
movement.

The first Kestrel began conventional flight trials on March 13, 1961,
in Britain. In 1962 the governments of the United States, Britain and
the Federal Republic of Germany ordered nine aircraft for combined
testing by those countries' representatives. They formed an evaluation
squadron that conducted Kestrel trials between April and September
1965. Six of these trial aircraft were later delivered to the United
States where, as XV-6As, they underwent additional testing of V/STOL
fighter techniques.

An improved version, known as the Harrier, became the world's first
operational V/STOL fighter when it entered Royal Air Force service in
1969.

On Oct 19, 8:47*am, William Mook wrote:
VTOL aircraft exist today. * They've always had their detractors and
supporters. *The programs that were not purchased says more about the
politics and less about the technology involved in each.

Of the 2 aircraft you mention only one has roots in the period we're
talking about in the 1950s. *The other is a modern derivative of the
earlier successful design.

The Hawker P.1127 was a British design began an 1957 and evolved into
the Kestrel which led to units that were evaluated.

Hawker's design was the only type of VSTOL aircraft to survive the
loss of interest by the US DOD in this technology throughout this
period, although tilt-fan systems did make a comeback much later. *The
survival of the Hawker design was due to enthusiastic support by the
builder, and RAF. *Later, it was the Marine Corps that took the lead
in bringing the Harrier into service in the 1970s for the USA - well
after the period we're talking about.

The British-built Kestrel was designed with vertical/short takeoff and
landing capabilities, making it possible to operate from grass or semi-
prepared surfaces offering great operational flexibility. * A feature
of all VTOL aircraft. *In the Hawker design four adjustable exhaust
nozzles beneath the wing roots could be rotated to provide thrust for
vertical, backward or hovering flight as well as conventional forward
movement.

The first Kestrel began conventional flight trials on March 13, 1961,
in Britain. In 1962 the governments of the United States, Britain and
the Federal Republic of Germany ordered nine aircraft for combined
testing by those countries' representatives. They formed an evaluation
squadron that conducted Kestrel trials between April and September
1965. Six of these trial aircraft were later delivered to the United
States where, as XV-6As, they underwent additional testing of V/STOL
fighter techniques.

An improved version, known as the Harrier, became the world's first
operational V/STOL fighter when it entered Royal Air Force service in
1969.

Rocket thrust exhaust that's hot enough to turn basalt into a liquid
is not exactly a good thing to have surrounding your tail-end.
However using three thrusters slightly tilted outward should more than
do the trick, especially if located an extra meter away from the main
spacecraft body.

The cooler exhaust using HTP plus a little hydrocarbon is a much
better alternative for several reasons, or if need be using just HTP.

~ BG