NASA's rocket procurement spec should fit on 1 page.

Dear prospective supplier

We would like to buy rocket launches.

1. It must carry X tons, Y1 metres in diamter and Y2m high to an orbit
at Z
2. It must be Man Rated (by a team not involved in the procurement
process)

simberg.interglobal@org.trash (Rand Simberg) wrote:
:>NASA's rocket procurement spec should fit on 1 page.
: [...]

:What does "Man Rated" mean?

If you look at the actual statistics, not much.

What it's SUPPOSED to mean is that the vehicle is certified to be much
more reliable (and frequently versatile) than 'non-man-rated' systems.

Under the usual rules, the Shuttle could never be Man Rated, since
solid fuel vehicles are inherently unsafe (no way to vary thrust or
turn them off short of blowing the sides or top out). In a classic
'Man Rated' vehicle, the SRBs would have had to be LRBs.

Lots of definitions, but I'd expect an independent (of NASA) agaency to
say yes, the chances of crew dying in a rocket launch is less than 1 in
X (and I guess X should be about 1000). Most EELVs with an escape tower
should manage this.

What do you think Rand?

:Not necessarily. SRBs don't have to be terminatable
:for there to be viable warning and escape systems for
:the crew riding on top.

Name a single man-rated solid fuel vehicle anywhere during the history
of space, other than the STS with SRBs.

In article <6p6b019hhp1qtip0qo9vo7c3svn2vmcldn@4ax.com>,
Fred J. McCall <fmccall@earthlink.net> wrote:
:Not necessarily. SRBs don't have to be terminatable
:for there to be viable warning and escape systems for
:the crew riding on top.

Name a single man-rated solid fuel vehicle anywhere during the
history
of space, other than the STS with SRBs.

The original Titan IIIC, which was built to carry Dyna-Soar.

Fred J. McCall <fmccall@earthlink.net> wrote:

Under the usual rules, the Shuttle could never be Man Rated, since
solid fuel vehicles are inherently unsafe (no way to vary thrust or
turn them off short of blowing the sides or top out). In a classic
'Man Rated' vehicle, the SRBs would have had to be LRBs.

Not necessarily. SRBs don't have to be terminatable
for there to be viable warning and escape systems for
the crew riding on top.

Large, fragile reusable orbiters and high energy aborts
don't match well, but that's different than banning SRBs
entirely.

A reasonable interpretation of "man rated" is that the
vehicle will provide gentle enough failure modes, and enough
problem diagnostics and warning and time to operate an
escape, that human passengers will survive credible bad
abort or launch failure cases. Said cases should include
at least basic structural failures in the launcher,
engine failures ranging from one to all engines,
and complete loss of control hard-over steering events.

-george william herbert
gherbert@retro.com

Isn't having a takeoff such that a human can survive it (so
not excessive vibrations, g forces etc) the first thing that
must be matched and isn't by many of todays launchers?

I think the early riders of launch craft aren't going to be stopped to
easily by a somewhat rough ride.