Subject: Re: A Proposed Launch Performance Standard
From: Daniel Adamo <[email-masked]>
Date: Wed, 17 Dec 2014 11:15:40 -0700

ATIG Members-

Many thanks to those of you who commented on the standard.  I've
incorporated that feedback, together with additional research, into a white
paper on this topic.  It may be downloaded from the Space Enterprise
Institute (SEI) website at
http://www.spaceenterpriseinstitute.org/2014/12/an-objective-launch-vehicle-
performance-standard/.

The SEI site does require you to register as a user before you can obtain
its free downloads.  This requires a name and email address, neither of
which must be valid.  Registration information is intended to suppress spam
on the site and is employed to send you emailed alerts when new SEI material
becomes available.

Happy holidays!

-Dan

From: Daniel Adamo <[email-masked]>
Date: Sun, 07 Dec 2014 17:06:58 -0800
Conversation: A Proposed Launch Performance Standard
Subject: A Proposed Launch Performance Standard

ATIG Members-

Many of you who correspond with me on "rocket science" matters are familiar
with my rant on absence of a performance standard for launch vehicles such
that "apples versus apples" comparisons may be made.  I couldn't tell you if
a Delta IV Heavy delivers more performance than an Ariane V because they
launch from different locations into different orbits.  There are also
claims regarding "the most powerful rocket ever flown" floating around out
there.  Just how powerful is that compared to other launch vehicles?  And
what is meant by "power" anyway?  Thrust at liftoff is likely a poor metric
for what really counts: initial mass delivered to low Earth orbit by a
single launch (IMLEO).  So, here's my proposed standard for an IMLEO-based
launch performance metric.

First, some relevant background is warranted.  Forty-two years ago today, on
7 Dec 1972, a Saturn V launched the Apollo XVII mission from KSC LC 39A
(28.608 deg N Lat, 80.604 deg W Lon, -32.0 m Alt) at an azimuth of 91.5 deg
E of N.  Some 11.9 min after launch, insertion into a 166.7 km altitude
circular orbit (reckoned with respect to an Earth radius of 6378.2 km) was
achieved.  Inclination of this orbit was 28.526 deg.  See Apollo: The
Definitive Sourcebook (Orloff & Harland, 2006), p. 511 for these statistics.
Additional data from the Sourcebook infer a total Apollo XVII vehicle mass
of 140,345 kg at orbit insertion.  This IMLEO achievement has never been
surpassed by a single launch, whether from Earth's surface or a carrier
aircraft.

Launch service providers with accurate simulation capabilities are invited
to duplicate the Apollo XVII launch circumstances, achieve a similar orbit
with their launch vehicle (whether operational or under design), and report
their IMLEO values via email along with the launch vehicle configuration
simulated.  These IMLEO results will be cited with the proposed standard at
http://spaceenterpriseinstitute.org/, facilitating an "apples versus apples"
performance comparison between launch vehicles.

I'd be very interested in any commentary regarding the proposed standard.
In particular, is anyone aware of a similar or somehow better standard?

One data point I might contribute would be from a MacMECO simulation of a
Shuttle launch into the Apollo XVII orbit.  Just how much Orbiter mass can
be inserted into this orbit without incurring a low level MPS cutoff?  If I
have to use OMS-2 to circularize at 166.7 km, that propellant will come out
of the IMLEO I report.  But I will report "useless" IMLEO mass like the
Orbiter's wings.

-Dan