A program has been written to enable (1) fast and easy searching of symbolic files for one or more strings of characters, dates, or numerical values in specific fields or columns and (2) summarizing results of searching other fields or columns

Snook, Bryan E.

NASA Technical Reports Server

NASA Tech Briefs, July 2010 13
Software
Automated Computer 
Access Request System
The Automated Computer Access Re-
quest (AutoCAR) system is a Web-based
account provisioning application that
replaces the time-consuming paper-
based computer-access request process
at Johnson Space Center (JSC). Auto-
CAR combines rules-based and role-
based functionality in one application
to provide a centralized system that is
easily and widely accessible. The system
features a work-flow engine that facili-
tates request routing, a user registration
directory containing contact informa-
tion and user metadata, an access re-
quest submission and tracking process,
and a system administrator account
management component. This provides
full, end-to-end disposition approval
chain accountability from the moment a
request is submitted. 
By blending both rules-based and role-
based functionality, AutoCAR has the
flexibility to route requests based on a
user’s nationality, JSC affiliation status,
and other export-control requirements,
while ensuring a user’s request is ad-
dressed by either a primary or backup ap-
prover. All user accounts that are tracked
in AutoCAR are recorded and mapped to
the native operating system schema on
the target platform where user accounts
reside. This allows for future extensibility
for supporting creation, deletion, and ac-
count management directly on the target
platforms by way of AutoCAR. The sys-
tem’s directory-based lookup and day-to-
day change analysis of directory informa-
tion determines personnel moves,
deletions, and additions, and automati-
cally notifies a user via e-mail to revalidate
his/her account access as a result of such
changes. AutoCAR is a Microsoft classic
active server page (ASP) application
hosted on a Microsoft Internet Informa-
tion Server (IIS).
This program was written by Bryan E.
Snook from Johnson Space Center. Further in-
formation is contained in a TSP (see page 1).
MSC-24174-1
Range Safety for an 
Autonomous Flight 
Safety System
The Range Safety Algorithm software
encapsulates the various constructs and
algorithms required to accomplish Time
Space Position Information (TSPI) data
management from multiple tracking
sources, autonomous mission mode de-
tection and management, and flight-ter-
mination mission rule evaluation. The
software evaluates various user-config-
urable rule sets that govern the qualifica-
tion of TSPI data sources, provides a pre-
launch autonomous hold-launch
function, performs the flight-monitor-
ing-and-termination functions, and per-
forms end-of-mission safing. 
Rule types are tailored to the Range
Safety problem domain and are based
on existing range practices with human-
in-the-loop flight-termination systems.
This module provides a cleanly deploy-
able software library for autonomously
executing a number of real-time range
safety decisional functions. Its key
strength is its ability to emulate the sub-
stantial variety of human-in-the-loop
flight safety mission rules using a com-
paratively small set of flight-termination
rule types. These four rules are: 
1. Generic Parameter Threshold Limit –
This rule is used to fire a terminate
condition in response to one or more
threshold conditions or Boolean truth
conditions. This rule may carry with it
an arbitrary number of interpolative
look-up tables. It can implement flight
azimuth constraints, erratic flight and
attitude rate limits, and vehicle per-
formance limits. 
2. Coordinate Boundary Rule – This
rule is used to determine whether or
not a specified point is contained
within a simple closed boundary rep-
resented by a table of coordinates.
The state of a variable is evaluated
using a ray crossing point-in-polygon
algorithm. During each update cycle,
the closest distance between the spec-
ified coordinate point and coordinate
boundary is computed. These can be
applied to present position, instanta-
neous impact point coordinates, flight
corridor inclusion limits, protected
area exclusion enforcement limits,
and upper-stage commit limits. 
3. Two-Point Gate Rule – This rule is
used to determine whether or not a
specified point has crossed a gate
formed by a line between two points,
and whether or not a specified point
is ahead of or behind the gate at any
point in time. These gates may be sta-
tistically located, or dynamically as-
signed via interpolative lookup tables.
The state of a variable is computed by
looking for intersections between the
gate and a line formed from the previ-
ous and current locations of the target
point. Another variable is computed
by comparing the relative location of
the specified coordinate set to the
gate. 
4. Trajectory Adaptable Green-Time
Rule – This rule is used to establish
the permissible time of flight with no
valid data, and to flag a destruct con-
dition when this time has been ex-
ceeded. Algorithms are used to com-
pute the worst-case instantaneous
impact point velocity as a function of
the current state, and of vehicle accel-
eration.
The software is configured by the user
via an XML configuration file. The algo-
rithms are implemented within a C++
container class that can be embedded in
and serviced by host application.
Presently, the software possesses approx-
imately 5,500 lines of code distributed
over 28 source files.
This work was done by Raymond J. Lanzi
of Goddard Space Flight Center and James C.
Simpson of Kennedy Space Center. Further
information is contained in a TSP (see page
1). GSC-15594-1
Fast and Easy Searching 
of Files in Unisys 2200 
Computers
A program has been written to enable
(1) fast and easy searching of symbolic
files for one or more strings of charac-
ters, dates, or numerical values in spe-
cific fields or columns and (2) summa-
rizing results of searching other fields or
columns. Intended for use in Unisys
2200-series computers under OS 2200,
the program implements a simplified
version of a UNIX AWK command im-
plemented in Unisys macro-assembler.
(AWK is an interpreted programming
language, included in most versions of
UNIX, for filtering and manipulating
textual data.) The program is given the
name of a file or an element thereof to
scan, the numbers of the fields or
columns that would contain the strings
of characters or numerical values that
are sought, and options to control the
type of search and display results. The
https://ntrs.nasa.gov/search.jsp?R=20100024422 2019-08-30T10:11:25+00:00Z
14 NASA Tech Briefs, July 2010
program uses standard Unisys library
routines for reading files that have stan-
dard structures and for editing and
printing output. The program can run
in a batch or an interactive mode.
This program was written by James S. Sarp
of United Space Alliance for Johnson Space
Center. For further information, contact the
Johnson Commercial Technology Office at
(281) 483-3809. MSC-23855-1
Parachute Drag Model
DTV-SIM is a computer program that
implements a mathematical model of
the flight dynamics of a missile-shaped
drop test vehicle (DTV) equipped with a
multistage parachute system that in-
cludes two simultaneously deployed
drogue parachutes and three main para-
chutes deployed subsequently and si-
multaneously by use of pilot parachutes.
DTV-SIM was written to support air-drop
tests of the DTV/parachute system,
which serves a simplified prototype of a
proposed crew capsule/parachute land-
ing system. 
The DTV-SIM model is of a point-mass
trajectory-integrator type and includes de-
tailed submodels of the staged deploy-
ment of, inflation of, and aerodynamic
drag on, the parachutes. The model simu-
lates (1) the forces on the parachutes and
the DTV and (2) the motion of the
DTV/parachute system from release until
landing. Before a planned test, DTV-SIM
is used to predict the flight of the
DTV/parachute system in order to de-
velop a flight envelope for the test. After
the test, DTV-SIM is used to reconstruct
the flight on the basis of data acquired
during the test and, while so doing, to op-
timize parameters in the parachute-infla-
tion simulation submodels.
This program was written by Peter Cuthbert
of Johnson Space Center. For further informa-
tion, contact the Johnson Commercial Tech-
nology Office at (281) 483-3809. MSC-
24361-1
Evolutionary Scheduler for
the Deep Space Network
A computer program assists human
schedulers in satisfying, to the maximum
extent possible, competing demands
from multiple spacecraft missions for uti-
lization of the transmitting/receiving
Earth stations of NASA’s Deep Space
Network. The program embodies a con-
cept of optimal scheduling to attain mul-
tiple objectives in the presence of multi-
ple constraints. Optimization of
schedules is performed through a selec-
tion-and-reproduction process inspired
by a biological evolution process. A
genome (a representation of design pa-
rameters in a genetic algorithm) is en-
coded such that a subset of the schedul-
ing constraints (e.g., the times when a
given spacecraft lies within the field of
view of a given antenna) are automati-
cally satisfied. Several fitness functions
are formulated to emphasize different as-
pects of the scheduling problem, and
multi-fitness functions are optimized si-
multaneously by use of multi-objective
optimization algorithms.
The output of the program consists of
a population of Pareto-optimal sched-
ules that demonstrate the compromises
made in solving the scheduling problem
and provide insight into a conflict reso-
lution process. These schedules are used
by human schedulers to choose the sim-
plest paths to resolution of conflicts as
items on schedules are changed and as
new items are added to schedules. 
This program was written by Alexandre Guil-
laume, Seungwon Lee, Yeou-Fang Wang, Hua
Zheng, Savio Chau, Yu-Wen Tung, Richard J.
Terrile, and Robert Hovden of Caltech for
NASA’s Jet Propulsion Laboratory. For more in-
formation, contact iaoffice@jpl.nasa.gov.
This software is available for commercial li-
censing. Please contact Daniel Broderick of the
California Institute of Technology at
danielb@caltech.edu. Refer to NPO-44821. 


Fast and Easy Searching of Files in Unisys 2200 Computers

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