1. Resources and Code O
Support
The Sounding Rocket Working Group (SRWG) acknowledges that
NASA is restructuring the manner in which it administers and supports
several of its flight programs. As the SRWG believes that a healthy
sounding rocket program is vital to the nation's space research
efforts, it also recognizes that such a program must make every effort
to optimize its performance within its allocated resources.
The SRWG is concerned that a large portion of the support for
the sounding rocket flight operations, particularly for field
operations, which traditionally has been covered by Code O resources,
may be lost in the current restructuring "shuffle". Sustained flight
ops resources are essential for the sounding rocket program, and even
more so under the NSROC arrangement. The SRWG thus urges that the
allocation of such vital Code O resources (now covered under the SOMO
arrangement), continue to be an enduring and protected asset of the
sounding rocket program, and that they be protected from redistribution
to other flight programs
2. NSROC and Project Scheduling
The SRWG is "cautiously optimistic" that the new NASA
Sounding Rocket Operations Contract (NSROC) will maintain several
important features of the sounding rocket program, such as flexibility,
innovation, and P. I. satisfaction. We look forward to working with the
selected contractor and Wallops during the transition period to help
facilitate the successful enactment of the new program. To this end, we
intend to encourage all outside users to attend our next meeting (in
the Fall, 1998) to meet the NSROC contractor, to learn about the new
aspects of the program, and to discuss what changes and new
opportunities NSROC entails for the user community.
One aspect of the new "look" of the program that was
presented at the last SRWG meeting and that is of particular concern to
us is the scheduling of reviews and launch dates, and, in particular,
the need to put these dates in "cement" at the onset of each new start
mission. In some cases, entire new payloads built at experimenter
institutions must be designed from scratch and in parallel with the
Wallops systems engineering. In cases where the launch does not involve
a remote campaign or other critical launch constraints, it would appear
that "nominal" dates should be established at the onset of each
program, for planning purposes, and that these dates be revisited at
the Design Review, when experimenter progress can then be more
definitively ascertained. Most missions will need to work towards a
well-defined launch date (or launch date period) at the onset, but we
believe it is inadvisable to prematurely box-in some of the special
payloads, which frequently foster some of the program’s most innovative
science results.
3. El Coqui II
The SRWG appreciates the detailed presentations by Prof.
Miguel Larsen of Clemson University and Mr. Mark Cording of Wallops
concerning the El Coqui II sounding rocket campaign which was carried
out in Puerto Rico from February-March, 1998.
It is abundantly evident that the Wallops crew and the
experimenters did a tremendous amount of hard work to carry out this
successful campaign and they deserve nothing but the highest praise
from the science community, and in particular from the Sounding Rocket
Working Group.
Despite the many successful launches, the El Coqui II
campaign was unique in that political activities by a small group
altered the normal course of the range operations for a few of the
experiments. Although we trust this will be an isolated event in the
annals of NASA’s remote field operations, the SRWG notes these reports
with concern. We hope that the various "lessons learned" from this
campaign will help circumvent any similar activities in the future,
insofar as possible. Better publicity and advance pre-campaign
notifications and meetings were put forward as suggestions to help
alleviate such problems for future campaigns, although we recognize
that such solutions may not always be as effective as one might wish.
Given the unique situation at the El Tortuguero range earlier
this year, we again salute the Wallops personnel, the experimenters,
and particularly the Campaign Scientist, Prof. Miguel Larsen, for their
exceptional performance in carrying out the successful El Coqui II
campaign.
4. Attitude Control Systems
The SRWG appreciates the presentations by the Wallops
engineering staff concerning the current status of the attitude control
systems, including both the fine-pointing and the coarse systems.
Discussing of the performance and limitations of the current systems
and to making suggestions for future ones are among the SRWG’s chief
functions. In each case, we hope these will be ongoing discussions, and
confine our comments here to some general remarks.
(a.) Coarse Pointing ACS
The coarse-pointing attitude control systems (ACS) are
basically utilized by the space plasma physics and ITM experiments. In
the past 5+ years, such systems have all been commercially procured
from Space Vector and use either a programmed set of commands to orient
the payload along a pre-determined set of vectors or a simpler,
auto-pointing system to align the payload with the Earth’s magnetic
field. Although the pointing requirements usually do not require
exactitude to better than a degree, such coarse ACS pointers continue
to experience problems. In some cases, the ACS failed simply because of
programming or procedural errors, and not due to any hardware
malfunction. Although such systems are great when they work, the
failure of the ACS usually results in grave misfortunes in terms of
experiment success.
The SRWG notes that Wallops has in the past used a simpler,
analog magnetic ACS that was very reliable and inexpensive, but is no
longer available as it was made "in house". Such a system also had the
capability to be made very lightweight.
The SRWG looks forward to working with the Wallops R and D
group as well as with the NSROC contractor to not only improve the
performance of the coarse ACS systems, but also to define the
experimenter requirements and desires for small, lightweight,
inexpensive, and highly reliable coarse-pointing ACS systems in the
future.
(b.)
Fine Pointing ACS
The fine-pointing attitude control systems (ACS) are utilized
by the astronomy, planetary, and solar experiments. These systems
include the SPARCS pointing system that has achieved almost 0.1
arc-second pointing stability over 10-30 seconds on a recent NASA
sounding rocket solar physics mission (reported to us by Dr. Clarence
Korendyke of NRL at the January 21, 1998 meeting). In contrast,
fine-pointed (non-solar) astronomy sounding rocket payloads are using
20-year-old technology that provide at best several arc-second
stability. For example, as noted by the SRWG in previous findings, the
Ball startracker currently used with the sounding rocket Mark VI
guidance system has some serious limitations: notably its inability to
guide on targets fainter than 4th magnitude and the need to have only
one bright object in its 4 or 2 degree field-of-view.
As with the coarse-pointing ACS systems, the SRWG seeks to
work closely with Wallops R and D engineers and the NSROC contractor to
define and develop new ACS systems that we believe will translate
directly to major new scientific accomplishments in the fields of
astronomy, planetary, and solar physics. One suggestion is for the SRWG
to establish a sub-committee (composed of both SRWG members and other
users) to establish and bring to fruition this next generation of
fine-pointing ACS systems.
5. Student Launch Program
The SRWG was delighted and impressed with the presentation on
the Student Launch program, in which students from four high schools
came to Wallops and successfully carried out a variety of science
experiments on an Orion vehicle. The video tape and CNN news coverage
showing the enthusiasm of the students was very well received, and we
were impressed with both how serious the students and their teachers
took this undertaking, as well as how much everyone seemed to enjoy the
experience.
We commend Wallops for carrying out such a successful program
and wish it much success for future, similar endeavors. We also note
that the unselfish giving of time by the Wallops engineering staff
helped make this program such a resounding success and for this we
offer our highest praise and appreciation.
NASA
Sounding Rocket Working Group
Dr.
Robert F. Pfaff, Jr. (Chair)
NASA/Goddard Space Flight Center
Prof.
Dave Burrows
The Pennsylvania State University
Prof.
Greg Earle
University of Texas at Dallas
Prof. Paul D. Feldman
Johns Hopkins University
Dr. Mark Hurwitz
University of California, Berkeley
Prof. Timothy J. Kane
The Pennsylvania State University
Prof. Craig Kletzing
University of Iowa
Dr.
Clarence Korendyke
Naval Research Laboratory
Dr. Fletcher Miller
NASA/Lewis Research Center
Dr. Alan Stern
Southwest Research Institute
Dean and Prof. Roy B. Torbert
University of New Hampshire
Prof. Edward C. Zipf
University of Pittsburgh
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