Findings & Concerns

Meeting of June 24, 1998
Sounding Rocket Working Group
National Aeronautics and Space Administration


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