Frontier Status Report #2
Frontier Status Report #2
June 12, 1996
Dale M. Gray
Several developments in the past week were noted that have significance to the space frontier. These include the 2nd and 3rd flights of the DC-Xa (Clipper Graham), analysis of the Ariane 5 failure, analysis of the Tether failure, and the upcoming Russian election.
Top news of the week, and quite possibly the year, is the second and third flights of the DC-Xa. The second flight reached an altitude of around 2000 feet and moved laterally 550 feet. After only 26 hours, the third flight flew to 10,300 feet and laterally 350 feet before returning to a concrete platform. A pluming test of the rocket and ground was conducted as the vehicle landed wherein the four engines were gimboled outward. Special points to consider:
The test is one step along the path to lower the cost of placing mass into orbit using a single-stage reusable launch system that is operated and maintained along the lines of modern airline operations. This has increased the technological (T) climate supporting a frontier. Historical examples of similar frontier changes might include the replacement of pack trains to the mining camps with freight wagons.
The DC-Xa has been renamed the Clipper Graham to honor an advocate of the technology. This is an interesting reflection of the increasing awareness in political circles of the importance of the program and that it will most likely have a place in history. (This is an increase in the Charisma characteristic for those of you following my frontier models).
The Failure hallmark of an active frontier was reflected in two just released studies on previous failures: the Ariane 5 and the Tethered Satellite system.
The recent loss of the first Ariane 5, apparently resulted from the gimboling of all three rocket engines which caused the booster to pitch and yaw at rates estimated at 30 deg./sec. Aerodynamic forces caused the vehicle to break-up and safety systems were triggered to destroy the rocket. Acoustic and vibratory loads were less than expected, but for some unknown reason, the on-board computer commanded the SRBs to maximum deflection which was quickly followed by the deflection of the Vulcain engine. The Ariane 5 has two on-board computers as opposed to the one less-powerful computer used on the Ariane 4. Software for the computers is based on the successful Ariane 4 programing, but the added complexity of the Ariane 5 software has been problematic in the past.
If it turns out to be a software problem, it will echo the problems that resulted in the loss of the Clementine probe after it left lunar orbit. Failure is a hallmark of an active frontier. One aspect of failure occurs from the advancement of relevant technologies taken at some level of risk. Failure of experiments is more the rule than the exception as larger advances are attempted. Often the failures are the result of seemingly trivial causes overlooked in the complexity of the task.
The explosion also destroyed an important scientific mission. Carried on-board the Ariane 5 was the "$500-million Cluster magnetospheric science mission, which planned to use the four 2,640-lb. (1,200-kg.) spacecraft in a complex set of maneuvers to obtain a three-dimensional picture of the various plasma field boundaries in the Earth's magnetosphere" (AW&ST).
Analysis of the Tethered Satellite System showed that debris embedded on the tether most likely caused the failure of the system on its February 25, 1996 deployment on Columbia. The remaining tether was examined and found to contain numerous flaws and imbedded debris. The flaws allowed the tether to arc to a ground - -causing separation. Tests with undamaged tether could not duplicate this arcing. Despite the break, a significant amount of data was collected and electrical generation exceeded expectations (AW&ST, FLATODAY).
A change in the Legislative characteristic of the frontier environment may be eminent. The Russian election later this week will have ramifications far beyond Russian borders. With the Russian responsibility to launch 7 of the first 11 components of the station including the critical first two components, the election could impact funding and priorities for the project. Communist candidate Gennady Zyuganov is not a particularly adamant supporter of the ISS and advocates a greater Russian control of the project. Boris Yeltsin's standings in the notoriously inexact Russian polls have improved in recent weeks, but he will likely not get the required majority. This will require a run-off election in July. (Halvorson, FLATODAY; NPR)
Other news of note includes the last Pegasus flight by Orbital Sciences Corp. The system is being replaced by the upgraded Pegasus XL (AW&ST). In a related posting >>NASA has selected Orbital Sciences Corp., Dulles, VA, for final negotiations leading to the award of a contract to build a small, reusable technology demonstrator vehicle, known as the X-34 demonstrator, and begin flight testing it in late summer of 1998.<< (SPACEF). This will increase the technology base required for the advancement of the frontier.
Two solar arrays manufactured in the US were attached to the MIR space station in May and one was recently installed (AW&ST).
US Military is now eyeing US medium-class boosters to replace some of the payloads of the Titan IV. Two forces at work are shaping this consideration: the reduction of weight of military pay-loads and the increase in capabilities in commercial launch vehicles. Currently, all of the US based launch systems are being upgraded. As a result the medium-class of boosters will soon extend into the lower range of today's Titan IVs which are used for heavy military satellites in polar, LEO and GEO. The upgraded class of boosters will soon be able to launch 20,000 pounds to LEO, giving motivation for the military to downsize some of its LEO payloads to fit on the more economic boosters (AW&ST).
Japan has announced plans to standardize three derivatives of their H-2 launcher. The two heaver lift models (B & C) will use the new Mitsubishi LE-7 engines as booster motors that will be supplemented with various combinations of SRBs. The C model is expected to be rated at 8,000 pounds to GEO. The A model, the lifting equivalent of the H-2, will use only the less expensive SRBs with only half the lifting capacity of the C model. This standardization is hoped to bring the costs associated with launching satellites down to the point where the system can compete with the Ariane 4. Presently the H-2 is 30% more expensive to launch than the Ariane 4. The additional boosting capabilities will allow Japan to resupply the space station (AW&ST).
Please feel free to comment on these developments, correct errors and add additional developments of the week. Expression of emotional reactions to the news and my comments is also sought (both positive and negative). Those unsure of my frontier model criteria may privately e-mail me for an explanation that has previously appeared in this forum.
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