henry@zoo.toronto.edu (Henry Spencer) (05/24/91)
[Unless I've mislaid it somewhere -- possible -- my copy of the April 1 issue didn't turn up. I'll do it if and when I find/get it.] The cover is "Military Space Technology Advances", the picture being an ultraviolet image of a sounding-rocket exhaust plume as seen from LACE. Editorial mentioning the 30th anniversary of Gagarin's flight, observing that the Soviets made a major effort to spruce up Baikonur for the celebration. Japan's Space Activities Commission approves initiation of Comets (a 2-ton research satellite to investigate mobile communications) and Lunar-A (an ISAS project to launch a lunar orbiter with three penetrators in 1996). Soviets approve launch of a US teacher to Mir in 1993, in an agreement between NPO Energia and Aerospace Ambassadors (a project of the Aviation Space Education Association). The teacher will fly free of charge, but sponsors are being sought to fund a set of experiments "to help defray costs" [it's not clear quite what this means]. [Hmm. Very hmm. With the Shuttle teacher-in-space program being postponed one year per year, this might well be the first US teacher in space.] Israel makes second test launch of its Arrow ATBM from a ship in the Mediterranean. Photograph, not very informative. The next flight will be an attempt to intercept another Arrow, later this year. Major management shakeup at Eosat. No reasons given. The big space story in this issue is definitely the leak of Timberwind. AW&ST says it has independent confirmation based on documents, although SDIO declines all comment. Timberwind has cost $40M to date [which makes it a small study program, by the way, not a major development effort], and would probably cost $7-8G through flight test. Timberwind is a fluidized-bed reactor, with small pellets of nuclear fuel supported by the gas stream. Exhaust velocity will be much higher than an oxyhydrogen engine, despite similar temperatures, because of the much lower molecular weight of the hydrogen exhaust. [Exhaust velocity scales inversely as square root of molecular weight, giving a factor of 2-3.] At least one fluidized-bed reactor was tested briefly in the mid-1980s, although it was not entirely successful. The engine would have a thrust of 45-75klbs initially, with possible growth to 250klbs. AW&ST's drawing indicates use of a telescoping exhaust nozzle to reduce length, *presumably* extended before ignition. Two design concepts using the Timberwind engine have been sketched. One is an Atlas-Centaur derivative, with the Centaur replaced by a huge stage (fatter than the Atlas and twice as long!!) using a single Timberwind. The Atlas sustainer phase would be eliminated, with all three Atlas engines cutting out simultaneously before staging. This configuration could lift about 27klbs to low orbit. The other concept is an "advanced Titan" scheme which sort of jacks up Titan's SRBs and slides an entirely new rocket in between, using three Timberwinds igniting at SRB burnout. Payload to low orbit would be 140klbs. [Hmm, I wonder if they've thought about the problems of nuclear clustering? One has to beware of interactions between reactors, since they are unshielded and right beside each other.] SDIO proposes initial engine testing at the Nevada Test Site, followed by a suborbital test over Antarctica. (Some small chance of an accident affecting New Zealand is noted.) NASA is interested in Timberwind but is wary of public outcry and suspects that commitment to a specific advanced reactor design is premature. [They would prefer to spend half a decade studying it first, as usual.] They are also skeptical about possible development problems, especially weight growth that could give it little advantage over a more conventional Nerva-type engine, and doubt that political approval could be had for igniting nuclear engines before reaching orbit. Lockheed gets the "technical partner" contract from Motorola for Iridium. The funding consortium, to which M+L would be prime contractors, remains unformed, and spectrum allocation for Iridium will be in doubt at least until the WARC meeting next Feb. First operational Almaz radarsat launched from Baikonur March 31. Images will be marketed through Space Commerce Corp. Some Soviet agencies think this is a mistake, saying that the Soviet Union needs to develop its own marketing expertise. Soviet general says USSR "considering retaliation", politically or with military development, if SDI development continues, claiming that SDIO's attempts to re-cast its plans in terms of tactical defence and accident prevention are a smokescreen for full deployment. He suggests one likely countermeasure: mass production of warheads and missiles to swamp any specific defensive system. The government of Kazakhstan is trying to charge the central Soviet government rent for the land occupied by Baikonur. Boom. Upgraded Titan IV SRB explodes during first test at Edwards. [AW&ST's pictures, however, are disappointing. The one on the front page of Space News was much better. Must have been quite some fireworks display.] No injuries, but the test stand is badly damaged, and that plus the failure will probably delay introduction of the new (Hercules) SRB. The current (United Technologies) SRBs are available in sufficient number that Titan launch schedules should not be affected. Cause of the explosion is not yet known, although some problem with the fuel is considered more likely than a flaw in the new composite casing. The new SRB is a major redesign, using longer segments (for the sake of fewer joints) in addition to the new casings and other improvements. Major story on military-space implications of Desert Storm. Smaller and lighter satellites dedicated to tactical applications are definitely in. Comsat capacity was grossly inadequate. An experimental Darpa lightsat saw operational use for digital data relay. Tactical missile warning is another big growth area. Details of various R&D projects, including the Truax/NRL project for a sea-launched recoverable booster. Weather-satellite night image of the Gulf, showing oilfield fires and complete lack of electrical power in Baghdad and surrounding areas. European interest in independent spysat capability, for early warning and treaty verification, sharply up in the wake of the Gulf War. One specific proposal is to follow the two Helios spysats currently planned with a third carrying an imaging radar. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry
petej@phred.UUCP (Peter Jarvis) (05/28/91)
In article <1991May24.041512.7497@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: > >.... [Hmm, I wonder if they've thought about the problems >of nuclear clustering? One has to beware of interactions between reactors, >since they are unshielded and right beside each other.] > They are in the business of thinking about such problems. >NASA is interested in Timberwind but is wary of public outcry and suspects >that commitment to a specific advanced reactor design is premature. [They >would prefer to spend half a decade studying it first, as usual.]...... > You don't just slap something like this together and launch it. Peter Jarvis............
henry@zoo.toronto.edu (Henry Spencer) (05/29/91)
In article <3405@phred.UUCP> petej@phred.UUCP (Peter Jarvis) writes: >>.... [Hmm, I wonder if they've thought about the problems >>of nuclear clustering? One has to beware of interactions between reactors, >>since they are unshielded and right beside each other.] >> >They are in the business of thinking about such problems. Are they? At least some of the nuclear-propulsion concepts currently being noised around have been criticized as having too many rocket people and not enough nuclear people involved. One should not automatically assume that subtle issues like this have been studied carefully. My (dim) recollection is that nuclear-engine clustering was all but abandoned in NERVA days due to nuclear interaction problems. >>NASA is interested in Timberwind but is wary of public outcry and suspects >>that commitment to a specific advanced reactor design is premature. [They >>would prefer to spend half a decade studying it first, as usual.]...... >> >You don't just slap something like this together and launch it. If you ever want to launch it, sooner or later you have to decide that concept X has had enough studies and it's time to build something. There is nothing wrong with continuing studies, but they should not be confused with developing useful hardware. NASA currently has far too many studies and far too little hardware development. It's time to pick the half-dozen most promising ideas and put some real development money into them, in full recognition that at least a couple will probably be blind alleys. "To find oil, drill lots of wells." -- "We're thinking about upgrading from | Henry Spencer @ U of Toronto Zoology SunOS 4.1.1 to SunOS 3.5." | henry@zoo.toronto.edu utzoo!henry
petej@phred.UUCP (Peter Jarvis) (06/03/91)
In article <1991May29.050238.23965@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: > >.... NASA currently has far too many studies >and far too little hardware development. It's time to pick the half-dozen >most promising ideas and put some real development money into them, in full >recognition that at least a couple will probably be blind alleys. "To find >oil, drill lots of wells." And how do you propose to get NASA the money to "drill lots of wells"? Congress can't even decide on how much to appropriate for a minimal Space Station......... Peter Jarvis........Physio-Control
henry@zoo.toronto.edu (Henry Spencer) (06/03/91)
In article <3408@phred.UUCP> petej@phred.UUCP (Peter Jarvis) writes: >>.... NASA currently has far too many studies >>and far too little hardware development. It's time to pick the half-dozen >>most promising ideas and put some real development money into them... > >And how do you propose to get NASA the money to "drill lots of wells"? >Congress can't even decide on how much to appropriate for a minimal Space >Station......... This may have more than a little to do with the fact that the Space Station has spent roughly a decade and $5G+ on studies to date, with no hardware to show for it... -- "We're thinking about upgrading from | Henry Spencer @ U of Toronto Zoology SunOS 4.1.1 to SunOS 3.5." | henry@zoo.toronto.edu utzoo!henry