Hi Ted...... and list. As Ted has found in the past , sometimes the mission patch can reveal some info... Have a look at... http://mysite.wanadoo-members.co.uk/satcom_transits/B26patches.jpg especially the one on the right. Are those just random stars , or do they hint at the satellite constellations. Also , from the last launch.... (NROL 22 ) http://mysite.wanadoo-members.co.uk/satcom_transits/NROL22.jpg John ----- Original Message ----- From: "Ted Molczan" <seesat@rogers.com> To: <SeeSat-L@satobs.org> Sent: Wednesday, October 19, 2005 12:32 PM Subject: NROL-20: 48 ft fairing > The mysterious 76 ft fairing shrank yesterday to a perhaps equally > mysterious 48 > ft, as reported by Spaceflight Now: > > http://www.spaceflightnow.com/titan/b26/status.html > > "The rocket is sporting an unusual 48-foot long nose cone to protect its > clandestine National Reconnaissance Office payload during the ascent > through the > atmosphere. The fairing started as a standard 76-foot shroud but was > modified to > the shortened length, Smith said. > > A similar fairing was used in May 1999 when a Titan 4 launched from > Vandenberg > carrying what hobbyist sky watchers consider to be a mysterious "stealth" > spy > satellite." > > In order to understand the possible significance of the reported 48 ft > fairing, > it is necessary to review the different types of Titan-IV fairings that > have > flown from VAFB. What follows is my present understanding, subject to > revision > as more is learned. > > For a long time, it was considered that VAFB payloads employed two lengths > of > fairing: > > T-IV Type Payload Fairing Orbit > 403 NOSS 56 ft 63.4 deg > 403 Lacrosse 66 57 or 68 deg > 404 KeyHole 66 98 deg > > In 1999 came the launch of the mysterious USA 144, on a 404B Titan, to a > 63.4 > deg orbit. Justin Ray, reporting for Florida Today at the time, learned > officially that the fairing had been 50 ft long. The launch occurred in > the > middle of a foggy night (how appropriate!), and the only photo I had at > the time > inadequately revealed the fairing, so I had no easy way to verify this. > > However, Phil Chien recalled that a 50 ft fairing had long been listed in > the > T-IV's promotional literature. Indeed, an early T-IV brochure, kindly > provided > by Phil, listed only a 50 ft fairing for the model 404, which was > confusing, > since the KeyHole 404 launches to that time, were thought to have employed > the > 66 ft fairing. > > Earlier this year, I made an effort to verify the fairing length of all > past > T-IV launches for which I could locate a useable photo, which led to me > this one > of USA 144: > > http://www.nro.gov/graphics/launch5_99.jpg > > Resolution and lighting are poor, but with moderate magnification and > brightness/contrast adjustment, I believe I can make out the boundary > between > the vehicle and adapter (aka boat tail) section of the fairing, and the > boundary > between the cylindrical and conical sections of the fairing. Likewise, I > believe > I can adequately resolve the diameter of the cylindrical section. I get a > ratio > of length to width of around 1.7, which when multiplied by the known 16.67 > ft > diameter, yields a length of 28.3 ft, which accounts for the boat tail and > cylindrical section. The conical section cannot be measured, but all of > them are > 19.86 ft long, which brings the overall length to 48 ft - pretty close to > the > reported 50 ft. > > In 2001 October, I learned of a new wrinkle in the story of VAFB fairings. > Charles Vick posted to FPSPACE that the fairings of the KeyHoles launched > in > 1992, 1995 and 1996 had not been 66 ft, but rather 50 ft, which sat atop a > special 14 ft adapter he describes as a bucket, which was permanently > attached > to the 2nd stage. This brought the overall length to just over 64 ft, > which > could easily have been mistaken for a 66 ft fairing. Adding yet another > wrinkle, > Charles also pointed out that the KeyHole launched in 2001 October was the > first > to have an actual 66 ft fairing. > > In my exercise this year, I found that the pre-2001 KeyHole overall > fairing > length was 62 ft, close to Charles Vick's value of 64 ft. This seemed to > roughly > confirm that the fairing was 50 ft on top of a 14 ft bucket, which might > explain > the confusing claim of 50 ft in the old T-IV brochure. > > Also, keeping in mind that the bucket was said to have remained attached > to the > 2nd stage, it might explain why the 2nd stage of the 1996 KeyHole (96072B > / > 24681) was so much brighter than other T-IV 2nd stages: > > http://satobs.org/seesat/Jan-1997/0003.html > > My analysis of launch photos also confirmed that the 2001 KeyHole launch > employed a 66 ft fairing. > > So, based on my present understanding of the fairings, I interpret the > news of a > 48 ft fairing on today's scheduled 404B T-IV for launch, as follows: > > If photographs reveal an overall length of 48 ft, then perhaps the payload > is a > Misty - the first to be targeted for one of the two standard KeyHole > orbital > planes. > > If the overall length is around 62 to 64 ft, then it would appear to be a > regular, i.e. non-stealthy KeyHole, reverting to the pre-2001 fairing > length. > > Ted Molczan > > > ------------------------------------------------------------------------- > Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: > http://www.satobs.org/seesat/seesatindex.html > > > ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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