Xref: utzoo sci.space:5932 sci.space.shuttle:804 Newsgroups: sci.space,sci.space.shuttle Path: utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: advance space news from June 6 AW&ST -- Pegasus! Message-ID: <1988Jun17.053132.5314@utzoo.uucp> Organization: U of Toronto Zoology Date: Fri, 17 Jun 88 05:31:32 GMT [As you have probably noticed, I am behind on AW&ST summaries. I will try and catch up a bit before I leave for Usenix. However, this one won't wait. The June 6 issue just arrived, and the lead story is the best news in years. So here's a special out-of-sequence report.] New launcher: Pegasus, a winged three-stage design that will be air- launched from a B-52. It's a joint effort of Orbital Sciences and Hercules, with Rutan building the wing. Payload is 600lb into low polar orbit, 900 into low equatorial orbit. Now the GOOD news... Pegasus is 100% private, although the first customer is DARPA. Total funding is $40-45M, about a third of it already spent. It has been underway about one year, they are already bending metal on the first one, and it flies NEXT YEAR! There is already a lineup of customers. Cost to orbit will be half or less that of similar-sized payloads on existing launchers. [At **LAST**, a launcher being built by sensible people! Note the modest size, the rapid schedule -- two years from startup to launch -- and the miniscule budget. Not to mention the lack of any attempt to force the taxpayers to fund it. This is how commercial launchers OUGHT to be done; thank all the gods that somebody had the guts to try doing it right!] DARPA is in the final stages of becoming the first customer, with a contract expected to be signed next week. The nature of the payload has not been released, but it is thought to be a small experimental comsat. Launch is set for July 1989. DARPA is buying launch services only, no funding for development is involved. Second launch will probably be another DoD payload from "a different agency" [betcha it's SDI] in Oct 1989. A NASA science payload is a candidate for number three in Dec 1989. OSC and Hercules are splitting the development cost 50-50 and will split profits the same way. Funding is entirely from internal resources and no outside capital is involved. Contractors have been picked, staff has been hired, parts are being built. Pegasus uses three new-design Hercules solid motors. Use of existing motors was considered, but new motors looked like a better bet. Cases are graphite composite, as is the wing, being developed by Burt Rutan. The thing is 49 feet long with a wing span of 22 feet, total weight 40klbs. These numbers are almost identical to those of the X-15, and the X-15's old B-52 will be the initial carrier aircraft. Gordon Fullerton, NASA research pilot and former astronaut (two shuttle missions) will command the B-52 for the first launch. Pegasus will pay NASA for the use of the aircraft for commercial launches. Up to 15 launches might be made from the NASA B-52, after which transition to a commercial heavy transport is expected. The aircraft has been picked but its identity is proprietary as yet. [Now why would they keep the identity of the aircraft secret? I mean, the 747 is the obvious choice. Unless... you don't suppose they're going to use an Airbus A340?!? Congress will be livid.] Drop will be at 40,000 ft. The first stage will light and fly a shallow wing-borne trajectory to Mach 8.7 at 208,000 ft. The wing is on the first stage, so the second and third stages fly more conventional upper-stage trajectories into orbit. The first launch will be into polar orbit, starting offshore from Vandenberg. Using air launch, of course, launch site and direction are pretty much arbitrary. It also means that Pegasus does not have to fight for access to launch facilities. [And they don't have to deal with the government, or mortgage their mothers to pay for insurance against launch-site damage.] Pegasus develoment is considered 50% complete; OSC+Hercules will hold a major engineering review this week. Late this month they will start using Ames's supercomputers for aerodynamic simulation -- Pegasus will not be wind-tunnel tested. They are already working with Ames people. [Eugene? You involved in this?] OSC+Hercules expect to price a Pegasus launch at under $10M. They forecast 10-12 per year and believe that it can support itself with half that. Breakeven will be reached after 16-18 launches, and with luck this will be two or three years after the first flight. Lots of people are interested, and a relatively diverse mix of customers is likely. This should give a fairly stable customer base. Pegasus's payload shroud is relatively large for the payload mass, 72in long by 46in wide, permitting a wide range of payload designs. Pegasus is being built for minimum prelaunch handling; eventually it is hoped that only 6-7 technicians will be needed for final assembly and launch. This will help costs a *lot*. Minimal ground hardware will be needed; no cranes. Also of interest, especially to Ames, is hypersonic flight testing at high altitudes and Mach numbers. The early Pegasus flights will carry quite a bit of Ames instrumentation to gather data relevant to the Aerospace Plane. 1500 lbs could be carried on a dedicated suborbital flight. Air launch turns out to give a 10-15% reduction in the necessary delta-V. The forward speed of the aircraft helps a bit. Launching at 40,000 ft helps much more: it reduces drag, reduces stress on the structure, reduces aerodynamic heating, reduces pressure loss in the exhaust, and permits a higher expansion ratio in the first-stage nozzle. The horizontal launch and the wing permit flying a much flatter and more efficient trajectory, and also greatly reduce the angle of attack needed for an air launch (a wingless air-launched rocket would have to make a sharp turn upward). The excellent supersonic wing (L:D 4:1) gives better performance than a similar weight of rocket fuel. (The wing will actually start to char just before first-stage burnout, but it doesn't matter since Pegasus is not reusable.) The net result is twice the payload mass fraction of a ground-launched booster. [Like I said, this is the best news in years. I hope OSC and Hercules make a bundle from this: they deserve it.] [Hmmm... 900 pounds, 42 inches. Kind of tight, and the upper-stage accelerations look uncomfortably high, but I bet you could man-rate it if you really tried.] -- Man is the best computer we can | Henry Spencer @ U of Toronto Zoology put aboard a spacecraft. --Von Braun | {ihnp4,decvax,uunet!mnetor}!utzoo!henry