Skyrocket - 16/10/2007 2:33 AMQuoteSkyrocket - 29/9/2007 12:44 AMQuoteantonioe - 28/9/2007 9:18 PMQuoteSkyrocket - 28/9/2007 11:11 AM If i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus. From Orbital???!!! I remember reading a report in (i think) Flight International at this time about OSC planning a wingless Pegasus version. Unfortunately i do not have a copy of it. Never heared about it again, but the report mentioned about half of the Pegasus payload performance and the Name Cygnus. Concerning this earlier incarnation of the Cygnus name for a ground launched Pegasus version, i found a usenet posting citing from a Orbital prospectus from 1992http://groups.google.com/group/sci.space/browse_thread/thread/2cdb6ec133f1e90d/4eae6420a7be501f?hl=en&lnk=st&q=osc+pegasus+cygnus#4eae6420a7be501fQuoteDuring 1989, OSC conducted design and analysis work on another Pegasus-derivedground-launched vehicle called Cygnus. The Company currently expects thatthe Cygnus vehicle will be similar to the Pegasus vehicle, except for theelimination of the Pegasus vehicle's wing and certain other minormodifications relating to ground-launched capability. Cygnus is expectedto use the ground-transportable pad and support equipment being developedfor Taurus or the Starbird suborbital launch vehicle's permanent groundsupport equipment. Lacking the air-launched and aerodynamic lift-assistedcharacteristics of Pegasus, Cygnus would provide approximately one-halfthe payload capacity of Pegasus. However, Cygnus is intended to meetrequirements of certain scientific and international users whose specialneeds dictate ground-launched vehicle. Cygnus is in the early design stage,no prototype exists and no contracts for Cygnus launch services havebeen obtained to date.
Skyrocket - 29/9/2007 12:44 AMQuoteantonioe - 28/9/2007 9:18 PMQuoteSkyrocket - 28/9/2007 11:11 AM If i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus. From Orbital???!!! I remember reading a report in (i think) Flight International at this time about OSC planning a wingless Pegasus version. Unfortunately i do not have a copy of it. Never heared about it again, but the report mentioned about half of the Pegasus payload performance and the Name Cygnus.
antonioe - 28/9/2007 9:18 PMQuoteSkyrocket - 28/9/2007 11:11 AM If i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus. From Orbital???!!!
Skyrocket - 28/9/2007 11:11 AM If i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus.
If i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus.
From Orbital???!!!
During 1989, OSC conducted design and analysis work on another Pegasus-derivedground-launched vehicle called Cygnus. The Company currently expects thatthe Cygnus vehicle will be similar to the Pegasus vehicle, except for theelimination of the Pegasus vehicle's wing and certain other minormodifications relating to ground-launched capability. Cygnus is expectedto use the ground-transportable pad and support equipment being developedfor Taurus or the Starbird suborbital launch vehicle's permanent groundsupport equipment. Lacking the air-launched and aerodynamic lift-assistedcharacteristics of Pegasus, Cygnus would provide approximately one-halfthe payload capacity of Pegasus. However, Cygnus is intended to meetrequirements of certain scientific and international users whose specialneeds dictate ground-launched vehicle. Cygnus is in the early design stage,no prototype exists and no contracts for Cygnus launch services havebeen obtained to date.
nobodyofconsequence - 15/10/2007 6:28 PM What about AirLaunch LLC's drop method with a strategically placed/sized drogue chute?Does the net lift of the wing generate that much advantage over the vertical thrust necessary to make up for the drop?-NofC
What about AirLaunch LLC's drop method with a strategically placed/sized drogue chute?
Does the net lift of the wing generate that much advantage over the vertical thrust necessary to make up for the drop?
-NofC
Early (1987) Pegasus simulation runs said YES in a BIG WAY!!! By the way, this is not obvious. My first concept used rocket thrust instead of aero lift. But lift wins even with pretty miserable L/D's like the Pegasus wing's. Also, including the mass of the wing and wing attachments (partially offset if you need some form of attachments anyway, such as for an external mount).
If anyone has run simulations that show the opposite trade result, I'd be interested in seeing them.
The advantages of wing lift over rocket thrust are more pronounced for relatively low T/W configurations (e.g., liquid stage 1), less for higher T/W cofigs, such as Pegasus. It is worth noting that the wing won even in a Pegasus-style, high T/W configuration!
aero313 - 16/10/2007 10:09 AM QuoteSkyrocket - 28/9/2007 11:11 AMIf i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus. This was a Chandler design. Performance was something like 100 lbs to LEO. Ironically, this vehicle became the GMD booster.
Skyrocket - 28/9/2007 11:11 AMIf i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus.
This was a Chandler design. Performance was something like 100 lbs to LEO. Ironically, this vehicle became the GMD booster.
Thanks, Joe. Yes, Chandler in the the early 90's, under Steve F.'s leadership, indeed "marched to the beat of a different drummer" than the rest of Orbital...
Skyrocket - 16/10/2007 2:33 AM Concerning this earlier incarnation of the Cygnus name for a ground launched Pegasus version, i found a usenet posting citing from a Orbital prospectus from 1992 http://groups.google.com/group/sci.space/browse_thread/thread/2cdb6ec133f1e90d/4eae6420a7be501f?hl=en&lnk=st&q=osc+pegasus+cygnus#4eae6420a7be501f
Actually, that 1990 (!) thread exposes a unique and nowadays rarely-seen view of Orbital's history. Those that follow so-called "new space" would be very well advised to read that fascinating thread... they may find some striking paralells with what Musk and others are trying to do today; what happened to Orbital after those days is a lesson for all of us (including those of us at Orbital that lived it - we tend to forget our own lessons...)
simonbp - 16/10/2007 3:12 PM In that thread, it mentions "Prometheus", a solar-electric LEO-to-GEO transfer stage; did anything ever come of that?
I'm afraid not. But we ended up building DAWN, which has a pretty sizeable JPL -designed and -supplied electric propulsion system!!!
Would it even work in practice? Simon
Technically, yes; for commercial GEOs, the economic trade (recurring cost vs. extra life on station for the same launch mass, vs. increased radiation exposure in the belts, vs. longer time to be placed in service, &tc, &tc) does not work out.
antonioe - 16/10/2007 3:37 PMQuotesimonbp - 16/10/2007 3:12 PM In that thread, it mentions "Prometheus", a solar-electric LEO-to-GEO transfer stage; did anything ever come of that?I'm afraid not. But we ended up building DAWN, which has a pretty sizeable JPL -designed and -supplied electric propulsion system!!!Quote Would it even work in practice? Simon Technically, yes; for commercial GEOs, the economic trade (recurring cost vs. extra life on station for the same launch mass, vs. increased radiation exposure in the belts, vs. longer time to be placed in service, &tc, &tc) does not work out.
Seer - 16/10/2007 4:16 PM If you had a reusable LV , say a Kistler K1, would the business case for a Prometheus type system close? Or would it still make more sense to use an Orbital Transfer Stage? I.e, an expendible?
I suspect that from an economic standpoint, the advantages of a high-performance electric transfer stage would still be overcome by the disadvantages I mentioned earlier, irregardless of the type of LV used to place it in parking or near-parking orbit.
antonioe - 16/10/2007 3:30 PMQuoteaero313 - 16/10/2007 10:09 AM QuoteSkyrocket - 28/9/2007 11:11 AMIf i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus. This was a Chandler design. Performance was something like 100 lbs to LEO. Ironically, this vehicle became the GMD booster.Thanks, Joe. Yes, Chandler in the the early 90's, under Steve F.'s leadership, indeed "marched to the beat of a different drummer" than the rest of Orbital...
antonioe - 11/10/2007 10:29 PMQuotetnphysics - 11/10/2007 4:59 PM Are you considering a cryogenic upper stage for Taurus 2?I would LOVE to! A nice, "mini-centaur" based on a single RL-10... yummy! Unfortunately, my peers think it's asking too much for us to go to a large LOX-kerosene CORE AND a cryo US in one step... they are probably right. So we are currently keeping this idea in the freezer (freezer... cryo.. get it? get it?) as a "planned (ahem!) product improvement".QuoteIt would allow EELV-class payloads to be liftedWell... not quite... but it will allow us to launch our own mid-class GeoComs (the so-called "StarBus" class). Now, whether it would be cost-competitive with Soyuz or Land Launch is another matter...QuoteAlso, would the first stage be SSTO capable?Not even close.
tnphysics - 11/10/2007 4:59 PM Are you considering a cryogenic upper stage for Taurus 2?
I would LOVE to! A nice, "mini-centaur" based on a single RL-10... yummy! Unfortunately, my peers think it's asking too much for us to go to a large LOX-kerosene CORE AND a cryo US in one step... they are probably right. So we are currently keeping this idea in the freezer (freezer... cryo.. get it? get it?) as a "planned (ahem!) product improvement".
It would allow EELV-class payloads to be lifted
Well... not quite... but it will allow us to launch our own mid-class GeoComs (the so-called "StarBus" class). Now, whether it would be cost-competitive with Soyuz or Land Launch is another matter...
Also, would the first stage be SSTO capable?
Not even close.
GncDude - 17/10/2007 9:50 PMChandler?
antonioe - 16/10/2007 2:18 PM Quotenobodyofconsequence - 15/10/2007 6:28 PM What about AirLaunch LLC's drop method with a strategically placed/sized drogue chute?Does the net lift of the wing generate that much advantage over the vertical thrust necessary to make up for the drop?-NofC Early (1987) Pegasus simulation runs said YES in a BIG WAY!!! By the way, this is not obvious....
Early (1987) Pegasus simulation runs said YES in a BIG WAY!!! By the way, this is not obvious....
I quite agree. Wings on boosters are a peculiar concept. Pegasus is in a very exclusive category. What's ironic about it is that most add wings for recovery ... yet its expendable.
But getting back to my first question - you didn't have the AirLaunch drop method in your list of alternatives - what about it?
antonioe - 13/9/2007 7:25 PMO.K., gang, here we go:Ron Grabe, who heads our Launch Systems Group (LSG) was conned into participating in an panel at the AIAA Space 2007 meeting next week in Long Beach ...I gave Ron a couple of VUGraphs ... The picture shows T II next to the lineup of Orbital's space and large subspace rockets, approximately at the same relative scale. ...
O.K., gang, here we go:
Ron Grabe, who heads our Launch Systems Group (LSG) was conned into participating in an panel at the AIAA Space 2007 meeting next week in Long Beach ...I gave Ron a couple of VUGraphs ... The picture shows T II next to the lineup of Orbital's space and large subspace rockets, approximately at the same relative scale. ...
edkyle99 - 18/10/2007 1:20 PMHave any Taurus II/Cygnus sketches made public appearances to date? - Ed Kyle
Not yet; among other things, part of the configuration (stage 2/3 details, the all-important fairing shape) have not been settled yet. Lots of details on Stage 1 guts. Steffy's team is so focused on hard-core engineering that we are not spending any time of fancy graphics, 3-D renditions, etc.
We have detailed Stage 1 propellant, valving and pneumatic schematics, but only a very crude configuration sketch! Brian Winters, the Stage 1 lead (formely the X-34 propulsion lead) must be in pig heaven! Topic of the day: how to unload all the Stage 1 propellant in less than 40 minutes...
The fast unloading? No, the idea is not to have access to the upper part of the vehicle when erected (access only at the level of the base). So if you have to, say, fool around with the payload, you must lower the vehicle and roll it back into the final assembly shed. Zenit does it in less than three hours. Payloaders love it: you can work on the satellite at ground level, indoors, without having to worry about "thunderstorms in the vicinity of the launch pad" stuff...
But to do it, the vehicle must be designed to accomodate those operations... things such as unloading props in 40 minutes (you can't lower the vehicle loaded...)
Jim,
Actually, about 90% of Orbital's Launch Systems Group is based in Chandler - it is a bit more than just a production facility. It was part of the acquisition, circa 1990, of Space Data Corporation by Orbital (not Space Vector) that Antonio referred to earlier. Other than Pegasus and Taurus (and Taurus II, apparently), all other launch vehicle programs are run out of Chandler
Cretan126 - 24/10/2007 8:46 PM Jim,Actually, about 90% of Orbital's Launch Systems Group is based in Chandler - it is a bit more than just a production facility. It was part of the acquisition, circa 1990, of Space Data Corporation by Orbital (not Space Vector) that Antonio referred to earlier. Other than Pegasus and Taurus (and Taurus II, apparently), all other launch vehicle programs are run out of Chandler
Right you are - 40%-45% of the Orbital staff work in Chandler - half of them (more or less) "engineers" and "scientists" (the latter being more of a rank or title that a job description - mostly they do what we would call engineering...) about 45%-50% at Dulles, the rest in various other locations, including Maryland (Greenbelt and Wallops I.) and California (VAFB).
Taurus II/Cygnus (alas! the T II monicker is starting to gell... when General Susan Helms call it "Taurus II" you start wondering...) is being designed by a combined Dulles/Chandler team.
Program Director Dave Steffy, Chief Engineer Mike Dorsch, Deputy PM Kurt Eberly, Stage 1 Manager Brian Winters and about 10-15 more people are at Dulles (actually at a luxurious off-site location dubbed "COSTCO View Estates" by Dave Steffy).
Deputy PM Mike Laidley (former Minotaur PM) and his staff of about 10 are at Chandler, responsible for the Upper Stage, Avionics, Structures (including fairing), Ordnance, specialty engineering (e.g., aero) and EGSE. Needless to say, these numbers will swell to about 50-60 after December.
MGSE, contracts, sales (Bob Richards, who "owns" the product) and vehicle integration is based at Dulles. For the first 5 or so flights, the program is managed out of Advanced Programs Group (yours truly), after that, from Launch Systems Group (Ron Grabe). Similar to what we did with Pegasus 20 years ago.
GncDude - 17/10/2007 9:50 PMQuoteantonioe - 16/10/2007 3:30 PMQuoteaero313 - 16/10/2007 10:09 AM QuoteSkyrocket - 28/9/2007 11:11 AMIf i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus. This was a Chandler design. Performance was something like 100 lbs to LEO. Ironically, this vehicle became the GMD booster.Thanks, Joe. Yes, Chandler in the the early 90's, under Steve F.'s leadership, indeed "marched to the beat of a different drummer" than the rest of Orbital... Chandler?
antonioe - 24/10/2007 10:56 PMTaurus II/Cygnus (alas! the T II monicker is starting to gell... )
Taurus II/Cygnus (alas! the T II monicker is starting to gell... )
aero313 - 25/10/2007 11:31 PMAsk your new Lockmart friends why every Martin Marietta launch vehicle was named "Titan".