COMMERCIAL VEHICLE SPARES : Now... would a small RLV be useful in supporting such a constellation?Yes -- but in a different way, and potentially with some slightly differing market-driven requirements, than this thread seems to be discussing. Building and installing those spare satellites on orbit costs money. The companies gladly pay this to provide assured services to their customers,but they would like to minimize this sunk additional cost. One way of doingthat is to make highly reliable satellites -- so the satellites don't blink out, or do so at a lower rate. (There's a trade here of course, betweensupremely expensive highly reliable satellites, and the cost of less expensiveand slightly less reliable satellites but needing more of them.) Another way is to put a lower level of service protection on-orbit initially -- say with fewer spares -- and only launching additional spareswhen the system looks like it's going to deplete the installed on-orbit levelof sparing and service protection. The problem with that approach is thatyou need to have fairly rapid launch capability -- and optimally would like to be able to call up a launch provider and say something like "I need a launch in 2 days", and get one scheduled. (Current systems require from 18-30
COMMERCIAL VEHICLE SPARES : Well, yes, but... If memory serves, Iridium has 11 satellites perplane and one spare per plane. One of the satellites has alreadyfailed, leaving that plane with zero spares (I would imagine they haveplans underway to fix this, but as far as I know it means adding alaunch, since I think the second launch to that plane was already fullat 7 satellites). If you think about it a little bit, money is noobject (within reason) if a launcher can deliver on a replacementlaunch with 6 months (or so) lead time instead of 18 (and likewise forthe payload). Or maybe they have already booked "extra" launches forthis contingency, I don't know.As noted above, Iridium is already at the minimum number of on-orbitspares.This doesn't eliminate the need for on-orbit spares, I don't think. Imean, you are going to have a maximum of two launch windows a day, andif we make some assumptions (possibly changeable) about on-orbitcheckout and such, this isn't going to help if people's phones havestopped working when the broken satellite is overhead. Now, toreplace the on-orbit spare after you put it into service, then this isa real need, but with lead time probably on the order of weeks tomonths rather than hours. Which is what I was getting at with myspeculation above about procuring extra launches (or options forsame, or trying to pay other customers to be bumped, or whatever mightwork. Wales probably knows more than I do about what businessarrangements are being considered for this).
COMMERCIAL VEHICLE SPARES : This was a response to a comment that you could get satellites up justas fast with a large fleet of slow turnaround vehicles and I overdid ita bit.What my customers have said is that they want to retain that level ofredundancy at all times if they can and when one fails they want to getanother up there as quickly as possible. My vehicle will have aturnaround time of 2 days to start and less later and that is attractiveto them. We will achieve this through a maximal use of aircraftpractices and operations. It also is more inexpensive than those thatrequire a large second vehicle for operations (i.e. the 747 of Kelly orthe tanker of Pioneer). That extra vehicle allows their launcher to getto orbital altitudes and use a star rocket motor to deploy but that is
COMMERCIAL VEHICLE SPARES : well no...I will agree in your example but it doesnt apply to myapplication. We did the analysis and we can do it cheaper our way.BTW...for payload launch we are actually TSTO...its just that our firststage, the Cosmos Mariner, does the brunt of the work and is fullyreusable and our second stage is a cheap single stage rocket. We optedfor this rather than schemes that require a second vehicle of the sizeof a tanker or a 747. This scheme is much cheaper.On Wed, 22 Oct 1997 08:35:20 -0500, "Dr. Norman J. LaFave" wrote:But Columbia, one-quarter of the Shuttle fleet, won't be used forSpace Station at all, and the number of non-Station NASA flightsin coming years is small. Hence, USA wants to use Columbia onsome commercial missions. More power to them, in my opinion.
COMMERCIAL VEHICLE SPARES : Actually, the heaviest Shuttle (and the relevant one, Columbia) isabout 180,000 lbs.But what about two 9,000 lb satellites? A couple of HS-601sper launch, maybe? That's better than an Ariane 4 or 5 can do.The marginal costs of a few extra Shuttle launches per year, if USAcan get the total costs down a little more, isn't that expensive.Anti-competitive, perhaps, but not too expensive. And who wouldcomplain about anti-competitive practices of Shuttle? LockMartand Boeing are the only two major players in the US, and eachhas a 50% stake in USA. Europe can complain, but they can beheld at bay until they prove that Ariane 5 isn't doing exactly thesame thing. Besides, they don't seem to be able to build Arianesfast enough to meet demand.But we're paying to maintain it anyway. If USA can start sellingtwo or three Shuttle launches per year and making some money,then maybe how much we pay to maintain it will come down alittle.
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