SpaceX is slated to launch the Air Force’s first third-generation GPS 3-series satellite no earlier than Dec. 15.A Falcon 9 rocket will deliver the navigation payload to an elliptical transfer orbit ranging between a few hundred miles above Earth to a maximum altitude of nearly 12,550 miles (20,200 kilometers). The first batch of 10 GPS 3-series craft, built by Lockheed Martin, will use on-board propellant to maneuver into their 12,550-mile-high circular orbits.
The GPS 3 satellite, designated Space Vehicle 1, or SV01 — rode an Air Force C-17 cargo plane from its Lockheed Martin factory in Colorado to Titusville, Florida, on Aug. 21 to begin launch preparations at the Astrotech spacecraft processing facility.The first of the GPS 3-series satellites to launch has been nicknamed “Vespucci” in honor of Amerigo Vespucci, the Italian explorer for whom the Americas were named. While the spaceraft was the first off Lockheed Martin’s GPS assembly line and will be first to go into space, it’s also known as the GPS 3-02 mission because it was the second GPS 3-series satellite assigned to a rocket.
The new satellite will also be the first GPS craft to broadcast the L1C navigation frequency, ensuring the U.S. navigation fleet’s compatibility with other networks, such as Europe’s Galileo system. The GPS 3 satellites will provide more accurate position measurements and debut improved anti-jamming features, but the multibillion-dollar program has been hamstrung by trouble developing ground control software.“The shipment of the first GPS 3 satellite to the launch processing facility is a hallmark achievement for the program,” said Lt. Gen. John Thompson, SMC commander and Air Force program executive officer for space. “The modernization of GPS has been an outstanding collaborative effort and this brings us another step closer to launch.”
The satellite will also be the first GPS craft to be attached to its launcher horizontally. The Air Force said the launch, which had been scheduled for October, was delayed to December to complete qualification and validation work on SpaceX’s upgraded Falcon 9 Block 5 rocket.
Some confirmations of various GPS III facts from this article--is there anything new?:Air Force releases new target dates for upcoming military launchesLaunch date and flight profile:QuoteSpaceX is slated to launch the Air Force’s first third-generation GPS 3-series satellite no earlier than Dec. 15.A Falcon 9 rocket will deliver the navigation payload to an elliptical transfer orbit ranging between a few hundred miles above Earth to a maximum altitude of nearly 12,550 miles (20,200 kilometers). The first batch of 10 GPS 3-series craft, built by Lockheed Martin, will use on-board propellant to maneuver into their 12,550-mile-high circular orbits.
The horizontal integration tidbit is new to me, although maybe you folks have heard that before. SpaceX still doesn't have vertical integration capability, does it? Seems all the payloads have elected to go horizontal rather than pay for VI?
Quote from: cscott on 09/12/2018 02:56 pmThe horizontal integration tidbit is new to me, although maybe you folks have heard that before. SpaceX still doesn't have vertical integration capability, does it? Seems all the payloads have elected to go horizontal rather than pay for VI?SpaceX has not built out any VI capability yet, but they have done studies for the Air Force on how they would do it when needed. The government probably still has some satellite programs requiring vertical integration.
Yes. But my point was that so far all those "programs requiring vertical integration" have ended up horizontal when it came time to fly.
Quote from: cscott on 09/13/2018 02:45 pmYes. But my point was that so far all those "programs requiring vertical integration" have ended up horizontal when it came time to fly.none of those programs have flown on Falcon. GPS-III program has been basically concurrent with Falcon 9
Quote from: Jim on 09/13/2018 02:48 pmQuote from: cscott on 09/13/2018 02:45 pmYes. But my point was that so far all those "programs requiring vertical integration" have ended up horizontal when it came time to fly.none of those programs have flown on Falcon. GPS-III program has been basically concurrent with Falcon 9So the GPS-III satellites have been built with horizontal integration in mind? Was that because SpaceX uses horizontal integration?
Quote from: oiorionsbelt on 09/13/2018 10:25 pmQuote from: Jim on 09/13/2018 02:48 pmQuote from: cscott on 09/13/2018 02:45 pmYes. But my point was that so far all those "programs requiring vertical integration" have ended up horizontal when it came time to fly.none of those programs have flown on Falcon. GPS-III program has been basically concurrent with Falcon 9So the GPS-III satellites have been built with horizontal integration in mind? Was that because SpaceX uses horizontal integration?GPS-III sats are built on Lockheed Martin's A2100 commercial satellite bus. So, given that the payloads aren't specialized structures requiring VI, it's not that surprising that they have been capable of horizontal integration from the start. I don't think it is in any way reasonable to have classed them as part of a "program requiring vertical integration."
Quote from: deruch on 09/13/2018 11:05 pmQuote from: oiorionsbelt on 09/13/2018 10:25 pmQuote from: Jim on 09/13/2018 02:48 pmQuote from: cscott on 09/13/2018 02:45 pmYes. But my point was that so far all those "programs requiring vertical integration" have ended up horizontal when it came time to fly.none of those programs have flown on Falcon. GPS-III program has been basically concurrent with Falcon 9So the GPS-III satellites have been built with horizontal integration in mind? Was that because SpaceX uses horizontal integration?GPS-III sats are built on Lockheed Martin's A2100 commercial satellite bus. So, given that the payloads aren't specialized structures requiring VI, it's not that surprising that they have been capable of horizontal integration from the start. I don't think it is in any way reasonable to have classed them as part of a "program requiring vertical integration." Do you have an example of a technical reason to require VI? I've been under the impression it's mostly about packaging to hide the satellite from view at all times.
Think large space-based cameras with precisely-aligned optics, designed so that all g-loading will always be in the same direction ("down, when mounted on the rocket").
Quote from: cscott on 09/14/2018 08:38 amThink large space-based cameras with precisely-aligned optics, designed so that all g-loading will always be in the same direction ("down, when mounted on the rocket").That would mean they would need to transport those payloads vertically on the ground as well, for example in trucks and planes. Due to the cylindrical shape of these payloads, I don't believe that is done. That is, they are built up either horizontally or vertically (or both), rotated to horizontal if necessary for transport, and then rotated to vertical for integration on the rocket. All SpaceX is doing is horizontal integration, and then just rotating the whole stack. Also, the vibrational side loads during ascent are quite high, from to 0.5g to 1.5g depending on the vehicle.
But "[t]he satellite will also be the first GPS craft to be attached to its launcher horizontally" according to the release. If I'm understanding Jim properly, he's suggesting that the reason is more to do with this generation of GPS satellite (eg, switching to an atomic clock implementation that doesn't require a delicate optical train) than feedback from SpaceX HI-vs-VI costs.
That would mean they would need to transport those payloads vertically on the ground as well, for example in trucks and planes.
Quote from: Steven Pietrobon on 09/14/2018 10:22 amThat would mean they would need to transport those payloads vertically on the ground as well, for example in trucks and planes. Not true. They have have additional supports in place while being transported horizontal. Or the spacecraft could be delivered in sections, with final assembly at the launch site.
Quote from: Jim on 09/14/2018 03:47 pmQuote from: Steven Pietrobon on 09/14/2018 10:22 amThat would mean they would need to transport those payloads vertically on the ground as well, for example in trucks and planes. Not true. They have have additional supports in place while being transported horizontal. Or the spacecraft could be delivered in sections, with final assembly at the launch site.I'm still having trouble picturing the specific physical requirements or reasons for a payload being required to stay vertical its entire life. Is it truly a known structural limit/margin that is being enforced, or is it sometimes just a case that the engineering study hasn't been done to "certify" that the payload can handle some loads in a horizontal versus vertical orientation?This GPSIII change makes it sound more like the latter, where it turns out its been fine for HI all along, but was simply never certified to do so because the launchers were capable of VI and it wasn't worth the money spent to certify for HI before.Probably completely wrong about all this but I'm hitting post anyway because I do find these inane details fascinating in their own right.