Sorry if this has been asked before, but...What are the relative (dis)advantages of horizontal and vertical payload integration?Why does Soyuz in Guiana have its payloads integrated vertical, while Soyuz at Baikonur have its payloads integrated horizontally?Why is (IIRC) the DoD requiring vertical integration for all of its payloads?Thanks for any info you can provide. :-)
Vertical provides 360 access at the pad
... With horizontal integration, the rocket has to be integrated without payload, then rolled to the pad for propellant testing, then rolled back to the hanger for payload integration, then rolled *back* to the pad to be reconnected yet again to the propellant and electrical umbilicals, etc...
Quote from: Jim on 10/23/2011 06:33 pmVertical provides 360 access at the padSpaceX obtain 360 degree access to their launcher in the horizontal integration facility by simply providing a motorised rotator mechanism on the stand...
I was talking spacecraft access.
But anyways, can't rotate the vehicle when attached to the launcher
Are there any advantages to horizontal integration? I guess that the buildings are cheaper and you don't have all the safety faff that comes with working at height...
The vertical integration of Soyuz payloads is the primary difference in the Spaceport's launch vehicle processing as compared to the long-operating Soyuz facilities at Baikonur Cosmodrome in Kazakhstan and Plesetsk Cosmodrome in Russia. This vertical procedure enables payloads to be installed as traditionally performed with Western launch systems – and is a change from the horizontal integration utilized at the Baikonur and Plesetsk Cosmodromes.
If your LV is integrated horizontally, then substantial infrastructure is required for vertical payload integration, as we see with Soyuz at CSG.If your LV already has significant elements that are integrated vertically, then the additional infrastructure required for vertical payload integration is much less significant. Large solids pretty much rule out horizontal LV integration.
Quote from: Jim on 10/23/2011 08:20 pmI was talking spacecraft access. So was I...QuoteBut anyways, can't rotate the vehicle when attached to the launcherWhy not? Do you mean that you can't rotate the vehicle when attached to the strongback? Because I guess that's true.
Quote from: edkyle99 on 10/23/2011 07:25 pm... With horizontal integration, the rocket has to be integrated without payload, then rolled to the pad for propellant testing, then rolled back to the hanger for payload integration, then rolled *back* to the pad to be reconnected yet again to the propellant and electrical umbilicals, etc...Is that typical in practice? Looking at, e.g., Sooyuz, the first time the LV sees the pad appears to be after everything is integrated: (1a) integrate payload + upper stage; (1b) integrate 1st + 2nd + 3rd stage; (2) integrate 1a + 1b; (3) rollout complete stack to pad.edit: correction, 3rd stage vs. upper stage.
At Baikonur, the Soyuz launchers undergo an integrated test on the pad two days prior to launch. I'm not sure if that includes propellant loading. I doubt very much that the hardware doesn't see its first cryo loading until launch day.
Suppose you have an all-liquid launch vehicle suitable for horizontal integration and intended to carry both unmanned and manned payloads. Being as the launch complex would need to provide a means for passengers to board the payload atop of the vertical stack on the launch pad, does it make any sense to integrate the payload horizontally, or does it make much more sense to incorporate vertical payload integration capability into the same pad facility used for passenger ingress? Further suppose that your company is well-known for maximizing commonality...You see what I'm getting at. I wouldn't be surprised if SpaceX moves to vertical payload integration at some point. The combination of horizontal off-pad LV integration and vertical on-pad payload integration seems to be ideal from an operational standpoint, and the higher capital investment is a lot easier to justify if you want to support manned launches from the same pad.
Wet dress rehearsals are, or have been, typical in western practice (i.e. at Kourou, Cape Canaveral, and Tanegashima). Soyuz went through such a test at Kourou prior to spacecraft mating.
At Baikonur, the Soyuz launchers undergo an integrated test on the pad two days prior to launch. I'm not sure if that includes propellant loading. I doubt very much that the hardware doesn't see its first cryo loading until launch day. - Ed Kyle
One advantage of integrating the launch vehicle and rolling it out to the pad horizontally is that it minimises the time on the pad, allowing for a rapid re-use of launch pads.