Payload designated as US-250
ULA note mission success!
If I understand the forum timetag behaviour correctly, you posted this at 2158 GMT which was 4h15 min after launch - this is about 1.5 hours EARLIER than one might normally expect for a 3-burn GEO delivery, but is consistent with a fast ascent using
a higher-than-normal transfer orbit apogee, say 200 x 40000 km, and a third burn at around GEO altitude before apogee was
reached. So I was originally surprised by the early time of this announcement, but I guess it's ok. Another implication
is that if perigee was over the equator (which doesn't have to be true) the inclination might be in the 5-7 degree range
as we've seen for some past SIGINT missions, rather than being 0 to 1 deg.
It is also possible that the "successful launch" announcement was made before the final burn - I believe that has happened before on NRO launches. I'd imagine if that were the case we'd probably be left with a near-GEO Centaur, so hopefully SeeSat will be able to shed some light on it before too long.
I don't believe you'd ever see ULA announcing mission success before spacecraft separation.
I've seen it before. To give one example from a past thread here, the "successful launch" press release for NROL-26 was posted an hour after liftoff. Spacecraft separation occurred in GSO so there is no way powered flight could have been completed before it was announced in that case. I think it is at least possible that the same is true here.
Yeah, you really have to read the fine print. This release talks about getting to orbit, while the L-26 release did not.
GoPro view from the pad (always love these):
Interesting to see - and hear - the big spherical LC 41 LOX tank venting immediately after liftoff. Does anyone know if the entire tank load is vented away after a liftoff?
- Ed Kyle
No!!!
So they are just venting the lines in this video?
- Ed Kyle
GoPro view from the pad (always love these):
Interesting to see - and hear - the big spherical LC 41 LOX tank venting immediately after liftoff. Does anyone know if the entire tank load is vented away after a liftoff?
- Ed Kyle
No!!!
So they are just venting the lines in this video?
- Ed Kyle
They are venting the tank at that point. What did you mean by the word "load"? To me, that sounds like you're talking about liquid.
They are venting the tank at that point. What did you mean by the word "load"? To me, that sounds like you're talking about liquid.
Liquid oxygen will completely boil off into vapor if the tank vent is left open indefinitely, but what I suspect is happening in the video is that the extra pressure that is allowed to build up in the tank to move propellant to the launch vehicle is being released post-launch. Once the pressure drops to a nominal storage value, the vent will close. Maybe.
I would like to know more about the launch pad LOX storage sphere properties. How long can LOX be stored there, etc?
- Ed Kyle
I would imagine there are KSC docs from LC-39 that are already public or could be FOIA'd with that information. It's pretty simple physics, with engineering well known in many industries.