[deleted]
SpaceX NASA returning human spaceflight to United States today (canceled)
301–310 of 340 posts
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#302It looks like the launch will be scrubbed due to the weather, lightning risk during propellant loading is too high. edit: yep, launch scrubbed. Too bad! But better safe than sorry, especially today with a crewed vehicle. Does anybody know if the crew dragon comes with different weather restrictions for LOX loading?
Can someone ELI5 why they sometimes need to have an “instantaneous launch window” that can’t be pushed even by a few minutes?
Physical constraints resulting in sub-optimal orbits increasing chance of mission failure or FAA rules limiting options for launch.
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#303It looks like the launch will be scrubbed due to the weather, lightning risk during propellant loading is too high. edit: yep, launch scrubbed. Too bad! But better safe than sorry, especially today with a crewed vehicle. Does anybody know if the crew dragon comes with different weather restrictions for LOX loading?
Can someone ELI5 why they sometimes need to have an “instantaneous launch window” that can’t be pushed even by a few minutes?
Long list but one of the big ones:
ISS travels at 7.6 km/s. Thats a lot of kms in those few minutes
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#304It looks like the launch will be scrubbed due to the weather, lightning risk during propellant loading is too high. edit: yep, launch scrubbed. Too bad! But better safe than sorry, especially today with a crewed vehicle. Does anybody know if the crew dragon comes with different weather restrictions for LOX loading?
Can someone ELI5 why they sometimes need to have an “instantaneous launch window” that can’t be pushed even by a few minutes?
It depends on the target orbit. For launches to the ISS, you have to launch at the correct instant because even a few minutes later means the ISS is so far ahead it will take much longer, and use more propellant, to rendezvous.
I think they could probably delay a few seconds without too much trouble, but I guess the extra complication of recalculating the rendezvous isn't worth it because most of the time a few seconds won't matter anyway.
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#305They finally announced it publicly: https://twitter.com/SpaceX/status/1265739654810091520
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#306It looks like the launch will be scrubbed due to the weather, lightning risk during propellant loading is too high. edit: yep, launch scrubbed. Too bad! But better safe than sorry, especially today with a crewed vehicle. Does anybody know if the crew dragon comes with different weather restrictions for LOX loading?
As I understand the timing, they scrubbed around T-15:00, and the first stage propellant loading started at T-35:00. https://www.spacex.com/launches/
So is that lightning strike concern limited to the second stage?
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#307The cold war is back, the fashion is back and out of all the things that are back I am glad that the USA is back in space flights. Wish you the best luck and hope that this will lead to some serious competition. Soyuz is great but we need to do more as species.
> do more as species Space exploration and exploitation is awesome, but shouldn't the first items on the "do more as species" todo list be about taking care of earth?
https://launiusr.wordpress.com/2012/02/08/why-explore-space-...
in general, there's a lot of items on the urgent list, there's so much money to go around and you don't want to invest everything in endeavour X only for Y to be worse and catch you by surprise.
so you allocate some budget to secondary research as well. NASA doesn't even burn that much in the grand scheme of things.
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#308Does anyone else feel super excited? I guess this was the feeling my parents had when they watched men landing on the Moon...
I'll admit I went and looked at SpaceX open positions...
There are tons of software openings! If you're excited about space, go check out https://www.spacex.com/careers.
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#309Earlier quoted context omitted.
The US kind of has to preserve at least a minimal manned spaceflight capability in case we really need it for something in the future. If we completely lose the infrastructure, supply chains, and institutional knowledge it will become impossible to restart from scratch in a reasonable time frame. Think about it like paying for an insurance policy. It's worth doing even if it eats into the budget for unmanned satellit…
I don't think the US as a nation (or anyone in particular, for that matter) "has to" do anything. As usual, there are simply various diverse interests - military, commercial, scientific - and it's up to these interested parties to do what and when they think benefits them.
Yes. GP said "kind of has to" and then went on to explain the incentives.
Re: SpaceX NASA returning human spaceflight to United States today (canceled)
#310Earlier quoted context omitted.
Can someone ELI5 why they sometimes need to have an “instantaneous launch window” that can’t be pushed even by a few minutes?
Long list but one of the big ones: ISS travels at 7.6 km/s. Thats a lot of kms in those few minutes
At that speed, you could run a marathon in 5.55 seconds.