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2 hours ago, Hannu2 said:

If I remember correctly, there was a delay in some Shuttle launch because there was bad weather on some airport intended to use in some abort situation. But it was more than a decade ago and I am not sure. Did they have suitable airbases for abort in Africa?

Canary Islands, I think? Let me see if I can dig up Shuttle abort sites.

Ah, so close. Azores. They also had four identified runways in Europe.

The only actual abort in the Shuttle history was an abort-to-orbit when one engine failed for STS-51-F.

Edited by mikegarrison
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I think they had two Abort TranOceanic sites for each flight. An article I shared a few pages back was a flight director talking about having to make the weather call for shuttle re-entry and how they had to be as sure as possible what the weather would be at the landing site in 2h time because once the call was made there was no going back!

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4 hours ago, mikegarrison said:

Canary Islands, I think? Let me see if I can dig up Shuttle abort sites.

Ah, so close. Azores. They also had four identified runways in Europe.

The only actual abort in the Shuttle history was an abort-to-orbit when one engine failed for STS-51-F.

There were numerous aborts prior to SRB ignition, when startup transients on the SSMEs were off-nominal. 

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5 minutes ago, sevenperforce said:

There were numerous aborts prior to SRB ignition, when startup transients on the SSMEs were off-nominal. 

I was talking about flight abort options related to weather (so it mapped somewhat to SpaceX ops WRT weather conditions in the recovery area for the booster).

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I, for one, am not surprised. Developing a dedicated smallsat launcher seems very risky, when big guys on the market offer rideshare flights semi-regularly. On a commercially tried and proven hardware to boot, which I'm sure matters when you want to buy insurance for your satellite.

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1 minute ago, Scotius said:

I, for one, am not surprised. Developing a dedicated smallsat launcher seems very risky, when big guys on the market offer rideshare flights semi-regularly. On a commercially tried and proven hardware to boot, which I'm sure matters when you want to buy insurance for your satellite.

Bespoke orbits can matter, but if the cost/kg allows for added size/propellants, the sat might be able to reach a target orbit itself.

The launch is 1M$ as a rideshare, vs 6M$ to target orbit. You could literally up the size of the sat from 200kg to nearly 1200kg, and still come in cheaper than the smallsat launch. You could make it slightly larger, with that size a propulsion element and get to any orbit you like (time would be a trade off vs mass, smaller and ion thruster, larger and a kick stage).

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4 hours ago, sevenperforce said:

There were numerous aborts prior to SRB ignition, when startup transients on the SSMEs were off-nominal. 

I was talking about in-flight aborts. While they did have all these abort scenarios like landing on the Azores or making a desperation glide back to Florida, they were never used except for the one abort-to-orbit. (That might have gone worse. I seem to recall that they later decided it was the engine sensors malfunctioning rather than the engines, and if they hadn't overridden the automatic engine shutdowns and prevented a second engine from also shutting down, they might have actually ended up in one of those other abort scenarios.)

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12 minutes ago, mikegarrison said:

I was talking about in-flight aborts. While they did have all these abort scenarios like landing on the Azores or making a desperation glide back to Florida, they were never used except for the one abort-to-orbit. (That might have gone worse. I seem to recall that they later decided it was the engine sensors malfunctioning rather than the engines, and if they hadn't overridden the automatic engine shutdowns and prevented a second engine from also shutting down, they might have actually ended up in one of those other abort scenarios.)

Correct -- except that at that point in the flight, they didn't have enough velocity to make even a contingency abort without at least two engines. If a second engine had crapped out it would have been LOCV. 

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2 hours ago, tater said:

Looks like the solar panels has cover and it wearing an cape. Don't get the cape? yes you would want to protect the inside of the trunk but the cape don't do that so its more like the plastic cover on stuff you buy like tires so they don't get scratched :) 

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6 minutes ago, sevenperforce said:

With all the buzz about Dragon 2, looking again at Dragon XL.

NSF-2020-03-27-18-54-00-196.jpg

Getting to NRHO at 300 s isp means it needs to be 18% props. FH's side-core-reuse throw to TLI is what, 18 tonnes? I am surprised it only delivers 5 tonnes of cargo.

Why would it need to deliver more? The crew of whatever is put in the lunar orbit probably won't be any bigger than the one on ISS.

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