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SpaceX launches first U.S. national security space mission

reuters.com

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Re: SpaceX launches first U.S. national security space mission

#41

Post by Phlarp »

sneak wrote: post #40
Phlarp wrote: post #38

Earlier quoted context omitted.

Civilian use is wide yes, but this is only because it is provided for free by DoD. None of those uses would be economically viable if they had to bear the costs of developing, launching and maintaining the system. Keeping track of the boats and missiles pays the bills. Everything else is just a happy accident of zero marginal use cost.

It’s not provided for free by DoD. We pay for it with taxes. Civilians do indeed bear the cost in full. I am not sure I understand where you are going with this. Doing war stuff with GPS does not generate any revenue. It costs American citizens the same amount of dollars regardless of whether it is used for war or not. It’s not national, and it’s not security.

Most of the world does not pay US taxes, it's completely free to them.

At this point I just assume you are trolling.

Re: SpaceX launches first U.S. national security space mission

#42

Post by debatem1 »

_0w8t wrote: post #18
walrus01 wrote: post #17

Earlier quoted context omitted.

Inclination changes are very "expensive" in terms of delta-V: https://www.google.com/search?q=plane+change+delta+v&ie=utf-...

Interesting. It makes sense then to launch such satellites closer to poles. That explains why there are plans in Norway to build a space launching site at around 70 latitude near Tromsø.

Tromso is also a hub for satellite communications and comms companies, which helps.

Re: SpaceX launches first U.S. national security space mission

#43

Post by debatem1 »

dingaling wrote: post #23
DeonPenny wrote: post #22

Earlier quoted context omitted.

yeh cause doing DOD projects from an American Company to increase GPS is a good thing

Not for those on the receiving end of JDAMs SpaceX is taking defense money to launch satellites that are primarily for military use in guiding platforms that deliver things to lethal terminal effect. That's just as martial as Raytheon building the Tomahawk guidance module. Thought experiment: would SpaceX take Russian money to launch GLONASS birds? I'd wager not because it would be 'immoral'.

SpaceX would almost certainly do so if Russia would let them. They launched PAZ, which was a Spanish spy satellite and have launched several cargoes for governments like Qatar and Thailand.

Edit: just to expand on this a bit, SpaceX is and always has been a US federal government contractor. If you have a problem with that as a potential hire you probably do not take that job. But if the US government doesn't have a problem with a launch, SpaceX is also a money-making enterprise and I would bet they'd take whatever launches people would pay them for.

Re: SpaceX launches first U.S. national security space mission

#44

Post by njarboe »

khuey wrote: post #35
njarboe wrote: post #34

Earlier quoted context omitted.

Correct. But the question is, if one wants an inclined orbit, why can't you launch out of Kennedy to the northeast or out of Vandenberg to the southwest. Wouldn't this save all the delta v correction you need to do after getting into an equatorial or polar orbit and then transitioning to an inclined orbit?

You can do both of those. NRO missions have launched out of Kennedy to the northeast (e.g. NROL-76) and Vandenberg to the southwest (e.g. NROL-25).

According to bisby at the head of this thread, one of the reasons that SpaceX did not recover the booster is that the rocket had to enter an inclined orbit. Maybe it did launch in the direction for an inclined orbit and used a little extra fuel, like a polar orbit does, due to the fact that you don't have all the speed of the spinning earth adding to your orbital velocity. I didn't know that the spinning Earth speed was a significant factor on payload to orbit of rockets.

Re: SpaceX launches first U.S. national security space mission

#45

Post by pilsetnieks »

the8472 wrote: post #39
5436436347 wrote: post #11

Earlier quoted context omitted.

Two things: 1. A GPS satellite is in a very high orbit compared to LEO, and so all stages were requested to burn to completion, to ensure the satellite has enough margin to reach that orbit. 2. The second stage ends at a ~800 km orbit, while the satellite itself needs to increase this to ~12,000 km (I'm rounding these numbers). The sat has to carry enough on-board propellant to raise it's orbit that much which necess…

> while the satellite itself needs to increase this to ~12,000 km (I'm rounding these numbers). The sat has to carry enough on-board propellant to raise it's orbit that much which necessarily increases it's wet-weight due to the rocket equation. Looks like they use a liquid fuel thruster lift it to its final orbit[0]. Some other missions have used ion engines for orbit raising[1]. I wonder why that wasn't incorporate…

Ion engines still need propellant, you might be thinking of the so far unproven EM drive.

Re: SpaceX launches first U.S. national security space mission

#46

Post by dba7dba »

dingaling wrote: post #23
DeonPenny wrote: post #22

Earlier quoted context omitted.

yeh cause doing DOD projects from an American Company to increase GPS is a good thing

Not for those on the receiving end of JDAMs SpaceX is taking defense money to launch satellites that are primarily for military use in guiding platforms that deliver things to lethal terminal effect. That's just as martial as Raytheon building the Tomahawk guidance module. Thought experiment: would SpaceX take Russian money to launch GLONASS birds? I'd wager not because it would be 'immoral'.

I am no expert but me thinks more lives have been saved due to the much increased safety in navigation due to GPS system, than the lives lost due to JDAMs.

And not to mention the very existence of computer, CPU, internet and pretty much a lot of modern technology we take granted for were conceived, developed, refined with funding from various governments paying for them, because they involved in active/inactive wars, including US, UK, Russia etc.

Re: SpaceX launches first U.S. national security space mission

#47

Post by walrus01 »

debatem1 wrote: post #42
_0w8t wrote: post #18

Earlier quoted context omitted.

Interesting. It makes sense then to launch such satellites closer to poles. That explains why there are plans in Norway to build a space launching site at around 70 latitude near Tromsø.

Tromso is also a hub for satellite communications and comms companies, which helps.

KSAT/Kongsberg satellite services punches well above its weight in terms of how important it is to global LEO and polar/inclined orbit data relay services.

Re: SpaceX launches first U.S. national security space mission

#48

Post by dlgeek »

trhway wrote: post #6

no employee protests against DOD projects :)

Not going to happen with SpaceX. Their work force skews very conservative/nationalist. They used to chant "USA! USA!" during every successful launch - you can hear it on their old webcasts. I think this got some media attention a while back and they mostly stopped for the more recent launches.

Re: SpaceX launches first U.S. national security space mission

#49

Post by xvilka »

Phlarp wrote: post #38
sneak wrote: post #28

Earlier quoted context omitted.

No, its primary purpose is civilian. Its original and occasional purpose is military, sure, but as I mentioned, it is used far more widely now, by several orders of magnitude. Its military applications are so eclipsed now by non-war-related uses that the military origins are practically irrelevant.

Civilian use is wide yes, but this is only because it is provided for free by DoD. None of those uses would be economically viable if they had to bear the costs of developing, launching and maintaining the system. Keeping track of the boats and missiles pays the bills. Everything else is just a happy accident of zero marginal use cost.

Galileo GNSS proves you wrong, since initially was designed primarily for civilian use.

Re: SpaceX launches first U.S. national security space mission

#50

Post by ricw »

Phlarp wrote: post #41
sneak wrote: post #40

Earlier quoted context omitted.

It’s not provided for free by DoD. We pay for it with taxes. Civilians do indeed bear the cost in full. I am not sure I understand where you are going with this. Doing war stuff with GPS does not generate any revenue. It costs American citizens the same amount of dollars regardless of whether it is used for war or not. It’s not national, and it’s not security.

Most of the world does not pay US taxes, it's completely free to them. At this point I just assume you are trolling.

Every GPS device pays a couple of cents to use the system, regardless of country. Whilst this initially may have been peanuts, I’d be pretty sure that this is a self-paying system by now.
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