SpaceX launches first U.S. national security space mission | Hacker News Reader

SpaceX launches first U.S. national security space mission

reuters.com

85 pointsjonbaer66 comments

I gather this was Falcon 9's first EELV-certified mission, but to call it its first national security mission is quite the overstatement. Falcon 9s have already launched an NRO spy satellite, the Air Force X-37B, and the mysterious Zuma.

More importantly it is SpaceX's 21st launch of the year. Making 2018 the year with the most launches ever. One of the things that contributes to this is a stock of 'previously flown' boosters that allowed for more launches without having to build more engines and boosters. As the cadence improves the financial picture for SpaceX only gets better as far as I can tell.

Do they mean first "successful" launch to orbit? I thought the launch where the payload failed to separate was the first launch, even though the launch was a success and the deployment failed. Why is this launch considered first?

They've successfully launched successful national security missions before that successfully separated (e.g. NROL 76). The headline is just wrong.

I think it is the first satellite in this particular set of related launches.

SpaceX had to use a fully expendable Falcon for this launch. What makes a GPS satellite so heavy?

They’re in geostationary orbit, which is much higher.

No GPS sat's are in GEO - they're all in MEO, which is about half as high, though comparative in terms of dV requirement.

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 necessarily increases it's wet-weight due to the rocket equation.

Still SpaceX routinely recovers the first stage after launching geostationary communication satellites. I thought GPS should be lighter as they are closer to Earth and needs to send much less information in their signal, so the power requirements and size of Solar panels should be lower.

This sattelite was some 8000kgs, vs. 4000-ish kgs for the previous-generation GPS satellites, if I remember correctly.

Any idea why their weight increased so much?

The latest generation of GPS satellites has more antennas and more powerful transmitters. This improves signal reception and reduces the impact of jamming.

GPS as received by a small hockey-puck sized antenna is a VERY weak signal, like -140 to -150dB. It only works because the channel size is so narrow and the modulation is very rudimentary. Having a satellite with much larger photovoltaic arrays and really powerful transmitters is one method to overcome regional jamming.

I wouldn't be surprised if the satellites had additional, classified capabilities.

Looks like GPS-III 3,880 kg at launch. That's fairly hefty, but Falcon 9 has launched other, more massive satellites all the way to GTO (Geostationary Transfer Orbit).

The only information I can find on why this one was so energy intensive has to do with the high inclination the GPS satellite has to be in (55 degrees), which is pretty far off from inclination of the launch pad in Florida.

Wikipedia says this launch was originally planned on a Delta IV. That would make sense because it has higher specific impulse hydrogen engines. The Falcon does well in LEO, but improved Isp really helps as you go farther out.

Here's a video comparing ULA's rockets to SpaceX: https://www.youtube.com/watch?v=QoUtgWQk-Y0

> 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 incorporated into the GPS design.

[0] https://en.wikipedia.org/wiki/Lockheed_Martin_A2100 [1] https://space.skyrocket.de/doc_sdat/ses-12.htm

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

Ion engines need propellant, but they need a lot less of it to achieve a similar result as a traditional rocket engine.

3. USAF requires the upper stage do a deorbit burn to avoid long lived high altitude space debris.

According to the SpaceX stream, it was a combination of satellite weight, high orbit, and inclination change (tilting the orbit)

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.

I think it is mostly about the path the rocket is allowed to travel during launch. In the US, for equatorial orbits, one launches from Cape Kennedy to the east, and for polar from Vandenburg to the south. Maybe off angle launches aren't allowed so a lot of correction is needed after the satellite reaches orbit to get to an inclined orbit? I am not an orbital mechanics specialist or space launch planner. Corrective comments are encouraged.

Vandenberg is mostly used for polar orbit launches because it's a path over the ocean. Not possible to launch eastbound from there because first stages would fall on populated areas. This is also the reason why the Israeli space program launches into rare retrograde orbits (opposite direction of earth's rotation), westbound over the ocean, because they don't want to drop 1st stages on their eastern neighbours.

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.

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.

Did they originally intend to use a bigger rocket? It seems unlike them to throw one away at any price.

This rocket was worth billions in opportunity dollars. I’m sure not a single tear was shed.

Hmm? Is the government paying billions for the launch? I doubt it.

SpaceX will happily sell you a single-use Falcon 9 (or Falcon Heavy) if you need the mass for your launch. Of course, one should expect to pay for the privilege.

Yeah I'm curious at what price. My guess is it massively contradicts their own PR on expected number of runs and thus their opportunity cost.

I expect price-wise they're much closer to the competition there, but given they're still getting launches they can't be completely uncompetitive.

That said, remember they could potentially be using a rocket that's flown twice before (and AFAIK three launches is the most they've done so far), and as such may view the rocket as largely expendable anyway (they lose the ability to use it for re-entry experiments and to pull it down after the launch, but nothing else).

Perhaps they used one of their earlier rockets that are only designed to be reused a couple of times.

no employee protests against DOD projects :)

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'.

So the signals from these GPS satellites are not available for public use? Because if they are then I would say it is hard to really say what is the primary use. The value of GPS for civilian use in the US economy is really high at this point.

Sort of like the US interstate highway system. Military use got the budget to build it, secondary use ends up being more important.

Beneficial civilian use of GPS is orders of magnitude more common than military uses. Military systems also never require GPS, because you can’t count on the enemy not to jam the signal or shoot down the satellites, so there are always alternate navigation methods. For example, JDAMs also use inertial navigation.

I would not want to work on a weapons system but I’d have no problem working on something like GPS.

I see no evidence for the conclusion to your thought experiment. You can’t just make up a conclusion to support your argument, it needs to actually be based on something.

Would Russia allow it? They wouldn't want Americans to get a close up look at their sensitive military hardware, and you can be sure SpaceX would allow them to.

Even if there's no novel or unusual technology on the Glonass sat, learning that is intelligence in itself.

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.

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.

i'm not arguing whether it is a good or bad thing - that mainly depends on whether you're on receiving end or not. I wonder how in one case employees determine that DOD/natsec project is a good thing and in the other that it is a bad thing.

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.

I would have chanted USA USA along with them but would never vote for a conservative American political candidate (at present)

I'd expect workers for a US space launch company to know that their work will likely be used to launch US national security payloads, and to be OK with it.

Unlike workers working for a company that explicitly had "don't be evil" as a motto, withdrew from the Chinese market after state-sponsored attacks targeted dissident's accounts, and that had very little previously known/discussed military involvement, nor activity in a typically highly military-related field.

How is an upgraded GPS satellite a “national security” mission?

Yes, I understand that precise and reliable global navigation is essential to fighting wars and guided weapons, but such uses pale in comparison to the billions of people who rely on GPS every day to do non-war, non-USA stuff. It is neither national nor security.

Or do they just mean “in the role of defense contractor”?

What are you talking about? US-launched GPS satellites are owned and operated by the USAF, which last I checked, is a national security outfit.

Please drop acerbic swipes like "What are you talking about?" from your comments here. Your comment would be much better with just the second sentence.

https://news.ycombinator.com/newsguidelines.html

The reason GPS came to exist is because of the US military. That billions use it now for other purposes is a happy side effect.

Also it is very much “national” as the US taxpayer pays for the GPS system billions of people use for their non-war, non-USA stuff. And it’s definitely security because if that GPS system were to go down, there’s be a serious and immediate economic effect. Protecting and improving GPS is every bit “national security” as building a tank. National security is more than just waging war; it’s the promotion of stability both political and economic across the world.

My neice once missed work when her phone broke and she hadnt learned they way there. I imagine there would be thousands if not millions in a similar situation should GPS go down.

GPS is lofted and maintained by the DoD. It's primary purpose is military. It would not exist as a free service without DoD's investment. Other satellite constellations with far fewer sats cost considerable amounts of money to use, and few of our modern applications for GPS would be very appealing at $xxx a month. Civillian GPS is a generous charity from US taxpayers to the rest of the world

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.

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.

Sure there is a royalty on some of the key parts of receiver hardware and software, but if you think that even comes close to the cost of the whole system you are in for a rude awakening. Those royalties won't have even paid for the original GPS sats, let alone the newer stuff going up in modern times.

The cheapest Iridium phone service plan is $50/month for just 10 minutes of talk time. Would you pay $50/month for 10 minutes of GPS navigation a month?

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

Galileo’s being primarily civilian in focus has no bearing on GPS’ main purpose. GPS is a US system, funded and directed by the military.

You are right, but it proves that GNSS system can be civilian primarily and would be still feasible.

Nice goal post moving.

Galileo GNSS is publicly justified as being primarily for civilian use.

Navstar-GPS works fine though, so there must be some other reason.

Possibilities: military use, jobs program, pride, etc.

It still economically viable for large governments to make their own for just civilian use, under the same logic that has government funding roads, parks and other public goods.

The GPS system cost ~$12 billion to make, and needs ~$750 million a year in maintenance (mainly launching new stats as they have a service life of 15 years). This means it costs each US taxpayer $5/year to run. Quite a few road/subway projects cost more than the GPS system.

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