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This is clearly a military oriented startup. For sending civilian payloads into space, it has a very low chance to reach a price point that is competitive with

by yholio 5y ago

This is clearly a military oriented startup. For sending civilian payloads into space, it has a very low chance to reach a price point that is competitive with reusable rockets. You either need an absolutely gargantuan centrifuge -> high capital costs - or you need to subject your payload to thousands of Gs. "The payload" is in this scenario must include 1 ton liquid fuel rocket for every 200Kg you want to put into space, or 1 ton solid for every 100Kg. You have to ensure this "second stage" will never explode inside your centrifuge despite being subjected to orders of magnitude higher loads than the typical rocket. This is possible but very expensive, you will need huge structural mass to hold what would appear to be thousands of tons of propelant at 1G. So the mass fraction goes down, the costs of the rocket and centrifuge "spin" out of control, and you provide a paltry orbital capacity of a few tens of Kg and only for specifically engineered satellites that no existing manufacturer knows how to build. A commercial dead end. For military applications on the other hand, it's close to perfect. You don't need orbital insertion, you can accelerate your payload silently without allowing for detection in the early phase of the attack, your projectile starts at essentially cruise speed and can only be detected by infrared emissions due to atmospheric heating for a few seconds until the launch ablative heatshields are ejected. It's a fantastic first strike weapon.

le-mark 5y ago
Spacex needs this (or a really large space gun) to refuel starship in orbit. I would not be surprised if Elon is an investor.
- NikolaeVarius 5y ago
  Why does SpaceX "need" this
- panick21_ 5y ago
  No. Just think about it for a few minutes. Starship can deliver a payload of 150 tons to Orbit, fully reusable. SpinLaunch needs a non-reusable second state and can deliver at best a few 100kg. So what do you think is cheaper, launch 1 Starship or 500+ SpinLaunch non-reusable rockets?
- rictic 5y ago
  If starship is cheaper per kg of cargo then SpaceX will just refuel starship with other starships as planned
  - le-mark 5y ago
    I believe it’s obvious that if a dumb projectile can be n% cheaper, Spacex would go for it. The question is what magnitude of n?
simonh 5y ago
I think you're dramatically overestimating the difficulty of building the projectiles. It's really not that difficult to build electronics that can withstand the required G forces. Here in the UK we built proximity fused warheads for artillery shells using glass vacuum tubes during WW2. The HARP program in the 1960s experimented with gun launched Martlet series of rockets. They tested several designs using solid fuelled rockets, but the program was cancelled before the liquid fuelled version was ready for testing.
- krallja 5y ago
  It’s not the electronics, it’s the fuel tanks that need to endure the highest forces.
  - yholio 5y ago
    Yes, my argument was that, because the second stage would be mechanically so hard to build, driving the cost of the whole installation up, it's unlikely they can offer launch services at a price point low enough to make satellite customers and manufacturers willing to invest in high-G satellites. I will change my mind when they offer payload to orbit at a price no more than half of what SpaceX can do. Currently, they launch 51 Starlink satellites of 260Kg at a price point of $50 milion, or about $4000/Kg. Any competitor looking to deploy a high-G constellation will need much better prices, less than $500K per 260Kg satellite, and Starship is on course to slash another zero from that.
    - simonh 5y ago
      They already have a design, so it seems like at least they think they have the engineering problems figured out. This test rig should allow them to verify that. They might well be able to compete based on differentiating factors other than cost, such as availability. Small sats riding on an F9 are generally on ride-share programs and can have to wait years for a slot. Unless you're commissioning a whole F9, you take what you can get. With this thing they can throw up a single small satellite whenever you like, and pretty much as many or as few as you like. Price may well be comparable to reusable F9, after all this thing puts the "upper stage" to about the same altitude as an F9 second stage, and as with this the F9 second stage isn't reusable. Also the "first stage" of this thing is a catapult that's functionally infinitely reusable, whereas F9 first stages have only racked up a maximum of 10 launches so far. This catapult should theoretically manage thousands of launches. Starship is a real game changer for sure, but we'll have to see how that pans out. It's still a long way from being a functioning service doing daily launches.
lonelyasacloud 5y ago
Not for first strike. First strike is about the ability to destroy or seriously degrade an enemy's ability to retailiate. With this it's huge, cannot be hidden or moved and the orientation would be obvious from a spy satellite. Any serious enemy would just have systems like this under 24/7 observation and would launch retaliation the moment it was fired, or even looked like it was going to be fired at them. Other applications perhaps.
- blincoln 5y ago
  Couldn't it be hidden underground (or in a mountain/large hill), with something like a ring shaped trench or slit leading to the launch aperture? Basically a big, camouflaged version of WWI/WWII-style concrete coastal gun emplacements. I'm no expert, but I thought ICBM launches were detected using thermal IR sensors on satellites. There wouldn't be any for this launcher. There would still be a heat signature from the second stage, but it wouldn't need to be anywhere near the launcher itself.
  - yholio 5y ago
    I believe the parent is right, you couldn't hide it. Even if you succeed in building them completely stealthy, it's just a matter of time until the enemy finds out the locations using espionage or signals intelligence, and after that they will place the site unde non-stop satellite surveillance. They are massive and can't be moved, so they are sitting ducks. As for launching, you are guaranteed to produce a thermal signature in the first few seconds of flight, since you hit the high density atmosphere at a 3-5 Km/s speed. You will leave a distinct, large and highly detectable infrared signature and the enemy will be alerted: https://youtu.be/JAczd3mt3X0?t=274 https://youtu.be/JAczd3mt3X0?t=274
bombas 5y ago
They would need to ensure a munition could withstand 10kGs tho
aaron695 5y ago
> This is clearly a military oriented startup. This is good spit balling take, but an bad top comment. I assume on HN if someone says something is for the military it has to be up-voted without thinking? > specifically engineered satellites that no existing manufacturer knows how to build. Your consumer phone could be launched fine as is. Most satellites are not different, this is a known problem with a know solution. There is nothing magical here. Electronics are fine. > It's a fantastic first strike weapon. No one wants this. North Korea doesn't want this. It means it will get bombed. They want second strike weapons. Obviously all locations this is at will be well know, to test it has to be fired. Rockets you can just put randomly under 200 tents. https://dailyuknews.com/us-news/china-is-spotted-building-a-second-new-nuclear-missile-base/ https://dailyuknews.com/us-news/china-is-spotted-building-a-... > This is possible but very expensive, you will need huge structural mass to hold what would appear to be thousands of tons of propelant at 1G. But you are politically happy to test nukes in this when civilians seem scared of propellant blowing up? This has clear civilian potential. This has limited military potential outside of the crossover with civilian. The economics is questionable, but if it works it'll be a game changer. It's great people are working on this stuff.
- yholio 5y ago
  > Your consumer phone could be launched fine as is. Most satellites are not different, this is a known problem with a know solution. Communication sat buses have critical mechanical components: solar panel assemblies, gyros, reaction wheels and momentum sinks, unfoldable antennas, propellant tanks and valves. Earth observation sats have optics so fragile that even applying 1 G perpendicular to the design launch vector will damage them beyond repair, so they can't be mated with the rocket in the horizontal state. All these can be probably beefed up and redesigned to withstand thousands of Gs, but it's certainly not a solved problem, and there is very little incentive for satellite designers to attempt it. > But you are politically happy to test nukes in this when civilians seem scared of propellant blowing up? A mechanical destruction of the warhead will not trigger a nuclear explosion, nuclear weapons are designed for this, it will just contaminate the launch stand. You also need much less conventional fuel if any since you are aiming at suborbital, and this reduces the loads and the damage after an explosion. Military risk tolerance is high, if there is a 10% chance if internal detonation then each facility will get to launch 10 warheads on average, probably more than they will ever have the chance during a real nuclear exchange - considering spinup time. An explosion inside the commercial orbital launcher will wipe out a large investment and might put the whole company in jeopardy, the energies are significantly higher while the acceptable probability of failure is much lower.

by yholio 5y ago

le-mark 5y ago

Spacex needs this (or a really large space gun) to refuel starship in orbit. I would not be surprised if Elon is an investor.

NikolaeVarius 5y ago
Why does SpaceX "need" this
panick21_ 5y ago
No. Just think about it for a few minutes. Starship can deliver a payload of 150 tons to Orbit, fully reusable. SpinLaunch needs a non-reusable second state and can deliver at best a few 100kg. So what do you think is cheaper, launch 1 Starship or 500+ SpinLaunch non-reusable rockets?
rictic 5y ago
If starship is cheaper per kg of cargo then SpaceX will just refuel starship with other starships as planned
- le-mark 5y ago
  I believe it’s obvious that if a dumb projectile can be n% cheaper, Spacex would go for it. The question is what magnitude of n?

simonh 5y ago

I think you're dramatically overestimating the difficulty of building the projectiles. It's really not that difficult to build electronics that can withstand the required G forces. Here in the UK we built proximity fused warheads for artillery shells using glass vacuum tubes during WW2. The HARP program in the 1960s experimented with gun launched Martlet series of rockets. They tested several designs using solid fuelled rockets, but the program was cancelled before the liquid fuelled version was ready for testing.

krallja 5y ago
It’s not the electronics, it’s the fuel tanks that need to endure the highest forces.
- yholio 5y ago
  Yes, my argument was that, because the second stage would be mechanically so hard to build, driving the cost of the whole installation up, it's unlikely they can offer launch services at a price point low enough to make satellite customers and manufacturers willing to invest in high-G satellites. I will change my mind when they offer payload to orbit at a price no more than half of what SpaceX can do. Currently, they launch 51 Starlink satellites of 260Kg at a price point of $50 milion, or about $4000/Kg. Any competitor looking to deploy a high-G constellation will need much better prices, less than $500K per 260Kg satellite, and Starship is on course to slash another zero from that.
  - simonh 5y ago
    They already have a design, so it seems like at least they think they have the engineering problems figured out. This test rig should allow them to verify that. They might well be able to compete based on differentiating factors other than cost, such as availability. Small sats riding on an F9 are generally on ride-share programs and can have to wait years for a slot. Unless you're commissioning a whole F9, you take what you can get. With this thing they can throw up a single small satellite whenever you like, and pretty much as many or as few as you like. Price may well be comparable to reusable F9, after all this thing puts the "upper stage" to about the same altitude as an F9 second stage, and as with this the F9 second stage isn't reusable. Also the "first stage" of this thing is a catapult that's functionally infinitely reusable, whereas F9 first stages have only racked up a maximum of 10 launches so far. This catapult should theoretically manage thousands of launches. Starship is a real game changer for sure, but we'll have to see how that pans out. It's still a long way from being a functioning service doing daily launches.

lonelyasacloud 5y ago

Not for first strike. First strike is about the ability to destroy or seriously degrade an enemy's ability to retailiate. With this it's huge, cannot be hidden or moved and the orientation would be obvious from a spy satellite. Any serious enemy would just have systems like this under 24/7 observation and would launch retaliation the moment it was fired, or even looked like it was going to be fired at them. Other applications perhaps.

blincoln 5y ago
Couldn't it be hidden underground (or in a mountain/large hill), with something like a ring shaped trench or slit leading to the launch aperture? Basically a big, camouflaged version of WWI/WWII-style concrete coastal gun emplacements. I'm no expert, but I thought ICBM launches were detected using thermal IR sensors on satellites. There wouldn't be any for this launcher. There would still be a heat signature from the second stage, but it wouldn't need to be anywhere near the launcher itself.
- yholio 5y ago
  I believe the parent is right, you couldn't hide it. Even if you succeed in building them completely stealthy, it's just a matter of time until the enemy finds out the locations using espionage or signals intelligence, and after that they will place the site unde non-stop satellite surveillance. They are massive and can't be moved, so they are sitting ducks. As for launching, you are guaranteed to produce a thermal signature in the first few seconds of flight, since you hit the high density atmosphere at a 3-5 Km/s speed. You will leave a distinct, large and highly detectable infrared signature and the enemy will be alerted: https://youtu.be/JAczd3mt3X0?t=274 https://youtu.be/JAczd3mt3X0?t=274

bombas 5y ago

They would need to ensure a munition could withstand 10kGs tho

aaron695 5y ago

> This is clearly a military oriented startup. This is good spit balling take, but an bad top comment. I assume on HN if someone says something is for the military it has to be up-voted without thinking? > specifically engineered satellites that no existing manufacturer knows how to build. Your consumer phone could be launched fine as is. Most satellites are not different, this is a known problem with a know solution. There is nothing magical here. Electronics are fine. > It's a fantastic first strike weapon. No one wants this. North Korea doesn't want this. It means it will get bombed. They want second strike weapons. Obviously all locations this is at will be well know, to test it has to be fired. Rockets you can just put randomly under 200 tents. https://dailyuknews.com/us-news/china-is-spotted-building-a-second-new-nuclear-missile-base/ https://dailyuknews.com/us-news/china-is-spotted-building-a-... > This is possible but very expensive, you will need huge structural mass to hold what would appear to be thousands of tons of propelant at 1G. But you are politically happy to test nukes in this when civilians seem scared of propellant blowing up? This has clear civilian potential. This has limited military potential outside of the crossover with civilian. The economics is questionable, but if it works it'll be a game changer. It's great people are working on this stuff.

yholio 5y ago
> Your consumer phone could be launched fine as is. Most satellites are not different, this is a known problem with a know solution. Communication sat buses have critical mechanical components: solar panel assemblies, gyros, reaction wheels and momentum sinks, unfoldable antennas, propellant tanks and valves. Earth observation sats have optics so fragile that even applying 1 G perpendicular to the design launch vector will damage them beyond repair, so they can't be mated with the rocket in the horizontal state. All these can be probably beefed up and redesigned to withstand thousands of Gs, but it's certainly not a solved problem, and there is very little incentive for satellite designers to attempt it. > But you are politically happy to test nukes in this when civilians seem scared of propellant blowing up? A mechanical destruction of the warhead will not trigger a nuclear explosion, nuclear weapons are designed for this, it will just contaminate the launch stand. You also need much less conventional fuel if any since you are aiming at suborbital, and this reduces the loads and the damage after an explosion. Military risk tolerance is high, if there is a 10% chance if internal detonation then each facility will get to launch 10 warheads on average, probably more than they will ever have the chance during a real nuclear exchange - considering spinup time. An explosion inside the commercial orbital launcher will wipe out a large investment and might put the whole company in jeopardy, the energies are significantly higher while the acceptable probability of failure is much lower.