SpinLaunch: General Company and Development Updates and Discussions

[meekGee]

https://spectrum.ieee.org/amp/spin-me-up-scotty-up-into-orbit-2656442408

SpinLaunch says it will announce the site for its full-scale orbital launcher within the next five months. It will likely be built on a coastline, far from populated areas and regular airplane service. Construction costs would be held down if the machine can be built up the side of a hill. If all goes well, expect to see the first satellite slung into orbit sometime around 2025.

Hang on a sec.. Why would construction costs "be held down if the machine can be built up the side of a hill"??  Surely (a) hauling up extremely heavy construction equipment, counterweights and the like and (b) building solid foundations that can handle forces generated in spinning up would be more expensive to install on the side of a hill?

And doesn't this concept require a ridiculous amount of power to spin up??  Unless they plan to steal the power feed to a regional city for a few hours, upsetting the locals in the process, remote areas don't tend to contain that kind of infrastructure.

I think the advantage of hillside mounting is that it doesn't have to be built entirely as a freestanding structure like the current prototype, which means you can reduce some aspects of it since it is supported completely on one face.

As for power, their big advantage here with a vacuum chamber is they can trade spin up power for spin up time, using a lesser local power generator. That will cap their launch rate though, but adding generators later is much easier to decrease  spin up times, up to the limits of the rotor motors themselves. That might mean front loading some costs by having a higher spec rotor motor than what their initial generator plan could power.

Ground (and hillsides) always shift.

So you build super fortified foundation slabs that basically make sure that even as the ground shifts, your structure remains rigid.

I also don't see how a hillside helps.

Now if this was a 10 mile rocket sled track that wants to terminate at an upwards angle and in rarified air, ok - that I get.

But this ain't that.

[PM3]

The orbital catapult will not stand vertical like the prototype, but tilted at a 35 degrees angle. And it is huge, 100 meters in diameter. Obviously this is easiest to build on a ~ 35 degrees hill slope. On flat ground it would need huge support structures.

[Lars-J]

The orbital catapult will not stand vertical like the prototype, but tilted at a 35 degrees angle. And it is huge, 100 meters in diameter. Obviously this is easiest to build on a ~ 35 degrees hill slope. On flat ground it would need huge support structures.

35 degrees from the horizontal, or vertical?

[whitelancer64]

SpinLaunch concept art shows it being built on a hillside. In practice, they would engineer a hillside to build it on.

[trimeta]

Ground (and hillsides) always shift.

So you build super fortified foundation slabs that basically make sure that even as the ground shifts, your structure remains rigid.

I also don't see how a hillside helps.

Now if this was a 10 mile rocket sled track that wants to terminate at an upwards angle and in rarified air, ok - that I get.

But this ain't that.

Sure, you'd still want to drive pilings into the ground to give a more solid foundation and not rely on the dirt itself. But driving pilings is cheaper than building an angled superstructure and then still driving pilings.

[edzieba]

If your options are:
- Truck in a few kilotons of dirt to build a big pile of dirt, then concrete over a side of that pile and build your launch system
- Find an already existing big pile of dirt, then concrete over a side of that pile and build your launch system
The latter is preferable in terms of cost and schedule, as long as your site contains a hill.

[Yggdrasill]

If you are going to build up dirt on flat ground, it makes more sense to use a mass-neutral profile instead of trucking in dirt. Basically, digging a hole and using the dirt to build up a ramp next to the hole. The launch system then ends up being 50% underground and 50% above ground, roughly.

[Conexion Espacial]

NASA has contracted a suborbital test mission with SpinLaunch to further test this novel launch system.
https://www.space.com/spinlaunch-nasa-suborbital-test-flight-agreement

[brice]

I've read several pages of comments here and elsewhere, and without claiming any expertise, it seems to me there must be a military angle. But maybe it's not weapons delivery or ICBM treaty evasion.

What if the goal is *not* to compete with LEO launch providers? What if the ultimate goal is to put micro reconnaissance satellites into temporary orbits? Intentionally expendable, low cost, on-demand. If orbits decay after a few days or weeks, launch more to replace them.

DARPA is big into swarms of micro satellites for on-demand reconnaissance (see quote below). I wonder if SpinLaunch is ultimately aimed at supporting expendable on-demand military reconnaissance? I don't understand orbital mechanics. Would SL's approach provide enough flexibility to put a small constellation of micro satellites into orbit over any point on earth? Assuming a desire for multiple passes per day?

With the near-future possibility / probability of anti-satellite warfare, it could be a game changer to have a rapid fire way to rebuild constellations. Reconnaissance assets would no longer be high value sitting ducks. Recovery from an orbital EMP attack could begin same day. Even if SL never gets to orbital insertion, having the ability to rapidly put up temporary constellations would buy time for regular launches. It would undermine the value of space warfare the same way missile interceptors undermine the value of ICBM first strikes.

I'm sure the military would gladly pay lots extra to have this capability. Any commercial launches would provide a thin veil for an open secret.

Another question: Would temporary orbits, with a duration of days or weeks, be significantly lower altitude than those of more permanent low earth orbits? Low enough to allow micro satellite sensors to perform better, closer to what their larger cousins see from higher up?

Anyhow, I'm curious if any of this makes operational sense? Because SlingLaunch makes no sense to me if there isn't some dual use military purpose. But it is *very* cool! I glad it's making progress.

For context, from DARPA:

Dense constellations of low-earth-orbit (LEO) micro-satellites can provide new intelligence, surveillance, and reconnaissance (ISR) capabilities, which are persistent, survivable and available on-demand for tactical warfighting applications. The Small Satellite Sensors program seeks to explore new sensor concepts that are well-matched to the capabilities achievable in small satellites. The program also seeks to develop and demonstrate enabling technologies and sub-systems needed for capable, but low-cost military satellites, such as secure and high-bandwidth RF and optical inter-satellite communications links.

[trimeta]

The dual use I've heard of is "creating targets for experimental hypersonic missiles to try shooting down." I don't know how many of those the US military expects to need, though.

[edzieba]

I've read several pages of comments here and elsewhere, and without claiming any expertise, it seems to me there must be a military angle. But maybe it's not weapons delivery or ICBM treaty evasion.

What if the goal is *not* to compete with LEO launch providers? What if the ultimate goal is to put micro reconnaissance satellites into temporary orbits? Intentionally expendable, low cost, on-demand. If orbits decay after a few days or weeks, launch more to replace them.

DARPA is big into swarms of micro satellites for on-demand reconnaissance (see quote below). I wonder if SpinLaunch is ultimately aimed at supporting expendable on-demand military reconnaissance? I don't understand orbital mechanics. Would SL's approach provide enough flexibility to put a small constellation of micro satellites into orbit over any point on earth? Assuming a desire for multiple passes per day?

With the near-future possibility / probability of anti-satellite warfare, it could be a game changer to have a rapid fire way to rebuild constellations. Reconnaissance assets would no longer be high value sitting ducks. Recovery from an orbital EMP attack could begin same day. Even if SL never gets to orbital insertion, having the ability to rapidly put up temporary constellations would buy time for regular launches. It would undermine the value of space warfare the same way missile interceptors undermine the value of ICBM first strikes.

I'm sure the military would gladly pay lots extra to have this capability. Any commercial launches would provide a thin veil for an open secret.

Another question: Would temporary orbits, with a duration of days or weeks, be significantly lower altitude than those of more permanent low earth orbits? Low enough to allow micro satellite sensors to perform better, closer to what their larger cousins see from higher up?

Anyhow, I'm curious if any of this makes operational sense? Because SlingLaunch makes no sense to me if there isn't some dual use military purpose. But it is *very* cool! I glad it's making progress.

For context, from DARPA:

Dense constellations of low-earth-orbit (LEO) micro-satellites can provide new intelligence, surveillance, and reconnaissance (ISR) capabilities, which are persistent, survivable and available on-demand for tactical warfighting applications. The Small Satellite Sensors program seeks to explore new sensor concepts that are well-matched to the capabilities achievable in small satellites. The program also seeks to develop and demonstrate enabling technologies and sub-systems needed for capable, but low-cost military satellites, such as secure and high-bandwidth RF and optical inter-satellite communications links.

The 'short term reconnaissance satellite' concept has been around since the days of film-based reconnaissance satellite half a century ago. The problem is the whole reason to do that is responsive capability (get a platform to precisely where you need it faster than waiting for any of the existing orbital platforms to fly over), but Spinlaunch specifically have a very limited capability to target multiple inclinations - in other words, they are not able to put your satellite where you want it.

[Kryten]

 There's always a tendency, when something doesn't seem to make sense, to assume it's the military behind it somehow. Actually dumb ideas with sufficiently charismatic people behind them get funded all the time, especially in a tech VC atmosphere as overheated as this one.
 For this specific case, the idea of quick-response recon sat launch gets brought up a lot but doesn't get much traction - prior DoD projects for this concept have been allowed to die on the vine with minimal funding, like SWORDS, SALVO/ALASA et.c. It doesn't really make sense for it suddenly to be backing some billion-dollar entirely custom launch solution, and an inherently fixed site at a known location is a bad choice for something that's supposed to be providing redundancy during an active war.

[Zed_Noir]

The performance of the Spinlaunch carrier vehicle is similar to the Sprint local defense anti-ballistic missile.

  Just for laughs. What is the feasibility of the Spinlaunch system being use for anti-ballistic defense against limited attacks on strategic targets. 

[Bob Shaw]

I can't see this being of any use on Earth, but it would make an excellent system for firing frozen ice from deep, dark Lunar craters up to some sort of safe landing zone outside the crater. I proposed a Lunar trebuchet for this task years ago but SpinLaunch is an even better way to do it. The ice bullets could be relatively small and fired uphill in darkness before sunrise then collected in the early Lunar morning.

[Kryten]

The performance of the Spinlaunch carrier vehicle is similar to the Sprint local defense anti-ballistic missile.

  Just for laughs. What is the feasibility of the Spinlaunch system being use for anti-ballistic defense against limited attacks on strategic targets. 

Sprint was a point-defense system, so unless you're counting the Spinlaunch installation itself as a 'strategic target', none.

[Zed_Noir]

The performance of the Spinlaunch carrier vehicle is similar to the Sprint local defense anti-ballistic missile.

  Just for laughs. What is the feasibility of the Spinlaunch system being use for anti-ballistic defense against limited attacks on strategic targets. 

Sprint was a point-defense system, so unless you're counting the Spinlaunch installation itself as a 'strategic target', none.

There could be many Spinlaunch systems in the target area (like the ICBM farms in the US mid-West). Spinlaunch systems is cheap compared to nuke tipped Sprint missiles, could also be use for grid power backup or stabilization.

Also the "point defense" range of the Sprint missile is about 40 km, enough to cover a medium size city from a single launch site. Spinlaunch should be a bit more capable in range than the Sprint missile since it is supposedly an orbital launch system.
 

[TrevorMonty]

I can't see this being of any use on Earth, but it would make an excellent system for firing frozen ice from deep, dark Lunar craters up to some sort of safe landing zone outside the crater. I proposed a Lunar trebuchet for this task years ago but SpinLaunch is an even better way to do it. The ice bullets could be relatively small and fired uphill in darkness before sunrise then collected in the early Lunar morning.

The DV for hopper to take ice few kms is not very much. Typically only few percent of ice would be used as fuel.

Spinlaunch is better for placing ice into lunar orbit or beyond. Needs to be packaged in space vehicle to handle launch forces plus stop it evaporating off into space. Vehicle can be simple metal shell with gas thrusters and basic avionics,. Idea is for space tug to retrieve it once in orbit.

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[Hobbes-22]

Ground (and hillsides) always shift.

So you build super fortified foundation slabs that basically make sure that even as the ground shifts, your structure remains rigid.

I also don't see how a hillside helps.

Now if this was a 10 mile rocket sled track that wants to terminate at an upwards angle and in rarified air, ok - that I get.

But this ain't that.

Sure, you'd still want to drive pilings into the ground to give a more solid foundation and not rely on the dirt itself. But driving pilings is cheaper than building an angled superstructure and then still driving pilings.

Or you find a hill that's not made out of dirt, but is solid rock.

[12345]

Whole concept have little practical benefits over traditional launchers, especially reusable. Plus crazy requirements for payload strength. Little sense for military purposes as well.
Looks like a fraud.

[Bob Niland]

Has SpinLaunch mentioned what the current & projected spin-up times are? A quick search didn't turn up anything, and their existing videos look like it's in the low minutes.

The number would affect applications where unscheduled prompt launches are a requirement.