Hacker News Reader

Comment by Klathmon | Hacker News Reader

I'm so curious what is causing this to launch on a Falcon Heavy!

Previous launches of the X-37B have been on a Falcon 9 with an RTLS landing, and now this one is using one of the largest launchers there is.

What is it doing with all that delta-v!?

View on HN

The boring answer would be that it's just sharing the ride with a bunch of other satellites, as it did on the last three occasions.

The fun answer would be that it's going way further than ever before. A Falcon Heavy can take 25 metric tons to GEO, and the X-37B is roughly 1/5 of that, so think a lot higher. What is there of interest to the US Space Force beyond GEO? Well...

https://spaceforcejournal.org/3859-2/

https://spacenews.com/space-force-studying-requirements-for-...

https://breakingdefense.com/2022/11/critically-important-new...

Edit: Falcon Heavy, not 9. Thanks, asadotzler.

Falcon heavy can't even take that much to GEO, only to GTO. But still, while it could have the fuel to send the X-37B into TLI it would not be possible to hide this. So they wouldn't lie about it.

Who says they are lying about it? From the article:

So far, Space Force has only stated that the mission will "expand the United States Space Force's knowledge of the space environment by experimenting with future space domain awareness technologies," according to the statement.

An F9 cannot take 25 t to GEO.

F9 does just under 23 t to LEO.

To GEO it's about 8 t expended or 5 and a half tonnes with a droneship recovery.

Thanks, fixed. I meant Falcon Heavy. And it's actually a little more than that to GTO, but then the thing has to get itself into GEO, so it's not all payload:

Falcon Heavy has the second highest lift capability of any operational rocket, with a payload of 63,800 kg (140,700 lb) to low Earth orbit, 26,700 kg (58,900 lb) to Geostationary Transfer Orbit, and 16,800 kg (37,000 lb) to trans-Mars injection.

https://en.wikipedia.org/wiki/Falcon_Heavy#Design

Yeah as others have pointed out, it probably wouldn't be possible to hide a TLI mission, so they'd probably be upfront about the mission instead, but this is fun enough science-fiction to think about that it is my headcanon now.

It actually make some sense if their official explanation for the purpose of the vehicle is true. If the main reason for the X-37b is to bring material to orbit and study the long term effect of being in space, then going higher make sense.

In an elliptical orbit, you can cross the Van Hallen belt and magnetic fields over and over again. Then after a couple years return those samples to earth for study. This gives you valuable data to build better satellites in the future.

For examples, the gyros flywheel on the Hubble and it's sibling spy telescope failed over and over until they realized the radiations caused some arcing in the bearings which degraded them much faster than predicted. When you spend billions on individual satellites, this isn't the kind of thing you want to discover in orbit.

Yes and some of these satellites cost more than an aircraft carrier.

Having the x37 try out new materials and parts etc is a great capability that is obviously needed if the US is to maintain its technical superiority.

Over on /r/spaceX everyone assumes it's going into a might higher orbit so they can eventually test re-entry with a lot more energy.

It seems the only logical answer... unless for some reason it's really heavy this time.

Does that imply nuclear weapons? It's not obvious to me if a payload of nuclear warheads would be that heavy to justify the delta-V though.

No.

Why would you bother to send a nuke to high orbit?

it's the only way to be sure.

We already have a way of delivering nuclear warheads from space - they're called ICBMs. What would a space plane add that existing launch platforms don't already provide?

about 2 minutes (or less) of launch detection/warning vs 30?

We also have SLBMs that can be launched directly off coast of a target. And, tossing nukes at enemies isn't going to go unnoticed and that thing doesn't have nearly the capacity to make for a sufficiently large first strike to prevent retaliation.

I guess it's possible, but (imo) it doesn't really make much sense.

That thing is essentially in beta/prototype. What happens when there's multiples of that thing? Is the time from a weapon being released to impact enough time to verify and take action?

I think if it is something to do with our deterrence it’s more likely to be testing an anti ICBM weapon than carrying a warhead.

The US stopped talking about missile defense because it’s destabilizing but they for sure did not stop working on it.

With the MIRV warheads the only realistic intercept opportunity is in space.

I've played Missle Command, and once they separate, it's a nightmare!

If there was a space based defense system, where would these items orbit? If it's a kinetic weapon, can something launched from geosync reach the target to cover the distance in time? Since most of the ICBMs would be coming over the pole, where else could you park your satellites that would be in position to defend against incoming missiles? Polar orbits are not stationary, so would you need a constant fleet of them over head like a Starlink constellation? Lost of questions that I've just never really slowed down to think about the logistics instead of just the old school "lasers are cool! pew pew pew!" that I thought about as kid when Ronnie Raygun was in office.

Yeah exactly! Separation and dummy decoy warheads become an exponential problem and shooting through atmosphere is hard at hyper super mega sonic speeds.

So interception in space but where, as you say.

The only real 'near peer' nuclear threats are Russia and China so other than their 'boomers' (does China have that?) we should know which way they'll be coming from and their ballistic arc roughly.

So we don't need global coverage 'just' GEO coverage of the parts we have intelligence on with pew pew laser line of sight which is of course lightspeed travel time and should be rapid aiming if there's enough of 'em.

These might even be one shot weapons themselves perhaps even fission devices for the laser to have enough energy instantly available.

Subs already have that timeframe covered.

And you're really only saving half of the time from an earth launch.

Subs have the weakness of being run by humans and shorter amount of time staying on station. A sub commander can always ignore the "Lock Out Changes" command where this thing might not.

Edit: also, how is it half the time? I would assume that the majority of the time is getting to altitude during launch. Once they are on return trajectories, they're moving mighty quick. Descent should be much less of the time involved, right?

Orbital kinetic impactor weapons - a quiver of giant heavy rocks - would be an extremely valid reason for a extra spectacularly big launch.

I'm not sure why x37b would be the ship for it, other than that it's proven technology with good manuverability. Feels like most any old satellite full of rocks could do though.

Ran into this next bug future article talking about what a ridiculous death-weapon Starship could be. https://www.nextbigfuture.com/2023/11/future-us-hypersonic-b...

I'm curious how much delta-v there X-37B itself has; the Heavy can definitely get it to GEO, but can it get itself back down from there?

Reply on news.ycombinator.com