US Space Force reveals first look at secretive X-37B space plane in orbit
space.comArs previously covered some additional information on the X-37B
https://arstechnica.com/space/2024/10/the-us-militarys-x-37b...
I can't be the only one who, when I read "space force" hears a deep, reverb-heavy, Buck Rogers kind of voice going "spaaaaaaaace foooooooorce"
You say Buck Rogers, but I hear the Muppets with Piiiigs in Spaaaaace!!
a pretty good satire of the whole thing: https://en.wikipedia.org/wiki/Space_Force_(TV_series)
Space Force song written just after the announcement: https://www.youtube.com/watch?v=_AUXpnB065o
schmoyoho are incredible at making these songs, and so quickly after each event. I'm amazed they usually only get 10s of thousands of views, with the odd exception over 1m.
The show has basically 0 relation to what the Space Force actually does
There were legitimate reasons for spitting USSF as its own service. The only reason people made fun of it was because Trump signed the order for it.
That was not the only reason, but for one that says that they will probably not accept the other reasons.
Why might it be desirable to have an observation craft so far away from the earth?
I'm having a hard time imagining the advantage compared to being a bit closer, unless it's a more energy-efficient parking situation while the vehicle isn't in active use.
My understanding is it’s on an offset elliptical orbit. This is essentially the farthest point away from earth with the other end of orbit being very close to Earth.
From a tactical perspective, that means this can interact with basically any other satellite.
With a far point so far away from Earth it also means that it requires only tiny amounts of fuel for major orbit changes.
My orbital mechanics is (like most people) weak, is this intended as a generalized physical threat to other satellites?
Not necessarily.
These types of orbits also have the property that the perceived loiter time is different for the perigee and apogee.
At perigee (closest to Earth) it will be moving very fast and so any changes to velocity will have a large impact (easily change orbit).
While at apogee it will appear to sit in space and move quite slowly. As an example this is used for the Russian GPS system so their satellites can sit in high earth latitudes for longer needing fewer satellites to cover Russia.
As an example this is used for the Russian GPS system so their satellites can sit in high earth latitudes for longer needing fewer satellites to cover Russia.
It's used for communications satellites and is called the Molniya orbit[1]. Their GLONASS (positioning system) satellites use circular medium altitude orbits, but with a higher inclination (about 65 deg vs. GPS's 55 deg).
Isn’t GLONASS in geostationary orbit like NAVSTAR/GPS? This would be a fixed orbital distance from Earth.
You may be thinking of highly-elliptical molniya/lightning orbits (1), which enabled state TV broadcasts for high-lat places in Siberia.
Gps isn't in geostationary orbit. They're in medium earth orbit and complete an orbit about twice a day
If you can easily adjust your orbit, it's easy to see lots of places on the earth, or tweak what time you will be over a part of the earth (eg if you want to look at something whose owners know to hide it when satellites are overhead)
Intended? I don't know, you'd have to ask NASA. Does it have that capability? Sure, if it can deploy arbitrary payloads on destination.
It has carried payloads before but little is known about its missions.
As well as change orbital characteristics (apogee, perigee, inclination) at reasonably low cost, enabling closer observation of specific portions of Earth, or of objects in space.
Burns at closest approach (perigee) have the largest influence on total orbital characteristics. Burns at furthest approach (apogee) can raise the entire orbit if desired.
(Or so I understand.)
Burns at perigee have best efficiency to make in-plane changes (raise or lower orbit) due to the Oberth effect.
Burns at apogee have best efficiency for out-of-plane maneuvers (change orbital inclination plane) due to lowest velocity of the spacecraft.
Highly elliptical orbits can do both at a few hours' notice.
Burns at perigee can only raise or lower part of the orbit though, right? A burn at perigee lowers or raises the apogee. To lower or raise the perigee, you need to burn at apogee.
Correct.
Burns don't have to happen only at perigee/apogee so there's more flexibility in practice. And counter intuitive stuff like bi-elliptic transfers.
Ahhhh, bi-elliptic transfers!
It's funny, I remember first learning to use such arcane maneuvers in a game called Children of a Dead Earth, in order to get into a terribly low orbit of Neptune to strike a methane refinery... My poor brain was always used to simple Hohmann transfers in games like KSP!
Thanks, I've got only a vague grasp of this.
Could another benefit be the ability to change payloads? If there was a desire to change the orbits and payloads, then could these serve a function as a more responsive version of existing satellites?
I'm not sure what you mean here.
The US Space Shuttle could similarly "change payloads", with its modular payload bay capable of carrying either one-time cargoes (often satellites for launch), or reusable modules such as Spacelab, parts of which flew on a total of 35 Shuttle missions.
<https://en.wikipedia.org/wiki/Spacelab>
But modularity is also inherent in conventional rocket-based launches, with cargoes fitting within the fairing bay capable of being deployed or orbited.
Changing payloads in space is a rather different prospect, though the ability to rendezvous with, take on-board, and de-orbit satellites (man-made or artificial, the US's own, or other nations') is another possible capability. The X37's small size gives only limited potential here, and I'm pretty sure that if the US were snatching other nations' satellites we'd have heard about it.
Past flights have been years long and are classified what might have even been achieved. I wonder how much of the space war doesn’t ever get published?
Interact as in fly-by repair? Or interact as in interfere/tamper/destroy?
Yes, also steal ala Glomar Explorer
Looks like it would be able to deploy high speed instant-action repair kits.
Unlikely, velocity difference would be too large for anything constructive. One thing about orbits is that velocity difference is sort of a distance dimension in itself.
One use for highly elliptical orbits is being able to linger over some part of the earth for longer periods.
https://en.wikipedia.org/wiki/Molniya_orbit
I haven't seen the orbital parameters of the X-37, so it may be in an elliptical orbit for some other reason, such as spying on or interfering with geostationary satellites or who knows what else.
This thing is definitely out of SAM range, so that's an advantage.
I was going to say, not out of range of anti-satellite missiles, at least at a low perigee... But maybe it's zipping too fast there to be easily shot down? Whereas at apogee, when it's slow, it's also very far away.
> But maybe it's zipping too fast there to be easily shot down?
A satellite in LEO already has a speed of about 8 km/s. The highest speed of a satellite in a highly elliptical orbit is 11 km/s. It you can shoot a satellite at 8 km/s, you probably can also shoot it at 11 km/s.
The problem is, of course, that the perigee of a satellite in a highly elliptical orbit can be over a different part of the planet than your SAM battery.
> It you can shoot a satellite at 8 km/s, you probably can also shoot it at 11 km/s.
Assuming all else is equal (same altitude, same targeting capability, same flight characteristics), an interceptor for an 11 km/s target needs about 89% more kinetic energy than an interceptor for an 8 km/s target. Realistically, between the rocket equation and atmospheric effects, the faster interceptor would likely need to be far larger still. You're probably talking about a 2.5 to 3 times bigger missile. While a country that could develop one could likely develop the other if they so chose, it doesn't seem like a safe assumption that a country with one has the other.
I dont think that it is correct to assume your interceptor needs to match velocity. Any speed will do if you can intercept it on approach instead of chase it down.
I'm not assuming the interceptor needs to match velocity. There is some point you detect the target x1, and some range for your missile from your position x0 to an interception point x2. Your interceptor needs to get from x0 to x2 by the time the time the target gets from x1 to x2. If your target is travelling 37.5% faster, you have 27.2% less time to get to the interception point, which means that you need to fly 37.5% faster, which requires 89% more kinetic energy, regardless of what the baseline speed required was. Alternatively you need to detect things from further away or fire from a closer distance, both of which pose their own issues.
That's not quite correct, is it? Consider shooting at a bird. A falcon travels twice as fast as a pigeon, but you don't need a bullet that is twice as fast to shot the falcon. You simply adjust the lead distance when you shoot at the falcon. In your argument you assume that you need to cover some distance in the same amount of time, but you don't need to. You simply lead the target a bit more. As for detection time, well, it is basically a guarantee that whoever is considering shooting at a space plane, has the tracking capabilities to know its position at all times. If they don't, they probably can find some reddit where people do that out in the open.
In this scenario increasing lead distance is equivalent to detecting and firing earlier (ie increasing distance between x1 and x2), which again has serious technical issues. Yes you can hit a falcon with the same bullet, but it's harder to hit. And the big difference in these scenarios is that the bullet is moving much faster than either the pigeon or the falcon, which means you can always buy more time for the falcon to get to the interception point by taking a less efficient path, whereas for the satellite interception where your interceptor is slower than the target, there is some optimal path (basically straight up from right below perigee) that sets a hard limit on how long it takes to get to any interception point.
If your interception point is say 500 km straight up from your launch point, just to get there you need a rocket that rapidly accelerates to over 3 km/s, and it takes a little over 5 minutes to get to the interception point. To hit an 8 km/s target, you need to fire when it is 2500 km away, to hit an 11 km/s target you need to fire when it is 3500 km away. If to score a hit you need to be within 10 meters of the target at interception, then you need to know the position and velocity of the 8 km/s target to within 4 ppm, you need to know it with an accuracy within less than 3 ppm. And note, if you are shooting from 15 km up in a fighter jet, the 8 km/s target is within your radar horizon, the 11 km/s target is not. Not to say that you couldn't build a system with target sharing and more precise tracking, but it would be a different system than the one you need for the less challenging use case.
Now it's not a strictly either or thing. You could use a missile with intermediate speed and fire it less early. There's a whole continuum of solutions, but it will always be harder to hit the faster moving target. And of course you have real world things to consider like if the target has any maneuverability or countermeasures and how much variation in conditions you can afford. Generally you are already using the best targeting system you can get and are already in the most advantageous position you can be in, so the knob you can turn is "how big of a missile do I need to get the performance I require?"
Agreed, it all depends on the use case. If you are trying to hit an evading target, you have to be faster. If you are trying to deny the ship from a destination, you don't.
If the ship's current position is 200 miles from its destination and you are 400 miles from its destination, you need to go faster than it to deny the ship from its destination. Conversely, if you are 40 miles from its destination, you can go much slower, though if you go too slow you still won't make it. You have to get to a point ahead of it before it gets there, and the faster its moving, the less time you have available to get to any particular point.
Dealing with evasion is a whole other matter. A stationary iceberg can hit a ship that tries to evade if it does so too late. Conversely simple error in your knowledge of a ship's position and velocity can cause it to be miles away from where you expect it later in the journey.
Like the parent says, you already know where it is. I'm struggling to understand the case where you are further from the destination than the x37B, with an orbit 60,000km from earth.
> Like the parent says, you already know where it is.
The parent is incorrect. You know approximately where it is. If your approximation is off by some amount, you miss. How good of an approximation you have is determined by your detection equipment. How good of an approximation you need is determined by the speed. For the same detection equipment, hitting the faster moving thing is harder.
> I'm struggling to understand the case where you are further from the destination than the x37B, with an orbit 60,000km from earth.
Well yeah, that's because the x37B interception scenario is the second case, where you are much closer to the destination but going much slower.
I thought the fundamental hypothesis under discussion here was that the x37 has the orbit to move quickly and avoid interception. It being the second case seems to rule against that hypothesis being true
That is the hypothesis here, and the second case in no way rules against it.
Again to clarify, no one here is arguing that to intercept a target you have to be moving faster than the target. The argument is you have to be moving faster than the minimum speed required to hit a slower target.
In math terms, you have two targets with velocites V1 and V2. To intercept there is some minimum velocity for each, v1 and v2. This is the best case scenario, you are perfectly in position, you can launch at the earliest possible time. v1 < V1 and v2 < V2 are both true. But since V1 < V2, v1 < v2 is also true. An interceptor that can achieve v1 doesn't necessarily have the capability to achieve v2.
I don't think that is quite right. You can hit a satellite with a suborbital projectile. The kinetic energy of the satellite is enough on its own if you hit it.
It's not about energy required to destroy it, it's about speed required to get to it.
Possibly easier for optics?
Lower orbit = faster velocity.
So your screaming by over Emutopia's enrichment plant, and trying to take photos.
Telephotography might be an easier solve than faster image capture for the same resolution and clarity. A higher orbit means you have to do less drastic tracking corrections to observe the same area while over it.
Alternative: it's a space plane and has been mentioned it uses aero braking for orbital adjustments. A highly elliptical orbit imparts a significant chunk of potential energy that can be expended for orbital changes using aero braking instead of needing to expend limited propellent.
Source: personal experience with several hundred hours of KSP.
I assume better survivability against anti-satellite weapons.
"Why might it be desirable to have an observation craft so far away from the earth?"
more range the merrier in case there is alien invasion. you would need aircraft that allow travel interplanetary system
I think he was asking for real tangible uses.
lets start with hit russia soil
maybe observing satellites, in real time, in multiple orbits, and yeah, maybe just free parking (and testing orbital transitions).
How can you tell that is the earth?
Less predictable orbit.
Given the military heritage of the Space Shuttle, I imagine this is what a hypothetical next generation civilian Space Shuttle might have looked like, too.
Given the constraints of reaching orbit, surviving reentry, and cross-range capabilities there's a general lack of variability in spacecraft design. Some of us are old enough to remember promotional/propaganda materials concerning the original Boeing X-20 "Dyna-Soar" engineering designs from the 1950s which strongly resemble the subsequent US Space Shuttle, the Soviet Buran orbiter, and the Boeing X-37B and X-40:
I recall reading that the Space Shuttle was a big improvement on Dynasoar. Perhaps that the Dynasoar was not a true "lifting body" ?
FYI I'm not familiar with this nor could I find anything. If you could surface a reference I'd be interested in details.
Something I read a long time ago. No reference.
No worries, thanks.
How big is the payload bay on this thing? The whole craft is only 29 feet long, so it's not carrying a Hubble in to orbit.
The NRO doesn't need this thing to lift its birds into orbit. Keyhole satellites have gotten rides on Deltas and Titans, so probably going to be sticking their thumbs out in the direction of SpaceX pretty soon.
Already have, SpaceX have been doing a few NRO launches. Delta and Titan are retired, and Atlas is down to its last few.
Great, but I specifically said Keyhole from which Hubble was a descendant. Which Keyhole bird was launched by SpaceX?
None, but that's why they said soon. I'm sure a modified FH or Starship could get deploy this hardware. The last launch of in 2022 on a Delta IV Heavy.
No, I said soon. The person I replied to said "already have".
Are there any books to read that talk about the military missions of the Space Shuttle?
Most missions are still classified but some information on general shuttle sources, into the black book and space above us podcast are interesting sources.
The wings say USAF, which is Air Force. Though clearly in space…
The US Space Force was part of the US Air Force until just a few years ago, and a around 75 years ago the US Air Force was the US Army Air Corps.
I think it still belongs to the Air Force RCO
How does it have enough Delta-V to get into that distant of an orbit? Is it able to maneuver to different orbits and inclination? Is it able to return to earth? Or, is it more of a satellite than a “plane”? This is my first time learning about this space plane, so apologies if my questions are naive.
This flight was launched with a Falcon Heavy, that is why it has more energy to reach high orbit than the previous launches with an Atlas V booster.
When you are in a highly eccentric orbit (meaning the point in the orbit farthest from Earth (apogee) is much higher than the lowest point (perigee)) like this one there are several maneuvers you can do to significantly change your orbit with relatively little energy. The article describes some of the things they are testing.
A small breaking burn at apogee will lower the perigee into the upper atmosphere and they can then do aerobreaking (use atmospheric drag to lose energy) to slow down enough to land.
Thanks for the great response! It's been a while since I played KSP, and I completely forgot about the apoapsis maneuvers :-)
As an aside, it's sad about KSP2. We need a good, open-source space simulator in the spirit of KSP, which has incredible enthusiasm in the modding community.
I can imagine there are folks that do their day job at the Space Force and come home to load up KSP to blow off some steam.
It has been to space several times, and there are photos and videos of it returning, shuttle-style on a runway.
By carefully timing boosting burns at different points in the orbit, you can change the orbit to become highly inclined - go prograde at the periapsis, and your raise the apogee.
From the image, I guess they are in a Molniar orbit [1].
Wow, thanks for sharing! I've never heard of Molniya orbit. Very interesting indeed.
By using an Atlas V booster.
Interestingly since Space Force was created by Trump who sees it as a prestige project and it depends on Musk's SpaceX for launches this is probably one of the most secure agencies in the current administration.
*Financially secure.
(until "let's deorbit and go to mars")
cant wait for space marine branch
Service guarantees citizenship! -Starship Troopers
How far from earth are they to took that picture?
Pretty far. In LEO it's hard to see much of Earth in one shot since you're still so close.
https://space.skyrocket.de/doc_sdat/x-37.htm
This source indicates an 38,000 km apogee, which is is about 1/10 the distance to the moon, and just barely beyond geostationary.
When even your secret programs have to do marketing. Don’t cancel me bro!
In the book Skunk Works, Ben Rich laments that Lockheed was often passed over for contracts and missions because their achievements were so classified that the various branches of the military didn't know that things like stealth technology were possible, let alone already in production. Sometimes weren't even invited to bid on projects to develop technology that they'd already developed.
Marketing of secret projects is a tricky business!
Was it Lockheed who simply ran a regular marketing campaign for NGAD and then later scrubbed references to it
That's exactly what I was thinking too. With all the chainsaws on display and rumors of deep cuts, makes sense for them to explain a bit to regulars about why they exist and how well things are going.
one would be excused to think you made this account just for the sake of aptronym and comment, but alas, 3k+ karma
In fairness, it's an insightful comment. The behavior of plenty of agencies is likely to be erratic or at the very least novel in the current climate.
That looks... out there. Is it parked at a Lagrange point?
Article mentions that it's in a highly elliptical orbit.
Imagine the next space station being that high up.
imagine if noah had this during the deluge mtsm
A mere month ago I would have been excited for the new US defence tech.