Wouldn't doubt it.
Hell, Kelly Johnson's 60's sliderule/technology of the SR-71 damn near got you there way back when. Imagine what the black project types have been able to work on with CAD computers and say 70's/80's technology. We've seen a lot of it in the stealth birds, but I suspect there's a lot we haven't seen too.
When I say capable of flying into space, I'm refering to near space. They were not capable of going orbital.
I bring this up because I've surmised that we do have the capability today to fly some of our aircraft into space. The Aurora, which is assumed to exist with some good basis in fact, may be capable of flying into space.
Our theories on space entry have been molded by huge Saturn rockets and a trajectory that sees it going down range as it gains height and speed to eventually go orbital. That isn't the only way to enter space. If you want to stay in space for a period of time, it's the way to do it. But if you just want to go up, do some business and come back, there's another way. When the X planes flew into near space, they essentially went straight up. Once in near space, they were subject to falling back to earth since they weren't orbital. But they could expend more fuel and maintain or go deeper into space.
Under little or no atmospheric pressure, these planes could travel across across the planet or simply do tests and maneuver. Once they were done, they could simply use thrusters to re-enter the atmosphere and land. Remember, they wouldn't be traveling upwards of 17,000 miles per hour. They would be dropping back into the atmosphere at a few hundred miles per hour. The problem with super-sonic heat degrading re-entry would not be present.
The X plane was capable of going five to six thousand miles per hour. If I understand this correctly, that was under atmospheric conditions. Let's consider what might be possible if this plane were to fly into near space. Once it was clear of atmosphere, this plane could excellerate to speeds much faster than the five or six thousand it could in the atmosphere. Would it be possible for it to excellerate to orbital speeds? I don't believe so, because it would be using engines that required oxygen to burn. Now I may be wrong here, because the propellent was probably made up of a mixture that had high oxygen content.
Where I'm going here, is to suggest that the Aurora or another craft is probably capable of the five to six thousand mile an hour range, possibly even the eight to twelve thousand mile per hour range. Once in near space, it could excellerate the rest of the way to go orbital. The problem is, they couldn't take heavy payloads with them.
I think it's highly likely that we have space planes now. They may not be what we'd like to see for full space inhabitation, but I do believe it's likely we've got a space plane cabability right now, for what it's worth.
I wouldn't be surprised at all to find that these planes can do surveylance anywhere on the planet by taking off from US airports. If push came to shove, I'll bet they could do other things as well.