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The X-37B: what is it for?

X-37B has successfully passed the 270 day milestone in its now extended mission.

Lots of people have speculated about the military’s plans for the X-37B. I think the Air Force is actually telling us in this quote:

“This is a test vehicle to prove the materials and capabilities, to put experiments in space and bring them back and check out the technologies,” Richard McKinney, deputy undersecretary of the Air Force for space programs, told Air Force Times in an interview after the first X-37B landed. “My words to others who might read anything else into that is, ‘Just listen to what we’re telling you,’ ” he said. “This is, pure and simple, a test vehicle so we can prove technologies and capabilities.”

The X-37B gives the Air Force the ability to launch a new instrument into space, fly there for a period of time to see how it works in that hostile environment, then return it safely to Earth for further testing. And believe me, this capability is not to be treated lightly. For example, in building their space station Mir, the Russians had no way to bring large materials and instruments back to Earth. They were thus badly hampered in finding out what was wrong when something failed, as they had no way to get it home to give it more rigorous testing than could be done in space.

Furthermore, when I went to Russia to interview cosmonauts and engineers for my book, Leaving Earth, they repeatedly complained about the U.S.’s insistence that Mir be de-orbited without using the shuttle to bring back parts of its hull and superstructure. “When else,” they would tell me, “will we get the opportunity to test materials that have been exposed to space for almost two decades?”

The reason these Russians wanted the shuttle to do this, however, was because their Soyuz spacecraft couldn’t. The Soyuz capsule has very little return cargo capacity, while the Progress freighter, which burns up in the atmosphere when its lifespan has ended, can bring nothing home. It was this lack that limited what could be learned from many experiments on Mir.

Thus, the flexibility the X-37B gives the Air Force is priceless. Too bad our civilian NASA program — which had initiated the X-37 program and then abandoned it to the Air Force — doesn’t have that capability.

Pioneer cover

From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

Unfortunately, that is exactly where that journey takes him.

The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.

He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.

Available everywhere for $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from the ebook publisher, ebookit. And if you buy it from ebookit you don't support the big tech companies and I get a bigger cut much sooner.


  • Chris Kirkendall

    I’ve been wondering – is there some reason the X37B cannot be configured to transport astronauts and/or supplies to the ISS? It’s already proved its spaceworthiness, and would seem to be large enough to carry a substantial amount of cargo. It may not be currently configured to dock with the ISS, but how difficult would it be to modify it for that role? I’m just asking this cause I really don’t know, and there are some pretty knowledgeable folks here who might want to weigh in on this…

  • Hi Chris,

    I suspect the primary problem to using X-37B as a crew ferry is that cargo bay is not pressurized. You would need a major redesign to make it capable of carrying people safely.

    Making a cargo craft for ISS would be far easier, which is why there have been some hints from Boeing that the company is considering offering it to NASA for this purpose. NASA of course would have to want to use it.

  • Elmar_M

    There are concepts for a larger cargo version and also a manned version of the X37. They would still be able to launch on an Atlas, but without the payloud shroud.

  • Coastal Ron

    Once SpaceX gets the cargo version of the Dragon operational, the need for a larger X-37 will probably go away. And if a company other than SpaceX gets their commercial crew vehicle operational, there will be even less incentive to build a larger X-37.

    Even though the X-37 has a cargo bay that can be exposed versus having to load and unload cargo into a pressurized cargo/crew vehicle, I still think the need for a larger X-37 won’t emerge. Even if it did, I think Sierra Nevada could probably build a cargo version of the Dream Chaser instead of upsizing the X-37.

  • Andy Hill

    There was a recent article on space,com by Leonard David on just this topic.

  • Chris Kirkendall

    Thanks, Bob, Almar, Andy & Ron – you guys really came thru with a lot of great information. You answered my question & then some.Thanks for the link to the article – very interesting. Hopefully other readers also benefitted from this. Bob, I always enjoy your guest slots with either George Noory on Coast to Coast or the John Batchelor show. As a kid growing up in the early days of the space race, I used to to think Jules Bergman, ABC News’ “Science” correspondent, had about the coolest job in the Universe. Bob, I think you’re now filling somewhat the same role. I wish more people took an active interest in Science and I think having someone who can explain complex concepts in layman’s terms helps a lot in that area…

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