X-37C: plans for a crewed version of the X-37

[Rocket Science]

The flaw in scaling is assuming a constant mass/volume ratio. In the case of Shuttle you would have a high M/V in the fore (cabin, RCS) and in the aft (engines, tanks). The center 60’ cargo bay would be relatively a low M/V and via a high percentage of overall dimension thus a source of error… Just for you to consider… Carry on

or the easy way is to see how they scaled the x-40 to the x-37B.  A good hint for you.

Yes, but that was not much of a leap...

[vulture4]

It appears that Boeing at least informally promoted a manned version of the X-37C in 2011, showing crew and APAS. I assume this was intended for civilian access to the ISS since if it were a DOD project it would presumably have been classified. Boeing apparently designated the Atlas as LV for the X-37C, so that sets an upper limit of about 20.5 metric tons even if the heaviest version (552) was used. http://en.wikipedia.org/wiki/Boeing_X-37

[BrightLight]

It appears that Boeing at least informally promoted a manned version of the X-37C in 2011, showing crew and APAS. I assume this was intended for civilian access to the ISS since if it were a DOD project it would presumably have been classified. Boeing apparently designated the Atlas as LV for the X-37C, so that sets an upper limit of about 20.5 metric tons even if the heaviest version (552) was used. http://en.wikipedia.org/wiki/Boeing_X-37

Since the Atlas was  declared as the LV - I think you nailed it with a upper limit on mass (My gut tells me it will be more like 30K lbs - pure arm waiving).  However, DOD (Air Force) has wanted man-in-the-loop for quite some time, since the days of the X-15 and X-20. The Air Force has a penchant for wings (X planes), so why not a DOD version of the HL-20/DC.  What is special about the X-37 form?

[Go4TLI]

The crewed version of the X-37 is not going to happen, as much as folks like to speculate  The Boeing proposal is the CST-100.

[clongton]

What is special about the X-37 form?

Wings. They're more efficient than a lifting body for cross range and stall speed.

[JBF]

What is special about the X-37 form?

Wings. They're more efficient than a lifting body for cross range and stall speed.

Which you only need for military and/or emergency situations. In all other situations they are a waste of mass.

[Patchouli]

The crewed version of the X-37 is not going to happen, as much as folks like to speculate  The Boeing proposal is the CST-100.

It could be a follow on to the CST-100 if it's successful.

Of course the X-37C could end up being mostly a robotic space plane or a vehicle tailored for military needs.

[clongton]

What is special about the X-37 form?

Wings. They're more efficient than a lifting body for cross range and stall speed.

Which you only need for military and/or emergency situations. In all other situations they are a waste of mass.

I didn't say they were better. I just answered the question:"What is special about the X-37 form?"
The general issue is "wings or lifting body?" Each has their own advantage.
That's the advantage wings has and that's the question that was asked.

[BrightLight]

The manned version of the X-37, the C model has some odd flavors to it - why 6 people, that sounds like an ISS need, yet the X-37 is a Air force/DOD program.  If the DOD wanted a manned, reusable, winged spacecraft why so many people? to have a all American DOD mission to ISS would be problematic with the Russians.  If Boeing were going to offer it as a CCDev solution what would the CST-100 become.  Unless the DOD has a program for manned missions, I am coming to to the conclusion that the X-37C manned version is a PR issue.

[Jim]

The manned version of the X-37, the C model has some odd flavors to it - why 6 people, that sounds like an ISS need, yet the X-37 is a Air force/DOD program.

No, can't make that comparison.  X-37 was originally a NASA program.  NASA dropped it and the DOD took it over. The DOD does not own the "legacy" of the program, X-37C is a Boeing commercial development and has no DOD influences.

[Prober]

The manned version of the X-37, the C model has some odd flavors to it - why 6 people, that sounds like an ISS need, yet the X-37 is a Air force/DOD program.

No, can't make that comparison.  X-37 was originally a NASA program.  NASA dropped it and the DOD took it over. The DOD does not own the "legacy" of the program, X-37C is a Boeing commercial development and has no DOD influences.

A well written answer.

[vulture4]

DOD (Air Force) has wanted man-in-the-loop for quite some time, since the days of the X-15 and X-20.

I agree, but that may be changing as more drones were procured last year than manned aircraft.

The Air Force has a penchant for wings (X planes), so why not a DOD version of the HL-20/DC.  What is special about the X-37 form?

Could it be because the DC doesn't HAVE wings?

The DC and X-37 bear a superficial resemblance, and both have been referred to loosely as "lifting bodies", as distinct from capsules. But they stem from different lines of thought and are totally different aerodynamic concepts.

The DC is based on the Soviet BOR-4 subscale prototype, but it stems culturally from the attempts of the 60's to build an airplane without wings. This began because it was felt (by NASA) that no material could tolerate the high temperature imposed on sharp leading edges by the hypersonic airflow during atmospheric entry. So it seemed natural, in an era when the impossible took only a little longer, to design an aircraft that did not need them. The downside was that lift-to-drag ratio (L/D) was marginal. Paradoxically the Dyna-Soar, an Air Force project that began before Mercury, had conventional wings and fuselage, and ultimately advances in materials made the Shuttle possible with its conventional delta wing and a L/D which was, except for the drag of the huge engine nozzles at the tail, exactly twice that of the HL-10. The X-37 was an evolution of the Shuttle design, with conventional delta wings, but with a separated V-tail added to improve control of pitch and CG tolerance.

So, in retrospect, the military has favored wings and NASA has not.This is a matter on which there is some disagreement, and I want to stress that I have great respect for other viewpoints. But we cannot forget history, or basic aerodynamics. Wings and fuselage do such different tasks that it is, in my opinion, impossible for one structure to do both tasks well.

[Jim]

However, DOD (Air Force) has wanted man-in-the-loop for quite some time, since the days of the X-15 and X-20.

And repeatedly has found that there is no benefit to it.

[mmeijeri]

And repeatedly has found that there is no benefit to it.

Besides, man in the loop doesn't mean man on board, compare drones for instance.

[vulture4]

And repeatedly has found that there is no benefit to it.

Besides, man in the loop doesn't mean man on board, compare drones for instance.

Alternatively, with the autonomous landing system they have just demonstrated, man on board doesn't necessarily mean man in the loop.

[Lars_J]

And repeatedly has found that there is no benefit to it.

Besides, man in the loop doesn't mean man on board, compare drones for instance.

Alternatively, with the autonomous landing system they have just demonstrated, man on board doesn't necessarily mean man in the loop.

Shhhhh! Don't tell the pilot wing of the Astronaut corps! 

[Star One]

And repeatedly has found that there is no benefit to it.

Besides, man in the loop doesn't mean man on board, compare drones for instance.

Alternatively, with the autonomous landing system they have just demonstrated, man on board doesn't necessarily mean man in the loop.

I wonder how much human input it has whilst on orbit as far as controlling it day to day is concerned or does it do most of the mundane stuff itself.

[Jim]

I wonder how much human input it has whilst on orbit as far as controlling it day to day is concerned or does it do most of the mundane stuff itself.

Most spacecraft are autonomous for day to day type operations

[vulture4]

I wonder how much human input it has whilst on orbit as far as controlling it day to day is concerned or does it do most of the mundane stuff itself.

Most spacecraft are autonomous for day to day type operations

Several press releases have said the landing was "autonomous" rather than remotely piloted.

[vulture4]

Even though it is unlikely this will ever come to be it would be a great addition to ISS. It will give us a way to bring up ORUs previously only the shuttle could bring up.

This, in my opinion, is the single biggest advantage of X-37 to ISS, since this is a unique capability that only the X-37 can offer.

Everyone misses the real “asset” of the x37b program.    It’s further along, tested, and it works!   That’s the real excitement here.   

NASA could have a real winner here and doesn’t really know it.  Right now I would love to see NASA work with USAF on this. Given the specs of the X37 run a test to fly to the ISS (no birthing) and after sometime return.     

This is a “mission change” for the test program, but could be well worth it in the future.  The Original design specs might have changed.   Some of the published x37b specs have an uber high orbit (much higher than the ISS).

I absolutely agree, but on the NASA side it is hard to find anyone who even understands the difference between the X-37C (a wing-and-fuselage design) and the Dreamchaser (a lifting body).