Thursday, June 04, 2009

X37 - some speculation

I'm pretty pleased about the story about the X37B in space.com. It's funny how USAF and DARPA seem to be playing tortoise to NASAs hare. While the US military may not be the most efficient organization either, at least they seem have a good handle on what 'operational' means and the importance of having a well thought out plan for maintaining and running a system when it gets past the development stage, and how important it is to design a system with operational requirements in mind. The X37B is, of course, an experimental platform but it is interesting to speculate on what it might develop into in conjunction with a suitable heavy lift launcher.

I assume that the planned tests will involve integrating the X37B into an EELV as purely a payload, ie the current 1st and 2nd stages of the launch vehicle will be used. This will put a small winged return vehicle into LEO. It is interesting to compare the possible capabilities of a hypothetical, operational follow up to this system with the needs of USAF in space.

As I understand the USAF would like to have the following:
-ability to protect/replace assets in space,
-rapid and repeated delivery of munitions anywhere, anytime,

A followup system to the X37 could possibly have the following capability:
-rapid launch to orbit via heavy lift including possible recovery of the first stage if SpaceX are eventually successful with that,
-rapid turnaround between flights if the turnaround time between heavy lift launches can be reduced,
-ability to insert an object into orbit and return to a designated landing site,
-(maybe) launch to a suborbital trajectory over a target location, followed by powered return to CONUS.
-ability to loiter in orbit, with scope for limited orbit changes,
-ability to drop a payload during some sections of its non-orbital flight path.

some limitations:
-Whether you think this limitation is a good or bad thing depends on your point of view, but I can't see this hypothetical system becoming a 'space weapon' capable of dropping munitions from orbit simply due to the impracticability of having to decelerate the payload from orbital velocity, and only being over the target every 90 minutes or so. (although I suppose such a system might solve a need to avoid overflights of aircraft or missiles of other non-participating nations)
-The second stage will be disposable for any standard launch system in the forseeable future.
-In the event of a full fledged attack on space borne assets, it would be vulnerable to orbital debris.

The best part is that a successful operational system will be a good demonstrator for a commercial reusable orbital stage so I'm hoping that something practical comes out of this program. Who knows if one day we might be seeing routine launches of winged orbiters atop VTVL launchers.

6 Comments:

At 4:36 PM , Anonymous Anonymous said...

I think that the next step for X-37 is for it to swallow the entire 2nd stage and for it to grow from 5 tons to 30 to 60 tons. At 30 to 60 tons it will look exactly like the 2nd stage of a 2-stage RLV that the Air Force has been planning for over 10 years. Look up the requirements for the AFRL Reusable Booster program and you will see a 240-ton reusable 1st stage that takes a 60-ton reusable 2nd stage (that looks exactly like the X-37) to a Mach 7 separation for an orbital insertion. Another option is to have a re-usable Falcon 9's 1st-stage to boost an enlarged X-37 (that is the size of a Falcon-9 2nd stage) to a Mach 10 separation for insertion into orbit.

 
At 12:39 AM , Blogger David Riseborough said...

Hi Anon.,
your description triggers a faint memory but a brief google search didn't turn up anything specific. If you provide a link, I'll update the main post.
I can't help thinking that an in-between system may be developed first, because a 30 ton second stage to orbit RLV seems like a huge leap to me. An EELV medium can deliver about 10 metric tons to LEO, so perhaps a larger X-37 with about 1 ton payload capacity could be launched as an EELV payload without modifying the rocket itself.

This would be a good topic for Chair Force Engineer (now in the links)

 
At 8:46 PM , Blogger William said...

Fascinating!

--Bill

 
At 2:11 PM , Anonymous Anonymous said...

The payload is a ram jet penetrator to slam into a bunker complex at 37,000 MPH. It would make a deep narrow crater when it hit without having to have any ordenance to make it milliterized. Jam and slam.

 
At 10:05 AM , Blogger Tom the Younger said...

An alternate use for something like the X-37 is as a reusable satellite bus. Depending on its payload capacity it could make a dandy reconnaissance satellite, particularly if it can start taking pictures/gathering data on the first or second orbit without a long checkout period. Such a satellite could be deorbited, recovered, and reused at will. It might be easier to keep its capabilities secret if it weren't in orbit long enough to catch a picture of it.

Perhaps more importantly, an X-37 type bus might have some launch abort capability to protect your giga-buck payload.

 
At 7:50 PM , Anonymous Anonymous said...

I still think put space shuttles in
space put ion engines on them and
use them to ferry goods around you
can use them to reach GSO orbit so rockets can lift more up to space
they can also ferry goods to the moon its better than them sitting on the ground wasting away

 

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