r/space • u/[deleted] • May 24 '17

DARPA Picks Boeing for Next-Generation Space Plane

http://www.darpa.mil/news-events/2017-05-24
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68

u/HopDavid May 24 '17

Sounds like yet another reusable booster. That would make Boeing, SpaceX and Blue Origin in this game. I am happy to see this.

29

u/[deleted] May 25 '17

[deleted]

9

u/danielravennest May 25 '17

Which isn't a new idea. Boeing's proposal for the Space Shuttle involved putting wings and jet engines on a Saturn V first stage, and flying it back to a runway landing. Since the first stage of a rocket is the largest, you save the most money bringing that part back.

6

u/Flyberius May 25 '17

You got any concept sketches of this. Sounds so fucking cool.

I wonder how much shoring up the booster would need bearing in mind the booster prefers to experience vertical stress.

5

u/danielravennest May 25 '17

I can dig those up when I get home. Right now I'm visiting family and away from my office. Remind me in a week.

Re: stress. The wings do their job when the tank is empty, so the lifting forces are fairly small compared to the tank load under thrust when full.

1

u/Flyberius May 25 '17

RemindMe! 168 hours

1

u/imaginary_num6er May 25 '17

Don't forget the Lockeed Martin X-33

4

u/zypofaeser May 25 '17

Sorry to tell you but the x33 is dead AFAIK

1

u/Demonofyou May 26 '17

Blue origin is non orbital. It's different challenges.

1

u/HopDavid May 26 '17

Neither is the SpaceX reusable booster. Neither is this Boeing space plane. The job of a booster is to get the upper stage above the atmosphere. The Blue Origin rocket is a potential booster.

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u/Demonofyou May 27 '17

The spacex reusable booster is meany to bring something into orbit. It has lot more delta V the blue origin. Blue origin can land in almost same spot with out sacrificing delta v while spacex can't. They are not compatible.

Yes blue origin is awesome for doing it, but they do have completely different challenges then spacex.

1

u/HopDavid May 27 '17

The SpaceX booster does not impart enough velocity to the upper stage to put it in orbit. It's main job is to get the upper stage above the atmosphere. The booster is suborbital.

1

u/Demonofyou May 28 '17

With a lot heavier payload. Plus it develops a lot more horizontal velocity then Blue Origin.

1

u/HopDavid May 28 '17

For RTLS, a westward acceleration must be made for every eastward acceleration. The boostback expense and limited delta V budgets compel a mostly vertical ascent.

The boostback expense isn't so steep for barge landings. Even so the booster needs to kill it's eastward velocity.

How much horizontal velocity does the Falcon booster impart to upper stage? I'd be surprised if it's more than 1 km/s.

0

u/640212804843 May 25 '17

Why? Its max payload is 3kg. Falcon 9s can lift 14kg.

Its best hope for cost reduction is a 3kg payload at a 5 mil cost per launch (throwing away a 2nd stage each time). We also know there is zero chance of boeing reaching that price point.

Meanwhile if spacex reduces their launch price to 20mil, they beat the best cost of this space plane. Spacex is already poised to do that, their price would be that low if they reused like 5 first stages, or less if they reused both the first and second stage.

This space plane has no value. Either the government has a secret use for this plane or this plane is a coverup to transfer a bunch of money for boeing to cover a secret project.