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SpaceNut

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From: New Hampshire

Registered: 2004-07-22

Posts: 29,433

Re: ESA study finds in-flight oxidiser collection possible

I had always wondered if there would be a penalty for collecting the oxygen as the rocket moves?

ESA study finds in-flight oxidiser collection possible

The first stage would collect air, liquefy it and separate the nitrogen, producing 10kg/s (22lb/s) with a 10,000kg (22,000lb) on-board liquefaction plant.

The advantage of such a system is that the preferred liquid-oxygen propellant does not have to be carried from the ground. Once collected, the oxygen-enriched liquefied air is stored in the second-stage reusable orbiter vehicle.

Carrier plane and rocket that is getting the collected oxygen.

Taking off from the 15,000ft (4,575m) runway at the Vandenberg US Air Force base in California, the gross lift-off weight would be 1,035,000kg.

That system has a dual-hull, hydrogen-fuelled aircraft using six General Electric 90b engines as the carrier aircraft. Between its two fuselages under the wing, it would carry an orbiter vehicle fuelled only with liquid hydrogen with a total mass of 90,000kg.

I wonder if the concept can be put with the hypersonic research?

noosfractal

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From: Biosphere 1

Registered: 2005-10-04

Posts: 824

Website

Re: ESA study finds in-flight oxidiser collection possible

I wonder if the concept can be put with the hypersonic research?

I think it is meant to avoid hypersonic airbreathing ...

http://www.andrews-space.com/images/vid … 00307).pdf

Table 4 below shows the advantages of airbreathing
first stages for horizontal takeoff TSTO RLVs.
Comprable takeoff weights for all-rocket horizontal
TSTO RLVs would be the in 2.5 Mlb range. Notice
that there is actually not much difference between the
inert weights and performance of the three concepts
when equivalent technologies are applied. In effect,
the higher specific impulse of the hypersonic airbreathers
is canceled out by the additional drag losses
relative to the air-launched rocket using [in-flight oxidizer collection].

Incidentally, this paper describes subsonic oxidizer collection.  I wonder how much benefit the ESA design gets out of supersonic oxidizer collection.

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