Hybrid balloon / glider suborbital plane?

[aeroseek]

Several companies have put forward plans for suborbital aircraft that use bouyancy to reach the edge of space. In fact, balloons can ascend to over 60,000 ft.

Would it be possible to design an aircraft that uses bouyancy to ascend and then somehow convert to a glider to land unpowered, using very little or no extra energy?

I will be posting my ideas here - should be an interesting virtual project.

Here is an inspiration : ( The space shuttle)

http://www.usflagballoon.com/

Some related links to start going...

http://en.wikipedia.org/wiki/Solar_balloon

http://www.fuellessflight.com/huntnews.html

 

[rcgldr]

NASA and other groups are already using balloons to lift model gliders and then releasing them. One of the NASA projects is to design gliders that could glide at high speed in the thin atmosphere of Mars. Some individuals are using balloons to lift radio control gliders with small cameras to around 30 km or so.

 

[aeroseek]

How about combining the two? Of course we can fix a plane underneath a balloon, but preferably this can be accomplished in one aircraft.

Let's establish the flight profile and some specifications"

Accommodation : single seat

Flight Profile: Solar heating of large cylindrical shaped streamlined envelopes on either side of an enclosed single seat cockpit.

On lift off, the aircraft climbs slightly nose up to its ceiling, in this case, let say 10,000 ft. At that point hot air is released from the envelopes and the aircraft slowly descends, using aerodynamic surfaces and controls.

I guess a picture is worth a 1,000 words. Will post

Update: Looks like it has been thought of before!

http://www.theatlantic.com/technology/archive/2011/03/the-rocky-road-to-discovery/72142/

http://www.gizmag.com/solar-ship-hybrid-airship/20263/

Pretty close to what I was thinking, but the design needs to look sleeker. And it needs to be retractable - large wheels hanging in the air really do not look very nice.

 

[aeroseek]

This company offers balloon rides to space. The flight profile is described in the graphic also shown.

http://edition.cnn.com/2013/10/24/travel/space-balloon-30km/

http://worldviewexperience.com/voyage/#flight-profile

Not sure why it would cost $75,000 a ticket, maybe it is to recoup initial costs. There will be no operational costs apart from helium and life support gases. Note that the balloon is jettisoned during the final descent.

The system I am thinking of will transport two occupants to a height of at least 70,000 ft and will use cheaper hot air generated by solar heaters to create the lift. If the capsule had wings, however, it could be landed at a small airport, reducing recovery costs and hazards. Similarly the balloon would also be fitted with wings and remote controlled in its descent.

The real design challenge is to build the balloon envelope and glider in one unit, making it easier to manage.

A "Kerbal Space Program" enthusiast has proposed a similar scheme with a rocket attached to a blimp that forms the first stage.

 

[aeroseek]

Looks like the balloon - lifted space plane will be tested this year: EADS Space Plane drop test:

"The same prototype will be used for the 2015 drop test from 100,000 feet, which will use a stratospheric balloon. For this test Chavagnac said, "What we have to find now is a stratospheric balloon and a test range, which is not such an issue.""

http://www.space.com/24901-europe-space-plane-drop-test.html

I have to ask - if the spacecraft can reach 100,000 ft, without using any fuel, and stay there for several hours if needed, without the added weight of on board fuel, why use a powered flight anyway? Keep the turbojets for safety - in case of a diversion or go - around, but I am not really sure why no-one has suggested the "Balloon - Launched - Spaceplane Glider" although an RC model was used recently in an attempt.

Maybe the balloon could be installed in a space plane cargo bay - and fold and store for the return flight?