DreamChaser partners with StratoLaunch

[Nibb31]

A little bit of news that will get the DreamChaser fans drooling:

http://aviationweek.com/space/sierra-nevada-turns-international-market-dream-chaser

Personally, I don't believe this will ever come to fruition. A scaled-down DreamChaser with a crew capacity of 3 isn't very useful for space tourism, NASA doesn't need it to service the ISS, and it really has nowhere else to go... unless of course Bigelow suddenly comes up with some miraculous customers for his own station. Also, a scaled down DC means that they are basically redesigning it from scratch. The only thing left is the X-28 moldline that they licensed from NASA. Who is going to pay for a whole new development program?

And then there are huge doubts about the economical viability of StratoLauncher itself, the most expensive and underperforming first stage ever, as well as its abort and scrub modes, especially for a manned vehicle.

But well, it's still interesting I guess.

[astropapi1]

It still makes me sad that Boeing got chosen just because it was boeing. I know the whole purpose of CCP wasn't to innovate, but to make a spacecraft that could meet the needs and nothing more...

... but spaceplanes are cool.

[sgt_flyer]

mmmh. after reading it, it seems they'll keep the exact same shape, but reduced all dimensions by 75%... so they'll have to build a new engine etc... (and they already did not manage to work with their current hybrid rocket engine)

the reduction would allow it to be launched from Stratolaunch's under devellopment 'flying launchpad' - if they airlaunch this scaled down version, it will really remind of the russian's 50/50 spiral concept (mig 105)

imagine a mini dreamchaser strapped in front of this thing... http://www.gizmag.com/stratolaunch-systems-air-launch/20839/

Edited October 1, 2014 by sgt_flyer

[NASAFanboy]

Best of luck to them, but I won't really count of it. Sounds more like a last-ditch attempt to keep face for stockholders than legitimate space effort, however.

[Nibb31]

... but spaceplanes are cool.

No they're not. And DreamChaser is not a space plane.

But this topic was to discuss the future (or lack of) of DreamChaser, not to rehash sour grapes about NASA's CCtDev program. Let's keep that in the other thread.

Best of luck to them, but I won't really count of it. Sounds more like a last-ditch attempt to keep face for stockholders than legitimate space effort, however.

SNC doesn't have stockholders. It's a privately-owned company.

[montyben101]

No they're not. And DreamChaser is not a space plane.

But this topic was to discuss the future (or lack of) of DreamChaser, not to rehash sour grapes about NASA's CCtDev program. Let's keep that in the other thread.

SNC doesn't have stockholders. It's a privately-owned company.

You really need to stop slamming people just because they say something good about dream chaser

[sojourner]

You really need to stop slamming people just because they say something good about dream chaser

You're going to have to point out where he did that. I've only seen him correct misconceptions about Dreamchaser.

[StolenWatson]

No they're not. And DreamChaser is not a space plane.

[\quote]

From wiki:

The Dream Chaser is a reusable crewed suborbital and orbital[6] lifting-body spaceplane being developed by Sierra Nevada Corporation (SNC) Space Systems.

SNC doesn't have stockholders. It's a privately-owned company.

oh.

Hm.

A shareholder or stockholder is an individual or institution (including a corporation) that legally owns a share of stock in a public or private corporation

I won't touch the cool comment, because I know you're the authority.

[Albert VDS]

From wiki:

The Dream Chaser is a reusable crewed suborbital and orbital[6] lifting-body spaceplane being developed by Sierra Nevada Corporation (SNC) Space Systems.

space·plane

ˈspÄÂsËŒplÄÂn/

noun

noun: space-plane

an aircraft that takes off and lands conventionally but is capable of entry into orbit or travel through space.

It's not a space plane, it's a lifting body on a rocket.

If it's on Wikipedia then that doesn't make it a fact.

[magnemoe]

No they're not. And DreamChaser is not a space plane.

A shareholder or stockholder is an individual or institution (including a corporation) that legally owns a share of stock in a public or private corporation

Most larger companies or companies with multiple owners are limited companies and have stocks.

One of the main benefits is liability if bankruptcy is loosing your stocks.

Very few of them are on the stock exchange, here totally new rules applies.

[magnemoe]

It's not a space plane, it's a lifting body on a rocket.

If it's on Wikipedia then that doesn't make it a fact.

Wikipedia: something who look like wings==Space plane. In KSP a space plane is something who accelerates close to orbital speed on atmospheric engines as in skylon who is an obvious space plane.

I see dream chaser as an mini shuttle, design has some benefits but lots of weaknesses over an capsule.

My pet idea is an large capsule, think space shuttle like orbital service facilities including the arm a small cargo hold and good eva facilities.

Whole system is reusable with powered landing dragon style, fallback is to drop everything but the cockpit and land on parachutes. Cockpit is not capable of reentry itself but bottom door is capable of water landing, escape mode is also capable of landing on land as the parts who remains makes an good enough crumble zone.

In short you get something like a space shuttle with an all around abort option and an far lower weight and should be launchable on a falcon heavy.

[StolenWatson]

It's not a space plane, it's a lifting body on a rocket.

If it's on Wikipedia then that doesn't make it a fact.

But you asserting your claim alone causes it to be so.

HTHL may be a "truer" interpretation of a spaceplane, but VTHL has been widely accepted as a valid spaceplane by nearly everyone in the industry.

[Rakaydos]

It's not a space plane, it's a lifting body on a rocket.

If it's on Wikipedia then that doesn't make it a fact.

Except now that it's launching from Statolaunch, the entire Stratolaunch/Dreamchaser assembily is technically a multistage spaceplane.

[Airlock]

Here's the concept image, from this article: http://www.nbcnews.com/science/space/sierra-nevada-stratolaunch-team-dream-chaser-space-plane-n215386

[sgt_flyer]

Mmh - there's some things that itches me when seeing the image. Having the DC placed on top of a vertical launch rocket is one thing (apart from a bird strike very early in the flight, there's not much that could collide with the unprotected heatshield.)

Here, horizontally placed on a runway, it could be more susceptible to foreign objects hitting the heatshield. (Especially as the carrier plane will build up more horizontal speed at lower altitudes than a rocket do).

I think they would maybe need some sort of protection cover at least for the heatshield while it's attached under the carrier plane (or even a full fairing to prevent it's lifting body shape from interfering too much with the carrier / winged rocket)

If it's just a protective cover, it could be ejected just after the carrier plane released the rocket. (To prevent risks of hitting the carrier plane with the cover)

[Tommygun]

I would think trying to eject a protective cover inflight could end up hitting the rocket behind Dream Chaser.

You may be better off just having the ground crew walking the runway before flight to get rid of any FOB.

[sgt_flyer]

It should not have much more chances than traditional fairings (and the stratolaunch rocket use fairings) - besides, a runway walk won't protect against birdstrikes after take-off.

http://www.airport-int.com/gallery/birdstrike-prevention-services/aircraft-nose-birdstrike_01.html

Without protection (and a fairing would be better - a frontal strike, even if it hits above the heatshield, could compromise the spacecraft's hull integrity), they would need to abort the launch for a full checkup of the small DC each time they have a birdstrike.

A rocket spends much less time at the altitudes birds fly than a plane (and the launch site can be equipped with things to repulse a lot of birds - outside an airport area, it 's harder to do)

[Arsonik]

It's not a space plane, it's a lifting body on a rocket.

If it's on Wikipedia then that doesn't make it a fact.

If it's on a random "dictionary" website on the internet doesn't make it a fact.

Also its obvious he mean't space shuttle. Whatever helps you sleep at night though.

And who is to say that taking off on top of a rocket is not conventional? Maybe not conventional for a PLANE but we are indeed discussion a SPACEplane.

[B787_300]

While it is a interesting proposal, *I personally* am not in favor of it

1. it is a TOTALLY new design, if you want to get technical it is scaled down but that actually causes more issues (most rocket stuff id hard to make when it is large or small, needs to be about in the middle to make it easy to manufacture to rocket tolerances)

2. when vertically launching on Atlas, the heat shield is only exposed to a short period when it can be hit by terrestrial debris. when launching on the Stratolaunch, it has a much longer period and the debris can go unnoticed until something goes drastically wrong (see the Concorde Crash, or any other issues with FOD on the runway). Adding a drop fairing of the TPS is an option but it adds complexity, especially if it does not jettison.

3. Honestly launching from stratolaunch is a bit dumb in the first place as it is a much more complex system than just launching vertically on a bigger rocket. For one using Cyrogenic Fuels is a lot harder because how do you keep them cold, Solids are a lot harder to use but can be stored but are not all that precise. You also have to design the booster to be aerodynamic with the load and have a good dropaway profile, which means the booster is more expensive (see Pegasus XL for another air launched rocket) Building/modifing the mothership can be challenging (they are essentially trying to strap 2 747s together).

overall i think this is a BAD idea...

MOD NOTE.... This thread is not the place to discuss what a spaceplane is or is not. This thread is for the SNC-Stratolaunch joint venture. If you want to have a discussion about what *IS* a spaceplane please make a new thread.

[Nibb31]

There is also a whole load of problems with abort and scrub modes.

- What happens if you have to scrub a launch after take-off? It's damn risky to land with a fully loaded rocket under the belly.

- What happens if you scrub the launch after release of the rocket or if the engine doesn't start? You lose the rocket and you have to abort the DreamChaser.

- DreamChaser needs a runway nearby for abort modes. This negates the point of StratoLaunch's "launch anywhere" advantage, meaning that you can't launch from out in the middle of the Ocean.

- If DreamChaser is to abort by splashing down in the Ocean, it needs to have a rescue ship prepositioned nearby, which also negates StratoLaunch's "quick response" advantage.

I'm sure there are plenty of other abort modes that people can think up. It's simply not going to work.

[Albert VDS]

Here's the concept image, from this article: http://www.nbcnews.com/science/space/sierra-nevada-stratolaunch-team-dream-chaser-space-plane-n215386

http://media4.s-nbcnews.com/j/newscms/2014_40/693911/141001-stratolaunch_586dfe9e3cce066008f830356f169a25.nbcnews-ux-1680-900.jpg

So correct me if I'm wrong, but does the launch go something like this:

1. The whole craft launches towards the max height and releases the second stage.

2. Second stage propels the craft even higher en releases the DC.

3. DC descents and lands on a runway, second stage also lands on a runway.

That to me sounds very inefficient, why not keep the second stage as one craft?

[Kryten]

Yeah, that's completely wrong. It's just a normal expendable rocket that happens to be launched from a plane and have a lifting body as the payload.

[Nibb31]

So correct me if I'm wrong, but does the launch go something like this:

1. The whole craft launches towards the max height and releases the second stage.

2. Second stage propels the craft even higher en releases the DC.

3. DC descents and lands on a runway, second stage also lands on a runway.

That to me sounds very inefficient, why not keep the second stage as one craft?

Nope. It goes like this:

1. Aircraft takes off with rocket flies to launch location, altitude, and azimuth.

2. Rocket release. Core stage ignition.

3. Separation. Upper stage ignition.

4. DC reaches orbit. Upper stage separation.

5. Mission.

6. DC reenters and lands.

Both rocket stages are expendable. Upper-stage is cryo (lower stage is TBD), which means that it suffers boil-off on the way up and needs topping up during the flight, which adds complex cryo storage and refueling systems to the carrier aircraft. The wings on the core stage are only to stabilise and point it upwards after the drop, which adds extra weight, control surfaces, and more complex avionics.

There is no benefit in terms of cost or delta-v and a whole lot of extra complexity and high-altitude stunt jobs. The aircraft is a very specialized and complex one-off that costs a lot to develop, can only operate from one or two airfields in the world, and spends most of its life in a giant hangar waiting for a launch and eating up maintenance costs. You would really be better off just replacing the whole aircraft boondoggle with a couple of SRBs for a similar gain in dV. The only real advantage is that it can launch rapidly and into any orbit. That flexibility might be useful for DoD launches, but that's about it.

Edited October 2, 2014 by Nibb31

[Kryten]

There are actually three stages; two solids of the same diameter and a LH₂/LOX stage that forms the bulge at the end.

[Frozen_Heart]

Though I love Dream Chaser, this stratolaunch seems to just add a stupid amount of complexity for no advantage.