The primary advantage of airplane launch is that you can fly to into a launch window for an orbital rendezvous. Otherwise you'd have to wait for the target's orbit to be just right w/respect to the launch site, or do a long orbit matching process.

This is very useful if say you want to very quickly and quietly launch something towards another satellite.

People are making comparisons with the Spruce Goose, but the Glomar Explorer may be a better analogy.

The largest downside is the rocket needs to be strong in more than one direction which adds a lot of weight. Sub Mach 1 first stage will save a little net weight but significantly less than you might diets assume.

Sure, but the strength it needs to have in the additional "hanging horizontal" orientation is only 1g -- much less than the many-g strength that all rockets need to have along their thrust axis. It adds some weight, but not enough to ruin the other benefits.

For those not familiar with cold war lore - Glomar Explorer was a submarine recovery operation which used the actual Howard Hughes as a cover [0].

[0] https://en.wikipedia.org/wiki/GSF_Explorer

Looks more like the Pineering Spirit, a ship made from 2 hulls side by side:

https://en.wikipedia.org/wiki/Pioneering_Spirit_(ship)

There are videos of this thing lifting an entire oil platform at once.

> This is very useful if say you want to very quickly and quietly launch something towards another satellite.

Surely you could already do that with Orbital ATK's Pegasus? 1000 lbs is plenty of explosives. It seems to me this is just a bigger version of that.

It would be potentially suitable for a larger payload akin to the X-37B. This would be handy if the intent isn't destruction, but rather interference or even retrieval. https://en.wikipedia.org/wiki/Boeing_X-37

The spruce Goose analogy comes from wingspan, which is directly from the article

He's hinting that this is a black program with a fake public cover story.

Right. Well I guess it would be useful to hit any satellite in the world within x hours

Could I take my captured satellite to a base inside an extinct Japanese volcano?

That would be SPECTREcular!

Ha also by Howard Hughes... ah I was obsessed with this guy for a while... I realize it's a movie but The Aviator is a favorite... Katherine Hepburn/Howard Golf scene haha

edit: CIA and kursk submarine, was it the kursk doesn't sound like the right time

edit: nope Kursk is 141, K-129 is the one they wanted (Glomar Explorer)

I like the jet-rotor tip helicopter too

edit: haha yeah beast (photo of the helicopter with massive rotors spinning I think at 88rpms)

https://s-media-cache-ak0.pinimg.com/736x/04/f9/9b/04f99b793...

You can also fly towards the equator before the launch for more boost. Further from the Earth's axis.

For example Cape Kennedy is 28 degrees north. If you fly to the equator, you get another 200 m/s.

Depends a bit to which orbit you're launching though.

Another good thing is flexibility if you are more constrained by launch windows in a stationary launch location. Hard to explain.

I had a big mistake in the comment above, it's 220 km/h or about 60 m/s.

    cos(28)=0.88 
    0.12*(2*pi*7000 km) = 5300 km
    5300 km / 24 h = 220 km/h
    220 km/h / 3.6 m/s/km/h = 61 m/s

Is 4. really doable? Would have thought landing while carrying a fully fueled rocket might be pretty high risk.

I haven't actually seen anyone mention it, but it shouldn't be much more risky than taking off fully-fueled. That said, landing with the rocket still on board might break some fuel-balancing assumptions.

Peagus rockets aren't cryogenic, they are solid monopropellant rockets. Not really all that dangerous.

Anyone who suggests to you that hydrazine isn't dangerous shouldn't be trusted.

Hydrazine is liquid; an equally toxic solid would be much less dangerous to work with.

Landing weights are usually a bit lower than take off weights due to the extra shock on landing.

for example the a340-600 has a MTOW of 380 tons but a Max landing weight of 265 tons. Just a bit of a difference.

That's the fuel the plane takes off with. I don't know how much this beast uses, but those six engines must be burning quite a lot of it. Also, the landing gears seem to be very robust.

The A340-600 has four engines, not six. But the point is still true with, say, a Boeing 787. Here are the figures for the 787-9: maximum takeoff weight: 560,000 lb; maximum landing weight: 425,000 lb [1]. In case of an emergency the pilot has to get rid of fuel before landing if the airliner is above maximum landing weight.

[1] Figures given in pounds on wikipedia, the kg version looks like a "dumb" conversion: https://en.wikipedia.org/wiki/Boeing_787_Dreamliner#Specific...

We don't know Roc's maximum landing weight but abort is possible if the maximum landing weight is more than weight of the whole craft plus its cargo minus the fuel. I assume it takes of with a lot of fuel because it has potentially 1.5x time fuel consumption of an old 747.

Fundamentally, landing speeds are lower than takeoff speeds. To travel at the same (low) speed and rate of descent with more weight means getting more lift at the same speed. That is done by increasing angle of attack or adding flaps. There is a limit to both.

Can the payload be dropped with a parachute? Is 200m/s safe for parachute deployment?

Could always dump fuel on the way back.

Not from the Pegasus solid rockets.

How much fuel the plane carries?

Avoiding drag could be a huge benefit if you envision an air breathing second stage (ramjet or scramjet).

Neat - I kind of intuitively knew about B. from playing KSP, but the other two are interesting.