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Richard Branson's Virgin Orbit reaches space on 2nd try

6 Comments
By JOHN ANTCZAK

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We need someone to begin collecting all of the out of date satellites and debris that are in orbit before sending more satellites up. (Space Roomba)

5 ( +5 / -0 )

Aircraft based launches will always support limited cargo sizes and weights.

Have you seen Scaled Composites Model 351, aka "Roc" (Roc is the mythical bird that could lift an elephant), the launch aircraft used by Stratolaunch? It's the world's largest aircraft. It has a max takeoff weight of 650 tons and It can carry a 250 ton payload to 35,000 feet and launch it. Since the rocket doesn't need a first state booster any satellite is a much greater proportion of the total launch weight than a ground launched rocker. It can also launch from any suitable runway, a consideration for wartime use where your fixed launch sites might be attacked and rendered useless. A lot of intelligence/communications satellites used by the US are in the 4 to 5.5 ton range so launching them using Stratolaunch is not necessarily a fantasy. There is some evidence the US has already been doing this with classified in-house launch platforms.

0 ( +0 / -0 )

Btw, I have seen Roc outside its hanger in Mojave and it is quit a sight. My wife worked on the project for a time as an engineering intern. To save costs Scaled hired BAE to study available used commercial aircraft to see which models were both abundant and had suitable components that could be harvested from retired examples of the chosen aircraft model, things like landing gear, flight control actuators, electrical and hydraulic components, etc.. BAE settled on the 747-400, no shortage of these in the boneyard at Mojave that still had plenty of life on their engines and other components and a couple of nice low hour examples became the source of parts for Roc.

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Aircraft-launched spacecraft seem like a great idea, until you want really heavy, large, payloads or need escape velocity from the Earth. How do you handle cryogenic fuel and oxidizer burn-off and refueling? Being mobile for launch seems like a plus, until you think about how satellites are built ... in huge buildings ... that don't move. Spy satellites get launched 1-2 times a decade, so having an entire launch platform maintained for 2 - 4 events (being generous) just isn't cost effective.

The numbers for a commercial solution just don't add up for a sustainable business.

0 ( +0 / -0 )

Spy satellites get launched 1-2 times a decade,

The US typically conducts 25-30 launches per year. The number of launches per year has been constant and linear since 1957 and has not tapered off as a result of the end of the Cold War. The former USSR conducted upwards of 90 launches per year but after the USSR dissolved the number for Russia has stabilized at about 17 per year. At the end of 2019 the US had 1327 satellites in orbit, 166 of these are military satellites and 31 of these are dual military and commercial use satellites. Russia has 89 operational military satellites and China has 84.

0 ( +0 / -0 )

FyI, Out of service satellites are moved to parking orbits out of the way from the most desirable orbits. When they have little power or fuel remaining, they are deorbited in a controlled way that burns up or hits a specific place on Earth.

Aircraft based launches will always support limited cargo sizes and weights. The launch location flexibility is slightly interesting but launch times and inclinations solve that for non-short duration spacecraft.

-1 ( +0 / -1 )

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