ESA: British Skylon spaceplane seems perfectly possible

I'm sure it's a lovely spaceship

But what's it like to write with?

I can see the future.....

...and in about 30 years time, Lewis Page will be lamenting a colossal UK/EU waste of money on this project and asking why on earth we had to build our own super-ambitious space vehicle when we could have just bought some poxy US rocket instead (which he will then produce some contrived and dubious evidence to argue is superior in every respect, and that this should have been obvious 30 years ago).

This document is likely to be *critical* for fund raising. It's a major milestone

Before it RE is a smallish company with a big idea.

After it RE are a smallish company whose idea has been *thoroughly* investigated by competent auditors with *no* vested interest in it working. The auditors have looked at even the *secret* bits and concluded they work.

This is the sort of hard nosed scientific deep cavity inspection that large scale investors *must* see in order to start signing cheques.

It is an area where companies have failed because the few groups of people qualified to be able to make a judgment on someones capability in reality have a vested interest in them *not* succeeding.

In the US it's known as the friend-at-NASA syndrome.

Note that in a recent interview Elon Musk stated the total investment to date for Spacex was c$800m. Had he had to borrow *all* that money through the financial markets his bill would have been a *lot* higher and this is despite the fact that the technology is relatively (let me just repeat that word *relatively*) pedestrian, although its *implementation* is very advanced.

RE's net worth is roughly 1/133 the size.

I wish them every success. I believe that if they do get to market their estimate of 30 customers will go down in history with Thomas Watson Jnr's assessment that the world market for mainframes *might* reach 14.

Birds

Reminder...

Requirements := Requirements + Surviving A Bird Strike*

* Canada Goose, fired directly into the frost-proof helium-powered super-beer-cooler thingy at Mach 6-ish. If they can handle that, then that's A Very Good Thing (TM).

Most comsats incorporate that final stage as part of *their* components

The last rocket stage might *point* them roughly into the direction and a bit of delta V but the bulk is usually provided by something called an "Apogee Kick Motor".

Historically it's been a big solid but for best performance you make the storeable propellant tanks on your satellite oversize. if the rocket has done a good job you get a *free* satellite life extension since you can keep it in its orbital box (comm sats are confined to a rectangular section of their orbit but they drift about it. Like a slow motion game of pong)

Note although RE show satellite launch from a Skylon in a stable *orbit* it has a 2300Km cross range. A sub-orbital launch could put up a *very* big sat pointed in the right direction and with as much delta v as a regular launcher, leaving the AKM to finish the job.

However a separate "tug" could be a *very* useful investment. Staying in space (ideally being re-fueled there), not taking up cargo pay space or mass on *every* flight it would deliver the idea of space as a "service" rather than a piece of hardware you *have* to acquire to fly your mission (in the way you have to buy a rocket to do so now).

Fundraising

If every human chips in 2 quid we can start building this thing tomorrow!

(checking pocket for loose change)

@John Savard

"Right now, what the world needs is a new way to get astronauts to and from the ISS, so the fact that this vehicle is unmanned limits its importance. "

Not really.

Uncrewed <> *incapable* of carrying passengers.

It's a subject that RE have looked at as you can see in this report.

http://www.reactionengines.co.uk/downloads/JBIS_v56_118-126.pdf

The unmanned thing may be a bit of a red herring. But as the UK never built a crewed rocket they never worked out a man rating requirement either. Note the Shuttle is *not* crew rated either. The aspects it does not deal with are met with "waivers."

I will observe that *not* being mated up to *huge* solid fuel boosters (which cannot be shut down in emergency) and a large tank with foam shedding issues ("mitigated" but not AFAIK *eliminated*) should put it head and shoulders above the Shuttle in the risky-features-we-cannot-do-much-about stakes.

More to the point would be how the US and/or Europe view it's crew worthiness. However if there were *other* places to go who did not care about such distinctions that would not matter.

Like an orbiting hotel for example.

However RE are *very* cautious about market projections as they *have* to be given the budget they need. This is why they are *very* cautious talking about *anything* but communications satellite business, which is *the* paying segment.

I will point out that a vehicle designed with a *very* small number of fluids (*the* key reducer of support costs on *several* NASA studies), basically LOX,LH2, hydraulic fluid and water, requiring *no* mating of components and with *no* on board crew *should* be able to substantially lower the price per Kg to orbit, given the propellant bill is roughly $1.68m. #

The bill for the Shuttle's expendable tank is about $1m, but the tank itself is roughly $12m and it's single use. However that $1.68m does not count topping up the water tanks and replacing they pyros (not cheap. The Shuttle has several 100 on board, along with their ignitors, each at about $400).

Unlike NASA RE has *no* standing army of people it's politically *required* to employ (and no desire to acquire one).