NASA funds research into self-building spaceships

While I'm all for advances in technology, this makes it clear that NASA simply DOES NOT UNDERSTAND THE PROBLEM.

If spacecraft are to be "constructed" using 3d printers, you still have to get the mass needed into orbit.

The problem is that it still costs vastly too much to get a pound of mass into orbit. As long as we are throwing away a multimillion dollar booster on each launch, that will continue to be the case. The fuel cost for an Apollo launch, at today's prices, would be about 5 million dollars. To put that in perspective, a Falcon 9 launch costs 54 million dollars to put up less than 1/10 the payload.

The Space Shuttle was a blunder that should never have been built. NASA should have followed the Air Force model and gone by small steps. Get the thermal protection system working right. Get the engines working right. Get each individual piece working right, then put them together in a slightly scaled up package and get that working right. Then scale it again. But instead NASA in their arrogance assumed that their untried engines and their untried thermal protection system and their untried solid rocket boosters and the rest would all work just as predicted, and when they didn't it was a disaster.

How about we just shoot NASA and give their budget to DARPA, that actually seems to do useful things with it?

I do not disagree with your assesment of the shuttle (although hindsight is usually more accurate than foresight), But I would not hold up DARPA as a paradigm of wise spending. They fund way more wacky, useless stuff than NASA. Most large corporations that fund their own research are no better; their bad decisions are just hidden from public view (and usually covered up inside the company as well).

Regarding the 3D printer project. It is not necessarily as silly as the above article makes it sound. Here is a better summary:

The point is to make kilometer scale objects that could never be launched, such as large interferometer baselines or long baseline radio telescope arrays. The 3D printing can also be used to reduce weight by making more complex truss patterns the same way they make lighter 3D printed bicycles.

$100,000 is not a lot of money for an engineering project, so it may be just an early proof of concept study.

DARPA funds "silly stuff" but they don't spend billions on single programs that turn out to be crap.

I don't have a problem with the notion of a 3d printer as an orbital fabricator, but NASA does not have their eye on the ball. They're looking for glory when what's needed is a Jeep.

Oh boy. NASA in charge of the software that's gonna keep us from being supplanted by machine-based life. Why do I not feel comforted?

I think NASA's point is that the mass needed for a spacecraft that's constructed in space is a lot lower than the mass needed for a spacecraft that's constructed here, then needs to withstand 6 or 8 or 10 g's, or whatever.

But your point about launch costs is well taken. Do you happen to have about 60km of really strong cable lying around?

Thats actually a VERY good idea, if they can make it work properly.

Spinning kilometer sized objects in direct sunlight..does seem fraught with some dangers however.

Gunner

-- "Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry

The failure was in not foreseeing that the USSR would soon fall.

"Although the KH-12 was originally designed to be place into orbit (and perhaps serviced and refueled in orbit) by the Shuttle,..."

What did you think drove the Shuttle's design requirements???

siv54

But lifting the manufacturing machinery means you have to build a minimum number of ships to break even. Maybe 10 or maybe 100.

60 km? xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I crossed out what I started to write about 45,000 miles (2 * geosync orbit) after looking at the article.

The article made me think...

OK, the counterweight means it can be shorter than 45,000 miles, and I guess it can move (reel itself in) to keep the center of mass in place.

Giant Weed Whacker!

I crossed out what I wrote when I realized you meant 60,000 miles. Right?

Thinking of a weed whacker, the chance of a collision with another satellite is much greater than sat-to-sat. We rely a great deal on the fact that sats at the same altitude are at the same speed.

I wonder what a large optical telescope array could see with long exposures and massive image processing.

Not if their eccentricity and inclination differ.

jsw

It could resolve more stars into disks instead of points:

there is a huge gap between imaging stars and imaging planets.

The search for planets by measuring stellar dimming from occultation puts limits on the likelihood of many massive unknown dark objects orbiting the stars we have checked.

jsw

Not many satellite orbits are very eccentric, but there is still a much greater chance of collision than between 2 satellites.

If the orbit is inclined the elevator still cuts across it twice a day.

My point is that collision avoidance would be a concern much more often than with other satellites. You would never avoid a collision thanks to altitude.