Home Forums Hunting & Shooting Hunter's Campfire A Very Sad Space Launch

Although we should consider keeping space junk free going forward, I think the probability of what you're implying is insignificantly low. First off, the sheer surface area around the exoatmosphere at any given altitude is enormous compared to the size of any junk in space. Then, you have to consider that both items would have to be at the same altitude to collide. It would be like shooting a bullet in a rural county area in a random direction and accidentally hitting a man 4 miles away center mass.

Theres kind of a big dif between an escaped round and space junk, Bro Blue.
Imagine if every round we fired past the backstop just kept on going three feet off the ground (same altitude, right) until it hits something. That's what happens in orbit, it comes around, and around again and around again. Not a question of if, but when, and how big be the bang?

Imagine if that round contained 100,000 ball bearings, and after exploding taking out said satellite they just kept going maintaining orbits in all directions taking out anything they came into contact with... big shot shells.


Phil.

Float on up and do some checking. I'll hold the string tied to your big toe.

You make some good points, Gus.

What happened to the space ladder project?

https://www.physicsforums.com/threads/space-ladder.91371/

https://en.wikipedia.org/wiki/Space_elevator

Live coverage coming up. Launching in a few minutes at 9:02 Eastern.

Beautiful launch to end an era with the Delta's 100th straight success.

Thanks Rocky for posting this. I always enjoy these launches.

That one was bittersweet for me, obviously. I love that bird and I'll miss it a lot.

But it well and truly marks the end of the first generation of space launchers. It went from a Model T to a Model A, and there are simply no payloads any more that need just a Model A delivery truck. The fact that it was in active service for half a century is astounding, really.

It may have been a Model A, but we have made some bad choices since then.

First we were going to put everything up on the Shuttle. Nixon thought it would save money and stopped building Saturn Vs to pay for to develop the Shuttle. The Shuttle was a remarkable machine, but it cost too much to fly.

The Air Force kept flying Atlas, Delta and Titan. These were reasonably priced when we were building hundreds or thousands of the missile they were based on, but by the 70's the ballistic missiles were all solid rocket motors sitting alert in silos. It was costing the Air Force a lot to keep three production lines open for a handful of launches a year. By the early 90's it looked like a large commercial market for constellations of satellites was developing. The Air Force thought they could get the big aerospace firms to carry the cost of developing new vehicles. This was probably a good plan, but the large launch market didn't develop in the time frame expected, and the aerospace firms made some poor choices. Boeing thought they could save money with a low tech engine that relied on hydrogen fuel to get high performance. They invested big in a new factory in Alabama, but the flight rate to cover the cost never materialized, and the hydrogen fueled vehicle was expensive to manufacture. Lockheed Martin got performance with a high tech Russian engine and kerosene fuel. Choosing a Russian engine seems boneheaded, but Pratt & Whitney planned to build a manufacturing line in the United States. When the flight rate didn't materialize Pratt chose not to invest in the new production line leaving Lockheed Martin stuck with the Russian engine.

In parallel NASA tried to go really high tech with a single stage to orbit program that encountered development problems and never got to production.

Fortunately, Elon Musk invested in a 1950's technology engine and evolved it to a reusable first stage. He may have saved some cost with modern manufacturing technology, but the biggest savings is probably the fact that he is not running a big aerospace firm with the high overhead typical of a traditional government contractor. He is probably also pricing on what he thinks he can get to on cost some day, not what it is actually costing him today. this gets his flight rate up which hastens the day he wil get his cost low enough to actually make money.

Lessons learned, don't stop building what works till the replacement is available, and develop incrementally. We got to Saturn V by way of I and Ib.

All true. Today, the launch market is finally huge - and growing. Growing in numbers as well as size of payload. With some communications satellites topping 30,000 pounds, the need for huge boosters is certainly there. Arianespace of Europe uses their incredibly reliable Ariane 5 hydrogen-powered booster to launch two commsats at a time, and is designing the even larger Ariane 6.

But so is the market for smaller, cheaper satellites that take advantage of miniaturization and single-purpose design - and the boosters to launch them. Witness Rocket Lab of California and New Zealand and their new rocket that puts 300 pound payloads into low orbit, and the milk crate-sized satellites it carries.

Then there are the military uses, which are (ahem) exploding. Commsats, GPS, spy sats, ship trackers, realtime observation sats, and who knows what else. All need boosters to get there.

This is a cool thread, though I have to agree seeing a part of ones misspent youth go away is always a bit melancholy. Have you considered buying one of the model versions as a bit of decor? It would make a sharp bit of gear for the den, I'd wager.

100 straight successes, eh?

Back around 1970 they'd launched about 110 Thor Deltas total and all but five or six were successes. When Hughes Aircraft Company designed the first truly successful commercial communications satellite, they worked like mad to make sure they could launch it on the Delta. Earlier satellites had required the Atlas Centaur, which was terribly unreliable in comparison.

I know. I was there.

BTW: Do you happen to know what the thrust was of the later Delta main engine? Back in the day it was 150,000 pounds, no strap on solids then.

in today's liberal controlled world? fat chance of that SAM....

if it is better, it will come from the Russians or the Chinese... the one's who are willing to make the sacrifices our nation USE to make 50 and 60 years ago for the space program.

Rocketscientist:

Don't blame Nixon for putting all our eggs in the Space Shuttle basket. It wasn't his fault that the shuttle didn't do what the NASA engineers had said it would do.

The Air Force could see disaster coming and pulled out of the program long before the Challenger disaster. Sad because their Shuttle launch pad at Vandenberg (for polar orbits) was abandoned. $4 billion down the drain. There were other compromises as well. For instance the Shuttle payload bay was sized for their spy satellites.

Incidentally the Hubble Space telescope is a modified spy satellite. If you know the diameter of its primary mirror (94 inches), you can calculate what it can resolve from any altitude. From 300 miles it can see a license plate but can't read the numbers.

The Shuttle's two worst design flaws, in my opinion (despite costing far more to build and maintain than had been promised) were (a) the only manned spacecraft with NO escape mechanism for the crew, and (b) solid rocket motors on a manned craft in the first place. Once lit, they cannot be throttled and cannot even be turned off until they run out of fuel.

Finally, SpaceX did not just return to 1950s technology. Their greatest innovation was a device like the one in the center of a garden hose nozzle, which lets the thrust be easily throttled. This allows them to land in one piece. Secondly, they use one turbine pump for both fuel and oxidizer. there are probably others.

Indy, the last version of the RS-27 engine put out 200,000 lbs of thrust, not throttlable. It is also a single-start engine so it can't be relit once it shuts down.

Rocky, the only complaint we had about the Delta in 1970 was that the third stage was not quite precise enough to insert our satellite properly into the circular 22,300 mile orbit. It got close but then we had to use on-board thrust for the final adjustments. If memory serves correctly, the third stage of the Delta was a small solid fuel rocket. Later versions, as you know, used larger and better upper stages. Our orbital insertion thrust was provided by a pressurized gas bottle.

Yup. Third stage was probably a Star 36 from Thiokol. As you say, performance with a solid can be close to quite close, but not exact.

Lastly, in case anyone else cares...here's the answer to "Why is it blue?"

DELTA BLUE