The future of Manned Spaceflight

AugustusMinimus

They can't seriously believe that is realistic ?

Why go to the bother to run without parachutes ?

Capt'n Midnight

Plug wrote: »

I think they might be a bit optimistic on the idea of landing the stages using rockets. It will take a massive amount of fuel to land them and you will have to bring extra fuel to make sure it can do that and eventually the rocket will get way too big.
Using a smaller amount of fuel to slow it down on its decent and then parachutes to guide it to the ocean might be a better idea.

Russians use retro rockets on their manned capsules. (Picks of Soyuz landing) And some future designs dispense with parachutes altogether

Fuel is about 2% of the launch costs when you take into account the development costs. Also for stage 1 excess fuel isn't really dead weight since you just have to elongate the tanks by a few %. The nice thing about carrying excess fuel is you could use it if you need to (at the expense of the first stage recovery). Saturn V's have had engine failures/shutdowns and still carried on.

Parachutes are just dead weight.


http://www.thehindu.com/opinion/lead/article2306053.ece

Now begins the era of the Soyuz
...
The cost of the 30-year space shuttle programme was more than $1 billion per launch, roughly equivalent to the cost of launching 20 Soyuz spacecraft.

The U.S. will save a lot of money by switching over to the Russian space vehicle. NASA contracts with Roskosmos for ferrying 18 U.S. astronauts to the ISS and back aboard Soyuz ships over the next five years (plus 24-month training for each astronaut, room and board, flight operations and crew rescue) will cost the U.S. only as much as a single shuttle flight.
...
Soyuz was more reliable and cost-effective. The spacecraft had an impeccable safety record: not a fatal accident over the past 40 years. The two Soyuz accidents involving fatalities date back to the early stages of the programme.
...
The only time Soyuz was struck by an accident similar to the one that destroyed Challenger, the crew were rescued thanks to the Russian ship's launch escape system. The accident occurred in 1983 at the Baikonur launch pad. The crew were in the spaceship waiting for takeoff when a leaking fuel valve at the base of the rocket set off a fire that engulfed the rocket within seconds. Ground controllers activated the escape system, which flung away the top sections of Soyuz with the cosmonauts inside, free from the three-stage rocket and lifted them more than one km before the descent capsule parachuted safely to land even as the launch pad crumbled in flames.
...
The construction of spacecraft has been put on assembly line in Russia: more than 30 ships are currently in the pipeline, with two-and-a-half years needed to build one spaceship

AugustusMinimus

Capt'n Midnight wrote: »

Parachutes are just dead weight.

Are you saying that per kg of weight, fuel will give better deceleration compared to a parachute ?

I find that incredibly hard to believe.

InvisibleBadger

We are in the 21st century and it's time to start making cool, cutting-edge stuff again. I hope SpaceX can pull this off!

Capt'n Midnight

AugustusMinimus wrote: »

Are you saying that per kg of weight, fuel will give better deceleration compared to a parachute ?

I find that incredibly hard to believe.

On the way up which would you rather , stage one having 1,000Kg of parachute or 1,000Kg of fuel ?

The shuttle SSRB weighs about 91,000Kg
the drouge chute is 540Kg - you'd probably need this anyway
each of the three main chutes weight 990Kg
I don't know how fast they hit the water, whether it's human ratable etc.

AugustusMinimus

Capt'n Midnight wrote: »

On the way up which would you rather , stage one having 1,000Kg of parachute or 1,000Kg of fuel ?

The shuttle SSRB weighs about 91,000Kg
the drouge chute is 540Kg - you'd probably need this anyway
each of the three main chutes weight 990Kg
I don't know how fast they hit the water, whether it's human ratable etc.

I seriously doubt 3,000kg of fuel will land a SSRB on it's tail again.

Add in another factor, wouldn't the SSRB's be somewhere over the Atlantic when they seperate from the shuttle ? THis would require even more fuel to turn around and land at Keneddy.

Either that or have a rocket land on it's tail, on a ship in the mid Atlantic.


I also wouldn't like the thought of landing in a capsule which depends on rockets to land. I have no idea why but I'd much prefer to have parachutes above me.

Capt'n Midnight

AugustusMinimus wrote: »

I seriously doubt 3,000kg of fuel will land a SSRB on it's tail again.

neither retro rockets or parachutes have to land it on it's tail since all it has to do is provide a water landing for a container designed to take several g , and about one thousand tonnes of thrust (they aren't fragile), like I said it's not human rated.

I also wouldn't like the thought of landing in a capsule which depends on rockets to land. I have no idea why but I'd much prefer to have parachutes above me.

Some might prefer the wings like on the shuttle. But...

Russians have been using a combination of parachutes at high altitude and retro-rockets just before landing for the last 50 years.

Like Apollo the Russians use an launch escape system rocket. It's designed to work on a rocket accelerating at 3-3.5g. From a standing start it will get up to half a mile altitude. For cushioning a parachute landing they use a smaller one
http://suzymchale.com/ruspace/soyescape.html

With flames rising from the launchpad and the entire rocket already leaning 20 degrees to the side, controllers scrambled madly to get the system to free.

Just 10 seconds after the flames first appeared, controllers miraculously managed to somehow do this, activating the escape system and throwing Titov, Strekalov and the Soyuz T capsule more than 3000 feet into the air. For five seconds the emergency engines fired, subjecting the two men to forces exceeding 15 g’s. Then the engines cut off, the descent module separated, and its parachutes unfolded.

At that moment, the entire rocket and launchpad exploded. The blast was so intense that the capsule, three miles away, was thrown sideways, and launchpad workers in underground bunkers felt the pressure wave.

Strekalov and Titov landed safely, their capsule hitting the ground with a hard bump that shook both men up but did them no damage. Rescuers quickly pulled them from the capsule, then gave them a glass of vodka to calm their nerves as everyone watched the nearby launchpad crumble in flames and clouds of smoke. It took 20 hours to put the fires out.

namloc1980

The first SpaceX demonstration flight to the ISS which was due to launch at the end of this month has been postponed until probably at least April next year. Funding for Commercial launch companies like SpaceX also got slashed in the new NASA budget.

Link

Super Freak

I see the future:pac:
http://www.dailymail.co.uk/news/article-2069222/Not-exactly-NASA-Ugandan-space-chief-builds-test-craft-mothers-yard-says-shuttle-orbit-2015.html