We need more giant leaps for mankind

Newsday ^ | 07/25/05 | BRUCE MURRAY

[KevinDavis]

How significant is NASA's delay of the launch of Space Shuttle Discovery?

Certainly NASA can be expected to be especially cautious when trying to return to flight for the first time since Columbia and its intrepid crew were lost during re-entry in February 2003. This tragedy came 17 years after Challenger suffered a similarly televised demise with the violent loss of another seven crew members.

But no amount of engineering caution can make space flight perfectly safe. The speeds and heating rates are extreme, and the technology is unavoidably pushed close to its limits. Every human flight carries a potentially deadly risk. Thus, every human space flight must pursue mission objectives worth dying for.

[Prime Choice]

Goddard, all the German rocket scientists, and everyone that worked on ICBM's.

Yes, Goddard's work was original and inspiring and it was by Goddard's white papers that Wernher von Braun based his work. This is openly acknowledged by...gee...naming a NASA center after Goddard (GSFC).

But it was von Braun's genius that made the Saturn V possible. This was above and beyond Goddard's work and the suborbital nature of ICBMs.

Rutan's achievement was done in a different way.

I don't discount Rutan's achievement...but claiming he should be heading up the space agency because he was able to reach an altitude of 377,000 feet is nonsense.

[myheroesareDeadandRegistered]

"...put Rutan in charge of its spacecraft program."

I'd like to see what that fellow could do with a larger checkbook. :)

[myheroesareDeadandRegistered]

"Let me know when Rutan gets a man on the moon and returns him safely to the Earth. Then we'll have something worth talking about."

First, let me say that I've always stood in awe with what NASA has pulled off. The achievements boogle the mind if you get into the nuts and bolts. I was trying to focus some attention where it was lacking. Toward Rutan. Sure NASA has sent all kind of manned craft up and back again. Most, if not all, has had to have heat tile to survive reentry. Rutan's brilliant design got a three man payload up and back without the big burn in. His feathering mechanism not only kept the reentry temps down, it made the return self righting. At that point the pilot doesn't even have to touch the controls. Just that little detail is a pure, beautiful (and cost effective) thing. NASA has it's giants, but I'd put Rutan up against any one of them.

[myheroesareDeadandRegistered]

"The big deal with Rutan is speed, efficiency, innovation, and enthusiasm."

Amen to that.

[RadioAstronomer]

Burt Rutan was able to use the data from the billions of dollars spend by the NACA, NASA, USAF, and private contractors over more than 50 years to achieve what he did. I am certainly not dissing Rutan. NASA cheered him on like everyone else did. However a suborbital up and down is not the same as achieving orbit with a payload capability that the Shuttle has.

myheroesareDeadandRegistered - "and no heat tiles for the return."

The Delta-V required for orbit is quite different for a suborbital up and down. Rutan's ship was not designed to withstand an atmospheric entry from orbit.

[Moonman62]

However a suborbital up and down is not the same as achieving orbit with a payload capability that the Shuttle has.

No it's not, but I don't recall anyone downplaying Alan Shepard's suborbital flight.

[RadioAstronomer]

I wasn't downplaying anything. However, that flight reached an altitude of 115 miles.

[Moonman62]

But Shepard had to land on the water and wait for someone to pick him up like a helpless kitten.

[El Sordo]

RA is talking about speed, I believe.

Rutan's bird flew along at many hundreds of miles per hour. He didn't need to worry about bleeding off much airspeed at all (by comparison). Let's say it flew at 750 and landed at 150. Then his delta-V is 600. Thus he didn't have the heat problems that an orbital reentry vehicle does.

In order for a vehicle to orbit the earth, it must attain a speed of around 17,000 miles per hour and is dependant on the elevation of the orbit (I think. I'm probably wrong on the number, but it is fast. Very fast). To de-orbit, you have to somehow brake from orbital velocity (17,000 mph or so at orbit) to whatever reasonable speed is required for landing. I understand this is done via atmospheric friction. If you orbit at 17,000 and land at 150, your delta-V is now 16850. That's a lot of heat to have to deal with.

Whoever does make an orbital vehicle will have to address this problem.

[Moonman62]

Actually, Rutan did have to deal with heat. Not as much as as a vehicle that went higher, or faster, but the problem was there. Rutan's success was that he did just enough to allow him to accomplish his goal, and that along with his innovation is why he came in first, and why people are so impressed.