Separate Cargo and Personnel Missions for NASA?

l8f57 writes "Hal Gerham (from the NASA CAIB report) is calling for cargo and people to be separated into different missions. He also goes on about how a re-usable spacecraft may not be the most cost efficient vehicle."

Comments

Is This Wise?

[Urantian]

Separate the cargo from the crew? That might make sense, but it raises other concerns. It is indeed a tragedy when a shuttle is lost. The crew, the ship, and the cargo are lost.

Are they attempting to minimize the impact of potential losses by proposing this separation? We already know that NASA projected the odds of losing a shuttle. What is it, about than 1 out of 200 or so missions could be a loss? What are the odds of losing both the crew and cargo shuttles during the same mission? If the shuttle carrying the crew is lost, they will be able to continue the mission of the cargo with a new crew, if they can avoid obvious delays.

I realize that NASA may be applying logic about how to make their missions safer, however it appears they are more concerned about protecting themselves, and their bottom line. The cargo is expensive, and may be impossible to replace. The crew CAN be replaced. It's just like corporations, in how they manage their infrastructure and employees. The employees are unfortunately expendable in many respects.

This story reminds me of the movie Capricorn One. NASA was shown as running scared, doing anything necessary to cover their mistakes.

Re:Is This Wise?

[stratjakt]

I believe this is about minimizing cost and lead times, not risk reduction.

I think the idea is that each type of ship would have different requirements, so you could design each to meet the requirements of its cargo, be it human or stuff.

Ie; a cargo shuttle full of tiny screws to be sorted in space doesnt need fancy atmospheric systems and oxygen recirculators and a seven million dollar toilet, etc.

The Russians did this, all through Mir. They had the Soyuz (sp?) rockets for people, and another kind to send supplies up. Or something like that.

Re:Is This Wise?

[gantzm]

Sorry, you are wrong. So if I purchase a lottery ticket tonight and win, are my odds now 1 in 1 of winning the lottery if I purchase another ticket? Past performance does not dictate future performance a string of close spaced events will most likely be outweighed put future events being spaced further apart.

Re:Is This Wise?

[RevMike]

Separate the cargo from the crew? ... The cargo is expensive, and may be impossible to replace. The crew CAN be replaced. It's just like corporations, in how they manage their infrastructure and employees. The employees are unfortunately expendable in many respects.

I don't think this is really what they intend. I think their fundamental premise is that the shuttle is needlessly complex - and therefore expensive and possibly dangerous - because it has to do too many missions at once. Operating a simple/cheap/reliable crew vehicle and a separate lift capability, which need not be as reliable, might be more effective.

This is the model that the Soviet space program followed: Soyuz (sp?) for crew and Progress for cargo. It has been effective. The Russian crew vehicle, I believe, only failed once in history.

I don't think the issue is cargo cost, either. The cargo is usually not very expensive compared to the cost of the launch. The issue is that an accident with a crewed vehicle puts us out of the manned space flight game for at least close to a year. When an Atlas rocket is lost, everyone says "oh well" and they launch again in a few weeks. Not so with a manned craft.

Re:Is This Wise?

[RevMike]

Name one thing that they would need to bring up as cargo, that NASA could not replace....?

If they sent up DVDs so the astronauts could watch movies, they could not replace them since the MPAA wouldn't let them rip a backup copy before the mission left.

Maybe, but....

[ChrisHanel]

Ironically, the astronaut's luggage would accidentaly be rerouted to Topeka.

Sure makes sense for large missions

[scottganyo]

For example, if you were planning to start a colony on Mars, you could use cheaper methods to send the suppies to the planet ahead of time. Then, use the most reliable methods to send the people. The whole enterprise would be cheaper, you could use the most reliable methods to ensure that the colonists would arrive safely, and you could guarantee that the supplies would be waiting for the colonists when they did arrive.

Re:Easier to have single-use ships?

[ChrisHanel]

...thank goodness we're not in the Federation yet, or we might have to worry about that.

Seriously, our ability to send any kind of material close to effecting another civilization of any kind is nil. We can't even get next door without hyperventilating, let alone outside the solar system to throw garbage on Spock's lawn.

Let's just have this conversation again in 100 years, k?

ENTER the space elevator

[Chuck Bucket]

This makes sense, and I'd love to see something like the space elevator that Arthur C. Clarke's brought up in Fountains of Paradise happen. This way, cargo could be brought up, followed by crew if the cargo run was successful.

An article written about the idea, this year:

Space Elevators Maybe Closer To Reality Than Imagined

Much more info here:

The Space Elevator Reference

CB

This is a good thing

[Dav3K]

I agree with this. By separating out the cargo, the personel-carrying missions can actually become more predictable (less variance due to cargo weights) and are unencumbered with the reusability goals. This means Safety can always be the primary goal for person-carrying missions.

Cargo missions are a much more appropriate area to experiment with reusability or cost-lowering goals as the failure costs are significantly lower. NASA would have a much easier time explaining how they blew up a $40 billion cargo payload to the press compared to the media frenzy created when an astronaut dies.

Just look at the media attention given to this last disaster - how much was covering the loss of human life and how much was covering the financial losses incurred?

Re-usable is only the cheapest when...

[cmowire]

You are using it all the time.

We really haven't explored the limits of reusability or expendability.

If we were to contract out for expendable boosters, built in as cheaply and expendably as possible in batches of 100, it would end up with the launch costs way below what they are now. Our current batch of expendable boosters are far too complicated and are built far too slowly to give us savings like this. This is what is called the "Big Dumb Booster" notion.

The shuttle is a poor example of reusable boosters. The cost for refurbishing between launches, maintaining an army of technicians, etc. is incredible. If we were able to fly one, with the same safety and without appreciable yearly budget increase, once every week, the shuttle would start to look good.

The CAIB's trying to say what has been repeated over and over and over again. One of the reasons why the shuttle has problems is because they tried to create one space vehicle that can do everything. It's like trying to combine a sedan, truck, and crane into one vehicle.

And it's probably easier to build an inexpensive production-grade partially or fully reusable craft before somebody gets a better idea if it just has to do one or the other.

Its about engineering economics

[numakris]

When you return with a ship of empty space (the cargo bay empty) you are paying an aoerodynamic PRICE. By discarding the cargo transporter, you save because that aerodynamic cost is left in orbit. The aerodynamic cost of the capsule to earth is TINY. That way you can bring back the crew in a capsule,which is easier and safer. So they have to splash down in the ocean, big frickin deal.

Finally!

[cybercuzco]

Finally, somone talking some sense about NASA. Its really stupid to send up the crew and the cargo simultaneously. Cargo missions can have a higher margin of error, which translates into cheaper. They can also be one use, which for the time being also translates to cheaper. Cargo by its nature is heavy, so its wiser to make a big cheap nonreusable cargo rocket and send things up that way. Most cargo on earth is not transported by Jet airplane, most is transported by ocean going ship or train. We need a container ship for space, and a little jet airplane for the people. Further, the smaller the craft the fewer parts it needs and the simpler it can be made. So by its very nature a smaller ship can be made safer than a larger more complex one.

Ultimately NASA needs to get back to its beginnings. NASA does the big expensive but basic R&D needed for commercial companies to take over. NASA should have a baseline rocket engine research program continually ongoing. They need to have a standard model rocket engine that is continually upgraded and simplified. the design is then published annually for any and all to use (with security clearance) Same needs to be done with tanks, guidance and control systems, reentry systems, spacesuits, life support systems etc.

Should we scrap the shuttle now?

[adeyadey]

Why continue to run the shuttle? Why not just use the money for fast development of new vehicles? Cheaper to buy Soyuz/Progress rockets from the Russians for now..

Now isnt that ironic - The US would end up having to buy what is essentially much the same rocket that Uri Gagarin used in 1961.. :-)

Re:Scrap the space station

[confused one]

What is the point of the space station?

To learn. To build an experience base for human operations in space. So we're not 100% clueless when we decide to actually put people into space to do something serious.

Sort of like practicing how to swim. If you've never practiced, what's gonna happen when you're thrown in the ocean?