Just Cancel The Shuttle Program - Not in five years, do it right now.

chat · 2004-12-25 08:24:36

Do we even need the shuttle.

If the main focus for the shuttle is getting to the ISS then i say scrap the shuttle.

It isn't safe, its very expensive, it doesn't launch satellites at commercial rates anymore, it takes to long to prepare but it does look pretty.

Let the Russians service the station while a new simple low cost ISS vehicle is created.

Or better yet put the money to the Russians to be the permanent ISS operations.

Then the USA can focus on the grand plans of the moon and mars, with lots of help from the new and improved Russian systems.

If we really want to go to mars then NASA must break up its long list of things to do into parts or it will never happen.

As far as i can see NASA right now has no clear goal, and the public no real interest in the hap hazard attempts it makes along the way.

Yang Liwei Rocket · 2004-12-27 02:07:16

This was posted on the other newmars thread, there are many questions now about how manned flights into space will continue

Let's begin by looking at the Shuttle program - the program that obviously is of most concern to you. At first blush, the President's proposal terminates the Shuttle program in 2010. That is a wise decision. There is simply no way to affordably fund new initiatives without tapping the money now consumed by the Shuttle program.
Moreover, it is time to develop a safer, more efficient, more up-to-date, more versatile vehicle. Finally, the White House was simply and understandably unwilling to spend the billions necessary to recertify the Shuttle to fly after 2010 - a requirement laid down by the Columbia Accident Investigation Board and accepted by NASA.
But it turns out that the Shuttle decision is a little more fluid than it first appears. NASA says the Shuttle will continue to fly until the construction of the International Space Station is completed, and 2010 is simply the target date for that milestone.
Can the Station be completed by 2010? That seems like a stretch. As we all know, the Shuttle now is not scheduled to resume flight until at least next March. (That's a decision I applaud, by the way. Administrator O'Keefe has kept his word that safety and safety alone will determine when the Shuttle launches again.) That's already a delay in the schedule on which the 2010 date was developed.

there is still much talk on the net about what good the shuttle has done in the past, and the risks and dangers of pushing the shuttle today, it is costly, there are still safety questions and a replacement has yet to come.

Nearly two years after Columbia shattered in the sky, NASA still has no way of repairing the kind of holes that could doom another shuttle, space agency officials acknowledged Monday in their latest status report on the return-to-flight effort.
The development of patches for the shuttle wings and other vulnerable locations is proving far more difficult than imagined just months ago and, along with devising a way for astronauts to inspect their spaceship in orbit, represents "one of the most challenging and extensive return-to-flight tasks," the 268-page report said.
The Space shuttle was originally supposed to push us out further into Space, it was to be cost effective, do wonderful groundbreaking science and fly every two weeks. It already had serious safety questions, it began costing over $450 million per launch, not enough science was done and it only went up about four or five times a year.
As the shuttle begins its return to Space there are people who have questions about the current space programe. NASA still has to get its management right, get the budget books in order and answer those questions of saftey. Some people like myself hoped that the Shuttle would be gone and NASA would have come up with a new and fantastic functional space craft.
The shuttle will be kept very busy after its return to flight, there is much science to catch up on and experiments to do. There is also the current problem with Hubble and the possibility that shuttle will be used to do this work. The shuttle will also need many other trips and will be required for the ISS, estimates are that about 25 ( minimum ) shuttle flights will be needed for NASA to finish its work and the shuttle can then bow out of service by 2010. Some think that 25 flights and pushing the shuttle until 2010 could be quiet dangerous and risk lives. I have been reading on some top scientists and astronauts ideas on how the ISS station could have provided safe haven for the Columbia crew while everybody scrambled to launch a second orbiter to bring them all home safely. Some think that this plan of an ISS safe haven cold be very important for the shuttle return.
CAPE CANAVERAL, Fla. (AP) -- Many NASA workers feel unappreciated by the agency and are still afraid to speak up about safety concerns.....

The astronaut Buzz Aldrin who has been helping commercialisation, privatization of space-flight, push space-tourism, written much material and made very important comments on NASA has also had some good views on the current situation. Buzz has had many fantastic insights into the future of Space, the Apollo 11 moonwalker Buzz Aldrin has been calling for rejuvenated space efforts, steeped in market economics. Aldrin had said how the shuttle was expected to be a lot more robust but Buzz Aldrin told the reality of the shuttle in flight is that it is "not robust" on launch and "hazardous". Buzz, the second man on the Moon also explained what NASA will have to do saying we may need to have some risky shuttle flights for a limited period of time, or we are going to stand down and fly Soyuz spacecraft. Buzz has already explained how future shuttle flights should be required to be lofted into an orbit that is compatible with that of the space station, so if problems came up or inspections/repairs were needed, shuttle crews would find safe-haven at the station. I hope everything works out fine and everything goes ahead safely.

serious work and real efforts need to be done to fix all of this, and with current economic concerns the manned spacecraft should be cost-effective aswell

SpaceNut · 2004-12-27 05:32:06

Yes cost effective is a must for any space activity.

The shuttle will be kept very busy after its return to flight, there is much science to catch up on and experiments to do.

Yes the max number of flights to finish the ISS.

So what science has been neglected or is this science that can only be done on the shuttle and not the ISS? ???

Yang Liwei Rocket · 2004-12-30 13:46:10

Yes cost effective is a must for any space activity.
The shuttle will be kept very busy after its return to flight, there is much science to catch up on and experiments to do.
Yes the max number of flights to finish the ISS.
So what science has been neglected or is this science that can only be done on the shuttle and not the ISS? ???

ex- NASA man speaks

A former NASA engineer fears the panel charged with evaluating NASA's progress returning the space shuttle to flight will issue a final report to a space agency that remains closed to a crew escape system.
The Stafford-Covey Task Group, set to meet in Huntsville today, is an independent group of space experts judging NASA's plan to return the space shuttle to flight. The panel is headed by former astronauts Tom Stafford and Dick Covey.
The lack of an escape system "will lead to the loss of another crew," said Don Nelson, a 36-year NASA veteran engineer who worked at Johnson Space Center and closely with Marshall Space Flight Center engineers during his career. "I have no doubt about that," he said.

have you seen these links
http://www.spaceref.com/news/viewsr.htm … ?pid=14843

http://www.al.com/news/huntsvilletimes/ … ...731.xml

http://msnbc.msn.com/id/6725880/]http:/ … d/6725880/

These next few moves made by NASA and the path it will take in the next few months are going to be very important, NASA has already done great things in the past let's hope it can overcome these obstacles and push forward

SpaceNut · 2004-12-30 14:05:02

So in the ex nasa man speaks it is the contention that without an escape tower that all would be better.

But that is only good on the way up there is no tower on the way down. So the problem therefore is only half solved...

Every vessel ever designed has its what if this happens ... that you would loss the crew. We can not fear the unknown we must instead make changes to not allow the what if to happen.

GCNRevenger · 2004-12-30 15:34:22

But on the other side of the coin, it will not be practical to do much in space without a ship that explodes and kills the crew too often. It is even of questionable morality to ask for volunteers for a mission that isn't vital to the nation that has a high risk of death.

Shuttle's heat shield is large, made of fragile materials, and can be easily damaged by launch debries. Shuttle has no mechanism to protect the crew in the event of a launch malfunction... hence, the crews' safety is dependant entirely on the reliability of the vehicle.

...Which isn't very good. Shuttle uses the poor heat shield material, the launch configuration, and has no escape system because it is too big and designed with too wide of a reentry cross range. These problems are inherint to the design and cannot be fixed, it is a signifigant risk NASA is taking to finish ISS with Shuttle at all.

A capsule or a small (under 20MT) spaceplane however would not have these failings: a capsule heat shield can be made quite durable or a light weight spaceplane could use a metal heat shield since it need not glide long distances. Both styles of vehicles could be their own escape pods, fitted with seperation rockets in the event of launch mishap. It is even possible to build a capsule or "sled" vehicle such that it can handle reentry without power at all.

Martian Republic · 2004-12-30 16:21:01

Do we even need the shuttle.
If the main focus for the shuttle is getting to the ISS then i say scrap the shuttle.
It isn't safe, its very expensive, it doesn't launch satellites at commercial rates anymore, it takes to long to prepare but it does look pretty.
Let the Russians service the station while a new simple low cost ISS vehicle is created.
Or better yet put the money to the Russians to be the permanent ISS operations.
Then the USA can focus on the grand plans of the moon and mars, with lots of help from the new and improved Russian systems.
If we really want to go to mars then NASA must break up its long list of things to do into parts or it will never happen.
As far as i can see NASA right now has no clear goal, and the public no real interest in the hap hazard attempts it makes along the way.

It is true that the current shuttle is a poorly designed. To have man rated with cargo added to the inefficiencies and increased the cost of the system for both man and just getting freight into space.

It is also true that it was built for the cheapest price, but also has a higher operation cost then it should have had if they had gone the other way around and designed for the operation cost ratio vs what it would have cost to engineer that way from the beginning.

I has a high cost ratio in almost every area, but the problem is we really don't have a replacement for it and if we not going to be building a replacement shuttle, we will be basically going backward with a less capable system than the current shuttle. It will cost us five to ten billion dollars to develop a new shuttle and maybe another ten to twenty billion dollars to build an entire fleet of new generation shuttles. For most of the people on this page, that twenty year eight to ten Mars Direct Mission. But, here where the problem comes in, you have to have re-usable shuttle to move people up and down and you can't just have we will use our rocket once and throw it away. As much as I don't like the current generation of shuttle, it was designed to serve as a pickup truck and we don't have anything that can replace it for either the ISS or any serious deep space mission. One use space ship will pretty much squash any serious colonization program.

Larry,

GCNRevenger · 2004-12-30 17:28:37

I has a high cost ratio in almost every area, but the problem is we really don't have a replacement for it and if we not going to be building a replacement shuttle, we will be basically going backward with a less capable system than the current shuttle. It will cost us five to ten billion dollars to develop a new shuttle and maybe another ten to twenty billion dollars to build an entire fleet of new generation shuttles. For most of the people on this page, that twenty year eight to ten Mars Direct Mission. But, here where the problem comes in, you have to have re-usable shuttle to move people up and down and you can't just have we will use our rocket once and throw it away. As much as I don't like the current generation of shuttle, it was designed to serve as a pickup truck and we don't have anything that can replace it for either the ISS or any serious deep space mission. One use space ship will pretty much squash any serious colonization program.

But we don't NEED a replacement for exploration, scouting, and setting up "McMurdro scale" bases, which we have the technology and money to do today.

Shuttle is such a terrible vehicle that going back to intermediate and large expendables wouldn't be "a step backward" at all, current boosters modified with today's technology instead of 1980's rocket tech have the capability of launching larger annual payloads quite a bit cheaper then even right now and far less then Shuttle.

Building Shuttle-II will be expensive and in the $20Bn range, but we won't need it until we want to start exploiting space for Earthly wealth.

Yang Liwei Rocket · 2004-12-30 19:28:20

But on the other side of the coin, it will not be practical to do much in space without a ship that explodes and kills the crew too often. It is even of questionable morality to ask for volunteers for a mission that isn't vital to the nation that has a high risk of death.
Shuttle's heat shield is large, made of fragile materials, and can be easily damaged by launch debries. Shuttle has no mechanism to protect the crew in the event of a launch malfunction... hence, the crews' safety is dependant entirely on the reliability of the vehicle.
...Which isn't very good. Shuttle uses the poor heat shield material, the launch configuration, and has no escape system because it is too big and designed with too wide of a reentry cross range. These problems are inherint to the design and cannot be fixed, it is a signifigant risk NASA is taking to finish ISS with Shuttle at all.
A capsule or a small (under 20MT) spaceplane however would not have these failings: a capsule heat shield can be made quite durable or a light weight spaceplane could use a metal heat shield since it need not glide long distances. Both styles of vehicles could be their own escape pods, fitted with seperation rockets in the event of launch mishap. It is even possible to build a capsule or "sled" vehicle such that it can handle reentry without power at all.

So a small capsule heat shield can be made for improvements, keeping astronauts and the science safe should be a top part of this mission, all efforts must be fully implemented in the area of safety.

NASA has done great things in the past, so it should be able to get things going again. When going into the shuttle debate I like to look at some of the thoughts made by NASA folk or some of America's great astronauts. The USA astronaut Buzz Aldrin who has been helping commercialisation, and trying to push space-tourism, made very important comments on NASA has also had some good views on the current situation. Buzz spelled it out when he said how the shuttle was expected to be a lot more robust, but the reality of the shuttle in flight is that it is "not robust" on launch and "hazardous". Buzz, the second man on the Moon also explained what NASA will have to do saying we may need to have some risky shuttle flights for a limited period of time, or we are going to stand down and fly Soyuz spacecraft. Some have estimated the shuttle will be pushed hard, launched almost too often, and made to take big risks so NASA can get its space science back on track, launch stuff and finish the ISS. Some think that 25 flights and pushing the shuttle until 2010 could be quiet dangerous and risk lives. The design of shuttle needs to be replaced so let's hope NASA will stay below that 25 flight number, however I've seen another news source say it may need to push beyond 30 to finish all the work needed to be done in space.

NASA has done wonderful stuff already, already done great things in the past let's hope it can overcome these obstacles and push forward. It should be very good to see the US return to manned flights in space, but let's also think about safety and a replacement for shuttle.

Dayton3 · 2004-12-30 19:32:59

If the Russians want to continue building and flying Soyuz capsules for the manned missions to orbit, lets just do that.

Lets be honest, most ISS missions were planned to be 4 month tours. Thats three manned launches per year.

Double that, and its still only six manned launches per year.

That kind of launch rate will NEVER justify a reusable shuttle system.

GCNRevenger · 2004-12-30 19:41:43

With due respect, listening to Astronauts is what helped keep NASA from canceling Shuttle after Challenger. Astronauts might make good advisors, but I don't trust their judgement to be leaders... too many Shuttle Huggers.

But why do we need a new Shuttle? Why? To go to the ISS? That really isn't much of a reason... the ISS simply does not have enough justification for its expense even if it had bimonthly Shuttle flights. There just isn't enough science that needs zero-g AND human tending. The ISS is also in the wrong orbit to efficently reach from any launch site in the US, and is not suited to being anything more then a science base because of its design... it would make a terrible base for missions beyond Earth orbit. A Shuttle-II will take quite a few years to develop and test too, which after the 2010 deadline the ISS won't have but a decade (maybe 1.5) left of practical service life.

The purpose of ISS has been from the very start... keep the maximum number of NASA and Russian rocket/missile engineers employed as possible for as long as possible. And in that, like many things NASA attempts, it suceeded at brilliantly... Oh, and NASA says they can "finish" the ISS, minus a few pieces, in only 18 flights perhaps.

It is quite simple. We don't need the ISS, and we don't need Shuttle-II for exploration... in fact, it would even be counter-productive given its high cost and need for orbital operations. You could afford to build a launcher of terrible power, able to lift over double what Saturn-V could for that kind of money... Maybe enough to develop a nuclear TMI stage or a super Lunar lander with whats left over.

Martian Republic · 2004-12-30 20:22:51

I has a high cost ratio in almost every area, but the problem is we really don't have a replacement for it and if we not going to be building a replacement shuttle, we will be basically going backward with a less capable system than the current shuttle. It will cost us five to ten billion dollars to develop a new shuttle and maybe another ten to twenty billion dollars to build an entire fleet of new generation shuttles. For most of the people on this page, that twenty year eight to ten Mars Direct Mission. But, here where the problem comes in, you have to have re-usable shuttle to move people up and down and you can't just have we will use our rocket once and throw it away. As much as I don't like the current generation of shuttle, it was designed to serve as a pickup truck and we don't have anything that can replace it for either the ISS or any serious deep space mission. One use space ship will pretty much squash any serious colonization program.
But we don't NEED a replacement for exploration, scouting, and setting up "McMurdro scale" bases, which we have the technology and money to do today.
Shuttle is such a terrible vehicle that going back to intermediate and large expendables wouldn't be "a step backward" at all, current boosters modified with today's technology instead of 1980's rocket tech have the capability of launching larger annual payloads quite a bit cheaper then even right now and far less then Shuttle.
Building Shuttle-II will be expensive and in the $20Bn range, but we won't need it until we want to start exploiting space for Earthly wealth.

You keep going back to the McMurdro bases in Ant-Artica.

OK, let use that as our model then!

We don't supply the McMurdro Bases in Ant-Artica with a one time use per ship like what most people want to do for the Mars base setup and/or re-supply. If we did, we probably would not have a McMurdro Base either, because of the price tag on what it would take to keep people at McMurdro Bases. We get much past an Apollo type mission that last just a few day to maybe a few month and if we don't have the infrastructure in place, it soon become logistically and financially a bad idea and will be prone to being canceled.

Larry,

Yang Liwei Rocket · 2004-12-30 20:53:50

If the Russians want to continue building and flying Soyuz capsules for the manned missions to orbit, lets just do that.
Lets be honest, most ISS missions were planned to be 4 month tours. Thats three manned launches per year.
Double that, and its still only six manned launches per year.
That kind of launch rate will NEVER justify a reusable shuttle system.

more news

No more free rides for US astronauts
29/12/2004

US astronauts travelling to the International Space Station (ISS) aboard Russian space shuttles will no longer be able to benefit from free travel, the Russian space agency announced today.
Due to financial difficulties at Roskosmos, which operates on a significantly smaller budget than its American counterpart Nasa, US astronauts will be ferried to the ISS on a "commercial basis".
Nasa ceased transport on its own shuttles in 2003 after several ISS astronauts were killed aboard Nasa's Columbia craft when it burnt up during re-entry in February of last year.
Although the US hopes to resume ISS services as early as May 2005, Roskosmos has warned that from 2006, any US astronauts taken to the ISS aboard Russian craft will have to pay for the privilege.
Anatoly Perminov, head of Roskosmos, said: "The Russian side shouldered the entire burden... for nearly two years.
"Starting from 2006, we shall bring American astronauts to the ISS on a commercial basis."
Nasa is yet to respond to the news

this could hurt the budget and NASA's financial projections for the next while

BWhite · 2004-12-30 21:02:02

If Bush and Putin have too big a falling out, perhaps bye-bye US involvement in ISS, and therefore the end of shuttle.

GCNRevenger · 2004-12-30 21:07:59

You keep going back to the McMurdro bases in Ant-Artica.
OK, let use that as our model then!
We don't supply the McMurdro Bases in Ant-Artica with a one time use per ship like what most people want to do for the Mars base setup and/or re-supply. If we did, we probably would not have a McMurdro Base either, because of the price tag on what it would take to keep people at McMurdro Bases. We get much past an Apollo type mission that last just a few day to maybe a few month and if we don't have the infrastructure in place, it soon become logistically and financially a bad idea and will be prone to being canceled.
Larry,

That analogy only goes so far, and is not so accurate since there is no worth in Antarctica beyond science experiments... we'll never use that place even for a nuclear dump.

We can very well tend a small Lunar or Martian base with expendable rockets, they are capable of launching payloads cheaply enough to sustain a presence on either body without breaking the bank to buy rockets or infrastructure, and infact this is what we should do following the planet/moon wide exploration phase but before the industrial development phase. The concept of ISRU and semiclosed LSS will reduce the mass of imported supplies sufficently to make this possible. With some luck, ingenuity, and overdesign a base tended by expendables could even grow to non-trivial industrial capacity without a huge funding increase to help pave the way for the future.

I remind you that Apollo was never intended to set up a Lunar base, it was never NASA's intention to begin with. The Apollo project was just about one primary goal: beat the Communists. Beat the Communists to the Moon as quickly as possible... all other concerns were secondary. NASA knew that the big Saturn-V was too inefficent, NASA knew that the Lunar Lander was too puny, but it didn't matter... It was fast and it worked, the science mission was a peripheral concern, and the future beyond Apollo wasn't even a blip on the radar to NASA or the Government.

Martian Republic · 2004-12-30 21:39:29

You keep going back to the McMurdro bases in Ant-Artica.
OK, let use that as our model then!
We don't supply the McMurdro Bases in Ant-Artica with a one time use per ship like what most people want to do for the Mars base setup and/or re-supply. If we did, we probably would not have a McMurdro Base either, because of the price tag on what it would take to keep people at McMurdro Bases. We get much past an Apollo type mission that last just a few day to maybe a few month and if we don't have the infrastructure in place, it soon become logistically and financially a bad idea and will be prone to being canceled.
Larry,
That analogy only goes so far, and is not so accurate since there is no worth in Antarctica beyond science experiments... we'll never use that place even for a nuclear dump.
We can very well tend a small Lunar or Martian base with expendable rockets, they are capable of launching payloads cheaply enough to sustain a presence on either body without breaking the bank to buy rockets or infrastructure, and infact this is what we should do following the planet/moon wide exploration phase but before the industrial development phase. The concept of ISRU and semiclosed LSS will reduce the mass of imported supplies sufficently to make this possible. With some luck, ingenuity, and overdesign a base tended by expendables could even grow to non-trivial industrial capacity without a huge funding increase to help pave the way for the future.
I remind you that Apollo was never intended to set up a Lunar base, it was never NASA's intention to begin with. The Apollo project was just about one primary goal: beat the Communists. Beat the Communists to the Moon as quickly as possible... all other concerns were secondary. NASA knew that the big Saturn-V was too inefficent, NASA knew that the Lunar Lander was too puny, but it didn't matter... It was fast and it worked, the science mission was a peripheral concern, and the future beyond Apollo wasn't even a blip on the radar to NASA or the Government.

I agree with you that the Apollo Moon landing were never intended to be a prominent base on the Moon and it probably a good thing too, because it took between 2% to 4% of the U.S. Federal budget for seven to eight years time frame to be able to finance those Lunar Landings. If they were going to build a prominent base in that time period on the moon, they would have had to have increased there budget by several more percentages points or they would never have the financing for that idea, because they would not have enough money to do that job.

Which bring us back to our original problem of going to Mars. Even a Mars Direct Mission is going to be a super sized Apollo Program of both the time we going to have to have people that we send to Mars and the amount of resources that we are going to have to send to Mars to support that Manned landing. Even if we use the resources that are on Mars, it still going to be several times bigger than one Apollo each time we send a new crew to Mars. That if we don't put down a prominent base on Mars and if we do put a prominent base on Mars, then we are really going to have to put resources up there to support them whether we use the resources on Mars or not.

Larry,

GCNRevenger · 2004-12-30 22:05:08

I agree with you that the Apollo Moon landing were never intended to be a prominent base on the Moon and it probably a good thing too, because it took between 2% to 4% of the U.S. Federal budget for seven to eight years time frame to be able to finance those Lunar Landings. If they were going to build a prominent base in that time period on the moon, they would have had to have increased there budget by several more percentages points or they would never have the financing for that idea, because they would not have enough money to do that job.
Which bring us back to our original problem of going to Mars. Even a Mars Direct Mission is going to be a super sized Apollo Program of both the time we going to have to have people that we send to Mars and the amount of resources that we are going to have to send to Mars to support that Manned landing. Even if we use the resources that are on Mars, it still going to be several times bigger than one Apollo each time we send a new crew to Mars. That if we don't put down a prominent base on Mars and if we do put a prominent base on Mars, then we are really going to have to put resources up there to support them whether we use the resources on Mars or not.

I don't think you fully understand...

Apollo was horribly inefficent, it used up far more money to get to the Moon then it needed because it was a rush job to beat the Communists and the secretive N-1 program. If we went to the Moon the smart way and took our time, with Earth orbit rendevous using medium/heavy launchers (like the stilborn Saturn-IV) for big payloads, direct flight with same for supplies, and aimed to set up a LOX factory then we could have stayed on the Moon indefinatly without the piles of money that even Apollo took perhaps, certainly without this "big budget increase" nonsense.

More efficent

And Mars, no, no it won't be any bigger then Apollo. In fact it will probobly be a bit smaller, because this time we aren't in a mad dash to plant a flag ahead of our enemies. The rockets are going to be much more efficent then the eleven-engine ten-meter Saturn monster, and we have gotton quite a bit better at building rockets lighter and more efficent since then.

Sending reasources is all about mass. Mass is the currency of space travel. With small NTR engines (which we can test today without new facilities) or heavy solar ion tugs (solar cells and engines being tested now) and aerobraking we can place substantial payloads on Mars without going broke. Furthermore the CO2 and limited nitrogen in the Martian atmosphere, and eventually Martian water, makes a huge difference... these remove such a signifigant amount of the mass we would have to launch to support a perminant Mars presence that the entire calculus of your thinking is simply obsolete and inaccurate.

The mass we would have to launch would no longer involve bulk supplies like water, oxygen, nitrogen for breathing... reduced food mass with greenhouses... no more hydrogen importing with Martian water... No more importing of bulk polymers. Maybe even Martian building materials and bulk metal refining. The lists of supplies and mass from Earth that fill the manifests will start to grow thin and light indeed.

Dayton3 · 2004-12-30 22:12:55

No offense GCN but your obsession with nuclear thermal engines makes you sound like Stanley Borowski.

GCNRevenger · 2004-12-30 22:22:35

It isn't an obsession... in fact I am against employing NTR engines for travel to the Moon at all for exploration or early bases, and it may not be a great idea for asteroid mining either. Using it to return from Mars for exploration and McMurdro phase is probobly not a great idea either.

The fact remains though... that NTR engines would increase the payload sent to Mars by 50-60+% (900-1000sec Isp) over chemical engines. NTR engines are well suited to sending large vehicles on escape velocity trajectories, multiplying the payload you can send for a given launcher. I think that NTR engines will be worthwhile to get humans to Mars since they could do much more and have a safer vehicle with better design margins with the extra payload afforded. Perhaps ion engines for cargo down the road, but NTR for initial missions.

Frankly, that sounds a little like a nuclear-a-phobe statement from you Dayton... tell me, does sending 300-400lbs of highly enriched "bomb grade" Uranium-235 and another, oh, 50-100lbs of Plutonium-238 to Mars bother you? Thats what the NASA plan calls for doing you know, and thats not counting the NTR engines the NASA plan calls for, to make the mission fit on Shuttle-C or Magnum which are cheaper rockets.

Edit: Nuclear engines are also closer at hand then you think... NASA actually built and test fired flight weight engines under the NERVA and subsequent programs, closed down in the early 70's I believe. These were almost ready to fly... we still have the designs and the technology. Pratt & Whitney I believe have even done design studies recently about an improved version of the engine, and they think it can be built for under a billion dollars. Facilities exsist today to test fire smaller NTR engines, no new test site would be needed and no radioactive exhaust would be vented into the air... And lastly, since Uranium has such low radioactivity, the reactors are only slightly less safe then dirt before being activated, and they would only be fired in orbit and only on escape velocity missions, where they would never come back.

Dayton3 · 2004-12-30 22:42:59

Oh I'm all for NTR engines GCN. NEPs and eventually fusion engines as well.

But I do think Dr. Zubrins worries that such a development program would bring too much criticism to a manned Mars program early on were valid.

WERE valid.

I'm not sure now. Ever since the 2001 California energy crisis, Americans seem somewhat more accepting of nuclear power.

Incidentally, GCN, I'm very familiar with your concerns about the inadequacies of basic Mars Direct.

With NTR engines, the amount of mass landed on Mars using Mars Direct would increase by something like 50%.

Thus, do you see NTR as making basic Mars Direct (two launches, direct to Mars, direct back, four astronauts) viable again?

As I'm sure you're aware, Dr. Zubrins Mars Direct is modifiable to incorporate NTR engines as soon as available.

GCNRevenger · 2004-12-30 23:01:03

Ahhh sorry, I am a rabid supporter of nuclear energy by and large

In any mission plan cooked up, a nuclear reactor or two is going to be a requirement to produce energy for the mission reliably. Solar power and storage systems aren't a practical alternative, but speaking that "solar power isn't good enough" is anathema to the environmentalists who hail solar energy as superior to nuclear period, not just that "nuclear energy is evil" and stuff. So what if the rocket will carry a few more reactors to boil Hydrogen to push the thing? We'll already be carrying one or two or three to Mars anyway.

Ahhh but there is a fundimental difference in Doc Zubrin's use of NTR engines on Ares compared to NASA DRM: that the NTR engine serves as the upper stage engine on Ares, and must therefore have MUCH more thrust and must be activated before reaching orbit, correct? Now that even me the nuclear geek is a little worried of if the upper stage failed to reach a stable orbit... that hot reactor could come back down and make quite a mess, especially being so large. Such an engine would be too big to test in current facilities too, and a whole new sealed test stand would have to be built and great expense... Doc Zubrin is wrong about Ares being easy (or even safe) to upgrade to NTR power.

Even with NTR power, MarsDirect is still fundimentally flawed. Lifting the entire ERV mass off the Martian surface is a signifigant inefficency, and even though there will be more mass available to build larger vehicles, they still will not carry a big enough crew (six) or payloads to the surface to fulfill heavy lift needs. MarsDirect's Ares tops out at 120MT to orbit range, but NASA DRM calls for 180-200MT to orbit. This difference in capacity should be clear. Furthermore, NTR doesn't change the fact that MarsDirect has no hope of evolutionary improvement: none of the componets can be made reuseable like the NASA DRM ERV or MAV... DRM can make the leap to being a reuseable system without being gutted, but MarsDirect would have to start from scratch.

Yang Liwei Rocket · 2004-12-31 05:24:05

No offense GCN but your obsession with nuclear thermal engines makes you sound like Stanley Borowski.

The shuttle must be replaced, its time for new craft, with safer designs and cheaper methods to try out into space. There is a problem with some of Zubrin's ideas and taht is he does not understand the polticis of Washington, sometimes his tone can be controversial and othertimes he pushes the wrong buttons in people. A space leader must be able to get through all these problems and understand the politics well enough to gather strong support from Washington and Congress, this is Zubrin's problem

GCNRevenger · 2004-12-31 08:57:02

No, Shuttle must NOT be replaced if the new era of space exploration is to begin. Building a reuseable light/medium launch vehicle simply does not make sense right now. If the RLV is mainly built to service the thrice-d***ed ISS, the feel-good international group hug sentimentality, the meager amount of useful science that nobody cares about, and keeping engineers employed indefinatly for no reason, is just not worth it. It just isn't... if that is NASA's motivation to vainly try to prop up the ISS for as long as possible, then NASA ought to be closed down.

Ditch the Shuttle, ditch the ISS, back to expendables, on to the Moon

Martian Republic · 2004-12-31 12:43:40

I agree with you that the Apollo Moon landing were never intended to be a prominent base on the Moon and it probably a good thing too, because it took between 2% to 4% of the U.S. Federal budget for seven to eight years time frame to be able to finance those Lunar Landings. If they were going to build a prominent base in that time period on the moon, they would have had to have increased there budget by several more percentages points or they would never have the financing for that idea, because they would not have enough money to do that job.
Which bring us back to our original problem of going to Mars. Even a Mars Direct Mission is going to be a super sized Apollo Program of both the time we going to have to have people that we send to Mars and the amount of resources that we are going to have to send to Mars to support that Manned landing. Even if we use the resources that are on Mars, it still going to be several times bigger than one Apollo each time we send a new crew to Mars. That if we don't put down a prominent base on Mars and if we do put a prominent base on Mars, then we are really going to have to put resources up there to support them whether we use the resources on Mars or not.
I don't think you fully understand...
Apollo was horribly inefficent, it used up far more money to get to the Moon then it needed because it was a rush job to beat the Communists and the secretive N-1 program. If we went to the Moon the smart way and took our time, with Earth orbit rendevous using medium/heavy launchers (like the stilborn Saturn-IV) for big payloads, direct flight with same for supplies, and aimed to set up a LOX factory then we could have stayed on the Moon indefinatly without the piles of money that even Apollo took perhaps, certainly without this "big budget increase" nonsense.
More efficent
And Mars, no, no it won't be any bigger then Apollo. In fact it will probobly be a bit smaller, because this time we aren't in a mad dash to plant a flag ahead of our enemies. The rockets are going to be much more efficent then the eleven-engine ten-meter Saturn monster, and we have gotton quite a bit better at building rockets lighter and more efficent since then.
Sending reasources is all about mass. Mass is the currency of space travel. With small NTR engines (which we can test today without new facilities) or heavy solar ion tugs (solar cells and engines being tested now) and aerobraking we can place substantial payloads on Mars without going broke. Furthermore the CO2 and limited nitrogen in the Martian atmosphere, and eventually Martian water, makes a huge difference... these remove such a signifigant amount of the mass we would have to launch to support a perminant Mars presence that the entire calculus of your thinking is simply obsolete and inaccurate.
The mass we would have to launch would no longer involve bulk supplies like water, oxygen, nitrogen for breathing... reduced food mass with greenhouses... no more hydrogen importing with Martian water... No more importing of bulk polymers. Maybe even Martian building materials and bulk metal refining. The lists of supplies and mass from Earth that fill the manifests will start to grow thin and light indeed.

I understand that a crash program like what Kennedy did cost more and the development of the new technology with the specks of how to build something or being able to engineer it also cost more. There also an expense to buy the equipment to build those rockets and train the engineers and people that are going to build that equipment too. But, having said that, there still a base price that we are going to have to spend per rocket that we send into orbit and/or space stations and/or Deep Space Rocket we sent to either Moon orbit and/or Mars orbit and/or lunar landing and/or Mars launders and/or the habitats that we put on either/or the Moon and Mars. Most of these resources are going to have to come from the Earth and not from the moon or mars or either an asteroid or comet for maybe the next twenty years or so. Even the resources on the Moon or Mars that you want to use are going to have to be recycled through something that you have to send from Earth. We going to recycle the nitrogen in the Martian air, the equipment has to come from the Earth and has to be maintained. We get the water on Mars, the equipment has to come from the Earth and has to be maintained. If we need pipeline to run the water through, that going to have to come from the earth too, at least in the beginning it will have to come from the earth and if the water is salty, it will also have to be desalted so we can use it and that equipment will also come from the earth and need to be maintained too. Oh, you said they can grow there own food. Fine, but most of the habitats that those Astronauts are living in will also have to come from the Earth too, besides those green houses for growing that food, they will also have to come from the earth until a manufacturing and mining complexes can be assemble on either the moon or mars which also has to be maintained. Any resource of either the Moon or Mars will be helpful in any mission to either of those places, but we will still have to suffer a net lose for a significant time frame until we can build up the infrastructure on both the Moon and Mars. From private business stand point, it will not be a profitable business venture.

As matter of fact, any attempt to sell this to any business or try to sell it on the bases that most people are trying to Mars Cause is waist of time and is a "Lost Cause".

Larry,

Dayton3 · 2004-12-31 12:47:16

Its my understanding GCN, that the NTR third stage that would be integrated into Mars Direct utilized one of the smallest NTR engines proposed and that it wouldn't be ignited until well after reaching orbit.

Now back to Mars Direct, I understand you in regards as to what you see in the inefficiency of sending the entire ERV to Mars surface.

But I think the inefficiency is more than balanced by having the entire ERV apparatus on the Martian surface, accessible to the astronauts, who if they found some kind of damage or mechanical fault would have a realistic chance at repairing or bypassing the damage.

This is opposed to Semi-Direct (NASA Reference Mission) in which you are parking the Mars Transfer Vehicle in orbit and hoping nothing goes wrong in the two years or so before you need it.

As for reusability.

You've got to be kidding.

Even if we launch larger Mars Missions with longer stay times to build a base, the launch rate is still going to be something like once every 2 years.

That launch rate does not justify reusability.

If Earth orbital mission don't justfiy reusability, then manned Mars missions most certainly do not.

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