Dr. Jeff Bell, Sunday, 9-4-11 September 5, 2011
Posted by The Space Show in Uncategorized.trackback
Dr. Jeff Bell, Sunday, 9-4-11
http://archived.thespaceshow.com/shows/1615-BWB-2011-09-04.mp3
Guest: Dr. Jeff Bell. Topics: Space Shuttle retirement, safety, and mythology. U.S. space policy, NASA, U.S. Congress. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, http://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. We welcomed Dr. Jeff Bell back to the show for a two hour plus discussion regarding the retirement of the space shuttle. Dr. Bell started out discussing shuttle safety and frequently referenced a recent NASA study found at http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110008208_2011007983.pdf. Several listeners have contacted me that this report is highly controversial & statistically flawed, but these people did not call or email in during yesterday’s discussion. As always, trust but verify. Jeff’s discussion on safety was wide ranging and covered all segments of the interview. He focused on various risk factors, SRBs, liquid SSMEs, & shuttle operations. As we started the second segment, Jeff was asked about the Space Launch System (SLS) re safety since it is to be derived in part from using shuttle components. Jeff had much to say about this, not particularly positive either. He then went into a lengthy discussion about SRBs , their safety, different technology, liquid rocket engines and Space X. He also talked about the Challenger accident and SRBs. His discussion then switched to cost plus contracting as compared to the Space Act Agreement (SAA). Later in the segment, he talked about X-37B and said that there was no real justification for a government manned space program. He repeated this statement a few times during the balance of the interview. He mentioned secrecy in the NewSpace sector and Tim called in from Huntsville to explore that with him. We talked about lunar tourism, the space elevator, and space solar power with the news of interest coming from China. Jeff returned to shuttle topics such as the fly back booster and Phase B shuttle plans. Jeff talked about the recent Blue Origin launch failure, the CCDEV companies & was unaware of the effort to bring CCDEV participants under a form of the FAR, thus doing away with the SAA. He continued talking about Space X and Dragon, more on space tourism including lunar tourism, and had much to say on the suborbital industry, including his thoughts that it would not compete for science missions with sounding rockets which he also suggested were not doing much anyway. Don’t miss his comments on this. Regarding policy, he said over and over again during the interview that congress was making decisions on pork for their districts. He also expressed his concern as did I that human spaceflight was very much at risk given our policy confusion and economic situation. As the end of this program was upon us, we fielded a few more listener questions but I also brought up the uniqueness of Steve Jobs and that we needed more gifted people in space like him, Elon, & others. We also talked about the contributions of Silicon Valley and Jeff had much to say about the Valley & its contributions, mentality, etc.. Jeff is not great at responding to emails but if you want to send him a question, do so through me and I will forward it to him. Please do post your comments and questions on the blog URL above.
In my view Dr. Bell’s take on the U.S. space program is way too negative. It seems to me he has reached burn out on the whole subject. At heart he is basically questioning why we have a government space program. The answer is very basic: No other entity has enough money and the license to spend it. In addition to this he brings a significant amount of misinformation to the discussion.
For example he claims that the U.S. space program is a reaction to Gagarin’s flight. In reality there was wide array of space projects were underway before that time. The U.S. was working toward a satellite launch even before Sputnik. Project Mercury was underway before Vostok I as was project Apollo. We also had a nuclear rocket program and Project Orion the nuclear impulse spacecraft being researched by the AEC. Gagarin’s flight did lead to our goal of a man on the Moon before 1970 and the money to make it happen. Without the Soviet first we would have gone into space ourselves but with a more modest program.
Dr. Bell went on at length with his criticisms of the space shuttle. I do agree with him on one point and that is the early two-stage shuttle concepts wouldn’t have been a good path to follow both on technical and economic grounds. I also believe that the shuttle was a bit too ambitious for its time and no doubt represented our post-moon landing hubris. Perhaps we should have just built a smaller spaceplane launched by a conventional rocket to gain experience with reusable spacecraft at a lower cost. However, we made a bolder move and produced a revolutionary spacecraft that served us well for 30 years.
It seems clear to me that the decision made in the aftermath of the loss of Columbia to end the shuttle program and replace it with the Constellation moon program was a major mistake. The simple fact that available budgets would not support the Constellation and that it was cancelled is evidence enough. It would have made more sense as I pointed out on the show to build more shuttle orbiters. If NASA had focused on the goal for getting new orbiters without pushing for any major performance increases this could have been accomplished with the budget stream available through FY 2011. The moneys that were spend on developing the five-segmented SRB, the J-2X engine, the Orion capsule, the Ares I-X test, and a lot of design studies would instead have been direct tooling up and producing orbiters. I assume there would be evolutionary changes in electronics and so forth. Think of this as analogous to a letter variant update of an aircraft and not a whole new system.
One clear advantage this alternate path would have is that NASA would be in a much better position to weather the current budget storm than it is now with no operational manned vehicles. Also, this path would give us far more capability for the next decade or more that we are going to have even if commercial crew, Orion, and SLS actually get funded. The only thing that the continued shuttle would lack is the ability to do limited missions beyond LEO, i.e. those that could orbit the moon or visit near Earth asteroids. Given the tenuousness of the SLS that seems to be a reasonable trade off.
Sadly, we are past the point of no return and we will have to do will less for at least a generation.
Wayne Hale (former head of shuttle operations) was asked a question about Shuttle at the 25:30 min point at
http://event.on24.com/clients/default/presentation/default.html?titlecolor=000000&eventid=345818&sessionid=1&username=&partnerref=&format=wmmulti&mobile=false&flashsupportedmobiledevice=false&helpcenter=false&key=DA9F2DAD3E431E12413E95437BD01C2E&text_language_id=en&playerwidth=920&playerheight=650&silverlight=true&eventuserid=53663832&contenttype=A&mediametricsessionid=44629921&mediametricid=751552&usercd=53663832&mode=launch
Said that Shuttles problem wasn’t that shuttle failed to deliver on low cost routine operations, but it delivered to well. It was always good enough as is to do all that was wanted, so the replacements (shuttle was originally to be replaced by shuttle 2 in the ’90′s) were deferred decade after decade as not necessary to get any projected mission done.
I think that’s a good point. It could easily be dramaticlly improved (with refits or next gen designs), but was always good enough to do what anyone really needed for what was being done, and no one was committed to bigger projects that would need the improved craft (and a improved craft would be a lot cheaper to operate, and require a much smaller staffing levels- which was unacceptable to voters/congressmen).
John I have to disagree that starting with a smaller shuttle would have helped. It wouldn’t have saved that much (a hundred fold smaller aircraft is usually only about 10 times cheaper. And with spacecraft can actually cost more!) but the smaller shuttle would have been to limited to do all the missions necessary, that the shuttle fleet could do. So you’ld need to build and operate a second fleet. Which would be much more expensive.
Agree were stuck for a decade or more now though. nothing flying, adn nothing with significant abilities even planed. (Possible exception being the DODs RLV based EELV replacement in the 2020′s if its built
My comments about not going straight to the full shuttle STS were mainly based on the thought that we might have flown a smaller prototype vehicle first in order to gain some experience with reusable vehicles. We had never flown a reusable space vehicle before and it seems we might have learned some things that would have helped us design a more supportable system. Of course what I’m proposing would provide little insight into the main propulsion system and that is a major issue. If we had went that way then Apollo derived systems would have been the basis or our 1970s/1980s program. In that case the shuttle would have waited a decade.
I would like to make a small supplement to my comments on the Phase B shuttle concepts. I think the problem with them is that they relied on two many SSMEs in the booster vehicle. If one were to build such a two-stage vehicle it would be wise to have a RP-1/LOX first-stage and higher thrust engines than the SSMEs. Regardless such two-stage shuttle concepts would have required a greater financial commitment.
But we did fly several resuables. Those were the x-planes.We earned a lot — much of which was ignored for the shuttles.
;/
As to a phase-B shuttle I’ld vote for a Biamese based on the orbiter that eliminates the need for the ET and SRB’s, using RP-LOx rockets. You could use the old RD 180s or F-1s or build a better new one.
What would you thin we need to learn in a subscale?.
I’m not able or qualified to comment on the NASA study or the statistics, but did learn a lot about Shuttle design and operations generally, as well as general Newspace stuff. Thanks David and Jeff.
Looking over the slide presentation Dr Bell references I noticed a few questionable numbers.
In page 4 under ejection seats t states
>>.. Given a scenario that is assumed to be recoverable, ejection seats are given a 90% success rate (i.e. there is a 10% chance that either crewmember will not survive)…<<
I was given a statistic that military aircraft have shown a 25% fatality rate among all those who use them. Why was NASA expecting Shuttle ejections would be so much safer? or were they going to be selective about what they considered a recoverable scenario?
I didn't notice them commenting on the SSME's being much safer after P&W redesign of critical (and overstressed) components.
In general, NASA has a well deserved reputation of shading reports and analysis according to what they want say (I saw rather disgusting examples of that post Challenger) — and as the Columbia accident showed, can use excessive analysis on insufficient data rather then a simple test, leading to wildly inaccurate conclusions. Such as their original projections of a 1 in 500 chance of loss of ship and crew per flight, vrs industry (Futrons?) more accurate 1 in 50 projection.
On the other hand the conclusion that shuttle now is likely 10 times safer then when they first started operating them is plausible from lessons learned basis. However given the accidents came from known risks NASA ordered the operations staffs to ignore – would learning lessons convince them to not take chances?