From: Andrew Johnson
Date: 2015-06-13 10:14:11
Attachments : Someone sent me a new article from Nexus Mag about the Orion programme – it’s on David Percy’s site here: http://www.aulis.com/moonbase3.htm Worth a read as it’s quite technical (written by a techie using a pseudonym). If you’re short on time, just look at Table 2 – which kind of “says it all” (CxP is the “Constellation” programme which was scrapped/replaced some years ago.) Towards A Moon Base:
Has anything been learned from Apollo? by Phil Kouts PhDNotwithstanding the claimed achievements of Apollo, NASA is now developing from scratch the technology and systems to enable safe travel to the Moon and back. Perhaps it should seek to join an international lunar project. Despite the announcement in 2010 that the Constellation Program (CxP) was cancelled, work on the technology for travelling beyond low-Earth orbit (LEO) has continued without interruption (NEXUS; Aulis, 2014). However, one substantial aspect of the program is now absent: the idea of developing a lunar outpost. Initially this idea was discussed in detail (Arch. Study, 2005, p.56) but is now missing from NASA’s current plans. A Moon base has been an exciting objective for over 20 years, even before the CxP (Lunar Base, 1999), and the program appeared to be obtainable within a viable time frame. Yet after five years of project research and design, some essential elements of the lunar visitation program have disappeared from the latest plans. NASA is now slowly and carefully working on a number of problems which should have been fully resolved decades ago if the Moon landings did really happen. Some progress was achieved over the last decade, but the impact is miniscule compared to the vast program of works allegedly completed over 40 years ago. Testing the Return Capsule Astronaut’s view of Orion craft re-entry through the atmosphere at T=2200°C (consider what it would look like at T=2700°C) view video clip A major recent event was the 5 December 2014 test flight of the Orion capsule intended to deliver crews to space destinations beyond LEO and, most importantly, provide a safe return to Earth. Orion reached an altitude of 5,800 km and then returned to Earth at the entry speed of 8.9 km per second with its heat shield temperature reaching 2,200°C (Orion Blog, 2014, 5 December). Splashdown of the capsule in the vicinity of the waiting USS Anchorage and USS and USNS Salvorwent as planned.The test was completed, but what was special about it? Ceramic tiles similar to those used on Space Shuttle were deployed on the walls of Orion a new element compared to the construction of the Apollo Command Module (CM). How critical is this innovation? If it is necessary, then how did the Apollo CM manage to withstand the heat of the plasma blanket which enveloped it during re-entry though the Earths atmosphere without such tiling?A crucial element of the capsules return method, i.e. skip entry, is still to be investigated experimentally following a thorough, theoretical research during the CxP (Bairstow, 2006; NASA Johnson, 2011). The majority of task statements have revolved around a new skip entry plan to achieve an accurate landing near the US Pacific coast (Arch Study, 2005, p.263; Kaya, 2008, p.65). This approach, which in essence is an extra convenience when returning from beyond LEO, is now represented as an actual objective of the latest R&D efforts as if all other problems have been resolved. However, this is just the icing on a cake which is still to be prepared and baked.The key problem which remains is the safe return of the crew. During the CxP, it was recognised that “
the difference between a direct entry for ISS return and a skip entry flight for lunar return was the amount of lofting that occurs during the entry. The Apollo program used a direct entry approach for returning crew from the moon. A skip entry flight has never been flown in a manned space flight program
” (NASA Johnson, 2011, p.5). Typical Apollo mission re-entry can be interpreted as a “double dip entry” (Kaya, 2008, p.26), which is fundamentally different from skip entry.The total time for the Apollo CM to slow down before opening its drogues was claimed to be around eight minutes, which is extremely short. Conversely, skip entry allows a brake of 40 to 120 minutes before the second phase of deceleration (Kaya, 2008, p.54), so this is a completely different scenario relative to both heat dissipation and gravitational loading on the crew. “After the skip, the vehicle spends most of its trajectory out of the atmosphere. As far as the heating constraints, this is very helpful for cooling down the vehicle out of the atmosphere and beginning a second entry with less energy.” (Kaya, 2008, p.57)Further, as one can see from the Apollo 8, 10 & 11 mission reports, the Apollo CM performed landings within a relatively short range not more than 3,000 km from the atmospheric entry interface location to the splashdown area. This was combined with optimistically modest peak decelerations loads, it was claimed. Atmospheric entry interface means a level above the Earths surface at an altitude of approx. 120 km. The Apollo deceleration values were claimed to be around 6.5g1 with a maximum of 6.84g for the Apollo 8 CM in combination with the shortest landing flight range of approx. 2,200 km before drogue deployment, compared to other Apollo CM landings. However, the claimed results contradict the combined conditions of modern estimates for Apollo-like scenarios, during which the deceleration overload at a non-skip entry can easily reach from 9g up to 15g. (Kaya, 2008, pp. 4-6; NASA Johnson, 2011, p. 29).Let’s compare the extreme conditions of a direct Apollo re-entry with conditions of a typical Space Shuttle where entry steering commands “control the entry trajectory from initial penetration of the Earth’s atmosphere (altitude of 122 km and range of approximately 7600 km from runway) until activation of the terminal area guidance.2” (Kaya, 2008, p.12) Space Shuttle return The Space Shuttle used to return from LEO with an initial speed of 7.8 km/sec maximum. A typical Apollo CM should have returned from beyond LEO with an entry speed of 11.2 km/sec, and the distance to drogue deployment was not more than 3,000 km. This should be compared with the newly introduced plan for a skip landing flight up to 8,900 km. In addition, the target accuracy of entry is now set to be around 10 km (Prelim. Report, 2011, p.18). The typical deviations claimed for the Apollo CM splashdowns, were around 3 km. To sum up, a safe lunar return is reliant on the tight combination of strict parameters: entry speed, angle of entry into the atmosphere, and flight range (including the route profile) to drogue deployment. This combination in turn defines an outcome combination: the maximum temperature of a return capsule and the maximum deceleration load on the onboard crew. The key point here is that the typical claimed Apollo combination of the input parameters is beyond all practicality, and is not in any way considered now as a benchmark set of requirements for future space missions. The recent set of parameters for the Orion test in December 2014 led to a deceleration value up to 8.2g at an interim entry speed (not even a full escape velocity value) of 8.9 km/sec, so the actual parameters required for Apollo-type lunar returns have not been tried yet.It looks as if NASA specialists are cautiously trying out techniques in conditions which are barely approaching the severity of those which were supposedly overcome by all the Apollo CMs. Skip entry is now recognised as a compulsory requirement for safe returns from lunar trajectory in the current configuration and scenario. It is crucial for saving the integrity of the CM capsule, and for health reasons, if not the very survival of the crew. Therefore there is nothing really to learn from Apollo CM entry stories except that we shouldn’t undertake missions in this way otherwise the entry will, in all probability, end up as a fatal disaster. Another significant point of note is related to traversing the lower Van Allen radiation belt. The cameras onboard Orion were turned off in order to protect them from radiation (Orion Blog, 2014, 5 December). Again, what about the Apollo CM with the onboard crew when the Apollo spacecraft were passing through the same area on their voyages to and from the Moon? This new assessment of possible damaging radiation effects is occurring without any reliance upon, or even reference to, those previous Apollo experiences.Apollo Management and Scheduling Rocketdyne F-1 Engine As a meaningful test for assessing the capability of travelling beyond LEO, where does this Orion flight fit into the overall sequence of events leading to a successful lunar mission?To understand this better we need to examine the actual sequence of major technical steps completed before the Apollo landings. It is worthwhile noting that in September 1963, an interim report presented at a management meeting at NASAs headquarters exposed very serious problems with the Apollo program including those concerning combustion instability in the F-1 engine. The development team reported that first, a “lunar landing cannot likely be attained within the decade with acceptable risk” and second, “the first attempt to land men on the moon would probably take place in late 1971.” (Apollo, 1989, p.153) In response, managers simply suggested coming up with a better statement.It is a common knowledge that by mid-1967, every major element of the Apollo program was still to be tested. The first ever trial of the Saturn V rocket took place on 7 November 1967, but other key elements such as a lunar module (LM), were still in development. By the end of 1967 the overall outline of milestones for a successful lunar mission was seen as follows (Apollo, 1989, p.316): A Apollo 4 and Apollo 6 unmanned Saturn V missions;B unmanned testing of LM in LEO onboard Apollo 5;C Apollo 7, the first manned mission scheduled for LEO in autumn 1968; D the first manned mission using both CM and LM still in LEO; E CM and LM in a high-Earth orbit up to 7,200 km of the Earth’s surface;F the first trip to the Moon, lunar orbiting but no landing; exercise LM,G the first lunar landing of a crew. It was recognised at the time that “[e]ach mission had its own reason for existence. None could safely be skipped.” (Apollo, 1989, p.316) If we set the Apollo 11 accomplishment as a target for the full list of these steps then they can be placed in chronological order like this: Table 1 Year 1967 1st half of 1968 2nd half of 1968 1969 Milestone A A/B C/D/E (?) E (?)/F/G This schedule, heavily weighted with radical tasks, was soon made even heavier. Now we know that even completing step A was problematic, due to the unsatisfactory outcome of Apollo 6 in April 1968: namely,serious pogo oscillations in the first stage, failures of two J-2 engines out of the five in the second stage, and failure of the J-2 engine in the third stage to reignite.Despite all this, just a few months later in August, the programs top management quietly and unexpectedly proposed “to fly to the moon on only the second manned Apollo spacecraft, the first manned Saturn V, and the first Saturn V to fly after the failure-ridden Apollo 6.” (Apollo, 1989, p.317) This new mission was purely an administrative decision to fly, despite all evident technical problems.A test flight without the LM could be seen as an expected outcome in the absence of this item, not due to be flight ready until early 1969. Yet the plan to send a crew on a fly-by around the Moon and back, without first having tested the return capsule on the full range re-entry conditions, was the highest risk imaginable for the astronauts. James E Webb This extraordinarily “brave” decision to fly straight to the Moon was taken by a group of top managers in the absence of NASA Administrator James Webb who was attending a United Nations conference in Vienna, Austria, on 14-27 August on the peaceful use of outer space. Webb’s reaction to their decision was unambiguous: total disbelief. A man of integrity who led NASA to fulfilment of the lunar program without compromise, Webb did not consider that circumlunar flight was achievable at that stage. As a result, on 16 September President Johnson suggested that he resign immediately and on 7 October James Webb left NASA. The agency held a press conference in late August 1968 revealing that Apollo 8 was going to be a “flexible mission” so the spacecraft could achieve high-Earth orbit, i.e. factually it was the E-step mission (see table 1 above), “with an apogee several thousand miles out.” (Apollo, 1989, p.323)The Orion development and testing saga has revealed one of the crucial technical elements which was missing in the “brave” plan of that circumlunar flight of 1968: step E-testing which would test a CM during a high speed re-entry. This element the success of which was vital for any lunar mission was omitted as if it wasn’t significant. A sub-orbital flight of a test capsule in 1966 in interim conditions (AS-202, 1967), had been a good step in the right direction but certainly insufficient for taking that 1968 decision to fly by the Moon.It still remains to be fully explained what had actually motivated the Apollo project managers to take such extreme risks with the astronauts lives. The explanation for this irrational decision was apparently political: “One purpose (though not publicly emphasized) of going circumlunar so quickly was to beat the Soviets to the punch.” (Apollo, 1989, p.322) Soviet Launches and NASA ResponsesSo what exactly had been happening with the Soviets lunar plans and at the time, what was making NASA managers so nervous? The Soviets signalled their skip-entry capabilities by the end of 1969 with a postage stamp sheet featuring two Zond missions. By mid-1968, the Soviets had already successfully sent Zond 4 to fly by the Moon with return to Earth (although the landing phase wasnt successful) and were preparing to launch Zond 5 (Zonds, 1968). Under pressure not to lose again to the Soviets who according to intelligence reports were preparing to fly by the Moon, the US space agency apparently embarked on a disastrously dangerous route involving further shortcuts.In September 1968, Zond 5 returned to Earth from a successful lunar fly by with small animals on board which had returned alive, for the first time in the history of space exploration.This missions important achievements, overshadowed by the Apollo glory, remains underestimated. In fact, the success of Zond 5 indicated that the Soviets had developed a technology of safe return at the speed equal to the escape velocity. So it appears that NASA was afraid that the Soviets were imminently capable of sending a man on a lunar fly-by and saw this as a real threat. In a desperate response to this threat, NASA claimed the declared “fixing” of the Apollo 6 problems as proof that the Saturn V launcher was flight ready for such a lunar mission (NEXUS; Aulis, 2014).In November 1968, with reference to the successful LEO flight in October 1968 of the Saturn 1B rocket (technically a much simpler if not an entirely different rocket from the Saturn V with its problematic F-1 engines), NASA announced that Apollo 8 would now be upgraded to a lunar orbital mission. In practice, this was a desperate, technically unsubstantiated move, and as a result, serious gaps opened up in NASAs spaceflight capabilities. As we will now see, these gaps havent been closed to this day.When a modern researcher admits that “[i]n place of a total skip entry, Apollo used a double dip entry”, he still interprets the Zonds’ feat as successfully returning to a specific location rather than the fact that the technique brings safe returns in principle: “The Soviet Union also used skip trajectories to return Zond robotic vehicles to a Russian landing site.” (Kaya, 2008, pp. 26-27) Given the complexity of the re-entry task as explained above, NASA’s announcement to send a crew to fly by the Moon in 1968 without developing proper equipment and/or a technique for returning the crew safely to Earth means only one thing: it was purely a political declaration. One should conclude beyond any doubt that, technically, crews have never been sent to the Moon for a fly-by or for a landing. Humanity has been dealing with a science fiction story about Apollo accomplishments, represented as truth. How this show was staged and has been supported for so long is beyond the scope of this article. The next step in unmanned CM re-entry trials is planned for 2018 as a full-range return after a fly-by, with provision for a manned repeat (similar to Apollo 8 in 1968) pencilled in for 2021 (GAO, 2015, pp. 8-9). A Lunar Lander is MissingWhile the design and technical specifications for a craft which could land and then take off from the lunar surface with subsequent rendezvous with the orbiting CM were considered at the outset of the CxP in great detail (Arch. Study, 2005, p.158), any such ideas have now disappeared from NASAs plans. To be more accurate, no request regarding a lunar lander concept was included in the NASA Authorization Act 2010, leaving the instrumental package for a successful Moon landing incomplete. So, if we imagine that the current plans for the Space Launch System (SLS)3 and Orion capsule were to be fulfilled as currently scheduled, say by 2021, there remains no indication that NASA will be capable of landing astronauts on the Moon any time soon. Especially as the very design of the Apollo LM is still posing questions as to whether it was ever a viable construction for the safe lift-off from the descent stage. LM descent stage note the totally flat continuous surface of the top deck with a shallow ‘hole’ in the middle, under which is the descent engine The descent-stage top deck of the LM had a continuous, firm upper surface with no routes through which the hot gases could escape when the ascent engine was fired. This elementary design detail was potentially fatal for the ascent module which, seconds after ignition (when the exhaust gases commenced building), would very likely tumble on a developing post of its own flame. To put it simply, there was a real danger of the ascent stage tipping over the very moment the engine fired. In his memoir, Thomas J. Kelly, chief engineer of the Apollo lunar lander, admits that “ascent engine combustion instability was a chronic problem that yielded only slowly and grudgingly to trial-and-error solutions” and was resolved by mid-1968 (Moon Lander, 2001, pp 132-136). Thomas J Kelly In all probability, ascent engine trials and testing would have taken a prohibitively long period of time, since Kelly, despite his considerably detailed descriptions of working with mock-up LM models, doesn’t describe any trials of a lightweight ascent stage mock-up on its lift-off in Earth’s gravity conditions although we have to assume that such trials did really occur. According to Kelly, the LM was successfully tried onboard Apollo 5 in LEO regarding its ability to perform an abrupt abort-stage maneuvre at the powered lunar descent. Kelly explains: “The ascent engine would start while still atop the descent stage, as in a liftoff from the Moon, and its exhaust would initially impinge upon and be deflected by the top surface of the decent stage, a condition known as fire in the hole, or FITH. NASA patch: Apollo 5 LM 1 test in orbit at the moment of firing the ascent engine ‘fire in the hole’ (FITH) “There was some concern that in an abort-stage maneuver the aerodynamic forces of FITH might cause the descent stage to tumble, since when separated from the ascent stage it had no attitude control. A tumbling descent stage could possibly impact the departing ascent stage.” (Moon Lander, 2001, p.194) Thomas Kelly describes this test as being equivalent to the process required for take-off from the Moon, yet in reality he is only describing the potential FITH problems related to separation in orbit. The FITH consequences of departure from a lunar surface configuration are different due to the gravity conditions, and potentially fatal with regard to the crews ability to leave the surface. The notion that this Apollo 5 orbital test rated the LM for a viable ascent from the lunar surface is largely questionable. Indeed, any idea of designing a LM where the ascent engine’s nozzle rim was in such close proximity to the flat-screened top surface of the descent stage, thereby preventing the outflow of exhaust gases, should have been discarded at its very conception. Fitting a LM ascent stage above the descent stage at Grumman Aerospace Bearing in mind that NASA was in a hurry to beat the Soviets after the Apollo 8 staged flight, it probably didn’t matter which way the overall system configuration was developed further (when it was likely not going to be deployed anyway).Regarding development of a lunar lander, currently, the lack of initiative from within NASA is very evident. Moreover, there is no sign of any pushing from the US government, so it is obvious that somewhere, on a strategic level, it has been decided to leave a large hole in the new Moon visitation plan, providing an excuse for postponing a landing for another period of several years after 2021 when SLS3 and Orion are expected to be ready.Choice of a Suitable EngineDuring the CxP there was no reliance on the Saturn Vs key elements, such as the first stage F-1 engine, so the choice of a suitable engine still remained to be made after the program was cancelled (NEXUS; Aulis, 2014). It has become absolutely clear that in the latest NASA plans for SLS, the new rocket appears to be based on developments which are not related to the Saturn V rocket at all. By 2009, a heavy rocket called the Evolved Expendable Launch Vehicle (EELV)4 was seen as a viable alternative to other rocket concepts of the CxP, in particular to the then-cancelled Ares series of launchers (Augustine, 2009). In turn, from both key reports of the CxP era (Arch. Study, 2005; Augustine, 2009) it is clear that the best engine in the EELV family, appears to be the Russian-made RD-180 engine. Since 2002, it has been routinely used (on more than 50 launches) on US rockets of the Atlas series.Even the acclaimed Lunar Reconnaissance Orbiter spacecraft, launched in 2009 and placed into lunar orbit as part of the CxP (and allegedly taking photos of the Apollo landing sites), was powered by RD-180 engines.NASA recognised the quality and reliability of this engine and proposed a new generation of heavy launchers, provisionally named Atlas 5 Phase 2 Heavy: “The EELV super-heavy uses two RD-180 rocket engines on each of the core and two boosters. The RD-180 engine has a long history of successful launches in Russia and in the U.S. on the Atlas V family of launch vehicles.” (Augustine, 2009, p.68) The Russian-built RD-180 engine In its cost-performance analysis, NASA contemplated the option of building an interim rocket of up to 75 metric tons: “Initially, the EELV-heritage super heavy vehicle would use the Russian RD-180 hydrocarbon fueled engine, currently used on the Atlas 5. In the cost analysis utilized by the Committee, provision was made for the development of a new large domestic engine to replace the RD-180 for both NASA and National Security missions.” (Augustine, 2009, p.93)Taking into account the fact that the Ares program was cancelled and the schedules considered in the NASA reports stretch to 2020 anyway, the current decade was supposed to be a period of continuous reliance on Russian RD-180 engines. Practically, this is what happening now despite back and forth decisions made throughout the year 2014 (Bloomberg, 2014, GAO 2014). “The liquid-fuel RD-180 engine has been a steady performer … with 100 percent of its missions launched successfully, says Bloomberg’s correspondent and then quotes an expert in space technology: United Launch Alliance will probably need to double its inventory beyond the current two-year supply of Russian-made engines to ensure that critical government and commercial missions continue unhindered while transitioning to a new technology.” (Bloomberg, 2014) After a new, simplified program was launched instead of the CxP in 2010, NASA has admitted that it cannot complete the development of a heavy launch vehicle by the end of 2016 as was requested in the NASA Administration Act 2010 (Prelim. Report, 2011). This admission has infuriated the US government not only because of its plain denial, but more probably due to the fact that NASAs new lunar program could not find anything better to rely upon than the Russian-built engines.The Senate Commerce Committee responded to NASA, which said that it cannot build new systems based on the cost and schedule outlined in the Act, stating that “…the production of a heavy-lift rocket and capsule is not optional. Its the law. NASA must use its decades of space know-how and billions of dollars in previous investments to come up with a concept that works.” (Senate Committee, 2011) This firm statement has become a favourite with the mass media and has been cited by multiple sources, including the New Scientist.Further slippage has continued: “The Orion program has submitted a schedule to NASA headquarters that indicates the program is now developing plans for a September 2018 EM-1 launch.” (GAO, 2015, p.8) This means an unmanned full range trial of the capsule after a fly-by of the Moon. “Also, the SLS and GSDO5programs have already slipped their committed launch readiness dates to November 2018, and Orion appears likely to follow suit. While these delays were appropriate actions on the agencys part to reduce risk, their compounding effect could have impacts on the first crewed flight EM-2 currently scheduled for 2021.” (GAO, 2015, p.9) So, officials already consider that the scheduled year of 2021 for a manned lunar fly-by will most likely also be pushed back.Further, an American analogue Staged Combustion core stage engine is expected to be replicated from the RD-180 by 2018, while an updated version of a J-2X class engine inherited from Apollo times with a lower thrust level, is expected by 2025 (Prelim. Report, 2011, p.9).At the outset of the CxP, NASA managers suggested that “[t]he RD-180 first-stage engine of the Atlas HLV will require modification to be certified for human rating. This work will, by necessity, have to be performed by the Russians.’ (Arch. Study, 2005, p.383) So this option would give international co-operation in the program a better chance, merely by expanding the scope of the on-going joint ventures.Instead, after the CxP was cancelled, the very term RD-180 has disappeared from NASA documents since the Authorization Act 2010 enactment. This is probably the major change in the policy, while the essence remains the same: NASA is reliant on these Russian-built engines.Throughout the CxP, the US rocket industry has become even more dependent upon these Russian-built engines. Now, a further deal with a Russian producer of RD-180 engines has recently been struck: “Orbital Sciences Corp. and Energia6 has signed a contract worth approximately $1 billion for up to 60 Russian-made RD-181 rocket engines to power the redesigned first stage of the commercial Antares launcher.” (RD-181, 2015) The first launch of an updated Antares rocket with these new engines is planned for 2016, which is the year in which NASA falls short in delivering the first SLS launch, despite all the pressure from the US government.A Lunar Outpost Concept for proposed NASA lunar outpost The idea of a Moon base was an exciting objective of the Architecture Study in 2005, where lunar surface systems were initially supposed to commence as early as 2013 (Arch. Study, 2005, p.668). Accordingly, the lunar lander was due to be developed from 2010 to 2018, so the 7th Human Lunar Landing was provisionally pencilled in not to the remote 2020 but as early as 2018 (Arch. Study, 2005, p.56).The enthusiasm for a return to the Moon with an idea of a lunar outpost was really infectious at the outset of the CxP. Even MIT students were saying “…NASA does not want just to repeat a previous space program the people at NASA are committed to forwarding the field of space exploration. The vision7 calls for an eventual permanent moonbase so they are thinking large-scale and long-term. (Bairstow, 2006, p.15)However, by 2009 the initial plans of the concurrent developments set out in 2005 have been deemed unaffordable. This change of plan has been broadly covered in the mass media as being rooted in financial problems and ambitious unsustainable targets. With NASAs massive experience in space systems, it is hard to understand how plans which didnt contain anything significantly revolutionary compared to those of the late 1960s, and designed to mature over a period twice as long were recognised as ambitious. If unsustainable refers to the lack of will to actually finance the program through to its end, it is quite possible that ambitious in fact refers rather more to the insurmountable technical problems that were never resolved during the Apollo epoch. Persuasive presentation of Apollo as a success for literally dozens of years, has created an environment of intellectual humility. Fortunately, those days are over: through its decision-making process, NASA has exposed the falsification of the lunar landings. What should have been done for a successful mission some 45 years ago as a concurrent development within a time frame of three to four years (see Table 1 above) is happening now at an extremely slow pace, on a sequential basis, within an entirely uncertain if not an indefinite time frame. Indeed, what was initially planned for the CxP to be completed within 15 years is now set out entirely as an open-ended scheme without any deadline for a human Moon landing (see table 2). Table 2 Event Program Govmt Initiative Problems & Critics UnmannedTrial Entry,Interim Condition (Message over 64 KB, truncated)
