SLS Program Manager Discusses Major Component Failure in Core Vehicle Engine

 

 

 

Green Run Update: Data and Inspections Indicate Core Stage in Good Condition

SLS Hot Fire Shutdown Due To Conservative Testing Parameters, Not Engine Malfunction

 

Boeing's 1968 Hyper Heavy Lift Vehicle Concept

Links and References

CONCEPT FOR A LARGE MULTIPURPOSE LAUNCH VEHICLE

Efficient Utilization of the Space Launch System in the Age of Propellant Depots

by Marcel F. Williams 

SLS Block I and Block IB (Credit: NASA)

With the successful test launch of Space X's  Falcon Heavy, some have questioned why NASA continues to support the development of the Boeing/Orbital ATK Space Launch System (SLS). The Falcon Heavy is now the most powerful rocket in operation with the capability of deploying up to 63 tonnes of payload to Low Earth Orbit (LEO). But next year,  NASA will test launch an even more  powerful heavy lift vehicle.  In its earliest incarnation, the SLS will be capable of deploying at least 70 tonnes of payload to LEO. By the time its Exploratory Upper Stage (EUS) is developed in the early 2020s, the SLS will be capable of deploying more than 105 tonnes of payload to LEO. Future advances or alternatives to the SLS solid rocket boosters also promise to enable the SLS to  deploy more than 130 tonnes of payload to orbit.

Maximum payload deployment to LEO:

SLS Block 2: 130 tonnes

SLS Block 1B: 105 tonnes

SLS Block 1: 70 tonnes

Falcon Heavy: 63 tonnes

Delta-IV Heavy: 28.8 tonnes

Falcon 9: 22.8 tonnes

Atlas-V: 20.5 tonnes

But  the Space Launch System will have an additional advantage over other launch vehicles in its ability to also accommodate  payloads with substantially larger dimensions. While the Falcon Heavy and most other launch vehicles will continue to be  limited to housing payloads within a maximum diameter of 4.6 meters, the SLS will be capable of deploying payloads within its  fairing up to 9.1 meters in diameter.

NASA's Hubble space telescope has a 2.4 in diameter mirror. The SLS would be the only vehicle capable of  accommodating space  telescopes with a single mirror  8 meters in diameter mirror or  segmented mirrors up to 16.8 meters in diameter.  The SLS would also be only launch vehicle with a fairing size capable of deploying Bigelow's 65 to 100 tonne BA-2100 Olympus space station which requires a fairing diameter of at least 8 meters.

Beyond the payload fairing dimensions, the SLS would also be the only rocket capable of deploying  Lockheed-Martin's reusable Mars landing vehicle (MADV) to orbit.
 

Notional  MADV on to of SLS (Credit: Lockheed Martin)

Maximum (internal) payload fairing diameter:

Space Launch System (SLS): 9.1 meters

Falcon Heavy: 4.6 meters

Falcon 9: 4.6 meters

Atlas-V: 4.6 meters

Delta-IV: 4.6 meters

The cost of an SLS launch will largely depend on how frequently the heavy lift vehicle is launched. NASA launched as many as eight space shuttle (a heavy lift vehicle) missions in one year. But since the expendable RS-25 engines for the core vehicle won't be ready until the early 2020s, the SLS can't be routinely launched into space until that time. However, sixteen RS-25 engines derived from the old Space Shuttle program are available for four SLS launches until the new expendable engines are ready.

But the success of the SLS will depend on how efficiently and frequently it is utilized. Once the new RS-25 engines are in production, it will be essential for NASA to launch the SLS at least twice per year during the 2020's and a lot more frequently during the 2030s. 

Propellant producing water depots are still the key to opening up the rest of the solar system for eventual commercialization and colonization of the rest of the solar system. Since most propellant depots concepts utilize existing propellant tanks or existing propellant tank technology, the SLS would have a distinct advantage over other launch technologies because of the size and volume of its propellant tanks.

An EUS modified with the ULA's Integrated Vehicle Fuel ( IVF) technology (WPD-OTV-128) could be deployed by the SLS to LEO or EML1 with a LOX/LH2 storage capacity of 128 tonnes with a 450 Kwe solar power plant. At EML1, such a propellant producing water depot would be capable of producing approximately 45 tonnes of LOX/LH2 propellant per month plus an additional 12 tonnes of LOX per month. The notional WPD-OTV-128 would also be capable of redeploying itself in orbit around Mars or Venus to enable crew returns to cis-lunar space from those worlds. Propellant producing water depots (WPD-OTV-128) at LEO and EML1 could be supplied with water from private commercial launch vehicles such as the Falcon Heavy.

Notional solar powered propellant producing water depot (WPD-OTV-128) at EML1.

An SLS Block IB might be capable of deploying up to 35 tonnes of payload to EML1. An IVF modified EUS utilized as a reusable OTV (Orbital Transfer Vehicle) would be capable of transporting at least 70 tonnes of payload from LEO to EML1. Two such OTVs (positioned on opposite sides of the cargo) would be capable of transporting at least  140 tonnes of payload from LEO to EML1. So by utilizing propellant depots, anything the SLS can launch to LEO could also be transported practically anywhere within cis-lunar space.

A larger orbital transfer vehicles (OTV-400) and propellant depots (WPD-OTV-400) could also be derived from SLS propellant tank technology and  used for crewed missions to the orbits of Mars and Venus.

Notional OTV-400 orbital transfer vehicle for crewed interplanetary missions

 Reusable LOX/LH2 spacecraft deployed by the SLS or by private commercial launch vehicles could be utilized for cargo and crew missions between EML1 and the lunar surface and between EML1 and LEO. Lockheed-Martin's reusable MADV could be used to land astronauts on the Moon and Mars or  transport them between LEO and EML1.   Reusable vehicle concepts such as the XEUS spacecraft or a notional Altair-like reusable vehicle (ETLV-4) utilizing Boeing's 2.4 meter in diameter cryotanks could be used to transport astronauts to and from the lunar surface to EML1 or between LEO and EML1.

XEUS lunar lander (Credit: ULA)

NASA plans a crew launch of the SLS in the early 2020s with a plan to deploy the Orion Multipurpose Crew Vehicle (MPCV) to the vicinity of the Moon. But reusable spacecraft using propellant depots would make Orion's European manufactured Service Module (SM) obsolete. The Service Module could be replaced by a reusable LOX/LH2 ACES 68 which could also be utilized with  the ULA's future Vulcan spacecraft to deploy the Orion to LEO.

Notional ETLV-4 lunar lander

Notional CLV-7 lunar cargo lander

Another SLS advantage over other launch vehicles would be the inherent  ability to use SLS propellant tanks or SLS propellant tank technology to deploy large habitats into orbit and to the surfaces of extraterrestrial worlds.


SLS propellant tank derived 8.4 meter in diameter microgravity habitats would have enough internal space to easily accommodate 20 centimeters or more of water shielding to protect astronauts from the deleterious effects of heavy nuclei and major solar events while still providing enough room to accommodate hypergravity centrifuges up to 6 meters in diameter that could be used to mitigate some of the deleterious effects of microgravity on human physiology. At least two SLS propellant tank derived microgravity habitats with 662 m3 of internal volume (more than twice the internal volume of Bigelow's BA-330) could be deployed to LEO-- with a single SLS launch. 

Notional SLS propellant tank derived microgravity habitat (Credit: NASA)

8.4 meter in diameter  SLS propellant tank habitats designed for the lunar and Martian surfaces could be easily placed with the SLS  payload fairing for deployment to the surfaces of the Moon or Mars.
 Such SLS propellant tank derived habitats could provide spacious multi-level habitats for the surfaces of the Moon and Mars that can be easily protected from the dangers of excessive cosmic radiation, major solar events, micrometeorites, and extreme thermal fluctuations by dumping regolith into an automatically deployed regolith wall that could allow up to two meters of regolith shielding, reducing radiation exposure well below that of radiation workers on Earth. 

X-Ray of notional Lunar Regolith Habitat

Notional twin Lunar Regolith Habitats on top of a sintered regolith

Three 8.4 meter in diameter SLS  propellant tank derived habitats joined together by cables and a retractable boom. When rotating at 2rpm, the cylindrical rings of the telescoping booms would expand the AGH approximately  224 meters in diameter, producing a simulated gravity up to 0.5 g within the counter balancing habitat modules. For crewed interplanetary missions, the booms could be easily retracted so that the AGH can be re-docked with an Orbital Transfer Vehicle for trajectory burns during the beginning or end of any interplanetary mission. The 0.5g simulated gravity aboard an AGH would be higher than on the surface of the Moon (0.17g) or Mars (0.38g). Appropriate radiation shielding against the heavy ion component of cosmic rays could be internally provided by water. Permanent internal shielding against excessive levels of cosmic radiation exposure could be provided by iron extracted from lunar regolith. 

X-Ray of notional SLS propellant tank derived artificial gravity habitat

Notional rotating artificial gravity habitat at EML1

While the Falcon Heavy wouldn't even come close to the launch capabilities of the SLS, Space X is currently working on a Super Heavy Lift vehicle that could.  The two stage methane fueled  BFR would be 9 meters in diameter (0.6 meters wider than the SLS) and be capable of deploying up to 150 tonnes to orbit (20 tonnes more than the SLS Block 2. Clearly, Elon Musk understands the value of large super heavy lift space rockets.


Links and References 


Lockheed Martin's Reusable Extraterrestrial Landing Vehicle Concept for the Moon and Mars

(Part II) Practical Timelines and Funding for Establishing Permanent Outpost on the Moon and Mars using Propellant Producing Water Depots and SLS and Commercial Launch Capability

Reusable Heavy Cargo and Crew Landing Vehicles for the Moon and Mars

The ULA's Future ACES Upper Stage Technology

SLS Derived Artificial Gravity Habitats for Space Stations and Interplanetary Vehicles

Space X BFR (Rocket)

NASA Chooses Future Space Launch System

Credit NASA

Credit NASA

Gary Lyles on NASA's Current HLV Concepts

Conquering Cis-Lunar Space with Shuttle and ULA Derived Technologies

by Marcel F. Williams

Congress has now made it clear that they want the immediate development of a heavy lift vehicle and a crew exploratory vehicle capable of beyond LEO missions and as a back up transport to the ISS. They have also made it clear that they want NASA to utilize technologies derived from both the Space Shuttle and Ares I/V programs since billions of tax payer money has already been invested in these technologies.

Some, however, have argued that utilizing a heavy lift vehicle as a crew transport to LEO violates the philosophy of improving safety by not combining crew transport with cargo transport. This was part of the driving philosophy of former NASA director, Griffin, when he decided to advocate the development of the Ares I as an ultra-safe crew transport vehicle and the Ares V as a mega-heavy lift cargo vehicle.

Recently, NASA has been promoting a philosophy of developing new transport systems that can be utilized not only by NASA but also potentially by the military space program and by private commercial space programs. The advantage of such a philosophy is that increased demand for common transport systems or components could reduce cost for everyone that utilizes such vehicles or components.

The deployment of space depots has been argued as another means for reducing the cost of space travel beyond LEO. And the development of reusable space craft that utilize in situ resources on the Moon or the asteroids has also been proposed as a way to reduce the cost of space travel.

But is there a way that NASA could cheaply incorporate all of these ideas? I believe the answer is yes!

The first step is to develop a simple shuttle derived core vehicle similar to that proposed by Boeing. The Boeing shuttle derived core vehicle could be utilized to transport humans into orbit without using solid rocket boosters (SRBs). But with SRBs, the Boeing core vehicle could be used as a heavy lift vehicle.

Boeing, however, advocates using four of the cheaper RS-68B engines for their crew launch vehicle concept while using the more fuel efficient RS-25E (disposable SSME) for the heavy lift vehicle. Man-rating the RS-68 rocket engines will probably increase the cost of these engines while making the RS-25 expendable will probably reduce their cost. Using the same engines in both the crew launch and the heavy lift vehicle will increase demand, further reducing production cost. So I advocate using the RS-25E in both the crew launch vehicle and the heavy lift vehicle.

Boeing also proposed using a stretched hypergolic fueled SM (Service Module), requiring an extra 8 to 9 metric tons of fuel in order for the crew launch vehicle to transport a 20 metric ton capsule and crew to LEO. The United Launch Alliance (ULA), however, has proposed using an ACES 41 as a LOX/LH2 fueled Service Module. Utilizing an ACES 41 SM with a shuttle derived crew launch booster which I'll call the SD-CV (shuttle derived core vehicle) could potentially lift more than 30 metric tons to LEO. Since the ULA plans to use the ACES 41 as a common upper stage for both the Atlas and the Delta IV, the high production demand for the ACES 41 by NASA and the ULA should help to reduce cost for the ACES 41.

SD-CV (Shuttle Derived Core Vehicle) and ULA's ACES 41 (credit ULA) concept used as a Service Module for an Orion capsule.

Boeing's heavy lift vehicle concept with an EDS could lift up to 120 metric tons to LEO while the crew vehicle could lift more than 30 metric tons to LEO (150 metric tons in combination). That's enough capacity to launch nearly 60 metric tons of payload to trans lunar injection or to the Earth-Lunar L1 Lagrange point.

The SD-HLV with an Altair lunar landing vehicle and the SD-CV with a Command Module (CM) and an ACES 41 Service Module (SM).

An SD-CV crew vehicle with the ability to launch over 30 metric tons into orbit would also give it approximately the same capabilities as the current space shuttle with the exception of not being able to return large payloads back to Earth. But the SD-CV should be substantially cheaper to operate than the shuttle since it does not require SRBs. The SD-CV could also be one of the safest manned launch vehicles ever developed since it would only have two stages, with each stage having multiple engines capable of supplementing a failed engine in both stages. Being hydrogen fueled would also make it potentially the greenest manned space vehicle ever developed. While a manned launched SD-HLV would still be safer than a space shuttle launch, the SD-CV should be equally as safe as a man rated Atlas V-401 and a substantially safer vehicle than an SD-HLV, Delta IV heavy, or a Falcon 9 (the two stage Falcon 9 only has one engine for the upper stage so a single engine failure in the upper stage would terminate the mission).

Any space capsule chosen by NASA for the Orion CEV (Crew Exploratory Vehicle) should be able to be used by NASA and private industry on top of an ACES 41 which could be used by an Atlas V or a Delta IV heavy. Again, the higher the demand for a particular crew capsule, the lower the capsule's production cost will be.

An SD-HLV lunar mission would launch an Altair into Earth orbit for a rendezvous with a CM-SM-ACES 41, or it could use the Altair to transport unmanned payloads (lunar base modules, vehicles, oxygen factories, etc.) weighing more than 10 metric tons to the lunar surface.

Because of its large payload capacity, some might question the private commercial viability of the SD-CV as a crew launcher against much smaller potentially manned rated launch vehicles like the Atlas 5 and the Falcon 9. However, if a payload carrier is placed between the command module and the service module, the shuttle derived crew carrier could also transport and additional 20 metric tons of cargo to LEO. While the space shuttle is banned from carrying commercial loads into orbit, a private commercial company would have no such restrictions!

SD-CV could be launched into to orbit for a rendezvous with the Altair for a lunar mission or it could be used to transports crew and cargo to the ISS or to private commercial space stations.

There are two principal options for the EDS (Earth Departure Stage) for the unmanned heavy lift vehicle: one that uses a single JX-2 engine and one that uses multiple RL 10 engines. Since the ACES 41 in this concept and the Altair lunar lander would also use RL-10 engines, using RL-10s in the EDS, Service Module, and Altair lunar lander would obviously increase the demand for the RL-10 which should reduce the production cost for the engine.

After the Orion-CM-SM-ACES 41 docks with the Altair and EDS (Earth Departure Stage), the EDS provides most of the delta-v for transferring the Altair and the Orion to the L1 Lagrange point.

The SM-ACES 41 provides the rest of the delta-v requirements for reaching L1 in addition to the delta-v for returning passengers to Earth. Limiting the Orion CM-SM-ACES 41 to L1 would substantially reduce the delta-v requirements for a lunar mission.

The single stage Altar vehicle would transport up to three metric tonnes of payload (crew transport module, cargo, and crew) from L1 to the lunar surface and back to L1. L1 departure for the Altair vehicle enhances the ability of the lunar lander to conveniently land at practically any point on the lunar surface.

The Altair lunar landing vehicle was originally proposed to have a LOX/LH2 descent stage and a hypergolic fueled ascent stage. However, there is no reason why a lunar landing vehicle can't be a single stage vehicle by simply using the descent stage to land and lift a small crew module weighing about 3 metric tons with four passengers and payload. This would mean that NASA would only have to develop one lunar vehicle instead of two, substantially reducing development cost. Plus the Altair descent stage would use an RL-10 engine which would further reduce the cost of the RL-10 engine used by both NASA and the ULA.

A single stage Altair vehicle with a crew transport module would be much cheaper to develop than the two stage Altair concept that uses both a LOX/LH2 descent stage and a hypergolic fueled ascent stage. For long term missions to a lunar base facility, a simple light weight aluminum sun shade could be used to cover and shield the vehicle from direct sunlight on the lunar surface in order to reduce hydrogen and oxygen fuel boil-off.

Any Moon base program that involves the production of oxygen and even hydrogen from lunar resources would have a dramatic effect on reducing the cost of space travel within cis-lunar space. Without the need for a vehicle to carry oxygen and hydrogen fuel to the lunar surface for its eventual return to orbit, manned missions to a lunar base could carry several metric tons of additional cargo plus additional passengers to the lunar surface instead of just a few hundred kilograms with crew as currently envisioned by the Constellation program. Lunar oxygen and hydrogen could also allow an Altair to be used as a reusable manned vehicle operating from the lunar surface to lunar orbit or from the lunar surface to L1.

A reusable single stage Altair crew transport vehicle could be fueled with oxygen and hydrogen from an L1 space depot for transporting passenger to the Moon and with in situ oxygen and hydrogen from the lunar surface for returning passengers to L1 requiring a much smaller vehicle that simply uses shorter cryogenic 0xygen and hydrogen fuel tanks.

A stretched Altair vehicle, using longer hydrogen and oxygen fuel tanks, combined with an ACES 41 tanker could be used to supply an L1 depot with oxygen and hydrogen produced on the lunar surface. Such a tanker could also be used to supply lunar bases not located near the poles with hydrogen.

So some day a paying tourist or a lunar lotto winner aboard a Falcon 9, Atlas V, Delta IV heavy, or a SD-CV could simply fly into orbit and dock with another ACES 41 (originally fueled with lunar oxygen and hydrogen at an L1 space depot) to travel to L1. At the Lagrange point, passengers would dock with an L1 fueled reusable Altair vehicle which would transport them to the Moon where they could perhaps stay at an appropriately mass shielded a Bigelow lunar hotel. The same lunar vehicle could be refueled with lunar oxygen and hydrogen for the tourist's return to L1 where they would dock with a CM-SM-ACES 41 equipped with an aerobreaking hypercone that would take them back to Earth orbit. There they would dock with a space capsule or Dreamchaser space plane that would finally return them to the Earth. That might be a very interesting vacation perhaps 15 or 20 years from now!

References and Links

1. Heavy Lift Launch Vehicles with Existing Propulsion Systems (Boeing Phantom Works)

2. Ambitious Ares Test Flight Proposed for HLV Demonstration

3. NASA Heavy Lift and Propulsion Trade Study

4. Completed SD HLV assessment highlights low-cost post-shuttle solution

5. ULA: Upper Stage Evolution

6. A Commercially Based Lunar Architecture

7. National Launch System

8. DIRECT

9. Boeing's New HLV Concept could be the DC-3 of Manned Rocket Boosters

10. No time for NASA complacency on crew safety

11. All of a Sudden, Everyone Wants to Be a Rocket Scientist

12. PWR Offers Shuttle Engine Alternative

Boeing's New HLV Concept could be the DC-3 of Manned Rocket Boosters

by Marcel F. Williams

On December 17th 1935, the Douglas Aircraft Company introduced an new airplane that revolutionized commercial air travel in America and around the world, the DC-3. Before the introduction of the DC-3, transcontinental flights entailed short range flights in smaller aircraft during the day combined with rail travel during the night. The DC-3, on the other hand, was able to cross the American continent completely by air with just three fueling stops and could take passengers from one coastline to the other in less than 18 hours. More than 16,000 DC-3s were built during its history. And 400 DC-3s are still in operation today!

Boeing Phantom Works has introduced a new shuttle derived heavy lift concept that is very similar to the DIRECT concept. An inline 8.4 meter in diameter core vehicle is used with either SSME (space shuttle main engines) or RS-68 engines. But instead of using the existing 4-segment SRBs (solid rocket boosters), there vehicle would use the 5-segment SRBs that are currently being developed for the Ares I rocket, a program that President Obama intends to terminate. However, unlike the DIRECT concept, Boeing has also proposed utilizing the inline booster without the SRBs as a crew only vehicle. Coupled with a manned space capsule and a stretched SM (service module), there would be no upper stage. And this would require the service module to perform the 2nd stage burn in order to achieve orbit.

NASA has recently (May 3rd) issued a request for information regarding potential heavy lift architectures that could be utilized by both NASA and commercial industries. Boeing's new heavy lift concept would seem to meet that criteria. With the SRBs and an upper stage, the core stage could be used by NASA or the DOD to lift up to 113 tons into low Earth orbit or send up to 45 tons to TLI (translunar injection). A dual launch scenario could transport up to 87 tons to TLI, a substantial increase over the 65 tons sent to TLI using the Ares I/V architecture.

But, additionally, without the SRBs and the upper stage, the LOX/LH2 core booster could be used by NASA, the military, or a private commercial company to transport up to 20 metric tons into orbit when utilizing a stretched SM (service module) to perform the second stage burn to achieve orbit. Such a hydrogen-oxygen fueled single stage booster could provide NASA and private industry with the simplest, safest, and most environmentally benign manned space rocket ever invented. And such a vehicle could usher in a new wave of space tourism!

There are polls that suggest that there may be thousands of wealthy individuals that would be willing to pay $20 million or more to fly into space to a space station. If such polls are even close to being accurate then manned launches for space tourism could greatly exceed government commissioned manned spaceflights to orbit with possible annual demands for space launches in the hundreds.

Such a high level of traffic into space would require the manufacturing of several hundred rocket engines every year. And such a high demand for rocket engines could introduce the serial mass production of rocket engines into US industries. Economies of mass production could substantially reduce the cost of rocket engines in the US. And polls have shown that lowering the cost of space travel would increase the demand for space tourism even higher!

A NASA heavy lift vehicle based on the same core vehicle would of course greatly benefit from the lower cost due to the high demand for the core booster by private industry. Eventually, the low cost of the core vehicle might become so attractive that NASA might contemplate replacing the SRBs with two additional core vehicles for heavy lift launches in a configuration similar to what is seen with the Delta IV heavy. This would be similar to one of the National Launch System (NLS) proposals of the 1990s.

It is also interesting that Boeing Phantom Works also produces the unmanned reusable X-37 experimental spaceplane for the US military which is currently in orbit after being launched into orbit by the ULA on top of an Atlas V rocket. Although the X-37 weighs about 5 metric tons, it has the basic Space Shuttle configuration. It uses a Rocketdyne AR-2/3 rocket engine, fuelled by JP-8 jet fuel and hydrogen peroxide. If Boeing decided to build a larger-- man rated-- version of the X-37, it could be the perfect compliment for the shuttle derived core vehicle also proposed by Boeing.


So America might retire one winged space vehicle, the space shuttle, while introducing a new winged manned space vehicle that can be used by NASA, the military, and private commercial industry. And a new era of manned space travel for government and private industry will have begun!

References and Links

1. Heavy Lift Launch Vehicles with Existing Propulsion Systems (Boeing Phantom Works)

2. Ambitious Ares Test Flight Proposed for HLV Demostration

3. NASA Heavy Lift and Propulsion Trade Study

4. X-37 Orbital Test Vehicle

5. Boeing X-37

6. Space Commercialization and the Lunar Lotto

7. National Launch System

8. DIRECT