Bigelow Commercial Space Station

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The Bigelow Next-Generation Commercial Space Station is a private orbital space station currently under development by Bigelow Aerospace. Previous concepts of the space station had included multiple modules such as two B330 expandable spacecraft modules as well as a central docking node, propulsion, solar arrays, and attached crew capsules. However it now appears that each B330 can operate as an independent space station. Attaching a B330 to the International Space Station or flying a B330 alone have been suggested by Robert Bigelow.

On 8 April 2016, NASA launched a Bigelow inflatable module and attached it to the ISS, where it has been tested for over two years. Any independent Bigelow Commercial space station will have to await the development of commercially available human rated orbital spacecraft. The first of these is expected to be the SpaceX Dragon 2 in 2019. Two B330 are expected to be ready by 2020 and a launch contract for one in 2021 followed by move to low lunar orbit in 2022 has been signed.

History

Early work at Bigelow Aerospace on expandable space habitats, with plans to eventually assemble them into on-orbit space stations, began in the early years after the company was formed in 1999. By 2004, plans made public included assembly of multiple modules "into a manned space facility in low Earth orbit for both privately- and publicly-funded research and for space tourism."

Two more formal concepts have since been made public. By 2005, Bigelow space station plans had been further conceptualized into Commercial Space Station Skywalker, or CSS Skywalker. In mid-2010, Bigelow announced their Next-Generation Commercial Space Station—later named "Space Complex Alpha".

The initial dates for the Alpha complex were not achieved. In January 2013, the Alpha complex was specified to be an in-space assemblage of only two B330 modules, with the first module to be launched no earlier than 2016.

CSS Skywalker

CSS Skywalker

Station statistics
Crew	5–7
Mass	100,000 kg (220,000 lb)
Height	30.0 m (98.4 ft)
Diameter	6.7 m (22 ft)
Pressurised volume	1,500 m3 (53,000 cu ft)

The CSS Skywalker (Commercial Space Station Skywalker) was a 2005 concept for the first "space hotel" by Bigelow Aerospace. The Skywalker was designed to be composed of multiple Nautilus (B330) habitat modules, which would be inflated and connected upon reaching orbit. An MDPM (Multi-Directional Propulsion Module) would allow the Skywalker to be moved into interplanetary or lunar trajectories.

In short, CSS Skywalker was "an effort to build the planet's first orbiting space hotel, [with a projected] room rate of USD$1 million per night", and a hoped-for launch date for the first Nautilus module of 2010.

Company challenges

Early assessments of the probability of success of the technology development and challenges of a commercial space station pointed to the importance of factors largely beyond Bigelow's control. For example, in 2005, John M. Logsdon, director of George Washington University's Space Policy Institute said "I have little doubt that the basic technology is likely to work ... The issue is whether there's a transportation system that can get people or things, or both, up there."

In practice, orbital launch plans were significantly delayed. First, after the Space Shuttle Columbia disaster in 2003, Bigelow had to compete with NASA for rides on the Russian Soyuz three-person rocket — "a distinctly untenable position." In mid-2009, Bigelow announced they were continuing to develop a variety of space habitat architectures.

Space transport

In 2008, Bigelow initially began talks with Lockheed Martin to potentially contract launch services on its Atlas V-401 vehicle for both crew and cargo launches.

By mid-2010, Bigelow was actively pursuing launch options for its space station modules and crew capsules from two launch systems: the Boeing CST-100 capsule on a ULA Atlas V launcher and also the SpaceX Dragon / Falcon 9 capsule/launcher combination. "Bigelow offers Boeing, SpaceX, and other vehicle developers ... the promise of a sustained, large market for space transportation services." With the initial Space Complex Alpha, Bigelow "would need six flights a year; with the launch of a second, larger station, that number would grow to 24, or two a month." After 2010, no further concrete plans have been announced for transport with Atlas V launch vehicles. 

In May 2012, almost simultaneously with the successful mission of SpaceX's Dragon capsule, launched by SpaceX's Falcon 9 vehicle, to the International Space Station, Bigelow and SpaceX jointly announced that they were teaming to offer private crewed missions to space, promoting the Bigelow space station and SpaceX transport systems.

In 2014, plans called for transport of humans and resupply cargo to the station to be via a SpaceX Dragon V2, with a round-trip seat priced at US$26.5 million. Lease of the on-orbit stations was priced at US$25 million to rent one-third of a B330 module for 60 days. The B330 modules and any of several tugs were planned for launch aboard a Falcon Heavy launch vehicle.

Space Complex Alpha

Space Complex Alpha

Station statistics
Crew	Up to 12
Pressurised volume	690 m3 (24,000 cu ft)

A full-scale mockup of Bigelow Aerospace's Space Station Alpha inside their Nevada facility.

 

The Bigelow Next-Generation Commercial Space Station was announced in mid-2010. The initial configuration for the 2014/2015 space assembly was two Sundancer modules and one B330 module, named Space Complex Alpha after October 2010.

Bigelow began to publicly refer to the initial configuration—two Sundancer modules and one B330 module— of the first Bigelow station as Space Complex Alpha in October 2010. If the entire station is leased out, it could mean up to 25 launches per year for crew and cargo. In early 2013, Bigelow Aerospace started referring to Alpha as consisting of two B330 modules instead of two Sundancer and one B330.

In October 2010, Bigelow announced that it has agreements with six sovereign nations to utilize the on-orbit facilities of the commercial space station: United Kingdom, Netherlands, Australia, Singapore, Japan and Sweden. A seventh country signed on in February 2011: the United Arab Emirate of Dubai.

In August 2015, Michael Gold stated that the timetable for the first B330 deployment is uncertain at the moment, since it is tied to the development of private astronaut taxis that can get people to orbit. With this projected to be 2017 or later Bigelow expects to be "ready when they are".

In April 2016, the two B330s attached together was also questioned by suggesting that the first B330 might ideally be attached to the International Space Station or that each B330 could operate on its own. The first liftoff was targeted for 2020.

Orbital complex construction

In 2010, Bigelow Aerospace began building a large production facility in North Las Vegas, Nevada to produce the space modules. The 16,800 m² (181,000 sq ft) facility will include three production lines for three distinct spacecraft, doubling the amount of floor space at Bigelow and transitioning the focus from research and development to production. Bigelow expects to hire approximately 1200 new employees to staff the plant, with production commencing in early 2012. Construction would require three medium lift launches and one heavy lift launch. In October 2011 Reuters reported that Bigelow had, "pared its 115-member workforce to 51 [...] because of delays developing space taxis needed to fly people to the outposts."

As of 2010, on-orbit assembly of the Bigelow Next-Generation Commercial Space Station components was projected to begin in 2014. As of July 2010, construction of the orbital complex was projected to occur in seven principal steps, based on an operations concept that included the on-orbit addition of two Sundancer modules and one B330 module.

• Unit 1: Sundancer-one module, with a pressurized volume of 180 cubic meters (m³), (unoccupied)
• Unit 2: Commercial crew capsule arrives with Bigelow Aerospace astronauts to set up Sundancer-one and carry additional supplies
• Unit 3: Supplemental power bus and docking node
• Unit 4: Sundancer-two
• Unit 5: Second commercial crew capsule brings additional crew and supplies, and provides a redundant method for crew return to Earth.
• Unit 6: B330, larger-volume module (330 m³)
• Unit 7: Third commercial crew capsule brings additional supplies and provides a double-redundant, robust solution for astronaut re-entry.

Commercial leasing

In January 2013, Bigelow announced that they would sell naming rights to the dual-B330-module Alpha complex for US$25 million per year.

In 2014, Bigelow announced that prices for human access to the space station were expected to be US$26.25 million aboard a SpaceX Dragon, or US$36.75 million aboard a Boeing CST-100.

The price for a two-month lease of one-third of a module (approximately 110 cubic metres (3,900 cubic feet; 110,000 litres)) was provisionally set at US$25 million.

Technical

Docking system

As of 2007 Bigelow was planning to equip its expandable space modules with both a Soyuz-style docking system on one end and a NASA-standard Low Impact Docking System on the other. The available docking port options for the Next Generation Commercial Space Station have not yet been released.

Test program

The "human-in-the-loop testing of the environmental control and life support system (ECLSS)" for Sundancer began in October 2010.

By January 2013, the Bigelow Expandable Activity Module (BEAM) pressurised module was under development by Bigelow Aerospace, being purchased by NASA for attachment to the International Space Station. The BEAM arrived at the ISS on April 10, 2016, was berthed to the station on April 16, and was expanded and pressurized on May 28, 2016. The initial plan was to test the expandable habitat technology for at least two years. During its flight mission, NASA has been testing and monitoring the module's structural integrity, leak rate, radiation dosage and temperature changes. The module has been performing well, and in October 2017, it was announced that the module would stay attached to the ISS until 2020, with options for two further one-year extensions. The module is being used to store up to 130 cargo transfer bags in an effort to free up additional space aboard the station.

Launch planning

Potential launch options are in the mid-heavy lift launch system class of launch vehicles, where Bigelow has now negotiated arrangements with two commercial launch providers. As of January 2013, both SpaceX—using the Falcon 9/Dragon— and United Launch Alliance/Boeing—using the Atlas V/CST-100—have signed to deliver launch services to Bigelow Space Station Alpha.

In February 2011, Bigelow announced that it would begin launching its unmanned space station modules in 2014 from Cape Canaveral using Atlas V launch vehicles.

In addition to the Atlas launches for the expandable modules, Bigelow had reserved a single 2014 launch on the SpaceX Falcon 9 rocket, but that launch had not taken place as of early 2019. As of August 2011, press reports indicate that Bigelow will launch at least some of their crews to the station on the human-rated Atlas V utilizing the Boeing CST-100 seven-person space capsule.

In April 2016, Bigelow signed an agreement with United Launch Alliance to launch the first B330 module in 2020 using an Atlas V rocket.

In October 2017, Bigelow Aerospace and United Launch Alliance (ULA) announced they are working together to launch a B330 expandable module on ULA's Vulcan launch vehicle. The launch would place a B330 module in Earth orbit, and after outfitting it would be boosted to low lunar orbit by two further Vulcan ACES launches by the end of 2022 to serve as a lunar depot. As this announcement stated that only a Vulcan had the performance and fairing capacity needed to launch a B330, it appears that any Atlas V launches would be for crew rather than B330 modules. The timeline may be 'aspirational' as ULA have indicated that the Vulcan will transition to using the ACES upper stage around 2024.

Long-term proposals

In late 2010, Bigelow indicated that the company would like to construct ten or more space stations and that there is a substantial commercial market to support such growth.

Future space station concepts

Space Complex Bravo

Station statistics
Crew	Up to 24
Pressurised volume	1,320 m3 (47,000 cu ft)

In 2010, Bigelow said that second orbital station—Space Complex Bravo—was scheduled to begin launches in 2016 and go into commercial operation in 2017. This complex would consist of four B330 modules. 

Bigelow has publicly shown space station design configurations with up to nine B330 modules containing 2,800 m³ (100,000 cu ft) of habitable space. The conceptual configurations are listed below.

• Advanced Medical Facility (3000 m³) - Nine B330 modules, three propulsion buses with docking node, three crew capsules.
• Biological Containment Station Low Earth Orbit (2800 m³ habitable, 660 m³ remotely controlled)
• Biological Research Station Low Earth Orbit (2000 m³)
• Deep Space Complex (1320 m³) - Four B330 modules, nine propulsion buses with docking node and three docking ports.
• Lunar Depot Ares (990 m³) - Three B330 modules, four propulsion buses with docking nodes. The entire station would land directly onto the moon. It is intended to hold 12 astronauts but is capable of holding 18. Near the lunar base there would be a solar array field. A model of this concept has been built.
• Mars Exploration (1320 m³) - Four B330 modules, three propulsion buses with docking node.
• Resupply Depot Hercules (8300 m³) - Announced Oct 2010 Six B330 modules, three BA 2100 modules, nine propulsion buses with docking node and three crew capsules.

Soyuz (spacecraft)

From Wikipedia, the free encyclopedia

Soyuz

Soyuz spacecraft (TMA version)
Manufacturer	RKK Energia
Country of origin	Soviet Union, Russian Federation
Operator	Soviet space program (1967–91) Roscosmos (1991 onwards)
Applications	Carry cosmonauts to orbit and back; originally intended for Soviet Moonshot and Salyut space station transportation.
Specifications
Design life	Up to six months docked to station
Regime	Low Earth orbit (circumlunar spaceflight during early program)
Production
Status	In service
First launch	(Unmanned) November 28, 1966 (Manned) Soyuz 1 April 23, 1967
Related spacecraft
Derivatives	Shenzhou, Progress

Soyuz (Russian: Сою́з, IPA: [sɐˈjus], lit. Union) is a series of spacecraft designed for the Soviet space program by the Korolev Design Bureau (now RKK Energia) in the 1960s that remains in service today. The Soyuz succeeded the Voskhod spacecraft and was originally built as part of the Soviet manned lunar programs. The Soyuz spacecraft is launched on a Soyuz rocket, the most reliable launch vehicle in the world to date. The Soyuz rocket design is based on the Vostok launcher, which in turn was based on the 8K74 or R-7A Semyorka, a Soviet intercontinental ballistic missile. All Soyuz spacecraft are launched from the Baikonur Cosmodrome in Kazakhstan. Soyuz is currently the only means for manned space flights in the world and is heavily used in the International Space Station program.

History

The first Soyuz flight was unmanned and started on November 28, 1966. The first Soyuz mission with a crew, Soyuz 1, launched on 23 April 1967 but ended with a crash due to a parachute failure, killing cosmonaut Vladimir Komarov. The following flight was unmanned. Soyuz 3, launched on October 26, 1968, became the program's first successful manned mission. The only other flight to suffer a fatal accident, Soyuz 11, killed its crew of three when the cabin depressurized prematurely just before reentry. These were the only humans to date to have died above the Kármán line. Despite these early incidents, Soyuz is widely considered the world's safest, most cost-effective human spaceflight vehicle, established by its unparalleled length of operational history. Soyuz spacecraft were used to carry cosmonauts to and from Salyut and later Mir Soviet space stations, and are now used for transport to and from the International Space Station (ISS). At least one Soyuz spacecraft is docked to ISS at all times for use as an escape craft in the event of an emergency. The spacecraft is intended to be replaced by the six-person Federation spacecraft.

Design

Diagram showing the three elements of the Soyuz TMA spacecraft.

 

A Soyuz spacecraft consists of three parts (from front to back):

• A spheroid orbital module, which provides accommodation for the crew during their mission;
• A small aerodynamic reentry module, which returns the crew to Earth;
• A cylindrical service module with solar panels attached, which contains the instruments and engines.

The orbital and service modules are single-use and are destroyed upon reentry in the atmosphere. Though this might seem wasteful, it reduces the amount of heat shielding required for reentry, saving mass compared to designs containing all of the living space and life support in a single capsule. This allows smaller rockets to launch the spacecraft or can be used to increase the habitable space available to the crew (6.2 m³ in Apollo CM vs 7.5 m³ in Soyuz) in the mass budget. The orbital and reentry portions are habitable living space, with the service module containing the fuel, main engines and instrumentation.

Soyuz can carry up to three crew members and provide life support for about 30 person days. The life support system provides a nitrogen/oxygen atmosphere at sea level partial pressures. The atmosphere is regenerated through potassium superoxide (KO₂) cylinders, which absorb most of the carbon dioxide (CO₂) and water produced by the crew and regenerates the oxygen, and lithium hydroxide (LiOH) cylinders which absorb leftover CO₂. 

The vehicle is protected during launch by a payload fairing, which is jettisoned along with the SAS at ​2 ¹⁄₂ minutes into launch. It has an automatic docking system. The ship can be operated automatically, or by a pilot independently of ground control.

Launch escape system

The Vostok spacecraft utilized an ejector seat to bail out the cosmonaut in the event of a low-altitude launch failure, as well as during reentry, however it would probably have been ineffective in the first 20 seconds after liftoff when the altitude would be too low for the parachute to deploy. Inspired by the Mercury LES, Soviet designers began work on a similar system in 1962. This included developing a complex sensing system to monitor various launch vehicle parameters and trigger an abort if a booster malfunction occurred. Based on data from R-7 launches over the years, engineers developed a list of the most likely failure modes for the vehicle and could narrow down abort conditions to premature separation of a strap-on booster, low engine thrust, loss of combustion chamber pressure, or loss of booster guidance. The Spacecraft Abort System (SAS; Russian: Система Аварийного Спасения, translit. Sistema Avarijnogo Spaseniya) could also be manually activated from the ground, but unlike American spacecraft, there was no way for the cosmonauts to trigger it themselves.

Since it turned out to be almost impossible to separate the entire payload shroud from the Soyuz service module cleanly, the decision was made to have the shroud split between the service module and descent module during an abort. Four folding stabilizers were added to improve aerodynamic stability during ascent. Two test runs of the SAS were carried out in 1966-67.

The basic design of the SAS has remained almost unchanged in 50 years of use and all Soyuz launches carry it. The only modification was in 1972 when the aerodynamic fairing over the SAS motor nozzles was removed for weight-saving reasons as the redesigned Soyuz 7K-T spacecraft carried extra life support equipment. The unmanned Progress resupply ferry has a dummy escape tower and removes the stabilizer fins from the payload shroud. There have been three failed launches of a manned Soyuz vehicle, Soyuz 18-1 in 1975, Soyuz T-10-1 in 1983 and Soyuz MS-10 in October 2018. The 1975 failure was aborted after escape tower jettison. In 1983, Soyuz T-10-1's SAS successfully rescued the cosmonauts from an on-pad fire and explosion of the launch vehicle. Most recently in 2018, the SAS sub-system in the payload shroud of Soyuz MS-10 successfully rescued the cosmonauts from a rocket failure 2 minutes and 45 second after liftoff after the escape tower had already been jettisoned.

Orbital module

Soyuz spacecraft's Orbital Module

 

The forepart of the spacecraft is the Orbital Module (Russian: бытовой отсек, translit. bytovoi otsek), also known as habitation section. It houses all the equipment that will not be needed for reentry, such as experiments, cameras or cargo. The module also contains a toilet, docking avionics and communications gear. Internal volume is 6 m³ (212 cu ft), living space 5 m³ (177 cu ft). On the latest Soyuz versions (since Soyuz TM), a small window was introduced, providing the crew with a forward view. 

A hatch between it and the Descent Module can be closed so as to isolate it to act as an airlock if needed, crew members exiting through its side port (near the descent module). On the launch pad, the crew enter the spacecraft through this port. 

This separation also lets the Orbital Module be customized to the mission with less risk to the life-critical descent module. The convention of orientation in a micro-g environment differs from that of the Descent Module, as crew members stand or sit with their heads to the docking port. Also the rescue of the crew whilst on the launch pad or with the SAS system is complicated because of the orbital module. 

Separation of the Orbital Module is critical for a safe landing; without separation of the Orbital Module, it is not possible for the crew to survive landing in the Descent Module. This is because the Orbital Module would interfere with proper deployment of the Descent Module's parachutes, and the extra mass exceeds the capability of the main parachute and braking engines to provide a safe soft landing speed. In view of this, the Orbital Module was separated before the ignition of the return engine until the late 1980s. This guaranteed that the Descent Module and Orbital Module would be separated before the Descent Module was placed in a reentry trajectory. However, after the problematic landing of Soyuz TM-5 in September 1988 this procedure was changed and the Orbital Module is now separated after the return maneuver. This change was made as the TM-5 crew could not deorbit for 24 hours after they jettisoned their Orbital Module, which contained their sanitation facilities and the docking collar needed to attach to MIR. The risk of not being able to separate the Orbital Module is effectively judged to be less than the risk of needing the facilities in it, following a failed deorbit.

Descent module

Replica of the Soyuz spacecraft's Entry Module at the Euro Space Center In Belgium

 

Soyuz spacecraft's Descent Module

 

The Descent Module (Russian: Спуска́емый Аппара́т, tr. Spuskáyemy Apparát), also known as a reentry capsule, is used for launch and the journey back to Earth. Half of the Descent Module is covered by a heat-resistant covering to protect it during reentry; this half faces the Earth during reentry. It is slowed initially by the atmosphere, then by a braking parachute, followed by the main parachute which slows the craft for landing. At one meter above the ground, solid-fuel braking engines mounted behind the heat shield are fired to give a soft landing. One of the design requirements for the Descent Module was for it to have the highest possible volumetric efficiency (internal volume divided by hull area). The best shape for this is a sphere — as the pioneering Vostok spacecraft's Descent Module used — but such a shape can provide no lift, which results in a purely ballistic reentry. Ballistic reentries are hard on the occupants due to high deceleration and cannot be steered beyond their initial deorbit burn. That is why it was decided to go with the "headlight" shape that the Soyuz uses – a hemispherical forward area joined by a barely angled (seven degrees) conical section to a classic spherical section heat shield. This shape allows a small amount of lift to be generated due to the unequal weight distribution. The nickname was thought up at a time when nearly every headlight was circular. The small dimensions of the Descent Module led to it having only two-man crews after the death of the Soyuz 11 crew. The later Soyuz T spacecraft solved this issue. Internal volume of Soyuz SA is 4 m³ (141 cu ft); 2.5 m³ (88 cu ft) is usable for crew (living space).

Service module

Soyuz spacecraft's Instrumentation/Propulsion Module

 

At the back of the vehicle is the Service Module (Russian: прибо́рно-агрега́тный отсе́к, tr. pribórno-agregátny otsék). It has a pressurized container shaped like a bulging can (instrumentation compartment, priborniy otsek) that contains systems for temperature control, electric power supply, long-range radio communications, radio telemetry, and instruments for orientation and control. A non-pressurized part of the Service Module (propulsion compartment, agregatniy otsek) contains the main engine and a liquid-fuelled propulsion system for maneuvering in orbit and initiating the descent back to Earth. The ship also has a system of low-thrust engines for orientation, attached to the intermediate compartment (perekhodnoi otsek). Outside the Service Module are the sensors for the orientation system and the solar array, which is oriented towards the Sun by rotating the ship. An incomplete separation between the Service and Reentry Modules led to emergency situations during Soyuz 5, Soyuz TMA-10 and Soyuz TMA-11, which led to an incorrect reentry orientation (crew ingress hatch first). The failure of several explosive bolts did not cut the connection between the Service/Reentry Modules on the latter two flights.

Reentry procedure

The Soyuz uses a method similar to the US Apollo command and service module to deorbit itself. The spacecraft is turned engine-forward and the main engine is fired for deorbiting on the far side of Earth ahead of its planned landing site. This requires the least propellant for reentry; the spacecraft travels on an elliptical Hohmann transfer orbit to the entry interface point where atmospheric drag slows it enough to fall out of orbit. 

Early Soyuz spacecraft would then have the Service and Orbital Modules detach simultaneously from the Descent Module. As they are connected by tubing and electrical cables to the Descent Module, this would aid in their separation and avoid having the Descent Module alter its orientation.^{[citation needed]} Later Soyuz spacecraft detached the Orbital Module before firing the main engine, which saved propellant. Since the Soyuz TM-5 landing issue, the Orbital Module is once again detached only after the reentry firing, which led to (but did not cause) emergency situations of Soyuz TMA-10 and TMA-11. The Orbital Module cannot remain in orbit as an addition to a space station, as the airlock hatch between the Orbital and Reentry Modules is a part of the Reentry Module, and the Orbital Module therefore depressurizes after separation.

Reentry firing is usually done on the "dawn" side of the Earth, so that the spacecraft can be seen by recovery helicopters as it descends in the evening twilight, illuminated by the Sun when it is above the shadow of the Earth. The Soyuz craft is designed to come down on land, usually somewhere in the deserts of Kazakhstan in central Asia. This is in contrast to early US manned spacecraft, which splashed down in the ocean.

Spacecraft systems

Soyuz diagram

 

Exploded plan of the Soyuz MS spacecraft.

• Thermal control system – Sistema Obespecheniya Teplovogo Rezhima, SOTR
• Life support system – Kompleks Sredstv Obespecheniya Zhiznideyatelnosti, KSOZh
• Power supply system – Sistema Elektropitaniya, SEP
• Communication and tracking systems – Rassvet (Dawn) radio communications system, onboard measurement system (SBI), Kvant-V spacecraft control, Klyost-M television system, orbit radio tracking (RKO)
• Onboard complex control system – Sistema Upravleniya Bortovym Kompleksom, SUBK
• Combined propulsion system – Kompleksnaya Dvigatelnaya Ustanovka, KDU
• Chaika-3 motion control system (SUD)
• Optical/visual devices (OVP) – VSK-4 (Vizir Spetsialniy Kosmicheskiy-4), night vision device (VNUK-K, Visir Nochnogo Upravleniya po Kursu), docking light, pilot's sight (VP-1, Vizir Pilota-1), laser rangefinder (LPR-1, Lazerniy Dalnomer-1)
• Kurs rendezvous system
• Docking system – Sistema Stykovki i Vnutrennego Perekhoda, SSVP
• Teleoperator control mode – Teleoperatorniy Rezhim Upravleniya, TORU
• Entry actuators system – Sistema Ispolnitelnikh Organov Spuska, SIO-S
• Landing aids kit – Kompleks Sredstv Prizemleniya, KSP
• Portable survival kit – Nosimiy Avariyniy Zapas, NAZ, containing a TP-82 Cosmonaut survival pistol or Makarov pistol
• Soyuz launch escape system – Sistema Avariynogo Spaseniya, SAS

Orbital module (A) 1 docking mechanism 2, 4 Kurs rendezvous radar antenna 3 television transmission antenna 5 camera 6 hatch

Descent module (B) 7 parachute compartment 8 periscope 9 porthole 11 heat shield

Service module (C) 10, 18 attitude control engines 12 Earth sensors 13 Sun sensor 14 solar panel attachment point 15 thermal sensor 16 Kurs antenna 17 main propulsion 19 communication antenna 20 fuel tanks 21 oxygen tank

Variants

The Soyuz spacecraft has been the subject of continuous evolution since the early 1960s. Thus several different versions, proposals and projects exist.

Specifications

Soyuz 7K (part of the 7K-9K-11K circumlunar complex) (1963)

Soyuz 7K manned spacecraft concept (1963).

Sergei Korolev initially promoted the Soyuz A-B-V circumlunar complex (7K-9K-11K) concept (also known as L1) in which a two-man craft Soyuz 7K would rendezvous with other components (9K and 11K) in Earth orbit to assemble a lunar excursion vehicle, the components being delivered by the proven R-7 rocket.

First generation

Soyuz 7K-OK(A) spacecraft with an active docking unit.

 

Soyuz 7K-OKS for Salyut space stations.

 

The manned Soyuz spacecraft can be classified into design generations. Soyuz 1 through Soyuz 11 (1967–1971) were first-generation vehicles, carrying a crew of up to three without spacesuits and distinguished from those following by their bent solar panels and their use of the Igla automatic docking navigation system, which required special radar antennas. This first generation encompassed the original Soyuz 7K-OK and the Soyuz 7K-OKS for docking with the Salyut 1 space station. The probe and drogue docking system permitted internal transfer of cosmonauts from the Soyuz to the station. 

The Soyuz 7K-L1 was designed to launch a crew from the Earth to circle the moon, and was the primary hope for a Soviet circumlunar flight. It had several test flights in the Zond program from 1967–1970 (Zond 4 to Zond 8), which produced multiple failures in the 7K-L1's reentry systems. The remaining 7K-L1s were scrapped. The Soyuz 7K-L3 was designed and developed in parallel to the Soyuz 7K-L1, but was also scrapped. Soyuz 1 was plagued with technical issues, and cosmonaut Vladimir Komarov was killed when the spacecraft crashed during its return to Earth. This was the first in-flight fatality in the history of spaceflight. 

The next manned version of the Soyuz was the Soyuz 7K-OKS. It was designed for space station flights and had a docking port that allowed internal transfer between spacecraft. The Soyuz 7K-OKS had two manned flights, both in 1971. Soyuz 11, the second flight, depressurized upon reentry, killing its three-man crew.

Second generation

Upgraded Soyuz 7K-T version.

The second generation, called Soyuz Ferry or Soyuz 7K-T, comprised Soyuz 12 through Soyuz 40 (1973–1981).

It was developed out of the military Soyuz concepts studied in previous years and was capable of carrying 2 cosmonauts with Sokol space suits (after the Soyuz 11 accident). Several models were planned, but none actually flew in space. These versions were named Soyuz P, Soyuz PPK, Soyuz R, Soyuz 7K-VI, and Soyuz OIS (Orbital Research Station). 

The Soyuz 7K-T/A9 version was used for the flights to the military Almaz space station.

Soyuz 7K-TM was the spacecraft used in the Apollo-Soyuz Test Project in 1975, which saw the first and only docking of a Soyuz spacecraft with an Apollo Command/Service Module. It was also flown in 1976 for the Earth-science mission, Soyuz 22. Soyuz 7K-TM served as a technological bridge to the third generation.

Third generation

Soyuz-T spacecraft.

The third generation Soyuz-T (T: Russian: транспортный, translit. transportnyi, lit. 'transport') spacecraft (1976–1986) featured solar panels allowing longer missions, a revised Igla rendezvous system and new translation/attitude thruster system on the Service module. It could carry a crew of three, now wearing spacesuits.

Fourth generation

Soyuz-TM (1986–2003)

Soyuz-TM spacecraft. Compare the antennas on the orbital module to those on Soyuz-T. Differences reflect the change from the Igla rendezvous system used on Soyuz-T to the Kurs rendezvous system used on Soyuz-TM.

The Soyuz-TM crew transports (M: Russian: модифицированный, translit. modifitsirovannyi, lit. 'modified') were fourth generation Soyuz spacecraft, and were used from 1986 to 2003 for ferry flights to Mir and the International Space Station.

Soyuz-TMA (2003–2012)

The Soyuz TMA-6

Soyuz TMA (A: Russian: антропометрический, translit. antropometricheskii, lit. 'anthropometric') features several changes to accommodate requirements requested by NASA in order to service the International Space Station, including more latitude in the height and weight of the crew and improved parachute systems. It is also the first expendable vehicle to feature "glass cockpit" technology. Soyuz-TMA looks identical to a Soyuz-TM spacecraft on the outside, but interior differences allow it to accommodate taller occupants with new adjustable crew couches.

Soyuz TMA-M (2010–2016)

The Soyuz TMA-M was an upgrade of the baseline Soyuz-TMA, using a new computer, digital interior displays, updated docking equipment, and the vehicle's total mass was reduced by 70 kilograms. The new version debuted on 7 October 2010 with the launch of TMA-01M, carrying the ISS Expedition 25 crew.

The Soyuz TMA-08M mission set a new record for the fastest manned docking with a space station. The mission used a new six-hour rendezvous, faster than the previous Soyuz launches, which had, since 1986, taken two days.

Soyuz MS (since 2016)

Soyuz MS-01 docked to the ISS

Soyuz MS is the final planned upgrade of the Soyuz spacecraft. Its maiden flight was in July 2016 with mission MS-01. Major changes include:

• more efficient solar panels
• modified docking and attitude control engine positions for redundancy during docking and de-orbit burns
• new Kurs NA approach and docking system which weighs half as much and consumes a third of the power of previous system
• new TsVM-101 computer, about one eighth the weight (8.3 kg vs. 70 kg) and much smaller than the previous Argon-16 computer
• unified digital command/telemetry system (MBITS) to relay telemetry via satellite, and control spacecraft when out of sight of ground stations; also provides the crew with position data when out of ground tracking range
• GLONASS/GPS and Cospas-Sarsat satellite systems for more accurate location during search/rescue operations after landing

Related craft

The unmanned Progress spacecraft were derived from Soyuz and are used for servicing space stations. 

While not being direct derivatives of Soyuz, the Chinese Shenzhou spacecraft uses Soyuz TM technology sold in 1984 and the Indian Orbital Vehicle follow the same general layout as that pioneered by Soyuz.

Aerospike engine

From Wikipedia, the free encyclopedia

XRS-2200 linear aerospike engine for the X-33 program being tested at the Stennis Space Center

 

The aerospike engine is a type of rocket engine that maintains its aerodynamic efficiency across a wide range of altitudes. It belongs to the class of altitude compensating nozzle engines. A vehicle with an aerospike engine uses 25–30% less fuel at low altitudes, where most missions have the greatest need for thrust. Aerospike engines have been studied for a number of years and are the baseline engines for many single-stage-to-orbit (SSTO) designs and were also a strong contender for the Space Shuttle main engine. However, no such engine is in commercial production, although some large-scale aerospikes are in testing phases.

The terminology in the literature surrounding this subject is somewhat confused—the term aerospike was originally used for a truncated plug nozzle with a very rough conical taper and some gas injection, forming an "air spike" to help make up for the absence of the plug tail. However, frequently, a full-length plug nozzle is now called an aerospike.

Principles

The purpose of any engine bell is to direct the exhaust of a rocket engine in one direction, generating thrust in the opposite direction. The exhaust, a high-temperature mix of gases, has an effectively random momentum distribution (i.e., the exhaust pushes in any direction it can). If the exhaust is allowed to escape in this form, only a small part of the flow will be moving in the correct direction and thus contribute to forward thrust. The bell redirects exhaust moving in the wrong direction so that it generates thrust in the correct direction. Ambient air pressure also imparts a small pressure against the exhaust, helping to keep it moving in the "right" direction as it exits the engine. As the vehicle travels upwards through the atmosphere, ambient air pressure is reduced. This causes the thrust-generating exhaust to begin to expand outside the edge of the bell. Since this exhaust begins traveling in the "wrong" direction (i.e., outward from the main exhaust plume), the efficiency of the engine is reduced as the rocket travels because this escaping exhaust is no longer contributing to the thrust of the engine. An aerospike rocket engine seeks to eliminate this loss of efficiency.

Comparison between the design of a bell-nozzle rocket (left) and an aerospike rocket (right)

 

Instead of firing the exhaust out of a small hole in the middle of a bell, an aerospike engine avoids this random distribution by firing along the outside edge of a wedge-shaped protrusion, the "spike", which serves the same function as a traditional engine bell. The spike forms one side of a "virtual" bell, with the other side being formed by the outside air—thus the "aerospike". 

The idea behind the aerospike design is that at low altitude the ambient pressure compresses the exhaust against the spike. Exhaust recirculation in the base zone of the spike can raise the pressure in that zone to nearly ambient. Since the pressure in front of the vehicle is ambient, this means that the exhaust at the base of the spike nearly balances out with the drag experienced by the vehicle. It gives no overall thrust, but this part of the nozzle also doesn't lose thrust by forming a partial vacuum. The thrust at the base part of the nozzle can be ignored at low altitude. 

As the vehicle climbs to higher altitudes, the air pressure holding the exhaust against the spike decreases, as does the drag in front of the vehicle. The recirculation zone at the base of the spike maintains the pressure in that zone to a fraction of 1 bar, higher than the near-vacuum in front of the vehicle, thus giving extra thrust as altitude increases. This effectively behaves like an "altitude compensator" in that the size of the bell automatically compensates as air pressure falls.

The disadvantages of aerospikes seem to be extra weight for the spike, and increased cooling requirements to the extra heated area, the spike. Furthermore, the larger cooled area can reduce performance below theoretical levels by reducing the pressure against the nozzle. Aerospikes work relatively poorly between Mach 1–3, where the airflow around the vehicle has reduced the pressure, thus reducing the thrust.

Variations

Several versions of the design exist, differentiated by their shapes. In the toroidal aerospike the spike is bowl-shaped with the exhaust exiting in a ring around the outer rim. In theory this requires an infinitely long spike for best efficiency, but by blowing a small amount of gas out of the center of a shorter truncated spike (like base bleed in an artillery shell), something similar can be achieved. 

In the linear aerospike the spike consists of a tapered wedge-shaped plate, with exhaust exiting on either side at the "thick" end. This design has the advantage of being stackable, allowing several smaller engines to be placed in a row to make one larger engine while augmenting steering performance with the use of individual engine throttle control.

Performance

Rocketdyne's J-2T-250k annular aerospike test firing.

 

Rocketdyne conducted a lengthy series of tests in the 1960s on various designs. Later models of these engines were based on their highly reliable J-2 engine machinery and provided the same sort of thrust levels as the conventional engines they were based on; 200,000 lbf (890 kN) in the J-2T-200k, and 250,000 lbf (1.1 MN) in the J-2T-250k (the T refers to the toroidal combustion chamber). Thirty years later their work was dusted off again for use in NASA's X-33 project. In this case the slightly upgraded J-2S engine machinery was used with a linear spike, creating the XRS-2200. After more development and considerable testing, this project was cancelled when the X-33's composite fuel tanks repeatedly failed. 

CSULB aerospike engine

 

Three XRS-2200 engines were built during the X-33 program and underwent testing at NASA's Stennis Space Center. The single-engine tests were a success, but the program was halted before the testing for the two-engine setup could be completed. The XRS-2200 produces 204,420 lbf (909,300 N) thrust with an I_sp of 339 seconds at sea level, and 266,230 lbf (1,184,300 N) thrust with an I_sp of 436.5 seconds in a vacuum. 

The RS-2200 Linear Aerospike Engine was derived from the XRS-2200. The RS-2200 was to power the VentureStar single-stage-to-orbit vehicle. In the latest design, seven RS-2200s producing 542,000 pounds-force (2,410 kN) each would boost the VentureStar into low earth orbit. The development on the RS-2200 was formally halted in early 2001 when the X-33 program did not receive Space Launch Initiative funding. Lockheed Martin chose to not continue the VentureStar program without any funding support from NASA. An engine of this type is on outdoor display on the grounds of the NASA Marshall Space Flight Center in Huntsville Alabama. 

NASA's Toroidal aerospike nozzle

 

The cancellation of the Lockheed Martin X-33 by the federal government in 2001 decreased funding availability, but aerospike engines remain an area of active research. For example, a milestone was achieved when a joint academic/industry team from California State University, Long Beach (CSULB) and Garvey Spacecraft Corporation successfully conducted a flight test of a liquid-propellant powered aerospike engine in the Mojave Desert on September 20, 2003. CSULB students had developed their Prospector 2 (P-2) rocket using a 1,000 lb_f (4.4 kN) LOX/ethanol aerospike engine. This work on aerospike engines continues; Prospector-10, a ten-chamber aerospike engine, was test-fired June 25, 2008.

Nozzle performance comparison of bell and aerospike nozzle

 

Further progress came in March 2004 when two successful tests sponsored by the NASA Dryden Flight Research Centre using high-power rockets manufactured by Blacksky Corporation, based in Carlsbad, California. The aerospike nozzles and solid rocket motors were developed and built by the rocket motor division of Cesaroni Technology Incorporated, north of Toronto, Ontario. The two rockets were solid-fuel powered and fitted with non-truncated toroidal aerospike nozzles. Flown at the Pecos County Aerospace Development Center, Fort Stockton, Texas, the rockets achieved apogees of 26,000 ft (7,900 m) and speeds of about Mach 1.5. 

Small-scale aerospike engine development using a hybrid rocket propellant configuration has been ongoing by members of the Reaction Research Society.

Implementations

Firefly Aerospace

In July 2014 Firefly Space Systems announced its planned Alpha launcher that uses an aerospike engine for its first stage. Intended for the small satellite launch market, it is designed to launch satellites into low-Earth orbit (LEO) at a price of US$8–9 million, much lower than with conventional launchers.

Firefly Alpha 1.0 was designed to carry payloads of up to 400 kilograms (880 lb). It uses carbon composite materials and uses the same basic design for both stages. The plug-cluster aerospike engine puts out 90,000 pounds-force (400 kN) of thrust. The engine has a bell-shaped nozzle that has been cut in half, then stretched to form a ring with the half-nozzle now forming the profile of a plug.

But this rocket design was never launched. The design was abandoned after Firefly Space Systems went bankrupt. A new company, Firefly Aerospace, has replaced the aerospike engine with a conventional engine in the Alpha 2.0 design.

ARCA Space

In March 2017 ARCA Space Corporation announced their intention to build a single-stage-to-orbit rocket, named Haas 2CA, using a linear aerospike engine. The rocket is designed to send up to 100kg into low-Earth orbit, at a price of US$ 1 million per launch. They later announced that their Executor Aerospike engine would produce 50,500 pounds-force (225 kN) of thrust at sea-level and 73,800 pounds-force (328 kN) of thrust in vacuum.

In June 2017, ARCA announced that they would fly their Demonstrator3 rocket to space, using a linear aerospike engine. This rocket was designed to test several components of their Haas 2CA at a lower cost. They announced a flight for August 2017. In September 2017, ARCA announced that after being delayed, their linear aerospike engine was ready to perform ground tests and flight tests on a Demonstrator3 rocket.

KSF Space and Interstellar Space

Another spike engine concept model, by KSF Space and Interstellar Space in Los Angeles, was designed for orbital vehicle named SATORI. Due to lack of funding, the concept is still undeveloped.

Rocketstar

Rocketstar announced that it would launch its 3D-printed aerospike rocket to an altitude of 50 miles in February 2019.