OrbitalHub

Credits: SpaceX

SpaceX recently reached two major milestones towards the goal of servicing the International Space Station (ISS) after the retirement of the Space Shuttle in September 2010.

The milestones are the successful testing of the heat shield material used for the thermal protective system of the Dragon spacecraft, and a mission-length firing of the Merlin Vacuum engine that powers the second stage of the Falcon 9 launch vehicle.

On February 23, 2009, SpaceX announced that the PICA-X high performance heat shield material passed an arc jet testing. During the test that recreates the conditions experienced during an atmospheric reentry, the material was subjected to temperatures as high as 1850 degrees Celsius.

PICA is short for Phenolic Impregnated Carbon Ablator. It is a material used for thermal protection, which was initially developed by NASA. PICA-X is an improved variation of the original PICA and was developed by SpaceX with the assistance of NASA. SpaceX becomes the second commercial source for this high-performance carbon-based material.

“We tested three different variants developed by SpaceX,” said Tom Mueller, VP of Propulsion, SpaceX. “Compared to the PICA heat shield flown successfully on NASA’s Stardust sample return capsule, our SpaceX versions equaled or improved the performance of the heritage material in all cases.”

Credits: SpaceX

The arc jet tests were performed at the Arc Jet Complex at NASA Ames Research Center, as the test center is capable of creating the reentry conditions. The Arc Jet Complex has a long history in the development of thermal protective systems.

PICA-X will protect the Dragon spacecraft and the crew during the reentry in the atmosphere from low Earth orbit (LEO).

One remarkable detail that I discovered when reading the press release is that PICA-X will also be used to coat the second stage of the Falcon 9 launch vehicle, as SpaceX plans to reuse the second stage of the launch vehicle as well.

On March 7, 2009, the Merlin Vacuum engine completed a full mission duration firing at the SpaceX Test Facility in McGregor, Texas. During the test that lasted 6 minutes, the engine consumed more than 100,000 pounds of liquid oxygen and rocket grade kerosene.

The Merlin Vacuum engine is a variation of the Merlin 1C engine that powers the Falcon 1 launch vehicle, and it accommodates changes that make it more efficient to fire in the vacuum of space (most notably the shape of the nozzle).

Credits: SpaceX

“Specific impulse, or Isp, indicates how efficiently a rocket engine converts propellant into thrust,” said Tom Mueller. “With a vacuum Isp of 342 seconds, the new Merlin Vacuum engine has exceeded our requirements, setting a new standard for American hydrocarbon engine performance in space.”

The engine uses a regeneratively cooled combustion chamber, which means that the propellant is injected into the walls of the combustion chamber and prevents them from melting.

The nozzle is radiatively cooled and much larger, and also has a larger exhaust section than the Merlin 1C. This results in an improved performance of the engine. The engine is capable of multiple restarts and can operate at reduced thrust, which will enable the upper stage to deliver payloads matching a broad range of orbital profiles.

“Falcon 9 was designed from the ground up to provide our customers with breakthrough advances in reliability,” said Elon Musk, CEO and CTO of SpaceX. “In successfully adapting our flight tested first stage engine for use on the second stage, this recent test further validates the architecture of Falcon 9, designed to provide customers with high reliability at a fraction of traditional costs.”

The first flight of the Falcon 9 /Dragon launch system is scheduled for late 2009 from Launch Pad SLC-40 at Cape Canaveral, Florida. For more information about SpaceX and the Falcon 9 /Dragon launch system, you can visit the SpaceX website.

Credits: NASA/RASA

The Alpha Magnetic Spectrometer (AMS) is a high-energy particle detector. AMS will detect electrons, positrons, protons, antiprotons, and nuclei in cosmic radiation.

AMS is a cooperative project that involved more than 200 scientists from 31 institutions and 15 countries. The data gathered by AMS during its three-year mission will help scientists answer important questions about antimatter and invisible mass in the Universe. AMS could detect many types of particles predicted by theorists and determine their astrophysical sources.

AMS could reveal to scientists unusual astrophysical objects like antimatter galaxies, dark matter, strangelets, microquasars, and primordial black holes.

AMS actually refers to two particle experiments: AMS-01 and AMS-02. AMS-01 flew in low Earth orbit (LEO) with Space Shuttle Discovery STS-91 in June 1998. AMS-01 was an AMS prototype (a simplified version of the spectrometer) and was used to test particle physics technology in LEO. AMS-02 is the Alpha Magnetic Spectrometer designed to be mounted and operated on the ISS.

Credits: NASA

AMS-02 is a cube-shaped structure with a mass of 6,731 kg. The spectrometer consists of a huge superconducting magnet and six specialized detectors, and requires 2,000 watts of power.

The experiment has a 10Gb/sec internal data pipeline and will have a dedicated 2MB/sec connection to ground stations. AMS-02 will gather approximately 200 TB of scientific data during its mission. Four 750 MHz PowerPC computers running Linux will provide the computing power.

The spectrometer also contains two star tracker cameras, which detect the orientation in space, and a thermal control system that will control the temperature of the whole experiment. The thermal control system is quite complex. Heat is collected from the detectors and the magnet, and then pushed through conductors to the radiators mounted on the outside of the AMS and radiated into space.

AMS-02 has a little bit of history associated with it … due to the Space Shuttle accidents, which reduced the number of orbiters available, and the decision to retire the Space Shuttle fleet, AMS-02 faced cancellation (a long list of elements meant to be part of the ISS were cancelled for the same reasons). Because an additional shuttle flight was added to the launch manifest, most likely AMS-02 will make it to the space station.

The plan for AMS-02 is that it will be attached to the zenith side of the S3 section of the Integrated Truss Structure on the ISS. A Payload Attachment System will be used to keep the spectrometer in place on the truss segment.

Credits: NASA

According to the missions schedule, AMS-02 will be installed on ISS as part of the Space Shuttle Discovery STS-134 mission, together with the last ExPRESS Logistics Carrier (ELC-4), in late 2010.

STS-134 will be the last Space Shuttle flight before the deadline set to end Space Shuttle operations on September 30, 2010.

To make things more interesting (and Space Shuttle operations cheaper), it has been proposed that the last mission should end through a destructive re-entry. In this scenario, the reduced crew of three will remain on the space station and return to Earth onboard Soyuz spacecraft.

You can read more about AMS-02 on a dedicated web page at MIT. There is also a web page dedicated to AMS-02 at CERN.

Credits: JAXA

HTV stands for H-II Transfer Vehicle. HTV is an unmanned spacecraft designed and built in Japan. HTV is designed to deliver supplies to the International Space Station (ISS).

The typical mission for HTV starts at the Tanegashima Space Center (TKSC) near Tsukuba, in Japan.

A H-IIB launch vehicle will inject the HTV on a low Earth orbit (LEO). After the separation from the H-IIB second stage, the transfer vehicle is able to navigate independently.

It will take approximately three days for HTV to reach the proximity of the ISS. During this time, it will maintain contact with the Control Center at TKSC (designated as HTV-CC) through the Tracking and Data Relay Satellite System (TDRSS). TDRSS is a network of satellites that allow a spacecraft in LEO to maintain permanent contact with the control center on the ground. HTV will use GPS to position itself at 7 km behind the ISS.

At this point, the berthing phase of the mission starts. HTV will approach the ISS within 500 m and use the Rendezvous Sensor (RVS) to move closer to the ISS. Reflectors that are installed on Kibo will allow HTV to maintain a distance of 10 m below the ISS.

Credits: JAXA

HTV does not have the capability to dock on its own to the ISS (as opposed to the European ATV), so the Canadarm2 robotic arm will be used to grab the transfer vehicle and berth it to the nadir side of the Node 2 module.

While the HTV is berthed to the ISS, supplies from the HTV’s pressurized section are transferred to the space station by the crew, and waste will be loaded from the ISS.

The cargo from the un-pressurized section will be unloaded using the robotic arm and attached either to the Exposed Facility of the Japanese Experiment Module (JEM) or the ISS Mobile Base System.

The HTV mission will end in a similar way to the European ATV: a destructive re-entry above the Pacific Ocean.

Here is some more background information about the HTV. The spacecraft is a cylinder-shaped structure 10 m long and 4.4 m in diameter. It has a total mass of 10,500 kg, of which 6,000 kg is cargo (divided into 4,500 kg pressurized cargo and 1,500 kg un-pressurized cargo). HTV can carry 6,000 kg of waste during the re-entry.

HTV consists of four modules: the Pressurized Logistics Carrier (PLC), the Unpressurized Logistics Carrier (UPLC), the Avionics Module, and the Propulsion Module. The UPLC carries the Exposed Pallet (EP), which can accommodate unpressurized payloads.

Credits: JAXA

The PLC is equipped with a Common Berthing Mechanism (CBM). This will allow the crew present on the station to enter the module in order to unload the supplies and load waste material.

The EP carried by the UPLC can be either Type I or Type III Exposed Pallets. The Type I EPs will carry payloads for the Kibo’s Exposed Facility (EF), while the Type III EPs will be used to deliver the Orbital Replacement Units (ORUs) to the ISS.

The systems in the avionics module enable HTV to execute the autonomous flight to the space station. The module also contains communication and power systems. The thirty-two thrusters installed on the propulsion module provide HTV with the capability to execute orbital adjustments and control the attitude during the mission.

HTV will add to the existing fleet of transfer vehicles that includes the Russian Soyuz and Progress spacecraft, as well as the European ATV. The first HTV mission is scheduled for late 2009.

For more information about HTV, you can visit the H-II Transfer Vehicle page on the JAXA web site.

Credits: NASA

The Valentine’s Day Edition of the Carnival of Space is hosted by Bruce Cordell at 21ST CENTURY WAVES.

The collision of the Iridium 33 and Cosmos 2251 satellites has sent ripples across the space blogosphere and debris into low Earth orbit. At this Carnival you can read about shielding interstellar spaceships, saving the Space Shuttle, Pluto, visualizing constellations, lakes on Titan, type III Kardashev civilizations, and much more.

OrbitalHub has submitted a post about the Japan Experiment Module a.k.a. Kibo. The Japanese Experiment Module (JEM) is the first contribution of the Japan Aerospace Exploration Agency (JAXA) to the International Space Station (ISS) program.

Credits: NASA

The Japanese Experiment Module (JEM) a.k.a. Kibo is the first contribution of the Japan Aerospace Exploration Agency (JAXA) to the International Space Station (ISS) program.

Kibo improves the research capabilities of the ISS by accommodating a maximum of four astronauts who can conduct scientific research activities and experiments in orbit.

JEM has six major components: the Pressurized Module (PM), the Exposed Facility (EF), the Experiment Logistics Module – Pressurized Section (ELM-PS), the Experiment Logistics Module – Exposed Section (ELM-ES), the Remote Manipulator System (JEMRMS), and the Inter-Orbit Communication System (ICS).

The PM is the largest component of JEM. It has a cylindrical shape, 4.4 m in diameter and 11.2 m in length. A total of twenty-three racks can be installed in the PM, six racks on each of the four walls, except for the zenith wall, which can accommodate a maximum of 5 racks. Some of the visible features are the airlock (which allows access to the EF), the two windows located above the airlock, the berthing mechanism for the EF (EFBM), an Active Common Berthing Mechanism (ACBM) on the zenith side for berthing the ELM-PS, and a Passive Common Berthing Mechanism (PCBM) used to connect with the port side ACBM of the Harmony module.

Credits: NASDA

The EF is a box-shaped structure, which is 5.0 m wide, has a length of 5.2 m, and a height of 3.8 m. The EF has 12 payload attachment locations. Each payload location can accommodate a science experiment that must be conducted in the exposed environment.

Kibo’s robotic arm (JEMRMS) is used for attaching and removing the payloads.

The ELM-PS is a cylindrical structure 4.4 m in diameter and 4.2 m in length. The ELM-PS contains a total of eight rack locations. ELM-PS can be used as storage space for experiments, samples, and spare items.

The ELM-ES provides storage space for up to three payloads. ELM-ES will be attached to the end of the EF. Besides the function of in-orbit exposed storage facility, the ELM-ES can also be used to return scientific payloads to Earth. The ELM-ES is a frame structure 4.9 m wide, with a length of 4.1 m, and a height of 2.2 m.

Credits: NASDA

The JEMRMS is a robotic manipulator system. JEMRMS will have two roles: supporting the experiments conducted on Kibo, and assisting with Kibo’s maintenance tasks.

A 10 m long Main Arm (MA), a 2.2 m long Small Fine Arm (SFA), and a robotic control workstation are the components of the robotic manipulator system.

The ICS has two subsystems: a Pressurized Module (ICS-PM) and an Exposed Facility (ICS-EF). The ICS-PM occupies a rack inside the PM, and provides command and data handling functions. The ICS-EF is basically the antenna used for communication.

Kibo is a large structure and more Space Shuttle missions are required to complete the deployment of all the components.

STS-123 Space Shuttle Endeavour delivered the ELM-PS component and ICS-PS to the ISS. JAXA astronaut Takao Doi was part of the STS-123 crew as mission specialist. During the mission, the ELM-PS was berthed to the zenith port of the Node 2 (Harmony) module. The ELM-PS carried the system racks and the experiment racks that are operated in the PM.

Credits: NASA

STS-124 Space Shuttle Discovery delivered the PM and the JEMRMS components to the ISS. The JAXA astronaut assigned to STS-124 as mission specialist was Akihiko Hoshide. STS-124 had to perform a number of operations in order to activate and assemble the pressurized components of JEM: installation and activation of PM, rack deployment, installation of JEMRMS, and the relocation of the ELM-PS from the zenith port of Node 2 to the zenith side of the PM.

The EF is the last major component of Kibo that has to be hauled to the ISS. The STS-127 mission will carry the EF, together with the ELM-ES and the ICS-EF components. The completion of Kibo will be done in two steps: the EF will be attached to the PM through the EFBM, and the ELM-ES will be attached to the EF as the last step. JAXA astronaut Koichi Wakata will be on board the ISS to supervise the operation as mission specialist.

The Japan Aerospace Exploration Agency has a web page dedicated to Kibo.

Credits: NASA

Forty years ago, on January 16, 1969, two Russian spacecraft (Soyuz 4 and Soyuz 5) carried out the first docking between two manned spacecraft and transfer of crew between the craft.

The Soyuz 4/5 mission was a critical milestone for the future of manned space missions, the rendezvous and docking of manned spacecraft being essential for the development of space stations.

Soyuz 4 was launched on January 14, 1969, with cosmonaut Vladimir Shatalov on board. Soyuz 5 was launched one day later. Soyuz 5 had three cosmonauts on board: Boris Volynov, Alexei Yeliseyev, and Yevgeny Khrunov. During the mission, Soyuz 5 acted as the passive ship, while Soyuz 4 was the active chaser craft.

The two spacecraft docked at 0820 UT over the Soviet territory. The docking mechanism did not connect the pressurized modules of the Soyuz spacecraft and two of the cosmonauts on board Soyuz 5, Yevgeny Khrunov and Alexei Yeliseyev, performed EVAs in order to transfer to Soyuz 4.

Credits: NASA/R.F.Gibbons

Soyuz 4 and 5 undocked after three hours and thirty-five minutes.

Soyuz 4 fired its retro-rockets on January 17 and landed somewhere near Karaganda, in Kazakhstan.

Soyuz 5 had an eventful landing. After the retro-fire, the instrument module failed to separate from the descent module, and the landing could have been catastrophic due to the fact that the heat shield was not oriented properly.

However, the re-entry heat caused the propellant tanks in the instrument module to explode and the two modules eventually separated. The parachute had problems deploying properly and a failure of the soft-landing rockets occurred, so the landing was much harder than usual. Apparently, the landing shock was so great that Boris Volynov was thrown across the cabin and broke some of his front teeth.

Volynov landed far off course, in the Ural Mountains near Orenburg, in Russia. The event was kept secret and it eventually came to light in 1997, when an official history book mentioned the incident.

Forty years later, the Soyuz spacecraft is still the workhorse of the Russian space program, and continues to this day to serve as a transfer vehicle to and from the International Space Station (ISS), performing rendezvous and docking maneuvers on each mission.