OrbitalHub

Credits: NASA/JPL

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a high-energy X-ray space telescope that will expand our understanding of the origins and the development of stars and galaxies.

NuSTAR was proposed to NASA in May 2003. In 2006, while NuSTAR was undergoing an extended feasibility study, NASA cancelled the program due to budgetary constraints. However, in September 2007, the program was restarted.

In 2007, Orbital Sciences Corporation was selected by NASA to design, manufacture, and test the NuSTAR telescope.

The spacecraft is based on a proven design, used by Orbital for other NASA Small Explorer missions: SORGE, GALEX, AIM, and OCO. NuSTAR will have a launch mass of 360 kg, and will be powered by articulated solar arrays providing 600 W.

The spacecraft incorporates a ten-meter long extendable mast. The mast allows the telescope to fit into a small launch vehicle.

The technology used to build the telescope is not new. A team of researchers, led by Dr. Fiona Harrison, professor of physics and astronomy at Caltech, has been improving the NuSTAR technology for the last ten years. A previous high energy X-ray telescope (High Energy Focusing Telescope or HEFT) was developed as part of a high altitude balloon payload.

The currently operational X-ray telescopes, Chandra and XMM-Newton, observe the sky in the low energy X-ray spectrum (X-ray energies less than 10 keV). NuSTAR will make observations in a higher range, up to 79 keV. As much of the energy emitted by a black hole is absorbed by the surrounding gas and dust, observations in the high-energy X-ray spectrum can reveal in greater detail what is happening closer to the event horizon.

Credit: NASA/CXC/CfA/R.Kraft et al./MPIfR/ESO/APEX/A.Weiss et al./ESO/WFI

The NuSTAR telescope will have a sensitivity two orders of magnitude greater than any other instrument used to detect black holes. NuSTAR will help scientists understand how black holes are distributed throughout the universe, and what powers the most active galaxies.

The NuSTAR instrument consists of two co-aligned hard X-ray telescopes. The ten-meter mast mentioned above separates the mirrors and the imaging detectors. The detectors are Cadmium Zinc Telluride (CdZnTe) detectors and do not require cryogenic operation.

On February 9, 2009, NASA awarded Orbital the launch services contract for the NuSTAR mission. The telescope will be launched in 2011 aboard a Pegasus XL launch vehicle. Pegasus XL will be carried beneath a L-1011 aircraft and released over the Pacific Ocean. The air-launch system is very cost-effective, providing flexibility during operation and requiring minimal ground support.

NuSTAR will be deployed into a 525×525 km low Earth orbit (LEO) with a twenty-seven degree inclination.

For more details about the science of NuSTAR, you can visit the mission’s home page at Caltech. Orbital has also posted a NuSTAR fact sheet on their web site.

Credits: NASA

Orbital will employ its Taurus II medium-lift launch vehicle and the Cygnus spacecraft in order to service the International Space Station (ISS) under the Commercial Resupply Services (CRS) contract.

Orbital is one of the two companies awarded CRS contracts under the Commercial Orbital Transportation Services Project (COTS).

NASA announced the COTS project on January 18, 2006. The purpose of the program is to stimulate the development of access to low Earth orbit (LEO) in the private sector. At the time, with the imminent retirement of the Space Shuttle fleet, NASA was faced with the option of buying orbital transportation services on foreign launch systems: the Russian Soyuz / Progress, the European Ariane 5 / ATV, or the Japanese H-II / HTV.

Another factor taken into consideration by NASA was that competition in the free market could lead to the development of more efficient and affordable launch systems compared to launch systems that a government agency could build and operate.

Credits: Orbital

Orbital relies on proven experience in launch vehicle technology. Taurus II is designed to provide low-cost and reliable access to space, and it uses systems from other members of Orbital’s family of successful launchers: Pegasus, Taurus, and Minotaur.

Taurus II is a two-stage launch vehicle that can use an additional third stage for achieving higher orbits. The payloads handled by Taurus II can have a mass of up to 5,400 kg.

Orbital is responsible for overall development and integration of the first stage. The two AJ26-62, designed and produced by Aerojet and Orbital, are powered by liquid oxygen and kerosene. The core design is driven by NPO Yuzhnoye, the designer of the Zenit launchers.

The AJ26-62 engines are basically the NK-33 engines designed by the Kuznetsov Design Bureau for the Russian N-1 launch vehicle, and remarketed by Aerojet under a new designation.

The second stage uses an ATK Castor-30 solid motor with thrust vectoring. This stage evolved from the Castor-120 solid stage.

The optional third stage is developed by Orbital. The stage was dubbed the Orbit Raising Kit (ORK) and it uses a helium pressure regulated bi-propellant propulsion system powered by nitrogen tetroxide and hydrazine. ORK evolved from the Orbital STAR Bus. Because it is a hypergolic stage, it allows several burns to be performed in orbit, and can be used for high-precision injections using various orbital profiles.

Credits: Orbital

Cygnus will only have cargo capability and will be able to deliver up to 2,300 kg of pressurized or un-pressurized cargo to the ISS. The spacecraft will also be able to return up to 1,200 kg of cargo from ISS to Earth.

The two components of the Cygnus spacecraft will be the service module and the cargo module.

The service module is based on the Orbital STAR bus (like the ORK stage), and will use two solar arrays for producing electrical power for the navigation systems onboard.

The pressurized cargo module is based on the Italian-built Multi-Purpose Logistics Module (MPLM). The un-pressurized cargo module is based on NASA’s ExPRESS Logistics Carrier.

Cygnus will not dock to the ISS in the same manner as the European ATV, but it will be able to maneuver close to the ISS where the Canadarm 2 robotic arm will be used to capture it and berth it to the Node 2 module, similar to the Japanese HTV or SpaceX’s Dragon spacecraft.

The Mid-Atlantic Regional Spaceport (MARS), located at NASA’s Wallops Island Flight Facility on Virginia’s Eastern shore, was chosen by Orbital to serve as the base of operations for the Taurus II launch vehicle.

MARS has two FAA licensed launch pads for LEO access. MARS also offers access to suborbital launchers, vehicle and payload storage, and processing and launch facilities.

Credits: NASA

Due to the location of the spaceport, latitude 37.8 degrees N, longitude 75.5 degrees W, optimal orbital inclinations for the launches performed at MARS are between 38 and 60 degrees. Polar and retrograde orbits can also be serviced with additional in-flight maneuvering.

The first flight of Orbital’s new Taurus II / Cygnus launch system under COTS is scheduled for late 2010.

Credits: NASA GSFC

The solar wind generated by our Sun carves out a protective bubble around the solar system, called the heliosphere. The interstellar medium, consisting of the gas and the dust found between the galaxies, interacts with the solar wind and defines the actual boundary, which is called the termination shock.

NASA has designed a mission to map the boundary of the solar system. The mission is called IBEX (Interstellar Boundary Explorer) and it is ready to launch. The data collected by IBEX will allow scientists to understand the interaction between our Sun and the galaxy for the first time. Understanding this interaction will help us protect future astronauts from the danger of galactic cosmic rays.

In January 2005, the Orbital Science Corporation was selected to develop, build, and launch a small spacecraft for NASA’s IBEX mission. The IBEX spacecraft is based on an already existing bus: the MicroStar satellite. IBEX will be launched by a Pegasus XL rocket, which will be dropped from an aircraft flying over the Pacific Ocean.

Credits: NASA GSFC

Pegasus began its commercial career in April 1990, and since then it has launched more than 80 satellites into space.

Pegasus is a three-stage launching system used to deploy small satellites weighing up to 1,000 pounds into Low Earth Orbit (LEO). An aircraft carries Pegasus to an altitude of 40,000 feet.

The rocket is released and free-falls before igniting its engines. It takes roughly ten minutes for Pegasus to deliver a satellite into orbit.

Pegasus will place IBEX into a 130 mile altitude orbit. An extra solid-fueled rocket will boost the spacecraft from the LEO. IBEX’s final orbit will be a highly elliptical orbit with the perigee at an altitude of 7,000 km and the apogee at 236,000 km. IBEX has to operate in this orbit because any interference from the Earth’s magnetosphere would make it impossible to take accurate measurements with the scientific instruments onboard.

Credits: NASA GSFC

IBEX has a mass of only 83.33 lbs (roughly 38 kg) and is described by NASA as being the size of a bus tire. The instruments onboard IBEX will collect particles called energetic neutral atoms (ENAs). The ENAs are radiated from the termination shock region. The ENA hits recorded by the instruments onboard IBEX will be used to create a map of this region.

The mission is scheduled to launch tomorrow, October 19th, 2008. The spacecraft will be operational for 24 months. You can find out more about the IBEX spacecraft on NASA’s IBEX mission web page.